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Edwards CR, Ahmad ZY, Vosseller JT, Moy MP, Wong TT. First MTP joint injuries: MR imaging findings in surgically managed patients. Skeletal Radiol 2023; 52:1729-1738. [PMID: 37043019 DOI: 10.1007/s00256-023-04327-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 03/19/2023] [Accepted: 03/20/2023] [Indexed: 04/13/2023]
Abstract
OBJECTIVES Determine whether MR imaging findings or demographics predict surgical management in patients with first MTP joint injuries. MATERIALS AND METHODS Retrospective study of 161 forefoot MRs for traumatic first MTP injury (M:F 92:69, mean age 33 ± 13 yrs.). Two radiologists reviewed imaging for ligamentous, osseous, and tendinous injuries. Ligaments and tendons were graded as 0:normal, 1:sprain or strain, 2:partial tear, 3:complete tear. Osseous injuries were classified as edema, fracture, or cartilage injury. Clinical data obtained included sex, age, injury acuity, sport participation, level of sport, and treatment. Imaging findings and demographic data were assessed to determine predictive factors for surgical management. Statistics included kappa, chi-squared, Fisher's exact, and logistic regression. RESULTS Logistic regression (odds ratio [95% CI], p-value) showed that grade 2 or 3 injuries of the plantar ligamentous complex (2.87, [1.10, 7.48], p = 0.031), grade 2 or 3 injuries of the medial collateral ligament (3.24, [1.16, 9.08], p = 0.025), and participation in collegiate or professional sports (4.34 [1.64, 11.52], p = 0.003) were associated with an increased rate of surgical intervention. k = ligamentous injury (0.71-0.83), osseous trauma (0.88-0.95), and tendon injury (0.78). All other imaging findings and demographic factors were not significant predictors of surgery (p > 0.05). CONCLUSION Participation in collegiate or professional sports and tears of the plantar ligamentous complex or medial collateral ligament predicted surgical management in patients with first MTP trauma.
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Affiliation(s)
- C R Edwards
- New York Presbyterian- Columbia University, New York, NY, USA.
| | - Z Y Ahmad
- New York Presbyterian- Columbia University, New York, NY, USA
| | - J T Vosseller
- Jacksonville Orthopaedic Institute, Jacksonville, FL, USA
| | - M P Moy
- New York Presbyterian- Columbia University, New York, NY, USA
| | - T T Wong
- New York Presbyterian- Columbia University, New York, NY, USA
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2
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Finkelstein MT, Nongpiur ME, Husain R, Perera S, Baskaran M, Wong TT, Aung T, Milea D, Najjar RP. Handheld chromatic pupillometry can reliably detect functional glaucomatous damage in eyes with high myopia. Br J Ophthalmol 2023:bjo-2023-323878. [PMID: 37524446 DOI: 10.1136/bjo-2023-323878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 07/12/2023] [Indexed: 08/02/2023]
Abstract
BACKGROUND/AIMS To assess pupillary light responses (PLRs) in eyes with high myopia (HM) and evaluate the ability of handheld chromatic pupillometry (HCP) to identify glaucomatous functional loss in eyes with HM. METHODS This prospective, cross-sectional study included 28 emmetropes (EM), 24 high myopes without glaucoma (HM) and 17 high myopes with confirmed glaucoma (HMG), recruited at the Singapore National Eye Center. Monocular PLRs were evaluated using a custom-built handheld pupillometer that recorded changes in horizontal pupil radius in response to 9 s of exponentially increasing blue (469.1 nm) and red (640.1 nm) lights. Fifteen pupillometric features were compared between groups. A logistic regression model (LRM) was used to distinguish HMG eyes from non-glaucomatous eyes (EM and HM). RESULTS All pupillometric features were similar between EM and HM groups. Phasic constriction to blue (p<0.001) and red (p=0.006) lights, and maximum constriction to blue light (p<0.001) were reduced in HMG compared with EM and HM. Pupillometric features of melanopsin function (postillumination pupillary response, PIPR area under the curve (AUC) 0-12 s (p<0.001) and PIPR 6 s (p=0.01) to blue light) were reduced in HMG. Using only three pupillometric features, the LRM could classify glaucomatous from non-glaucomatous eyes with an AUC of 0.89 (95% CI 0.77 to 1.00), sensitivity 94.1% (95% CI 82.4% to 100.0%) and specificity 78.8% (95% CI 67.3% to 90.4%). CONCLUSION PLRs to ramping-up light stimuli are unaltered in highly myopic eyes without other diagnosed ocular conditions. Conversely, HCP can distinguish glaucomatous functional loss in eyes with HM and can be a useful tool to detect/confirm the presence of glaucoma in patients with HM.
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Affiliation(s)
| | - Monisha Esther Nongpiur
- Glaucoma, Singapore Eye Research Institute, Singapore
- Glaucoma, Singapore National Eye Centre, Singapore
- Ophthalmology & Visual Sciences, Duke-NUS Medical School, Singapore
| | - Rahat Husain
- Glaucoma, Singapore Eye Research Institute, Singapore
- Glaucoma, Singapore National Eye Centre, Singapore
- Ophthalmology & Visual Sciences, Duke-NUS Medical School, Singapore
| | - Shamira Perera
- Glaucoma, Singapore Eye Research Institute, Singapore
- Glaucoma, Singapore National Eye Centre, Singapore
- Ophthalmology & Visual Sciences, Duke-NUS Medical School, Singapore
| | - Mani Baskaran
- Glaucoma, Singapore Eye Research Institute, Singapore
- Glaucoma, Singapore National Eye Centre, Singapore
| | - Tina T Wong
- Glaucoma, Singapore Eye Research Institute, Singapore
- Glaucoma, Singapore National Eye Centre, Singapore
- Ophthalmology & Visual Sciences, Duke-NUS Medical School, Singapore
- Ocular Therapeutics & Drug Delivery, Singapore Eye Research Institute, Singapore
| | - Tin Aung
- Glaucoma, Singapore Eye Research Institute, Singapore
- Glaucoma, Singapore National Eye Centre, Singapore
- Ophthalmology & Visual Sciences, Duke-NUS Medical School, Singapore
| | - Dan Milea
- Visual Neurosciences, Singapore Eye Research Institute, Singapore
- Ophthalmology & Visual Sciences, Duke-NUS Medical School, Singapore
- Neuro-ophthalmology, Singapore National Eye Centre, Singapore
| | - Raymond P Najjar
- Visual Neurosciences, Singapore Eye Research Institute, Singapore
- Ophthalmology & Visual Sciences, Duke-NUS Medical School, Singapore
- Ophthalmology, National University of Singapore, Singapore
- Biomedical Engineering, National University of Singapore, Singapore
- Center for Innovation & Precision Eye Health, National University of Singapore, Singapore
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Lee YF, Chay J, Husain R, Wong TT, Ho CL, Lamoureux EL, Chew ACY. Three-year Outcomes of an Expanded Asynchronous Virtual Glaucoma Clinic in Singapore. Asia Pac J Ophthalmol (Phila) 2023; 12:364-369. [PMID: 37523427 DOI: 10.1097/apo.0000000000000620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 05/11/2023] [Indexed: 08/02/2023] Open
Abstract
PURPOSE Virtual glaucoma clinics can help increase health care capacity, easing the disease burden of glaucoma. This study assesses the safety, rate of glaucoma progression, time efficiency, and cost-savings of our expanded Glaucoma Observation Clinic (GLOC) at the Singapore National Eye Centre over 3 years. METHODS All patients seen at GLOC between July 2018 and June 2021 were included. Visual acuity, intraocular pressure, and visual fields or optic nerve head imaging were recorded, followed by a virtual review of the data by an ophthalmologist. An objective review of the management of 100 patients was conducted by 2 senior consultants independently as a safety audit. Patient outcomes including the rate of instability (due to worsening of clinical parameters necessitating a conventional clinic visit), glaucoma progression, the consultation review time efficiency, and cost-savings of GLOC were measured. RESULTS Of 3458 patients, 16% had glaucoma, and the others had risk factors for glaucoma. The safety audit demonstrated a 95% interobserver agreement. The rate of instability was 14.6%, of which true progression was observed in 3.12%. The time taken for a glaucoma specialist to review a GLOC patient was 5.75±0.75 minutes compared with 13.7±2.3 minutes in a conventional clinic. The per capita manpower cost per GLOC patient per visit was $36.77 compared with $65.62 in the conventional clinic. This translates to a cost-saving of $280.65 over the lifetime of a hypothetical patient. CONCLUSIONS Our expanded virtual glaucoma clinic is a safe, time-efficient, and cost-effective model with low rates of glaucoma progression, which could allow for significant health care capacity expansion.
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Affiliation(s)
- Yi Fang Lee
- Glaucoma Service, Singapore National Eye Centre, Singapore
- Singapore Eye Research Institute, Singapore
- Duke-NUS Medical School, Singapore
| | - Junxing Chay
- Health Services and Systems Research, Duke-NUS Medical School, Singapore
| | - Rahat Husain
- Glaucoma Service, Singapore National Eye Centre, Singapore
- Singapore Eye Research Institute, Singapore
- Duke-NUS Medical School, Singapore
| | - Tina T Wong
- Glaucoma Service, Singapore National Eye Centre, Singapore
- Singapore Eye Research Institute, Singapore
- Duke-NUS Medical School, Singapore
| | - Ching Lin Ho
- Glaucoma Service, Singapore National Eye Centre, Singapore
- Singapore Eye Research Institute, Singapore
- Duke-NUS Medical School, Singapore
| | - Ecosse L Lamoureux
- Glaucoma Service, Singapore National Eye Centre, Singapore
- Singapore Eye Research Institute, Singapore
- Duke-NUS Medical School, Singapore
- Health Services and Systems Research, Duke-NUS Medical School, Singapore
| | - Annabel C Y Chew
- Glaucoma Service, Singapore National Eye Centre, Singapore
- Singapore Eye Research Institute, Singapore
- Duke-NUS Medical School, Singapore
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Sim JJL, Man REK, Foo RCM, Huang OS, Betzler BK, Husain R, Ho CL, Boey PY, Perera SA, Low JR, Aung T, Lamoureux EL, Wong TT. Oral Ibuprofen is Associated With Reduced Likelihood of Early Bleb Failure After Trabeculectomy in High-Risk Glaucoma Patients. J Glaucoma 2023; 32:237-244. [PMID: 36930580 DOI: 10.1097/ijg.0000000000002188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 01/14/2023] [Indexed: 03/18/2023]
Abstract
PRCIS Individuals prescribed ibuprofen after trabeculectomy have better postoperative intraocular pressure (IOP) control and a higher chance of bleb survival despite being at a higher risk of scarring. PURPOSE To investigate the effects of early adjunctive oral ibuprofen treatment on IOP and bleb failure in eyes at high risk of scarring. METHODS In these retrospective analyses, 288 eyes of 273 patients (mean ± SD age: 68.56 ± 10.47 y; 32.60% females) with primary glaucoma who underwent trabeculectomy/phacotrabeculectomy at the Singapore National Eye Centre between April 2020 and April 2021 with a follow-up duration ≥1 year were included. Of these, 77 (26.7%) eyes deemed to be at high risk of scarring were administered oral ibuprofen ≥3 months postoperatively (mean ± SD ibuprofen administration duration: 4.08 ± 2.28 wk). Participant's IOPs at baseline and at postoperative weeks 1, 2-3; and months 1, 2, 3, 6, and 12 were recorded. Bleb failure was defined as 2 consecutive IOP readings of >21, >18, and >15 mm Hg, and/or requiring remedial postoperative laser or surgery. RESULTS The ibuprofen group experienced significantly greater postoperative IOP reductions at week 1 [mean difference, 95%CI: -2.89 (-5.22, -0.56) mm Hg] and month 1 [-2.29 (-4.53, -0.05) mm Hg]; and substantially lower odds of bleb failure at the >18 mm Hg [odds ratio, 95% CI: 0.39 (0.20-0.79)] and >15 mm Hg [0.52 (0.29-0.94)] thresholds, compared with the non-ibuprofen group. No differences in adverse ocular hypotony events were observed. CONCLUSION Early adjunctive oral ibuprofen administered to individuals at high risk of posttrabeculectomy scarring is associated with greater IOP reductions and reduced likelihood of bleb failure. Our results suggest that oral nonsteroidal anti-inflammatory drugs may be a safe way of improving trabeculectomy survival in high-risk eyes.
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Affiliation(s)
| | - Ryan Eyn Kidd Man
- Duke-NUS Medical School, National University of Singapore
- Singapore National Eye Centre
- Singapore Eye Research Institute, Singapore
| | | | - Olivia S Huang
- Duke-NUS Medical School, National University of Singapore
- Singapore National Eye Centre
| | | | - Rahat Husain
- Duke-NUS Medical School, National University of Singapore
- Singapore National Eye Centre
| | - Ching Lin Ho
- Duke-NUS Medical School, National University of Singapore
- Singapore National Eye Centre
| | - Pui Yi Boey
- Duke-NUS Medical School, National University of Singapore
- Singapore National Eye Centre
| | - Shamira A Perera
- Duke-NUS Medical School, National University of Singapore
- Singapore National Eye Centre
- Singapore Eye Research Institute, Singapore
| | - Jin Rong Low
- Singapore National Eye Centre
- Singapore Eye Research Institute, Singapore
| | - Tin Aung
- Yong Loo Lin School of Medicine
- Duke-NUS Medical School, National University of Singapore
- Singapore National Eye Centre
- Singapore Eye Research Institute, Singapore
| | - Ecosse L Lamoureux
- Duke-NUS Medical School, National University of Singapore
- Singapore National Eye Centre
- Singapore Eye Research Institute, Singapore
- Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital
- Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Victoria, Australia
| | - Tina T Wong
- Yong Loo Lin School of Medicine
- Duke-NUS Medical School, National University of Singapore
- Singapore National Eye Centre
- Singapore Eye Research Institute, Singapore
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Fenwick EK, Lim B, Man REK, Baskaran M, Nongpiur ME, Sng CCA, Iyer JV, Husain R, Perera SA, Wong TT, Low JR, Shimin OH, Lun K, Aung T, Lamoureux EL. The development of a glaucoma-specific health-related quality of life item bank supporting a novel computerized adaptive testing system in Asia. J Patient Rep Outcomes 2022; 6:107. [PMID: 36219349 PMCID: PMC9554106 DOI: 10.1186/s41687-022-00513-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 09/16/2022] [Indexed: 11/07/2022] Open
Abstract
Background A glaucoma-specific health-related quality of life (HRQoL) item bank (IB) and computerized adaptive testing (CAT) system relevant to Asian populations is not currently available. We aimed to develop content for an IB focusing on HRQoL domains important to Asian people with glaucoma; and to compare the content coverage of our new instrument with established glaucoma-specific instruments.
Methods In this qualitative study of glaucoma patients recruited from the Singapore National Eye Centre (November 2018-November 2019), items/domains were generated from: (1) glaucoma-specific questionnaires; (2) published articles; (3) focus groups/semi-structured interviews with glaucoma patients (n = 27); and (4) feedback from glaucoma experts. Data were analyzed using the constant comparative method. Items were systematically refined to a concise set, and pre-tested using cognitive interviews with 27 additional glaucoma patients.
Results Of the 54 patients (mean ± standard deviation [SD] age 66.9 ± 9.8; 53.7% male), 67 (62.0%), 30 (27.8%), and 11 (10.2%) eyes had primary open angle glaucoma, angle closure glaucoma, and no glaucoma respectively. Eighteen (33.3%), 11 (20.4%), 8 (14.8%), 12 (22.2%), and 5 (9.3%) patients had no, mild, moderate, severe, or advanced/end-stage glaucoma (better eye), respectively. Initially, 311 items within nine HRQoL domains were identified: Visual Symptoms, Ocular Comfort Symptoms, Activity Limitation, Driving, Lighting, Mobility, Psychosocial, Glaucoma management, and Work; however, Driving and Visual Symptoms were subsequently removed during the refinement process. During cognitive interviews, 12, 23 and 10 items were added, dropped and modified, respectively.
Conclusion Following a rigorous process, we developed a 221-item, 7-domain Asian glaucoma-specific IB. Once operationalised using CAT, this new instrument will enable precise, rapid, and comprehensive assessment of the HRQoL impact of glaucoma and associated treatment efficacy.
Supplementary Information The online version contains supplementary material available at 10.1186/s41687-022-00513-3.
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Affiliation(s)
- Eva K. Fenwick
- grid.272555.20000 0001 0706 4670Singapore National Eye Centre, Singapore Eye Research Institute (SERI), The Academia, 20 College Road, Level 6, Singapore, 169856 Singapore ,grid.4280.e0000 0001 2180 6431Duke–NUS Medical School, National University of Singapore, Singapore, Singapore
| | - Belicia Lim
- grid.272555.20000 0001 0706 4670Singapore National Eye Centre, Singapore Eye Research Institute (SERI), The Academia, 20 College Road, Level 6, Singapore, 169856 Singapore
| | - Ryan E. K. Man
- grid.272555.20000 0001 0706 4670Singapore National Eye Centre, Singapore Eye Research Institute (SERI), The Academia, 20 College Road, Level 6, Singapore, 169856 Singapore ,grid.4280.e0000 0001 2180 6431Duke–NUS Medical School, National University of Singapore, Singapore, Singapore
| | - Mani Baskaran
- grid.272555.20000 0001 0706 4670Singapore National Eye Centre, Singapore Eye Research Institute (SERI), The Academia, 20 College Road, Level 6, Singapore, 169856 Singapore ,grid.414795.a0000 0004 1767 4984Medical and Vision Research Foundation, Sankara Nethralaya, Chennai, India
| | - Monisha E. Nongpiur
- grid.272555.20000 0001 0706 4670Singapore National Eye Centre, Singapore Eye Research Institute (SERI), The Academia, 20 College Road, Level 6, Singapore, 169856 Singapore
| | - Chelvin C. A. Sng
- grid.272555.20000 0001 0706 4670Singapore National Eye Centre, Singapore Eye Research Institute (SERI), The Academia, 20 College Road, Level 6, Singapore, 169856 Singapore ,grid.410759.e0000 0004 0451 6143National University Health System, Singapore, Singapore
| | - Jayant V. Iyer
- grid.272555.20000 0001 0706 4670Singapore National Eye Centre, Singapore Eye Research Institute (SERI), The Academia, 20 College Road, Level 6, Singapore, 169856 Singapore
| | - Rahat Husain
- grid.272555.20000 0001 0706 4670Singapore National Eye Centre, Singapore Eye Research Institute (SERI), The Academia, 20 College Road, Level 6, Singapore, 169856 Singapore
| | - Shamira A. Perera
- grid.272555.20000 0001 0706 4670Singapore National Eye Centre, Singapore Eye Research Institute (SERI), The Academia, 20 College Road, Level 6, Singapore, 169856 Singapore
| | - Tina T. Wong
- grid.272555.20000 0001 0706 4670Singapore National Eye Centre, Singapore Eye Research Institute (SERI), The Academia, 20 College Road, Level 6, Singapore, 169856 Singapore ,grid.4280.e0000 0001 2180 6431Duke–NUS Medical School, National University of Singapore, Singapore, Singapore
| | - Jin Rong Low
- grid.272555.20000 0001 0706 4670Singapore National Eye Centre, Singapore Eye Research Institute (SERI), The Academia, 20 College Road, Level 6, Singapore, 169856 Singapore
| | - Olivia Huang Shimin
- grid.272555.20000 0001 0706 4670Singapore National Eye Centre, Singapore Eye Research Institute (SERI), The Academia, 20 College Road, Level 6, Singapore, 169856 Singapore ,grid.4280.e0000 0001 2180 6431Duke–NUS Medical School, National University of Singapore, Singapore, Singapore
| | - Katherine Lun
- grid.414795.a0000 0004 1767 4984Medical and Vision Research Foundation, Sankara Nethralaya, Chennai, India
| | - Tin Aung
- grid.272555.20000 0001 0706 4670Singapore National Eye Centre, Singapore Eye Research Institute (SERI), The Academia, 20 College Road, Level 6, Singapore, 169856 Singapore ,grid.4280.e0000 0001 2180 6431Duke–NUS Medical School, National University of Singapore, Singapore, Singapore ,grid.410759.e0000 0004 0451 6143National University Health System, Singapore, Singapore
| | - Ecosse L. Lamoureux
- grid.272555.20000 0001 0706 4670Singapore National Eye Centre, Singapore Eye Research Institute (SERI), The Academia, 20 College Road, Level 6, Singapore, 169856 Singapore ,grid.4280.e0000 0001 2180 6431Duke–NUS Medical School, National University of Singapore, Singapore, Singapore ,grid.1008.90000 0001 2179 088XThe University of Melbourne, Melbourne, Australia
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Tumbocon JA, Wong TT, Sangapillai T, Yen YC, Park SW, Lim HH, Ruangvaravate N. A Pooled Assessment of Ocular Surface Disease After Switching from Preserved Prostaglandins to Tafluprost Across Six Countries in Asia. Clin Ophthalmol 2022; 16:2669-2676. [PMID: 35999967 PMCID: PMC9393018 DOI: 10.2147/opth.s372312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 08/01/2022] [Indexed: 11/23/2022] Open
Abstract
Background Preserved prostaglandin analogs (PGAs) have been linked to ocular surface disease (OSD). While the benefits of preservative-low (PL) or -free (PF) Tafluprost (Santen Inc., Japan) were reported in real-world studies in Western countries, this is the first study in Asia to assess the effectiveness and safety of switching from preserved PGA to PL or PF-Tafluprost. Methods We conducted a meta-analysis on studies that included adults (>18 years of age) with a Corneal Fluorescein Staining Score (CFS) >1. These individuals had switched to PL or PF-tafluprost after using a preserved PGA therapy for at least 3 months for glaucoma and were identified from Santen’s tafluprost study database. A total of six studies from South Korea, Philippines, Malaysia, Singapore, Thailand, Taiwan were pooled for analysis. Results An intraocular pressure (IOP) reduction of 5.9% (0.91 mmHg) was seen in 265 patients. However, this result was not statistically significant (95% CI: −3.64, 1.81; Figure 1). Among 132 patients, a 47.9% reduction in the CFS (95% CI: −3.65, −1.91) was seen. Tear film break-up (n=183) significantly increased by 1.06 seconds (95% CI: 0.65, 1.47). In 88 patients, the bulbar conjunctiva score decreased by −0.46 (95% CI: −0.81, −0.10) and palpebral conjunctiva score decreased by −0.42 (95% CI: −0.67–0.17). One or more new adverse reactions were reported in 3% of the individuals after switching. Conclusion Tafluprost IOP reduction is comparable to other PGAs, with significant improvements in the ocular surface and minimal adverse reactions which were already previously reported.
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Affiliation(s)
- Joseph Anthony Tumbocon
- Eye Institute, St. Luke’s Medical Center, Quezon City, Philippines
- Department of Ophthalmology, St. Luke’s Medical Center College of Medicine, Quezon City, Philippines
- Correspondence: Joseph Anthony Tumbocon, Eye Institute, St. Luke’s Medical Center, 279 E Rodriguez Sr. Ave, Quezon City, Metro Manila, 1112, Philippines, Email
| | - Tina T Wong
- Glaucoma Department, Singapore National Eye Centre, Singapore, Singapore
- Cataract & Comprehensive Ophthalmology Department, Singapore Eye Research Institute, Singapore, Singapore
- Ophthalmology & Visual Sciences, Duke-NUS Graduate Medical School, Singapore, Singapore
| | | | - Yung-Chang Yen
- Department of Ophthalmology, Chi Mei Medical Center, Tainan City, Taiwan
| | - Sang-Woo Park
- Department of Ophthalmology, Chonnam National University Medical School and Hospital, Gwangju, South Korea
| | - Hsien Han Lim
- Eye Centre, Sunway Medical Centre, Petaling Jaya, Selangor, Malaysia
| | - Ngamkae Ruangvaravate
- Department of Ophthalmology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
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Chew ACY, Seet LF, Chu SWL, Lwin NC, Wong TT. Effect of peripheral iridectomy on VEGF-A and TGF-β levels in rabbit aqueous humour. BMC Ophthalmol 2022; 22:23. [PMID: 35031016 PMCID: PMC8759248 DOI: 10.1186/s12886-022-02249-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Accepted: 12/20/2021] [Indexed: 11/15/2022] Open
Abstract
Background Peripheral iridectomy (PI), routinely performed during glaucoma filtration surgery, may contribute to scarring. This study aims to determine whether PI alters the concentrations of VEGF-A and TGF-β isoforms in the rabbit aqueous humour. Methods Anterior chamber paracentesis (ACP) was performed in both eyes of six New Zealand white rabbits, with additional surgical PI performed in the right eyes. Eyes were examined on postoperative days (PODs) 1, 7, 30 and 60 by means of the tonopen, slit-lamp biomicroscopy, and bead-based cytokine assays for TGF-β and VEGF-A concentrations in the aqueous humor. Results ACP caused a significant reduction in intraocular pressure (IOP) from mean preoperative 11.47 ± 1.01 mmHg to 5.67 ± 1.63 mmHg on POD 1 while PI did not cause further IOP reduction. Limbal conjunctival vasculature appeared slightly increased on POD 1 in both ACP and PI eyes with PI also causing mild bleeding from damaged iris vessels. Two PI eyes developed fibrinous anterior chamber reaction and/ or peripheral anterior synechiae. Aqueous VEGF-A levels were not significantly different between eyes treated with ACP and PI. Aqueous TGF-β concentrations distributed in the ratio of 4:800:1 for TGF-β1:TGF-β2:TGF-β3 respectively. While aqueous TGF-β2 was not significantly induced by either procedure at any time point, TGF-β1 and TGF-β3 were significantly induced above baseline levels by PI on POD 1. Conclusion PI increases the risk of inflammation. The combined induction of aqueous TGF-β1 and TGF-β3 by PI in glaucoma surgery may impact surgery success in glaucoma subtypes sensitive to these isoforms.
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Affiliation(s)
- Annabel C Y Chew
- Singapore National Eye Centre, 11 Third Hospital Avenue, Singapore, 168751, Singapore.,Singapore Eye Research Institute, Singapore, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Duke-NUS Medical School Singapore, Singapore, Singapore
| | - Li-Fong Seet
- Singapore Eye Research Institute, Singapore, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Duke-NUS Medical School Singapore, Singapore, Singapore
| | | | - Nyein C Lwin
- Singapore Eye Research Institute, Singapore, Singapore
| | - Tina T Wong
- Singapore National Eye Centre, 11 Third Hospital Avenue, Singapore, 168751, Singapore. .,Singapore Eye Research Institute, Singapore, Singapore. .,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore. .,Duke-NUS Medical School Singapore, Singapore, Singapore.
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8
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Seet LF, Yap ZL, Chu SWL, Toh LZ, Ibrahim FI, Teng X, Wong TT. Effects of Valproic Acid and Mitomycin C Combination Therapy in a Rabbit Model of Minimally Invasive Glaucoma Surgery. Transl Vis Sci Technol 2022; 11:30. [PMID: 35044442 PMCID: PMC8787605 DOI: 10.1167/tvst.11.1.30] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose This study aimed to compare the effectiveness of combination therapy consisting of low-dose mitomycin C (MMC) and valproic acid (VPA) against high-dose MMC for improving the scar phenotype in minimally invasive glaucoma surgery (MIGS). Methods A rabbit model of MIGS incorporating the PreserFlo MicroShunt was treated with high (0.4 mg/mL) or low (0.1 mg/mL) doses of MMC or with combination therapy consisting of low-dose (0.1 mg/mL) MMC and VPA. Operated eyes were examined by live ocular imaging, histochemical evaluation, multiphoton quantitation of collagen characteristics, and molecular analyses. Results Although high-dose MMC obliterated the vasculature, combination therapy vastly improved the postoperative tissue morphology by maintaining the vasculature without increased vascularization. Combination therapy also altered collagen morphology and reduced encapsulation of the MicroShunt distal end, which remained at risk with MMC treatment alone. Multiphoton quantitation indicated that the combination therapy significantly reduced collagen density and fiber dimensions compared with monotherapy. At the molecular level, combination therapy significantly reduced Vegfa, Vegfc, and Vegfd expression and inhibited Col1a1 upregulation from baseline levels, all of which low-dose MMC alone was unable to achieve. Notably, COL1A1 protein levels appeared more consistently suppressed by combination therapy compared with high-dose MMC alone. Conclusions Compared with high-dose MMC, combination therapy was less toxic by sparing the vasculature and potentially more effective in reducing scarring via the regulation of collagen content and organization. Translational Relevance VPA may be combined with low-dose MMC to replace high-dose MMC to deliver safe and effective anti-scarring outcomes.
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Affiliation(s)
- Li-Fong Seet
- Singapore Eye Research Institute, Singapore.,Duke-NUS Medical School Singapore, Singapore
| | - Zhu Li Yap
- Singapore Eye Research Institute, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Duke-NUS Medical School Singapore, Singapore.,Singapore National Eye Centre, Singapore
| | | | | | | | | | - Tina T Wong
- Singapore Eye Research Institute, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Duke-NUS Medical School Singapore, Singapore.,Singapore National Eye Centre, Singapore
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9
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Wong CW, Wong E, Metselaar JM, Storm G, Wong TT. Liposomal drug delivery system for anti-inflammatory treatment after cataract surgery: a phase I/II clinical trial. Drug Deliv Transl Res 2022; 12:7-14. [PMID: 33569720 DOI: 10.1007/s13346-021-00912-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/15/2021] [Indexed: 12/20/2022]
Abstract
Liposomes as a drug delivery system may overcome the problems associated with non-compliance to eyedrops and inadequate control of inflammation after cataract surgery. We evaluated the safety and efficacy of a single subconjunctival injection of liposomal prednisolone phosphate (LPP) for the treatment of post-cataract surgery inflammation. This is a phase I/II, open-label non-comparative interventional trial of patients undergoing cataract surgery. All patients received a single injection of subconjunctival LPP intraoperatively. The primary outcome measure was the proportion of eyes with an anterior chamber cell count of 0 at postoperative month 1. Ocular and non-ocular adverse events, including elevated intraocular pressure, rebound iritis and pseudophakic macular edema were monitored. Five patients were enrolled in this study. The mean age was 66.6 ± 6.2 and 4 (80%) were male. The proportion of patients with AC cell grading of 0 was 0%, 80%, 80%, and 100% at day 1, week 1, month 1, and month 2 after cataract surgery, respectively. Mean laser flare photometry readings were significantly elevated at week 1 after cataract surgery (48.8 ± 18.9, p = 0.03) compared with baseline, decreasing to 25.8 ± 9.2 (p = 0.04) at month 1 and returned to baseline by month 2 (10.9 ± 5.1, p = 1.0). No ocular or non-ocular adverse events were observed. Liposomal prednisolone phosphate, administered as a single subconjunctival injection intraoperatively, can be a safe and effective treatment for post-cataract surgery inflammation. The delivery of steroids with a liposomal drug delivery system could potentially replace eyedrops as anti-inflammatory therapy following cataract surgery.
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Affiliation(s)
- Chee Wai Wong
- Singapore National Eye Centre (SNEC), 11 Third Hospital Avenue, Singapore City, 168751, Singapore
- Singapore Eye Research Institute, 11 Third Hospital Avenue, Singapore City, 168751, Singapore
- Duke-National University of Singapore Medical School, 8 College Rd, Singapore City, 169857, Singapore
| | - Edmund Wong
- Singapore National Eye Centre (SNEC), 11 Third Hospital Avenue, Singapore City, 168751, Singapore
- Singapore Eye Research Institute, 11 Third Hospital Avenue, Singapore City, 168751, Singapore
- Duke-National University of Singapore Medical School, 8 College Rd, Singapore City, 169857, Singapore
| | - Josbert M Metselaar
- Department of Experimental Molecular Imaging, University Clinic and Helmholtz Institute for Biomedical Engineering, RWTH Aachen University, 52074, Aachen, Germany
| | - Gert Storm
- Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences (UIPS), Utrecht University, PO Box 80082, 3508 TB, Utrecht, The Netherlands
| | - Tina T Wong
- Singapore National Eye Centre (SNEC), 11 Third Hospital Avenue, Singapore City, 168751, Singapore.
- Singapore Eye Research Institute, 11 Third Hospital Avenue, Singapore City, 168751, Singapore.
- Duke-National University of Singapore Medical School, 8 College Rd, Singapore City, 169857, Singapore.
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10
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Yap ZL, Seet LF, Chu SW, Toh LZ, Ibrahim FI, Wong TT. Effect of valproic acid on functional bleb morphology in a rabbit model of minimally invasive surgery. Br J Ophthalmol 2021; 106:1028-1036. [PMID: 34266858 PMCID: PMC9234410 DOI: 10.1136/bjophthalmol-2020-318691] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Accepted: 06/19/2021] [Indexed: 01/02/2023]
Abstract
Purpose To determine the effect of valproic acid (VPA) on bleb morphology and scar characteristics in a rabbit model of minimally invasive glaucoma surgery (MIGS). Methods Nine New Zealand white rabbits were subjected to MIGS with intraoperative implantation of the PreserFlo MicroShunt. Rabbits were then administered with subconjunctival injections of phosphate buffered saline (PBS) (n=4) or with VPA (n=5). Bleb morphology was examined by slit-lamp biomicroscopy and in vivo confocal microscopy. Postoperative day 28 tissues were examined by immunohistochemical evaluation and label-free multiphoton microscopy to visualise the collagen matrix, by terminal deoxynucleotidyl transferase dUTP nick-end labelling assay and immunofluorescent labelling for Ki67 expression to detect apoptosis and cell growth, and by real-time quantitative PCR to measure Col1a1, Fn, and Smad6 transcript expression. Results VPA-treated blebs were detectable on day 28, while the PBS-treated blebs were not detectable by day 14. VPA-treated blebs were diffuse, extended posteriorly with near normal conjunctival vascularity and featured a combination of reticular/blurred stromal pattern with evidence of relatively large stromal cysts. Instead of the deposition of thick, disorganised collagen fibres characteristic of the PBS bleb, the VPA bleb contained conspicuously thinner collagen fibres which were associated with similarly thinner fibronectin fibres. In corroboration, Col1a1 and Fn mRNA expression was reduced in the VPA blebs, while increased Smad6 expression implicated the disruption of the transforming growth factor beta pathway. Apoptosis and cell growth profiles appeared similar with both treatments. Conclusions The results support the application of VPA to enhance bleb morphology associated with good bleb function in MIGS with no apparent cytotoxicity.
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Affiliation(s)
- Zhu Li Yap
- Department of Ophthalmology, Singapore Eye Research Institute, Singapore
| | - Li-Fong Seet
- Department of Ophthalmology, Singapore Eye Research Institute, Singapore
| | - Stephanie Wl Chu
- Ocular Therapeutics & Drug Delivery, Singapore Eye Research Institute, Singapore
| | - Li Zhen Toh
- Ocular Therapeutics & Drug Delivery, Singapore Eye Research Institute, Singapore
| | | | - Tina T Wong
- Department of Ophthalmology, Singapore Eye Research Institute, Singapore
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11
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Yao X, Tan B, Ho Y, Liu X, Wong D, Chua J, Wong TT, Perera S, Ang M, Werkmeister RM, Schmetterer L. Full circumferential morphological analysis of Schlemm's canal in human eyes using megahertz swept source OCT. Biomed Opt Express 2021; 12:3865-3877. [PMID: 34457385 PMCID: PMC8367246 DOI: 10.1364/boe.426218] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/03/2021] [Accepted: 05/05/2021] [Indexed: 05/16/2023]
Abstract
We performed full circumferential imaging of the Schlemm's canal (SC) of two human eyes using a Fourier domain mode-lock laser (FDML) based 1.66-MHz SS-OCT prototype at 1060 nm. Eight volumes with overlapping margins were acquired around the limbal area with customized raster scanning patterns designed to fully cover the SC while minimizing motion artifacts. The SC was segmented from the volumes using a semi-automated active contour segmentation algorithm, whose mean dice similarity coefficient was 0.76 compared to the manual segmentation results. We also reconstructed three-dimensional (3D) renderings of the 360° SC by stitching the segmented SCs from the volumetric datasets. Quantitative metrics of the full circumferential SC were provided, including the mean and standard deviation (SD) of the cross-sectional area (CSA), the maximum CSA, the minimum and maximum SC opening width, and the number of collector channels (CC) stemming from the SC.
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Affiliation(s)
- Xinwen Yao
- SERI-NTU Advanced Ocular Engineering (STANCE), Singapore
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Bingyao Tan
- SERI-NTU Advanced Ocular Engineering (STANCE), Singapore
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Yijie Ho
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Xinyu Liu
- SERI-NTU Advanced Ocular Engineering (STANCE), Singapore
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Damon Wong
- SERI-NTU Advanced Ocular Engineering (STANCE), Singapore
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Jacqueline Chua
- SERI-NTU Advanced Ocular Engineering (STANCE), Singapore
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- Academic Clinical Program, Duke-NUS Medical School, Singapore
| | - Tina T. Wong
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- Academic Clinical Program, Duke-NUS Medical School, Singapore
| | - Shamira Perera
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- Academic Clinical Program, Duke-NUS Medical School, Singapore
| | - Marcus Ang
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- Academic Clinical Program, Duke-NUS Medical School, Singapore
| | - René M. Werkmeister
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Leopold Schmetterer
- SERI-NTU Advanced Ocular Engineering (STANCE), Singapore
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- Academic Clinical Program, Duke-NUS Medical School, Singapore
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
- Institute of Molecular and Clinical Ophthalmology, Basel, Switzerland
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12
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Huang OS, Chew ACY, Finkelstein EA, Wong TT, Lamoureux EL. Outcomes of an Asynchronous Virtual Glaucoma Clinic in Monitoring Patients at Low Risk of Glaucoma Progression in Singapore. Asia Pac J Ophthalmol (Phila) 2021; 10:328-334. [PMID: 34383723 DOI: 10.1097/apo.0000000000000402] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
PURPOSE To assess the implementation outcomes of a new asynchronous virtual clinic, the Glaucoma Observation Clinic (GLOC), at the Singapore National Eye Center, in monitoring patients at low risk for glaucoma progression. METHODS Patients with low risk of glaucoma progression were followed up at GLOC. Visual acuity, intraocular pressure, and visual field testing or optic nerve head imaging were assessed by nurses and technicians, with virtual review of data by an ophthalmologist separately. The implementation outcomes were defined as patient satisfaction, assessed by a nurse-administered questionnaire; the rate of referrals back to the glaucoma outpatient department; the patients' journey time (minutes); the time taken for the specialist review (minutes), and the per capita manpower cost compared with current glaucoma outpatient model. RESULTS A total of 377 patients were included, with the majority being glaucoma disc suspects (n = 250, 66.4%) and primary angle closure suspects (n = 54, 14.3%). Most patients (more than 90%) reported being satisfied, and only 7.7% (n = 29) were referred back to the specialist outpatient glaucoma clinic due to possible glaucoma progression. Compared with the glaucoma outpatient clinic, the average journey time in GLOC was 50% less (59.3 mins vs 132 mins), the average time for a specialist review was 3 times faster (5.8 mins vs 19.5 mins), and the per capita manpower cost of GLOC was halved ($20.07 vs $39.78). CONCLUSIONS GLOC is a time-efficient, cost-saving, and sustainable model of care for managing patients with low risk of glaucoma progression. It was well received by patients and freed up the conventional clinic to treat patients with complex needs.
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Affiliation(s)
- Olivia S Huang
- Singapore National Eye Center and Singapore Eye Research Institute, Singapore
- Duke-NUS Medical School, Singapore
| | - Annabel C Y Chew
- Singapore National Eye Center and Singapore Eye Research Institute, Singapore
- Department of Ophthalmology, National University of Singapore, Singapore
- Duke-NUS Medical School, Singapore
| | - Eric A Finkelstein
- Duke-NUS Medical School, Singapore
- School of Public Health, National University of Singapore, Singapore
| | - Tina T Wong
- Singapore National Eye Center and Singapore Eye Research Institute, Singapore
- Department of Ophthalmology, National University of Singapore, Singapore
- Duke-NUS Medical School, Singapore
- School of Materials Science and Engineering, Nanyang Technological University, Singapore
| | - Ecosse L Lamoureux
- Singapore National Eye Center and Singapore Eye Research Institute, Singapore
- Department of Ophthalmology, National University of Singapore, Singapore
- Duke-NUS Medical School, Singapore
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13
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Abstract
Glaucoma filtration surgery plays an important role in achieving intraocular pressure (IOP) reduction in patients who have high IOP despite maximum medical therapy. Preclinical experimental models of glaucoma filtration surgery contribute a great deal to our knowledge of the wound healing processes that predispose to scarring and may lead to poor outcomes. However, this research needs to be interpreted in the light of the specific study design, animal model and methods used. We review the existing literature addressing various models of experimental glaucoma filtration surgery, discuss the considerations in assessing these models and describe future steps in evaluating potential therapeutics and bleb characteristics that could impact translational research in this field.
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Affiliation(s)
- Rachel S Chong
- Singapore National Eye Centre Singapore Singapore
- Singapore Eye Research Institute Singapore Singapore
- Duke‐NUS Medical School Singapore Singapore
- Genome Institute of Singapore Agency for Science Technology and Research Singapore Singapore
| | - Jonathan G Crowston
- Singapore National Eye Centre Singapore Singapore
- Singapore Eye Research Institute Singapore Singapore
- Duke‐NUS Medical School Singapore Singapore
| | - Tina T Wong
- Singapore National Eye Centre Singapore Singapore
- Singapore Eye Research Institute Singapore Singapore
- Duke‐NUS Medical School Singapore Singapore
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14
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Huang OS, Seet LF, Ho HW, Chu SW, Narayanaswamy A, Perera SA, Husain R, Aung T, Wong TT. Altered Iris Aquaporin Expression and Aqueous Humor Osmolality in Glaucoma. Invest Ophthalmol Vis Sci 2021; 62:34. [PMID: 33616622 PMCID: PMC7910645 DOI: 10.1167/iovs.62.2.34] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Aquaporins (AQPs) facilitate transmembrane osmotic water transport and may play a role in iris fluid conductivity, which is implicated in the pathophysiology of glaucoma. In this study, we compared the iris expression of AQPs and aqueous osmolality between primary angle closure glaucoma (PACG), primary open-angle glaucoma (POAG), and nonglaucoma eyes. Methods AQP1-5 transcripts from a cohort of 36 PACG, 34 POAG and 26 nonglaucoma irises were measured by quantitative real-time PCR. Osmolality of aqueous humor from another cohort of 49 PACG, 50 POAG, and 50 nonglaucoma eyes were measured using an osmometer. The localization of AQP1 in both glaucoma and nonglaucoma irises was determined by immunofluorescent analysis. Results Of the five AQP genes evaluated, AQP1 and AQP2 transcripts were significantly upregulated in both PACG (3.48- and 8.07-fold, respectively) and POAG (3.12- and 11.58-fold, respectively) irises relative to nonglaucoma counterparts. The aqueous osmolalities of PACG (303.68 mmol/kg) and POAG (300.79 mmol/kg) eyes were significantly lower compared to nonglaucoma eyes (312.6 mmol/kg). There was no significant difference in expression of AQP transcripts or aqueous osmolality between PACG and POAG eyes. Conclusions PACG and POAG eyes featured significant increase in AQP1 and AQP2 expression in the iris and reduced aqueous osmolality compared to nonglaucoma eyes. These findings suggest that the iris may be involved in altered aqueous humor dynamics in glaucoma pathophysiology. Because PACG did not differ from POAG in both properties studied, it is likely that they are common to glaucoma disease in general.
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Affiliation(s)
- Olivia S Huang
- Singapore National Eye Centre, Singapore.,Duke-NUS Medical School, Singapore
| | - Li-Fong Seet
- Singapore Eye Research Institute, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Duke-NUS Medical School, Singapore
| | | | | | | | - Shamira A Perera
- Singapore National Eye Centre, Singapore.,Singapore Eye Research Institute, Singapore.,Duke-NUS Medical School, Singapore
| | - Rahat Husain
- Singapore National Eye Centre, Singapore.,Singapore Eye Research Institute, Singapore.,Duke-NUS Medical School, Singapore
| | - Tin Aung
- Singapore National Eye Centre, Singapore.,Singapore Eye Research Institute, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Duke-NUS Medical School, Singapore
| | - Tina T Wong
- Singapore National Eye Centre, Singapore.,Singapore Eye Research Institute, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Duke-NUS Medical School, Singapore.,School of Materials Science and Engineering, Nanyang Technological University, Singapore
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15
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Chun YY, Yap ZL, Seet LF, Chan HH, Toh LZ, Chu SWL, Lee YS, Wong TT, Tan TTY. Positive-charge tuned gelatin hydrogel-siSPARC injectable for siRNA anti-scarring therapy in post glaucoma filtration surgery. Sci Rep 2021; 11:1470. [PMID: 33446775 PMCID: PMC7809290 DOI: 10.1038/s41598-020-80542-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 12/18/2020] [Indexed: 11/18/2022] Open
Abstract
Small interfering RNA (siRNA) therapy is a promising epigenetic silencing strategy. However, its widespread adoption has been severely impeded by its ineffective delivery into the cellular environment. Here, a biocompatible injectable gelatin-based hydrogel with positive-charge tuned surface charge is presented as an effective platform for siRNA protection and delivery. We demonstrate a two-step synthesis of a gelatin-tyramine (Gtn-Tyr) hydrogel with simultaneous charge tunability and crosslinking ability. We discuss how different physiochemical properties of the hydrogel interact with siSPARC (siRNA for secreted protein, acidic and rich in cysteine), and study the positive-charge tuned gelatin hydrogel as an effective delivery platform for siSPARC in anti-fibrotic treatment. Through in vitro studies using mouse tenon fibroblasts, the positive-charge tuned Gtn-Tyr hydrogel shows sustained siSPARC cellular internalization and effective SPARC silencing with excellent biocompatibility. Similarly, the same hydrogel platform delivering siSPARC in an in vivo assessment employing a rabbit model shows an effective reduction in subconjunctival scarring in post glaucoma filtration surgery, and is non-cytotoxic compared to a commonly used anti-scarring agent, mitomycin-C. Overall, the current siRNA delivery strategy involving the positive-charge tuned gelatin hydrogel shows effective delivery of gene silencing siSPARC for anti-fibrotic treatment. The current charge tunable hydrogel delivery system is simple to fabricate and highly scalable. We believe this delivery platform has strong translational potential for effective siRNA delivery and epigenetic silencing therapy.
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Affiliation(s)
- Yong Yao Chun
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Dr, Singapore, 637459, Singapore
- Ocular Imaging, Singapore Eye Research Institute, 20 College Road Discovery Tower Level 6, The Academia, Singapore, 169856, Singapore
| | - Zhu Li Yap
- Ocular Therapeutics and Drug Delivery, Singapore Eye Research Institute, 20 College Road Discovery Tower Level 6, The Academia, Singapore, 169856, Singapore
- Glaucoma Service, Singapore National Eye Centre, 11 Third Hospital Ave, Singapore, 168751, Singapore
| | - Li Fong Seet
- Ocular Therapeutics and Drug Delivery, Singapore Eye Research Institute, 20 College Road Discovery Tower Level 6, The Academia, Singapore, 169856, Singapore
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, 10 Medical Dr, Singapore, 117597, Singapore
- Duke-NUS Medical School, 8 College Rd, Singapore, 169857, Singapore
| | - Hiok Hong Chan
- Glaucoma Service, Singapore National Eye Centre, 11 Third Hospital Ave, Singapore, 168751, Singapore
| | - Li Zhen Toh
- Ocular Therapeutics and Drug Delivery, Singapore Eye Research Institute, 20 College Road Discovery Tower Level 6, The Academia, Singapore, 169856, Singapore
| | - Stephanie W L Chu
- Ocular Therapeutics and Drug Delivery, Singapore Eye Research Institute, 20 College Road Discovery Tower Level 6, The Academia, Singapore, 169856, Singapore
| | - Ying Shi Lee
- Ocular Therapeutics and Drug Delivery, Singapore Eye Research Institute, 20 College Road Discovery Tower Level 6, The Academia, Singapore, 169856, Singapore
- Glaucoma Service, Singapore National Eye Centre, 11 Third Hospital Ave, Singapore, 168751, Singapore
| | - Tina T Wong
- Ocular Therapeutics and Drug Delivery, Singapore Eye Research Institute, 20 College Road Discovery Tower Level 6, The Academia, Singapore, 169856, Singapore.
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, 10 Medical Dr, Singapore, 117597, Singapore.
- Duke-NUS Medical School, 8 College Rd, Singapore, 169857, Singapore.
- Glaucoma Service, Singapore National Eye Centre, 11 Third Hospital Ave, Singapore, 168751, Singapore.
- School of Materials Science and Engineering, Nanyang Technological University, 11 Faculty Ave, Singapore, 639977, Singapore.
| | - Timothy T Y Tan
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Dr, Singapore, 637459, Singapore.
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16
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Nongpiur ME, Verma S, Tun TA, Wong TT, Perera SA, Aung T. Plateau Iris and Severity of Primary Angle Closure Glaucoma. Am J Ophthalmol 2020; 220:1-8. [PMID: 32735788 DOI: 10.1016/j.ajo.2020.07.033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 07/21/2020] [Accepted: 07/21/2020] [Indexed: 10/23/2022]
Abstract
PURPOSE To compare the distribution of plateau iris in eyes across varying severity of primary angle closure glaucoma (PACG) using standardized ultrasound biomicroscopy (UBM) criteria. DESIGN Cross-sectional study. METHODS UBM was performed on 210 patients with PACG who had previously undergone laser peripheral iridotomy. Plateau iris was defined as the presence of all the following UBM criteria in ≥2 quadrants of the angle: anteriorly directed ciliary body, absent ciliary sulcus, iris angulation, flat iris plane, and iridotrabecular contact. Disease severity was based on the visual field mean deviation (MD) and classified as early-to-moderate (MD ≥ -12 dB), advanced (-12.01 dB to -20 dB), and severe (MD < -20 dB). RESULTS Of 210 subjects recruited, 23 were excluded because of poor quality UBM images. The remaining 187 patients were categorized as having early-to-moderate (n = 103), advanced (n = 38), and severe PACG (n = 46). Of these subjects, 48.1% were male, and 90.9% were of Chinese ethnicity. The overall proportion of plateau iris was 36.9%, with 32.0% (33/103) in early-to-moderate, 34.2% (13/38) in advanced, and 50% (23/46) in severe PACG (P = .03, comparing severe PACG with early-to-moderate groups). Among the severe PACG group, those with plateau iris configuration had significantly smaller anterior chamber area (P = .03) and volume (P = .01) compared with those without plateau iris. CONCLUSION The higher proportion of plateau iris configuration in eyes with severe PACG compared with early-to-moderate PACG suggest that this may be a contributory factor for disease severity.
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17
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Seet LF, Chu SWL, Teng X, Toh LZ, Wong TT. Assessment of progressive alterations in collagen organization in the postoperative conjunctiva by multiphoton microscopy. Biomed Opt Express 2020; 11:6495-6515. [PMID: 33282504 PMCID: PMC7687938 DOI: 10.1364/boe.403555] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 09/14/2020] [Accepted: 09/15/2020] [Indexed: 06/12/2023]
Abstract
Glaucoma filtration surgery (GFS) commonly fails due to excessive fibrosis. As collagen structure aberrations is implicated in adverse fibrotic progression, this study aims to uncover collagen organization alterations during postoperative scarring. Via quantitative second harmonic generation/two photon excitation multiphoton imaging, we reveal the scar development and phenotype in the mouse model of conjunctival scarring. We also show that multiphoton imaging corroborated the collagen ultrastructure anomaly characteristic of the SPARC-/- mouse postoperative conjunctiva. These data improve our understanding of postoperative conjunctival scarring and further enhance the utility of this model for the development of anti-fibrotic therapeutics for GFS.
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Affiliation(s)
- Li-Fong Seet
- Ocular Therapeutics and Drug Delivery, Singapore Eye Research Institute, Singapore
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Duke-NUS Medical School, Singapore
- Co-corresponding authors
| | - Stephanie W L Chu
- Ocular Therapeutics and Drug Delivery, Singapore Eye Research Institute, Singapore
| | | | - Li Zhen Toh
- Ocular Therapeutics and Drug Delivery, Singapore Eye Research Institute, Singapore
| | - Tina T Wong
- Ocular Therapeutics and Drug Delivery, Singapore Eye Research Institute, Singapore
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Duke-NUS Medical School, Singapore
- Glaucoma Service, Singapore National Eye Centre, Singapore
- Co-corresponding authors
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18
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Wong CW, Metselaar JM, Storm G, Wong TT. A review of the clinical applications of drug delivery systems for the treatment of ocular anterior segment inflammation. Br J Ophthalmol 2020; 105:1617-1622. [DOI: 10.1136/bjophthalmol-2020-315911] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 09/08/2020] [Accepted: 10/12/2020] [Indexed: 01/14/2023]
Abstract
Ocular anterior segment inflammation is a medical problem that is seen in cases of cataract surgery and non-infectious anterior uveitis. Inadequately treated anterior segment inflammation can lead to sight-threatening conditions such as corneal oedema, glaucoma and cystoid macular oedema. The mainstay of treatment for anterior segment inflammation is topical steroid eye-drops. However, several drawbacks limit the critical value of this treatment, including low bioavailability, poor patient compliance, relatively difficult administration manner and risk of blurring of vision and ocular irritation. A drug delivery system (DDS) that can provide increased bioavailability and sustained delivery while being specifically targeted towards inflamed ocular tissue can potentially replace daily eye-drops as the gold standard for management of anterior segment inflammation. The various DDS for anti-inflammatory drugs for the treatment of anterior segment inflammation are listed and summarised in this review, with a focus on commercially available products and those in clinical trials. Dextenza, INVELTYS, Dexycu and Bromsite are examples of DDS that have enjoyed success in clinical trials leading to FDA approval. Nanoparticles and ocular iontophoresis form the next wave of DDS that have the potential to replace topical steroids eye-drops as the treatment of choice for anterior segment inflammation. With the current relentless pace of ophthalmic drug delivery research, the pursuit of a new standard of treatment that eliminates the problems of low bioavailability and patient compliance may soon be realised.
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19
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Liu YC, Lin MTY, Ng AHC, Wong TT, Mehta JS. Nanotechnology for the Treatment of Allergic Conjunctival Diseases. Pharmaceuticals (Basel) 2020; 13:E351. [PMID: 33138064 PMCID: PMC7694068 DOI: 10.3390/ph13110351] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 10/26/2020] [Accepted: 10/27/2020] [Indexed: 02/07/2023] Open
Abstract
Allergic conjunctivitis is one of the most common external eye diseases and the prevalence has been increasing. The mainstay of treatment is topical eye drops. However, low bioavailability, low ocular drug penetration, transient resident time on the ocular surface due to tear turnover, frequent topical applications and dependence on patient compliance, are the main drawbacks associated with topical administration. Nanotechnology-based medicine has emerged to circumvent these limitations, by encapsulating the drugs and preventing them from degradation and therefore providing sustained and controlled release. Using a nanotechnology-based approach to load the drug is particularly useful for the delivery of hydrophobic drugs such as immunomodulatory agents, which are commonly used in allergic conjunctival diseases. In this review, different nanotechnology-based drug delivery systems, including nanoemulsions, liposomes, nanomicelles, nanosuspension, polymeric and lipid nanoparticles, and their potential ophthalmic applications, as well as advantages and disadvantages, are discussed. We also summarize the results of present studies on the loading of immunomodulators or nonsteroidal anti-inflammatory drugs to nano-scaled drug delivery systems. For future potential clinical use, research should focus on the optimization of drug delivery designs that provide adequate and effective doses with safe and satisfactory pharmacokinetic and pharmaco-toxic profiles.
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Affiliation(s)
- Yu-Chi Liu
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore 169856, Singapore; (Y.-C.L.); (M.T.-Y.L.)
- Department of Cornea and External Eye Disease, Singapore National Eye Centre, Singapore 168751, Singapore;
- Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore 169857, Singapore
| | - Molly Tzu-Yu Lin
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore 169856, Singapore; (Y.-C.L.); (M.T.-Y.L.)
| | - Anthony Herr Cheun Ng
- School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore;
| | - Tina T. Wong
- Department of Cornea and External Eye Disease, Singapore National Eye Centre, Singapore 168751, Singapore;
- Ocular Therapeutics and Drug Delivery Group, Singapore Eye Research Institute, Singapore 169856, Singapore
- Department of Glaucoma, Singapore National Eye Centre, Singapore 168751, Singapore
| | - Jodhbir S. Mehta
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore 169856, Singapore; (Y.-C.L.); (M.T.-Y.L.)
- Department of Cornea and External Eye Disease, Singapore National Eye Centre, Singapore 168751, Singapore;
- Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore 169857, Singapore
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20
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Wong CW, Busoy JMF, Cheung N, Barathi VA, Storm G, Wong TT. Endogenous or Exogenous Retinal Pigment Epithelial Cells: A Comparison of Two Experimental Animal Models of Proliferative Vitreoretinopathy. Transl Vis Sci Technol 2020; 9:46. [PMID: 32934896 PMCID: PMC7463202 DOI: 10.1167/tvst.9.9.46] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 08/08/2020] [Indexed: 11/24/2022] Open
Abstract
Purpose Proliferative vitreoretinopathy (PVR) is a blinding condition that can occur following ocular penetrating injury and retinal detachment. To develop effective therapeutics for PVR, it is imperative to establish an animal model that is reproducible, closest in anatomy to the human eye, and most representative of the human disease. We compared two in vivo models of PVR in minipig eyes to assess reproducibility and consistency. Methods Six minipigs underwent PVR induction with procedure A and six underwent procedure B. In both procedures, PVR was induced with vitrectomy, bleb retinal detachment, retinotomy, and injection of platelet-rich plasma. In procedure A, retinal pigment epithelial (RPE) cells were harvested from cadaveric pig eyes and injected at the end of surgery. In procedure B, native RPE cells were released into the vitreous cavity by creating a RPE detachment and scraping the RPE layer. PVR severity was graded on fundoscopic examination with a modified Silicone Study Classification System for PVR. Severe PVR was defined as stages 2 to 5. Results Three eyes (50%) and five eyes (83.3%) developed re-detachment of the retina from severe PVR in procedures A and B, respectively (P = 0.55). Median PVR stage was higher in eyes that underwent procedure B compared to eyes that underwent procedure A, although the difference was not statistically significant (2.5 vs. 1.5, P = 0.26). Conclusions This new model utilizing native RPE cells achieved a high consistency in inducing severe PVR in the minipig. Translational Relevance Our model closely follows pathogenic events in human PVR, making it ideal for preclinical testing of novel therapeutics for PVR.
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Affiliation(s)
- Chee Wai Wong
- Singapore National Eye Centre, Singapore.,Singapore Eye Research Institute, Singapore.,Duke-NUS Graduate Medical School, Singapore
| | | | - Ning Cheung
- Singapore National Eye Centre, Singapore.,Singapore Eye Research Institute, Singapore.,Duke-NUS Graduate Medical School, Singapore
| | | | - Gert Storm
- Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands.,Department of Experimental Molecular Imaging, University Clinic and Helmholtz Institute for Biomedical Engineering, RWTH Aachen University, Aachen, Germany
| | - Tina T Wong
- Singapore National Eye Centre, Singapore.,Singapore Eye Research Institute, Singapore.,Duke-NUS Graduate Medical School, Singapore
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21
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Soh ZD, Chee ML, Thakur S, Tham YC, Tao Y, Lim ZW, Mani B, Wong TT, Aung T, Cheng CY. Asian-specific vertical cup-to-disc ratio cut-off for glaucoma screening: An evidence-based recommendation from a multi-ethnic Asian population. Clin Exp Ophthalmol 2020; 48:1210-1218. [PMID: 32734654 DOI: 10.1111/ceo.13836] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 07/08/2020] [Accepted: 07/25/2020] [Indexed: 11/29/2022]
Abstract
IMPORTANCE Evidence-based guidelines are essential for glaucoma screening to work effectively. BACKGROUND To derive a vertical cup-to-disc ratio (VCDR) cut-off for glaucoma screening in a multi-ethnic Asian population. DESIGN The Singapore Epidemiology of Eye Diseases (SEED) study is a population-based study conducted from 2004 to 2011 in a single tertiary care research institute. PARTICIPANTS SEED comprised of 10 033 Chinese, Malay and Indian adults aged ≥40 (response rate 75.6%). After excluding participants with a history of glaucoma medication or surgery, 9673 participants were included for analysis. METHODS A systematic eye examination, which included applanation tonometry, visual field testing, gonioscopy and dilated fundus examination was conducted. MAIN OUTCOME MEASURE Diagnosis of glaucoma. RESULTS The distribution of VCDR and VCDR asymmetry were relatively homogenous in this multi-ethnic Asian population, with a 97.5th percentile value of 0.67 and 0.17, respectively. In the absence of more definite signs of glaucoma, VCDR ≥0.60 and VCDR asymmetry ≥0.20 provided the best balance between sensitivity (95.1%) and specificity (90.9%) in detecting glaucoma. For larger optic disc (≥2.0 mm), VCDR ≥0.65 with VCDR asymmetry ≥0.20 provided the best balance between sensitivity (84.8%) and specificity (93.2%). CONCLUSION AND RELEVANCE Overall, VCDR ≥0.60 with VCDR ≥0.20 asymmetry provides a good balance between sensitivity and specificity in detecting glaucoma. For larger optic disc, VCDR ≥0.65 should be considered instead to mitigate against false-referrals due to larger physiological disc cupping. Our findings may act as a reference to populations with similar VCDR distribution.
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Affiliation(s)
- Zhi Da Soh
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
| | - Miao Li Chee
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
| | - Sahil Thakur
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
| | - Yih Chung Tham
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
| | - Yijin Tao
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
| | - Zhi Wei Lim
- School of Medicine, University of New South Wales, Sydney, New South Wales, Australia
| | - Baskaran Mani
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.,Ophthalmology and Visual Sciences Academic Clinical Program (Eye ACP), Duke-NUS Medical School, Singapore, Singapore
| | - Tina T Wong
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.,Centre for Quantitative Medicine, Duke-NUS Medical School, Singapore, Singapore
| | - Tin Aung
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.,Ophthalmology and Visual Sciences Academic Clinical Program (Eye ACP), Duke-NUS Medical School, Singapore, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Ching-Yu Cheng
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.,Ophthalmology and Visual Sciences Academic Clinical Program (Eye ACP), Duke-NUS Medical School, Singapore, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
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22
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Rakshit M, Gautam A, Toh LZ, Lee YS, Lai HY, Wong TT, Ng KW. Hydroxyapatite Particles Induced Modulation of Collagen Expression and Secretion in Primary Human Dermal Fibroblasts. Int J Nanomedicine 2020; 15:4943-4956. [PMID: 32764927 PMCID: PMC7367744 DOI: 10.2147/ijn.s245500] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 05/09/2020] [Indexed: 01/31/2023] Open
Abstract
Background Hydroxyapatite (HA) [Ca5(PO4)3(OH)] is a naturally occurring calcium phosphate which makes up 60–70% of the dry weight of human bones. Nano-scale HA particles are increasingly being used as carriers for controlled and targeted delivery of bioactive agents like drugs, proteins, and nucleic acids due to their high porosity, negative charge, and biodegradability. Purpose Although much effort has been devoted to understanding the delivery kinetics and effects of the payloads in such carriers, a thorough understanding of the influence of the carriers themselves is lacking. Methods HA particles (300 µg/mL) were administered to primary human dermal fibroblasts (HDFs). The uptake and intracellular localization of the particles were determined by flow cytometry, confocal imaging, and transmission electron microscopy (TEM). Immunological assays and PCR were performed to determine the levels of pro-inflammatory cytokines and collagens in cell lysates and media supernatant. Results The current study explores the effects of poly-dispersed HA particles on primary HDFs as a model system. The majority of the particles were determined to range between 150 and 200 nm in diameter. Upon exposure to HA suspensions, primary HDFs internalized the particles by endocytosis within 6 hours of exposure, showing maximum uptake at 72 hours following which the particles were exocytosed by 168 hours. This correlated to reduced secretion of various pro-inflammatory and pro-collagenic cytokines. Biochemical analysis further revealed a reduction in Type I collagen expression and secretion. Conclusion HA particles have an immune-modulatory effect on dermal fibroblasts and reduce collagen production, which may impact the integrity of the extracellular matrix (ECM). This study demonstrates the need to consider the secondary effects of particulate carriers like HA, beyond basic cytotoxicity, in the specific tissue environment where the intended function is to be realized.
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Affiliation(s)
- Moumita Rakshit
- School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Archana Gautam
- School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Li Zhen Toh
- Ocular Therapeutics and Drug Delivery, Singapore Eye Research Institute, Singapore 169856, Singapore
| | - Ying Shi Lee
- Ocular Therapeutics and Drug Delivery, Singapore Eye Research Institute, Singapore 169856, Singapore
| | - Hui Ying Lai
- School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Tina T Wong
- School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore.,Ocular Therapeutics and Drug Delivery, Singapore Eye Research Institute, Singapore 169856, Singapore
| | - Kee Woei Ng
- School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore.,Environmental Chemistry and Materials Centre, Nanyang Environment & Water Research Institute, Singapore 637141, Singapore.,Skin Research Institute of Singapore, Singapore 138648, Singapore.,Center for Nanotechnology and Nanotoxicology, Harvard T.H. Chan School of Public Health, Cambridge, MA 02115, USA
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23
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Wu Y, Seong YJ, Li K, Choi D, Park E, Daghlian GH, Jung E, Bui K, Zhao L, Madhavan S, Daghlian S, Daghlian P, Chin D, Cho IT, Wong AK, Heur M, Zhang-Nunes S, Tan JC, Ema M, Wong TT, Huang AS, Hong YK. Organogenesis and distribution of the ocular lymphatic vessels in the anterior eye. JCI Insight 2020; 5:135121. [PMID: 32641580 DOI: 10.1172/jci.insight.135121] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 05/27/2020] [Indexed: 12/16/2022] Open
Abstract
Glaucoma surgeries, such as trabeculectomy, are performed to lower intraocular pressure to reduce risk of vision loss. These surgeries create a new passage in the eye that reroutes the aqueous humor outflow to the subconjunctival space, where the fluid is presumably absorbed by the conjunctival lymphatics. Here, we characterized the development and function of the ocular lymphatics using transgenic lymphatic reporter mice and rats. We found that the limbal and conjunctival lymphatic networks are progressively formed from a primary lymphatic vessel that grows from the nasal-side medial canthus region at birth. This primary lymphatic vessel immediately branches out, invades the limbus and conjunctiva, and bidirectionally encircles the cornea. As a result, the distribution of the ocular lymphatics is significantly polarized toward the nasal side, and the limbal lymphatics are directly connected to the conjunctival lymphatics. New lymphatic sprouts are produced mainly from the nasal-side limbal lymphatics, posing the nasal side of the eye as more responsive to fluid drainage and inflammatory stimuli. Consistent with this polarized distribution of the ocular lymphatics, a higher drainage efficiency was observed in the nasal side than the temporal side of the eye when injected with a fluorescent tracer. In contrast, blood vessels are evenly distributed at the anterior surface of the eyes. Also, we found that these distinct vascular distribution patterns were conserved in human eyes. Together, our study demonstrated that the ocular surface lymphatics are more densely present in the nasal side and uncovered the potential clinical benefits in selecting the nasal side as a glaucoma surgery site to improve fluid drainage.
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Affiliation(s)
- Yifan Wu
- Department of Surgery and.,Department of Biochemistry and Molecular Medicine, Norris Comprehensive Cancer Center, Keck School of Medicine of USC, USC, Los Angeles, California, USA
| | - Young Jin Seong
- Department of Surgery and.,Department of Biochemistry and Molecular Medicine, Norris Comprehensive Cancer Center, Keck School of Medicine of USC, USC, Los Angeles, California, USA
| | - Kin Li
- Department of Surgery and.,Department of Biochemistry and Molecular Medicine, Norris Comprehensive Cancer Center, Keck School of Medicine of USC, USC, Los Angeles, California, USA.,College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, California, USA
| | - Dongwon Choi
- Department of Surgery and.,Department of Biochemistry and Molecular Medicine, Norris Comprehensive Cancer Center, Keck School of Medicine of USC, USC, Los Angeles, California, USA
| | - Eunkyung Park
- Department of Surgery and.,Department of Biochemistry and Molecular Medicine, Norris Comprehensive Cancer Center, Keck School of Medicine of USC, USC, Los Angeles, California, USA
| | - George H Daghlian
- Department of Surgery and.,Department of Biochemistry and Molecular Medicine, Norris Comprehensive Cancer Center, Keck School of Medicine of USC, USC, Los Angeles, California, USA
| | - Eunson Jung
- Department of Surgery and.,Department of Biochemistry and Molecular Medicine, Norris Comprehensive Cancer Center, Keck School of Medicine of USC, USC, Los Angeles, California, USA
| | - Khoa Bui
- Department of Surgery and.,Department of Biochemistry and Molecular Medicine, Norris Comprehensive Cancer Center, Keck School of Medicine of USC, USC, Los Angeles, California, USA
| | - Luping Zhao
- Department of Surgery and.,Department of Biochemistry and Molecular Medicine, Norris Comprehensive Cancer Center, Keck School of Medicine of USC, USC, Los Angeles, California, USA
| | - Shrimika Madhavan
- Department of Surgery and.,Department of Biochemistry and Molecular Medicine, Norris Comprehensive Cancer Center, Keck School of Medicine of USC, USC, Los Angeles, California, USA
| | - Saren Daghlian
- Department of Surgery and.,Department of Biochemistry and Molecular Medicine, Norris Comprehensive Cancer Center, Keck School of Medicine of USC, USC, Los Angeles, California, USA
| | - Patill Daghlian
- Department of Surgery and.,Department of Biochemistry and Molecular Medicine, Norris Comprehensive Cancer Center, Keck School of Medicine of USC, USC, Los Angeles, California, USA
| | - Desmond Chin
- Department of Surgery and.,Department of Biochemistry and Molecular Medicine, Norris Comprehensive Cancer Center, Keck School of Medicine of USC, USC, Los Angeles, California, USA
| | - Il-Taeg Cho
- Department of Surgery and.,Department of Biochemistry and Molecular Medicine, Norris Comprehensive Cancer Center, Keck School of Medicine of USC, USC, Los Angeles, California, USA
| | | | - Martin Heur
- Department of Ophthalmology, USC Roski Eye Institute, Keck School of Medicine of USC, USC, Los Angeles, California, USA
| | - Sandy Zhang-Nunes
- Department of Ophthalmology, USC Roski Eye Institute, Keck School of Medicine of USC, USC, Los Angeles, California, USA
| | - James C Tan
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, UCLA, Los Angeles, California, USA
| | - Masatsugu Ema
- Department of Stem Cells and Human Disease Models Research Center for Animal Life, Science Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu, Shiga, Japan
| | - Tina T Wong
- Singapore Eye Research Institute, Duke NUS Graduate Medical School, Singapore
| | - Alex S Huang
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, UCLA, Los Angeles, California, USA
| | - Young-Kwon Hong
- Department of Surgery and.,Department of Biochemistry and Molecular Medicine, Norris Comprehensive Cancer Center, Keck School of Medicine of USC, USC, Los Angeles, California, USA
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24
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Akiyama G, Saraswathy S, Bogarin T, Pan X, Barron E, Wong TT, Kaneko MK, Kato Y, Hong Y, Huang AS. Functional, structural, and molecular identification of lymphatic outflow from subconjunctival blebs. Exp Eye Res 2020; 196:108049. [PMID: 32387381 PMCID: PMC7328765 DOI: 10.1016/j.exer.2020.108049] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 04/05/2020] [Accepted: 04/27/2020] [Indexed: 01/26/2023]
Abstract
The purpose of this study is to evaluate outflow pathways from subconjunctival blebs and to identify their identity. Post-mortem porcine (n = 20), human (n = 1), and bovine (n = 1) eyes were acquired, and tracers (fluorescein, indocyanine green, or fixable/fluorescent dextrans) were injected into the subconjunctival space to create raised blebs where outflow pathways were visualized qualitatively and quantitatively. Rodents with fluorescent reporter transgenes were imaged for structural comparison. Concurrent optical coherence tomography (OCT) was obtained to study the structural nature of these pathways. Using fixable/fluorescent dextrans, tracers were trapped to the bleb outflow pathway lumen walls for histological visualization and molecular identification using immunofluorescence against lymphatic and blood vessel markers. Bleb outflow pathways could be observed using all tracers in all species. Quantitative analysis showed that the nasal quadrant had more bleb-related outflow pathways compared to the temporal quadrant (nasal: 1.9±0.3 pathways vs. temporal: 0.7±0.2 pathways; p = 0.003). However, not all blebs resulted in an outflow pathway (0-pathways = 18.2%; 1-pathway = 36.4%; 2-pathways = 38.6%; and 3-pathways = 6.8%). Outflow signal was validated as true luminal pathways using optical coherence tomography and histology. Bicuspid valves were identified in the direction of flow in porcine eyes. Immunofluorescence of labeled pathways demonstrated a lymphatic (Prox-1 and podoplanin) but not a blood vessel (CD31) identity. Therefore, subconjunctival bleb outflow occurs in discrete luminal pathways. They are lymphatic as assessed by structural identification of valves and molecular identification of lymphatic markers. Better understanding of lymphatic outflow may lead to improved eye care for glaucoma surgery and ocular drug delivery.
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Affiliation(s)
- Goichi Akiyama
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA; Jikei School of Medicine, Tokyo, Japan
| | - Sindhu Saraswathy
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Thania Bogarin
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Xiaojing Pan
- Qingdao Eye Hospital, Shandong Eye Institute, Shandong First Medical University, Qingdao, China
| | - Ernesto Barron
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Tina T Wong
- Singapore National Eye Center and Singapore Research Institute, Singapore, Singapore
| | - Mika K Kaneko
- Tohoku University Graduate School of Medicine, Miyagi, Japan
| | - Yukinari Kato
- Tohoku University Graduate School of Medicine, Miyagi, Japan; New Industry Creation Hatchery Center, Tohoku University, Miyagi, Japan
| | - Young Hong
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Norris Comprehensive Cancer Center Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Alex S Huang
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
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25
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Atalay E, Nongpiur ME, Baskaran M, Perera SA, Wong TT, Quek D, Aung T. Intraocular pressure change after phacoemulsification in angle-closure eyes without medical therapy. J Cataract Refract Surg 2019; 43:767-773. [PMID: 28732610 DOI: 10.1016/j.jcrs.2017.03.031] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 03/07/2017] [Accepted: 03/07/2017] [Indexed: 11/27/2022]
Abstract
PURPOSE To evaluate the intraocular pressure (IOP) change and associated factors 6 months after phacoemulsification in eyes with primary angle-closure suspect (PACS) and eyes with primary angle closure (PAC) that had no medical therapy. SETTING Singapore National Eye Center, Singapore, Singapore. DESIGN Retrospective case series. METHODS Patients with PACS or PAC (with corrected distance visual acuity <20/40) who had uneventful phacoemulsification were recruited. Patients were excluded if they were on IOP-lowering medications within 6 months preoperatively and postoperatively. Preoperative gonioscopy, A-scan biometry, anterior segment optical coherence tomography, and automated refraction were reviewed. Factors related to the percentage of and absolute IOP change were assessed using multiple linear regression analyses after adjusting for age, sex, and diagnosis. RESULTS The study evaluated 85 patients (85 eyes; 52 PACS, 33 PAC) after 7 eyes (1 PACS, 6 PAC) were excluded because of poor quality imaging. Overall, IOP decreased by 19.9% from the preoperative mean of 16.1 mm Hg ± 3.1 (SD) to 12.9 ± 2.7 mm Hg. The IOP change between the PACS group (-3.3 ± 2.8 mm Hg; -20.6%) and the PAC group (-3.2 ± 4.7 mm Hg; -19.6%) was similar (P > .05). In multiple linear regression analyses, a higher preoperative IOP (β = 0.68, P < .001) and fewer clock hours of peripheral anterior synechiae (PAS) (β = -0.30, P = .03) predicted a greater absolute change in and percentage of reduction in IOP, respectively. CONCLUSIONS The mean IOP reduction 6 months after phacoemulsification was 20%. Less IOP reduction was observed in the presence of lower preoperative IOP and more extensive PAS.
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Affiliation(s)
- Eray Atalay
- From the Singapore Eye Research Institute (Atalay, Nongpiur, Baskaran, Perera, Wong, Aung), the Duke-NUS Graduate Medical School (Nongpiur, Baskaran, Wong), the Yong Loo Lin School of Medicine (Aung), National University of Singapore, and the Singapore National Eye Centre (Perera, Wong, Quek, Aung), Singapore, Singapore
| | - Monisha E Nongpiur
- From the Singapore Eye Research Institute (Atalay, Nongpiur, Baskaran, Perera, Wong, Aung), the Duke-NUS Graduate Medical School (Nongpiur, Baskaran, Wong), the Yong Loo Lin School of Medicine (Aung), National University of Singapore, and the Singapore National Eye Centre (Perera, Wong, Quek, Aung), Singapore, Singapore
| | - Mani Baskaran
- From the Singapore Eye Research Institute (Atalay, Nongpiur, Baskaran, Perera, Wong, Aung), the Duke-NUS Graduate Medical School (Nongpiur, Baskaran, Wong), the Yong Loo Lin School of Medicine (Aung), National University of Singapore, and the Singapore National Eye Centre (Perera, Wong, Quek, Aung), Singapore, Singapore
| | - Shamira A Perera
- From the Singapore Eye Research Institute (Atalay, Nongpiur, Baskaran, Perera, Wong, Aung), the Duke-NUS Graduate Medical School (Nongpiur, Baskaran, Wong), the Yong Loo Lin School of Medicine (Aung), National University of Singapore, and the Singapore National Eye Centre (Perera, Wong, Quek, Aung), Singapore, Singapore
| | - Tina T Wong
- From the Singapore Eye Research Institute (Atalay, Nongpiur, Baskaran, Perera, Wong, Aung), the Duke-NUS Graduate Medical School (Nongpiur, Baskaran, Wong), the Yong Loo Lin School of Medicine (Aung), National University of Singapore, and the Singapore National Eye Centre (Perera, Wong, Quek, Aung), Singapore, Singapore
| | - Desmond Quek
- From the Singapore Eye Research Institute (Atalay, Nongpiur, Baskaran, Perera, Wong, Aung), the Duke-NUS Graduate Medical School (Nongpiur, Baskaran, Wong), the Yong Loo Lin School of Medicine (Aung), National University of Singapore, and the Singapore National Eye Centre (Perera, Wong, Quek, Aung), Singapore, Singapore
| | - Tin Aung
- From the Singapore Eye Research Institute (Atalay, Nongpiur, Baskaran, Perera, Wong, Aung), the Duke-NUS Graduate Medical School (Nongpiur, Baskaran, Wong), the Yong Loo Lin School of Medicine (Aung), National University of Singapore, and the Singapore National Eye Centre (Perera, Wong, Quek, Aung), Singapore, Singapore.
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26
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Bilger M, Wong TT, Lee JY, Howard KL, Bundoc FG, Lamoureux EL, Finkelstein EA. Using Adherence-Contingent Rebates on Chronic Disease Treatment Costs to Promote Medication Adherence: Results from a Randomized Controlled Trial. Appl Health Econ Health Policy 2019; 17:841-855. [PMID: 31317511 PMCID: PMC6885505 DOI: 10.1007/s40258-019-00497-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
BACKGROUND Poor adherence to medications is a global public health concern with substantial health and cost implications, especially for chronic conditions. In the USA, poor adherence is estimated to cause 125,000 deaths and cost $US100 billion annually. The most successful adherence-promoting strategies that have been identified so far have moderate effect, are relatively costly, and raise availability, feasibility, and/or scalability issues. OBJECTIVE The main objective of SIGMA (Study on Incentives for Glaucoma Medication Adherence) was to measure the effectiveness on medication adherence of a novel incentive strategy based on behavioral economics that we refer to as adherence-contingent rebates. These rebates offered patients a near-term benefit while leveraging loss aversion and regret and increasing the salience of adherence. METHODS SIGMA is a 6-month randomized, controlled, open-label, single-center superiority trial with two parallel arms. A total of 100 non-adherent glaucoma patients from the Singapore National Eye Centre were randomized into intervention (adherence-contingent rebates) and usual care (no rebates) arms in a 1:1 ratio. The primary outcome was the mean change from baseline in percentage of adherent days at Month 6. The trial registration number is NCT02271269 and a detailed study protocol has been published elsewhere. FINDINGS We found that participants who were offered adherence-contingent rebates were adherent to all their medications on 73.1% of the days after 6 months, which is 12.2 percentage points (p = 0.027) higher than in those not receiving the rebates after controlling for baseline differences. This better behavioral outcome was achieved by rebates averaging 8.07 Singapore dollars ($US5.94 as of 2 November 2017) per month during the intervention period. CONCLUSION This study shows that simultaneously leveraging several insights from behavioral economics can significantly improve medication adherence rates. The relatively low cost of the rebates and significant health and cost implications of medication non-adherence suggest that this strategy has the potential to cost-effectively improve health outcomes for many conditions.
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Affiliation(s)
- Marcel Bilger
- Health Economics and Policy, Vienna University of Business and Economics, Welthandelsplatz 1, Building D4, 1020, Vienna, Austria.
- Health Services & Systems Research Program, Duke-NUS Medical School, Singapore, Singapore.
| | - Tina T Wong
- Singapore National Eye Centre, Singapore Eye Research Institute, Singapore, Singapore
| | - Jia Yi Lee
- Singapore National Eye Centre, Singapore Eye Research Institute, Singapore, Singapore
| | - Kaye L Howard
- Health Services & Systems Research Program, Duke-NUS Medical School, Singapore, Singapore
| | - Filipinas G Bundoc
- Health Services & Systems Research Program, Duke-NUS Medical School, Singapore, Singapore
| | - Ecosse L Lamoureux
- Health Services & Systems Research Program, Duke-NUS Medical School, Singapore, Singapore
- Singapore National Eye Centre, Singapore Eye Research Institute, Singapore, Singapore
| | - Eric A Finkelstein
- Health Services & Systems Research Program, Duke-NUS Medical School, Singapore, Singapore
- Duke Global Health Institute, Duke University, Durham, NC, USA
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27
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Wong CW, Cheung N, Ho C, Barathi V, Storm G, Wong TT. Characterisation of the inflammatory cytokine and growth factor profile in a rabbit model of proliferative vitreoretinopathy. Sci Rep 2019; 9:15419. [PMID: 31659187 PMCID: PMC6817814 DOI: 10.1038/s41598-019-51633-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 07/27/2019] [Indexed: 12/15/2022] Open
Abstract
To clarify the mechanisms and their temporal relationship in the development of proliferative vitreoretinopathy (PVR), we measured vitreous levels of pro-inflammatory cytokines and growth factors in a rabbit model of PVR. PVR was surgically induced in 11 rabbit eyes by vitrectomy, retinotomy, cryotherapy and injection of platelet-rich plasma at baseline. Severity of PVR was assessed on dilated fundal examination with indirect binocular ophthalmoscopy and graded based on the revised experimental PVR classification. Severe PVR was defined as stage 5 or worse. Vitreous concentrations of interleukin 6 (IL-6), interleukin 8 (IL-8), interleukin 1 beta (IL-1 β), tumor necrosis factor beta (TNF-β), granulocyte macrophage colony stimulating factor (GM-CSF), interferon gamma (IFN-γ), C reactive protein; (CRP), placental growth factor (PlGF), platelet derived growth factor BB (PDGF-BB), vascular endothelial growth factor (VEGF) and angiopoietin 2 (Ang-2) at weeks 2, 3 and 4 were compared to baseline and correlations between the cytokines with PVR severity were assessed. Four weeks after PVR induction, 5 eyes (45.5%) had developed severe PVR. IL-8 was raised at 2 weeks post PVR induction (1.46 ± 0.48 pg/ml vs 0.53 ± 0.25 pg/ml, p = 0.04) and remained significantly elevated at week 4 (2.6 ± 3.1 pg/ml, p = 0.03). CRP was significantly raised at week 4 (34.8 ± 12.0 pg/ml vs 13.0 ± 13.1 pg/ml, p < 0.001). Among the growth factors, PDGF-BB was the earliest to show significantly elevated levels, at 3 weeks (50.4 ± 19.0 pg/ml vs 6.2 ± 10.1 pg/ml) and remained elevated at week 4 (p = 0.002), while PlGF (11.2 ± 7.7 pg/ml vs 5.3 ± 3.8 pg/ml, p = 0.002) and Ang2 (13617.0 ± 8170.2 pg/ml vs 38593.8 ± 8313.4, p = 0.02) were significantly raised at week 4. IFN-γ (p = 0.03), PDGF-BB (p = 0.02) and VEGF (p = 0.02) were significantly associated with PVR severity. We demonstrated that inflammatory cytokines IL-6, -8, elevation post PVR induction is followed by elevated levels of fibroproliferative growth factors, Ang2, PlGF, VEGF and PDGF-BB in the development of PVR. These findings will guide future studies targeting appropriate therapeutic strategies for the treatment of PVR.
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Affiliation(s)
- Chee Wai Wong
- Singapore National Eye Centre (SNEC), 11 Third Hospital Avenue, Singapore, 168751, Singapore.,Singapore Eye Research Institute, 11 Third Hospital Avenue, Singapore, 168751, Singapore.,Ophthalmology and Visual Sciences Academic Clinical Program, Duke NUS Medical School, 8 College Rd, Singapore, 169857, Singapore
| | - Ning Cheung
- Singapore National Eye Centre (SNEC), 11 Third Hospital Avenue, Singapore, 168751, Singapore.,Singapore Eye Research Institute, 11 Third Hospital Avenue, Singapore, 168751, Singapore.,Ophthalmology and Visual Sciences Academic Clinical Program, Duke NUS Medical School, 8 College Rd, Singapore, 169857, Singapore
| | - Candice Ho
- Singapore Eye Research Institute, 11 Third Hospital Avenue, Singapore, 168751, Singapore
| | - Veluchamy Barathi
- Singapore Eye Research Institute, 11 Third Hospital Avenue, Singapore, 168751, Singapore.,Ophthalmology and Visual Sciences Academic Clinical Program, Duke NUS Medical School, 8 College Rd, Singapore, 169857, Singapore
| | - Gert Storm
- Department Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences (UIPS), Utrecht University, PO Box 80082, 3508 TB, Utrecht, The Netherlands.,Department Biomaterials Science & Technology (BST), Section Targeted Therapeutics, University of Twente, PO Box 217, 7500 AE, Enschede, The Netherlands
| | - Tina T Wong
- Singapore National Eye Centre (SNEC), 11 Third Hospital Avenue, Singapore, 168751, Singapore. .,Singapore Eye Research Institute, 11 Third Hospital Avenue, Singapore, 168751, Singapore. .,School of Materials Science and Engineering (MSE), Nanyang Technological University, 11 Faculty Avenue, Singapore, 639977, Singapore. .,Ophthalmology and Visual Sciences Academic Clinical Program, Duke NUS Medical School, 8 College Rd, Singapore, 169857, Singapore.
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Abstract
Purpose: This study investigated the involvement of NF-kB in regulating postoperative conjunctival inflammation.Methods: Experimental surgery was performed as described for the mouse model of conjunctival scarring. Expression of NF-κB in postoperative conjunctival tissues or conjunctival fibroblasts were assessed by real-time PCR, immunoblotting and immunofluorescence analyses. Downregulation of RelB was achieved using small interfering RNA. Cellular cytokine secretion was determined using multiplex cytokine assay.Results: RelB was the most highly induced member of the NF-kB family on day 2 post-surgery. Elevated RelB may be found associated with vimentin-positive cells and fibroblasts in vivo and in vitro. In conjunctival fibroblasts, RelB may be induced by TNF-α but not TGF-β2 while its silencing caused selective induction of CCL2 secretion by both basal and TNF-α-stimulated fibroblasts.Conclusions: High RelB induction in the inflammatory phase and the selective modulation of CCL2 suggest a specific anti-inflammatory role for RelB in the postoperative conjunctiva.
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Affiliation(s)
- Li-Fong Seet
- Ocular Therapeutics and Drug Delivery, Singapore Eye Research Institute, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Duke-NUS Medical School, Singapore
| | - Li Zhen Toh
- Ocular Therapeutics and Drug Delivery, Singapore Eye Research Institute, Singapore
| | - Stephanie W L Chu
- Ocular Therapeutics and Drug Delivery, Singapore Eye Research Institute, Singapore
| | - Tina T Wong
- Ocular Therapeutics and Drug Delivery, Singapore Eye Research Institute, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Duke-NUS Medical School, Singapore.,Glaucoma Service, Singapore National Eye Center, Singapore.,School of Materials Science and Engineering, Nanyang Technological University, Singapore
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Narayanaswamy A, Nai MH, Nongpiur ME, Htoon HM, Thomas A, Sangtam T, Lim CT, Wong TT, Aung T. Young's Modulus Determination of Normal and Glaucomatous Human Iris. ACTA ACUST UNITED AC 2019; 60:2690-2695. [DOI: 10.1167/iovs.18-26455] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Arun Narayanaswamy
- Singapore Eye Research Institute and Singapore National Eye Center, Singapore
| | - Mui Hoon Nai
- Department of Biomedical Engineering, National University of Singapore, Singapore
| | - Monisha E. Nongpiur
- Singapore Eye Research Institute and Singapore National Eye Center, Singapore
- Duke-NUS Graduate Medical School, Singapore
| | - Hla Myint Htoon
- Singapore Eye Research Institute and Singapore National Eye Center, Singapore
- Duke-NUS Graduate Medical School, Singapore
| | - Anoop Thomas
- Department of Ophthalmology & Visual Sciences Khoo Teck Puat Hospital, Singapore
| | - Tiakumzuk Sangtam
- Department of Ophthalmology & Visual Sciences Khoo Teck Puat Hospital, Singapore
| | - Chwee Teck Lim
- Department of Biomedical Engineering, National University of Singapore, Singapore
- Mechanobiology Institute, National University of Singapore, Singapore
- Biomedical Institute for Global Health Research and Technology, National University of Singapore, Singapore
| | - Tina T. Wong
- Singapore Eye Research Institute and Singapore National Eye Center, Singapore
- Duke-NUS Graduate Medical School, Singapore
| | - Tin Aung
- Singapore Eye Research Institute and Singapore National Eye Center, Singapore
- Duke-NUS Graduate Medical School, Singapore
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore
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Wong CW, Wong TT. Posterior segment drug delivery for the treatment of exudative age-related macular degeneration and diabetic macular oedema. Br J Ophthalmol 2019; 103:1356-1360. [PMID: 31040133 DOI: 10.1136/bjophthalmol-2018-313462] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2018] [Revised: 04/04/2019] [Accepted: 04/07/2019] [Indexed: 12/22/2022]
Abstract
Inhibitors of vascular endothelial growth factors are used to treat a myriad of retinal conditions, including exudative age-related macular degeneration (AMD), diabetic macular oedema (DME) and diabetic retinopathy. Although effective, long-term efficacy is limited by the need for frequent and invasive intravitreal injections. The quest for sustained action therapeutics that can be delivered to target tissue in the least invasive manner is an arduous endeavour that has ended in premature failure for several technologies in Phase II or III trials. Nevertheless, there have been promising preclinical studies, and more are on the horizon: port delivery systems for the treatment of exudative AMD have entered Phase III trials and a wide array of preclinical studies have demonstrated the potential for nanoparticles, such as liposomes, dendrimers and cell penetrating peptides to deliver therapeutics into the posterior segment via minimally invasive routes. In this review, we discuss the challenges posed by ocular barriers for drug penetration and present the recent advancements of the most pertinent drug delivery platforms with a focus on the treatment of exudative AMD and DME.
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Affiliation(s)
- Chee Wai Wong
- Surgical Retina, Singapore National Eye Centre, Singapore, Singapore.,Duke-NUS Graduate Medical School, Singapore, Singapore
| | - Tina T Wong
- Duke-NUS Graduate Medical School, Singapore, Singapore .,Glaucoma, Singapore National Eye Centre, Singapore, Singapore
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Verma S, Nongpiur ME, Husain R, Wong TT, Boey PY, Quek D, Perera SA, Aung T. Characteristics of the Corneal Endothelium Across the Primary Angle Closure Disease Spectrum. Invest Ophthalmol Vis Sci 2019; 59:4525-4530. [PMID: 30208420 DOI: 10.1167/iovs.18-24939] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Purpose To evaluate the corneal endothelial characteristics across the primary angle closure (PAC) disease spectrum amongst patients diagnosed as PAC suspects (PACS), PAC, PAC glaucoma (PACG), and previous acute PAC (APAC). Methods We analyzed a total of 529 subjects (51 PACS, 170 PAC, 234 PACG, and 74 with previous APAC). All subjects had undergone laser peripheral iridotomy prior to study recruitment. Corneal endothelial parameters were measured using a noncontact specular microscope and the following parameters were obtained: mean central endothelial cell density (ECD; cells/mm2), coefficient of variation (CV) in cell area, and percentage of hexagonal cells. Results The mean age of the subjects was 65.1 ± 8.2 years, and 55.2% were females. The mean central ECD was 2582.0 ± 472.8 cells/mm2 in PACS, 2566.0 ± 408.3 cells/mm2 in PAC, 2523.8 ± 406.8 cells/mm2 in PACG, and 2504.0 ± 558.1 cells/mm2 in APAC, with no significant differences in ECD across the subgroups (P = 0.61). The CV was lowest in PACS (34.38 ± 6.05 μm2/cell), and highest in APAC (37.61 ± 7.98 μm2/cell), but the differences were not significant (P = 0.07). Likewise, the percentage of hexagonality was not significantly different between the groups. A subgroup analysis on the eyes with previous APAC with their fellow eye also showed no significant differences in the corneal endothelial characteristics. Conclusions The corneal ECD and morphological characteristics such as CV and hexagonality are not significantly different across the PAC disease spectrum. This may reflect the lack of a sustained and/or dramatic IOP insult and/or an insignificant deleterious effect from medications, age, and chronicity on corneal endothelial parameters.
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Affiliation(s)
- Sushma Verma
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Monisha E Nongpiur
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.,Duke-NUS Graduate Medical School, Singapore
| | - Rahat Husain
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Tina T Wong
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Pui Yi Boey
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Desmond Quek
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Shamira A Perera
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Tin Aung
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
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Tan YF, Lee YS, Seet LF, Ng KW, Wong TT, Venkatraman S. Design and in vitro release study of siRNA loaded Layer by Layer nanoparticles with sustained gene silencing effect. Expert Opin Drug Deliv 2018; 15:937-949. [PMID: 30173580 DOI: 10.1080/17425247.2018.1518426] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
OBJECTIVES Clinical translation of siRNA therapeutics has been severely limited due to the lack of stable and sustained siRNA delivery systems. Furthermore, when nanocarrier systems with siRNA are administered systemically to treat diseases, insufficient doses reach the target tissue. Here we report the successful development of a new nanocarrier system for the management of fibrosis. METHODS The new carrier has a hydroxyapatite core, with alternating layers of siRNA and a cationic peptide. The siRNA used here targets secreted protein acidic and rich in cysteine (SPARC), a key matricellular protein involved in the regulation of collagen fibrillogenesis and assembly. We have also used FRET studies to elucidate the fate of the particles inside cells, including the mechanistic details of layer-by-layer detachment. RESULTS In vitro studies using murine conjunctiva fibroblasts show sustained release over 2 weeks, and that such released siRNA sustained SPARC knockdown without affecting cell growth, and maintained siRNA presence in the cells for at least two weeks with a single-dose treatment. Release studies of siRNA from particles in vitro gave insight on how the particles delivered prolonged gene-silencing effects. CONCLUSION A single treatment of the layer-by-layer nanoparticle designed can achieve sustained gene silencing over 2 weeks. Localized delivery of stabilized siRNA with sustained-release capabilities opens the door for many other applications of siRNA-based gene regulation.
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Affiliation(s)
- Yang Fei Tan
- a School of Materials Science and Engineering , Nanyang Technological University , Singapore
| | - Ying Shi Lee
- b Ocular Therapeutics and Drug Delivery , Singapore Eye Research Institute , Singapore
| | - Li-Fong Seet
- b Ocular Therapeutics and Drug Delivery , Singapore Eye Research Institute , Singapore.,c Department of Ophthalmology, Yong Loo Lin School of Medicine , National University of Singapore , Singapore.,d Duke-NUS Medical School , Singapore
| | - Kee Woei Ng
- a School of Materials Science and Engineering , Nanyang Technological University , Singapore
| | - Tina T Wong
- a School of Materials Science and Engineering , Nanyang Technological University , Singapore.,b Ocular Therapeutics and Drug Delivery , Singapore Eye Research Institute , Singapore.,c Department of Ophthalmology, Yong Loo Lin School of Medicine , National University of Singapore , Singapore.,d Duke-NUS Medical School , Singapore.,e Glaucoma Service , Singapore National Eye Centre , Singapore
| | - Subbu Venkatraman
- a School of Materials Science and Engineering , Nanyang Technological University , Singapore.,b Ocular Therapeutics and Drug Delivery , Singapore Eye Research Institute , Singapore.,f NTU-Northwestern University Institute for Nanomedicine , Singapore.,g MedTech , National Heart Centre , Singapore
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Seet LF, Toh LZ, Chu S, Finger SN, Ginhoux F, Hong W, Wong TT. Bevacizumab Promotes T-Cell-Mediated Collagen Deposition in the Mouse Model of Conjunctival Scarring. Invest Ophthalmol Vis Sci 2018; 59:1682-1692. [PMID: 29625495 DOI: 10.1167/iovs.17-22694] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose We determine the effects of bevacizumab on collagen production in a mouse model of conjunctival scarring. Methods Experimental surgery was performed as described for the mouse model of conjunctival scarring, and bevacizumab was introduced by conjunctival injection. The capacity of bevacizumab to recognize conjunctival VEGF-A was determined by ELISA. Col1a1 was measured by real-time PCR and immunoblotting. T cells and collagen were visualized by immunofluorescence and picrosirius red staining of bleb cryosections. Conjunctival CD4+ or CD8a+ T cells were counted by flow cytometry. Mouse splenic T cells were cultured with bevacizumab/IgG and their numbers, cell cycle, and collagen production were measured using a cell counter, flow cytometry, and sircol soluble collagen assay, respectively. Reconstitution experiments in severe combined immunodeficiency (SCID) mice were performed by injection of freshly isolated T cells on day 2 postoperatively. Results Bevacizumab recognized approximately 20% of endogenous murine VEGF-A. Injection of bevacizumab raised Col1a1 expression in the blebs at mRNA and protein levels. Bevacizumab did not induce collagen in conjunctival fibroblasts, but increased CD4+ and CD8a+ cell numbers as well as collagen production by these cells. Collagen appeared to accumulate in the vicinity of T cells in the bevacizumab-treated blebs. While SCID blebs did not show elevated collagen levels, reconstitution with CD4+ or CD8a+ cells resulted in increased Col1a1 expression at mRNA and protein levels. Conclusions Bevacizumab increased collagen production in the mouse model of conjunctival scarring. This collagen induction was mediated by T cells that were also stimulated by bevacizumab to increase in numbers.
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Affiliation(s)
- Li-Fong Seet
- Singapore Eye Research Institute, Singapore.,Duke-NUS Medical School, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | | | | | | | - Florent Ginhoux
- Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (A*STAR), Singapore
| | - Wanjin Hong
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore
| | - Tina T Wong
- Singapore Eye Research Institute, Singapore.,Duke-NUS Medical School, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Singapore National Eye Centre, Singapore.,School of Materials Science and Engineering, Nanyang Technological University, Singapore
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Liu YC, Ng XW, Teo EPW, Ang HP, Lwin NC, Chan NSW, Venkatraman SS, Wong TT, Mehta JS. A Biodegradable, Sustained-Released, Tacrolimus Microfilm Drug Delivery System for the Management of Allergic Conjunctivitis in a Mouse Model. Invest Ophthalmol Vis Sci 2018; 59:675-684. [PMID: 29392313 DOI: 10.1167/iovs.17-23066] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To investigate the drug release profiles of a tacrolimus-loaded poly(D,L-lactide-co-ε-caprolactone) (PLC) microfilm, and to evaluate its efficacy on the treatment of allergic conjunctivitis using a mouse model. Methods The in vitro and in vivo drug release profiles were first characterized. Balb/c mice were immunized with short ragweed (SRW) injection followed by re-challenges with topical SRW solution. The mice were divided into six groups (n = 12 in each): negative control (NC); positive control (PC); tacrolimus eye drops (Te); subconjunctival tacrolimus microfilm (Tm); dexamethasone eye drops (De); and tacrolimus + dexamethasone eye drops (Te+De). The mice were evaluated for 28 days by a scoring system for allergic conjunctivitis. Histopathologic and immunohistochemical staining with CD11c, CD4, and IL-4 were performed. Results The microfilms were biocompatible and delivered clinically sufficient dose in a sustained manner, with a steady rate of 0.212 to 0.243 μg/day in vivo. Compared to the PC groups, the Te, Tm, De, and Te+De groups significantly reduced the allergic clinical scores throughout the study period (all P < 0.01; 0.0 ± 0.0, 5.6 ± 0.9, 3.3 ± 0.9, 3.2 ± 0.9, 1.9 ± 0.4 and 1.7 ± 0.8 for the NC, PC, Tm, Te, De, and Te+De groups, respectively, at 4 weeks after treatment). The suppressed eosinophils, CD11c, CD4, and IL-4 expression were also observed in all treatment groups, with more reduction in the Te+De group. Conclusions Tacrolimus-loaded microfilms display good biocompatibility and desirable sustained drug release. It was as effective as conventional tacrolimus eye drops on the treatment of allergic conjunctivitis, providing a promising clinically applicable alternative for controlling allergic disease activity, or other immune-mediated ocular diseases.
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Affiliation(s)
- Yu-Chi Liu
- Singapore Eye Research Institute, Singapore.,Singapore National Eye Centre, Singapore.,Ophthalmology and Visual Sciences Academic Clinical Programme, Duke-NUS Medical School, Singapore
| | - Xu Wen Ng
- School of Materials Science and Engineering, Nanyang Technological University, Singapore, Singapore
| | | | | | | | | | - Subbu S Venkatraman
- School of Materials Science and Engineering, Nanyang Technological University, Singapore, Singapore
| | - Tina T Wong
- Singapore Eye Research Institute, Singapore.,Singapore National Eye Centre, Singapore.,Ophthalmology and Visual Sciences Academic Clinical Programme, Duke-NUS Medical School, Singapore.,School of Materials Science and Engineering, Nanyang Technological University, Singapore, Singapore
| | - Jodhbir S Mehta
- Singapore Eye Research Institute, Singapore.,Singapore National Eye Centre, Singapore.,Ophthalmology and Visual Sciences Academic Clinical Programme, Duke-NUS Medical School, Singapore.,School of Material Science & Engineering and School of Mechanical and Aerospace Engineering, Nanyang Technological University
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Seet LF, Tan YF, Toh LZ, Chu SW, Lee YS, Venkatraman SS, Wong TT. Targeted therapy for the post-operative conjunctiva: SPARC silencing reduces collagen deposition. Br J Ophthalmol 2018; 102:1460-1470. [PMID: 30021812 PMCID: PMC6173823 DOI: 10.1136/bjophthalmol-2018-311937] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 04/22/2018] [Accepted: 05/24/2018] [Indexed: 11/03/2022]
Abstract
BACKGROUND To develop targeted antifibrotic therapy for glaucoma filtration surgery; this study determines the effectiveness of small interfering RNA (siRNA) to reduce in vivo secreted protein acidic and rich in cysteine (SPARC) expression using the mouse model of conjunctival scarring. METHODS Experimental surgery was performed as described for the mouse model of conjunctival scarring. Scrambled (siScram) or Sparc (siSparc) siRNAs, loaded on layer-by-layer (LbL) nanoparticles, were injected into the conjunctiva immediately after surgery. Expression of Sparc, Col1a1, Fn1 and Mmp14 was measured by real-time PCR and immunoblotting on days 7 and 14 postsurgery. Live imaging of the operated eyes was performed using slit lamp, anterior segment-optical coherence tomography and confocal microscopy. Tissue pathology was evaluated by histochemical and immunofluorescent analyses of operated conjunctival cryosections. Tissue apoptosis was quantitated by annexin V assay. RESULTS : siSparc, delivered via expanded LbL nanoparticles, significantly inhibited Sparc transcription in both day 7 (2.04-fold) and day 14 (1.39-fold) treated tissues. Sparc suppression on day 7 was associated with a significant reduction of Col1a1 (2.52-fold), Fn1 (2.89-fold) and Mmp14 (2.23-fold) mRNAs. At the protein level, both SPARC and collagen 1A1 (COL1A1) were significantly reduced at both time points with siSparc treatment. Nanoparticles were visualised within cell-like structures by confocal microscopy, while overt tissue response or apoptosis was not observed. CONCLUSIONS : SPARC targeted therapy effectively reduced both SPARC and collagen production in the operated mouse conjunctiva. This proof-of-concept study suggests that targeted treatment of fibrosis in glaucoma surgery is safe and feasible, with the potential to extend to a range of potential genes associated with fibrosis.
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Affiliation(s)
- Li Fong Seet
- Ocular Therapeutics and Drug Delivery, Singapore Eye Research Institute, Singapore, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Duke-NUS Medical School, Singapore, Singapore
| | - Yang Fei Tan
- School of Materials Science and Engineering, Nanyang Technological University, Singapore, Singapore
| | - Li Zhen Toh
- Ocular Therapeutics and Drug Delivery, Singapore Eye Research Institute, Singapore, Singapore
| | - Stephanie Wl Chu
- Ocular Therapeutics and Drug Delivery, Singapore Eye Research Institute, Singapore, Singapore
| | - Ying Shi Lee
- Ocular Therapeutics and Drug Delivery, Singapore Eye Research Institute, Singapore, Singapore
| | - Subbu S Venkatraman
- Ocular Therapeutics and Drug Delivery, Singapore Eye Research Institute, Singapore, Singapore .,School of Materials Science and Engineering, Nanyang Technological University, Singapore, Singapore.,NTU - Northwestern University Institute for Nanomedicine, Singapore, Singapore.,MedTech, National Heart Centre, Singapore, Singapore
| | - Tina T Wong
- Ocular Therapeutics and Drug Delivery, Singapore Eye Research Institute, Singapore, Singapore .,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Duke-NUS Medical School, Singapore, Singapore.,School of Materials Science and Engineering, Nanyang Technological University, Singapore, Singapore.,Glaucoma Service, Singapore National Eye Centre, Singapore, Singapore
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Wong TT, Aung T, Ho CL. Ocular surface status in glaucoma and ocular hypertension patients with existing corneal disorders switched from latanoprost 0.005% to tafluprost 0.0015%: comparison of two prostaglandin analogues with different concentrations of benzalkonium chloride. Clin Exp Ophthalmol 2018; 46:1028-1034. [PMID: 29802759 PMCID: PMC6585858 DOI: 10.1111/ceo.13329] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2017] [Revised: 04/14/2018] [Accepted: 05/20/2018] [Indexed: 11/29/2022]
Abstract
IMPORTANCE Glaucoma treatment has often been associated with adverse side-effects from preservatives that are included in the used eye drops. BACKGROUND To evaluate changes in the ocular surface and the presence of prostaglandin-induced corneal disorders after being switched from latanoprost 0.005% to low preservative tafluprost 0.0015% ophthalmic solution. DESIGN Single centre, prospective study. PARTICIPANTS Patients with primary open-angle glaucoma or ocular hypertension that had received treatment with once daily latanoprost 0.005% ophthalmic solution for control of intraocular pressure (IOP) for 3 months, with a score of above 1 on the National Eye Institute (NEI) ocular surface staining scale. METHODS Following the ≥3 month latanoprost treatment period, patients were switched to once daily low preservative tafluprost 0.0015% ophthalmic solution. Patients were followed for a minimum of 3 months. MAIN OUTCOME MEASURES Ocular surface changes were assessed by fluorescein staining score (NEI scale). Additional evaluations included tear break-up time, hyperaemia score, subjective symptoms, changes in intraocular pressure and presence of adverse reactions. RESULTS Out of 59 patients enrolled, 51 were included in the final analysis. Fluorescein staining scores at baseline, prior to treatment switch, were 6.9 ± 3.1 and 3.3 ± 2.7 at the end of the study period (change in scores was -3.6 ± 2.2 [P < 0.001]). At last follow-up, significant improvements were observed in tear break-up time, hyperaemia score and subjective symptoms (all P < 0.05). CONCLUSIONS AND RELEVANCE The clinical signs of ocular surface disease and subjective symptoms of dry eyes improved following the switch to low preservative tafluprost and demonstrated comparable IOP lowering effectiveness.
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Affiliation(s)
- Tina T Wong
- Singapore National Eye Centre (SNEC), Singapore, Singapore.,Singapore Eye Research Institute (SERI), Singapore, Singapore.,Duke-NUS Graduate Medical School, Singapore, Singapore
| | - Tin Aung
- Singapore National Eye Centre (SNEC), Singapore, Singapore.,Singapore Eye Research Institute (SERI), Singapore, Singapore.,Duke-NUS Graduate Medical School, Singapore, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Ching Lin Ho
- Singapore National Eye Centre (SNEC), Singapore, Singapore
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Tong L, Hou AH, Wong TT. Altered expression level of inflammation-related genes and long-term changes in ocular surface after trabeculectomy, a prospective cohort study. Ocul Surf 2018; 16:441-447. [PMID: 29935986 DOI: 10.1016/j.jtos.2018.06.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 06/11/2018] [Accepted: 06/20/2018] [Indexed: 12/12/2022]
Abstract
PURPOSE We aim to evaluate changes in the ocular surface in a cohort of post-trabeculectomy patients and whether these were associated with conjunctival inflammatory gene expression. METHODS This is a single-arm interventional cohort performed in a tertiary referral center. These were assessed: dry eye symptom questionnaire, tear osmolarity, Schirmer's test, non-invasive tear break up time (BUT), conjunctival redness and corneal fluorescein staining evaluation. Conjunctival impressions were performed using Eyeprim, and after RNA extraction, transcripts of 255 inflammatory genes were analysed using the Nanostring nCounter assay. RESULTS Thirty three patients were recruited with age 66.88 ± 9.76 at baseline, with a predominance of men. There was a significant decrease in inferior corneal staining at 6 months (p < 0.05) (n = 22) and significant decrease in tear osmolarity at 12 months (p < 0.01) (n = 27). No patient required glaucoma eyedrops post-surgery up to 3 years. At baseline 31/33 transcript profiles passed the quality control, and after normalization, 249 transcripts were subsequently analysed. Increased discomfort was associated with higher Protein Tyrosine Kinase-2 at the cross-sectional analysis at baseline. Lower baseline complement factor-D and higher levels of Mitogen associated kinase-8, MAP3K1 and MyD88, were associated with presence of corneal staining at 6 months. Nine genes, including the proinflammatory lipo-oxygenase (ALOX5) showed a significantly reduced level at 3 years (n = 5). CONCLUSIONS Glaucoma surgery may confer long term beneficial effect on the ocular surface, if anti-glaucoma eyedrops are no longer necessary. This may be due to reduced expression of conjunctival proinflammatory genes and immune-related genes.
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Affiliation(s)
- L Tong
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Singapore Eye Research Institute, Singapore; Singapore National Eye Centre, Singapore; Duke-NUS Medical School, Singapore.
| | - A H Hou
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Singapore Eye Research Institute, Singapore
| | - T T Wong
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Singapore Eye Research Institute, Singapore; Singapore National Eye Centre, Singapore; Duke-NUS Medical School, Singapore; School of Materials Science and Engineering, Nanyang Technological University, Singapore.
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Wong CW, Czarny B, Metselaar JM, Ho C, Ng SR, Barathi AV, Storm G, Wong TT. Evaluation of subconjunctival liposomal steroids for the treatment of experimental uveitis. Sci Rep 2018; 8:6604. [PMID: 29700320 PMCID: PMC5919899 DOI: 10.1038/s41598-018-24545-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 03/20/2018] [Indexed: 12/30/2022] Open
Abstract
Non-infectious anterior uveitis (AU) is a potentially sight threatening inflammatory condition. The current gold standard for treatment is topical steroids, but low ocular bioavailability and compliance issues with the intensive dosing regimen limit the efficacy of this treatment. Liposomes as a drug delivery system may help to overcome these problems. We studied the efficacy of a PEG-liposomal formulation of liposomal steroids, administered as a single subconjunctival dose, in the treatment of experimental uveitis in rabbit eyes. Rabbits that received subconjunctival liposomal triamcinolone acetonide phosphate (LTAP) or liposomal prednisolone phosphate (LPP) had significantly lower mean inflammatory scores than untreated controls on Day 4 after induction of uveitis (LPP vs controls, p = 0.049) and 8 (LPP vs controls, p = 0.007; LTAP vs controls, p = 0.019), and lower scores than rabbits given topical PredForte1% 4 times a day on Day 8 (p = 0.03). After antigen rechallenge, the subconjunctival liposomal steroid groups continued to have greater suppression of inflammation than untreated controls on Day 11 (p = 0.02). Localization of liposomes in inflamed ocular tissue was confirmed by histology and immunostaining, and persisted in the eye for at least one month. Our study demonstrates that a single subconjunctival injection of liposomal steroids induces effective and sustained anti-inflammatory action.
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Affiliation(s)
- Chee Wai Wong
- Singapore National Eye Centre (SNEC), 11 Third Hospital Avenue, Singapore, 168751, Singapore.,Singapore Eye Research Institute, 11 Third Hospital Avenue, Singapore, 168751, Singapore
| | - Bertrand Czarny
- Department Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences (UIPS), Utrecht University, PO Box 80082, 3508 TB, Utrecht, The Netherlands.,School of Materials Science and Engineering (MSE), Nanyang Technological University, 11 Faculty Avenue, Singapore, 639977, Singapore.,Lee Kong Chian school of medicine (LKCmedicine), Nanyang Technological University, 11 Mandalay Road, Singapore, 308232, Singapore
| | - Josbert M Metselaar
- Department of Experimental Molecular Imaging, University Clinic and Helmholtz Institute for Biomedical Engineering, RWTH Aachen University, Aachen, 52074, Germany
| | - Candice Ho
- Singapore Eye Research Institute, 11 Third Hospital Avenue, Singapore, 168751, Singapore
| | - Si Rui Ng
- Singapore National Eye Centre (SNEC), 11 Third Hospital Avenue, Singapore, 168751, Singapore.,Singapore Eye Research Institute, 11 Third Hospital Avenue, Singapore, 168751, Singapore
| | | | - Gert Storm
- Department Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences (UIPS), Utrecht University, PO Box 80082, 3508 TB, Utrecht, The Netherlands. .,Department of Experimental Molecular Imaging, University Clinic and Helmholtz Institute for Biomedical Engineering, RWTH Aachen University, Aachen, 52074, Germany.
| | - Tina T Wong
- Singapore National Eye Centre (SNEC), 11 Third Hospital Avenue, Singapore, 168751, Singapore. .,Singapore Eye Research Institute, 11 Third Hospital Avenue, Singapore, 168751, Singapore.
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Nongpiur ME, Cheng CY, Duvesh R, Vijayan S, Baskaran M, Khor CC, Allen J, Kavitha S, Venkatesh R, Goh D, Husain R, Boey PY, Quek D, Ho CL, Wong TT, Perera S, Wong TY, Krishnadas SR, Sundaresan P, Aung T, Vithana EN. Evaluation of Primary Angle-Closure Glaucoma Susceptibility Loci in Patients with Early Stages of Angle-Closure Disease. Ophthalmology 2018; 125:664-670. [PMID: 29310965 DOI: 10.1016/j.ophtha.2017.11.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 08/07/2017] [Accepted: 11/08/2017] [Indexed: 11/25/2022] Open
Abstract
PURPOSE To investigate whether newly identified genetic loci for primary angle-closure glaucoma (PACG) are associated with early stage angle-closure disease defined as primary angle closure suspect (PACS). DESIGN Case-control study. PARTICIPANTS A total of 1397 PACS patients and 943 controls of Chinese ethnicity from Singapore and 604 PACS patients and 287 controls of Indian ethnicity. METHODS The 8 PACG single nucleotide polymorphisms (SNPs; rs11024102 at PLEKHA7, rs3753841 at COL11A1, rs1015213 located between PCMTD1 and ST18 son chromosome 8q, rs3816415 at EPDR1, rs1258267 at CHAT, rs736893 at GLIS3, rs7494379 at FERMT2, and rs3739821 mapping in between DPM2 and FAM102A) were genotyped by Taqman assays. The association between SNP genotypes and PACS status was measured using logistic regression. A P value of 0.006 was set to account for the testing of 8 genetic loci using a Bonferroni correction. A meta-analysis was conducted to calculate the overall P value and accompanying per-allele odds ratios for each SNP analyzed. MAIN OUTCOME MEASURES Association of PACG loci with PACS status. RESULTS The PACS patients were significantly older in both cohorts (Chinese, P < 0.001; Indian, P = 0.002), and there were also more women (P < 0.001, both Chinese and Indian cohorts). In the Chinese cohort, significant evidence of association was noted at 3 SNPs: rs1015213 [A] in PCMTD1-ST18 (odds ratio [OR], 2.36; 95% confidence interval [CI], 1.36-4.11; P = 0.002), rs3816415 [A] in EPDR1 (OR, 1.49; 95% CI, 1.19-1.85; P < 0.001), and rs3739821 [G] in DPM2-FAM102A (OR, 1.40; 95% CI, 1.18-1.65; P < 0.001). Only PCMTD1-ST-18 was replicated modestly in the Indian population (P = 0.056). Meta-analysis showed significant evidence of association for PCMTD1-ST-18 (OR, 1.55; 95% CI, 1.18-2.04; P = 0.002) and DPM2-FAM102A (OR, 1.27; 95% CI, 1.12-1.45; P = 0.0002). CONCLUSIONS In this study, 2 of 8 PACG-associated loci were associated significantly with PACS status, the earliest stage in the angle-closure glaucoma disease course. The association of these PACG loci with PACS status suggests that these loci may confer susceptibility to a narrow angle configuration.
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Affiliation(s)
- Monisha E Nongpiur
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Republic of Singapore; Duke-National University of Singapore Medical School, Singapore, Republic of Singapore
| | - Ching-Yu Cheng
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Republic of Singapore; Duke-National University of Singapore Medical School, Singapore, Republic of Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Republic of Singapore
| | - Roopam Duvesh
- Department of Genetics, Aravind Medical Research Foundation, Madurai, India
| | - Saravanan Vijayan
- Department of Genetics, Aravind Medical Research Foundation, Madurai, India
| | - Mani Baskaran
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Republic of Singapore; Duke-National University of Singapore Medical School, Singapore, Republic of Singapore
| | - Chiea-Chuen Khor
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Republic of Singapore; Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Republic of Singapore; Human Genetics, Genome Institute of Singapore, Singapore, Republic of Singapore
| | - John Allen
- Duke-National University of Singapore Medical School, Singapore, Republic of Singapore
| | | | | | - David Goh
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Republic of Singapore
| | - Rahat Husain
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Republic of Singapore
| | - Pui Yi Boey
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Republic of Singapore
| | - Desmond Quek
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Republic of Singapore
| | - Ching Lin Ho
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Republic of Singapore
| | - Tina T Wong
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Republic of Singapore
| | - Shamira Perera
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Republic of Singapore
| | - Tien Yin Wong
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Republic of Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Republic of Singapore
| | | | | | - Tin Aung
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Republic of Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Republic of Singapore
| | - Eranga N Vithana
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Republic of Singapore; Duke-National University of Singapore Medical School, Singapore, Republic of Singapore.
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Chung KL, Wong TT, Yuen MK, Kam CW. Sonography of Quadriceps Tendon Ruptures. HONG KONG J EMERG ME 2017. [DOI: 10.1177/102490790401100307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Quadriceps tendon rupture is an uncommon injury, which may benefit from early operative repair. However, clinical assessment is frequently inaccurate and delayed diagnosis is common. Ultrasound has been shown to be sensitive in detecting quadriceps tendon rupture. We report a case of bilateral quadriceps tendon ruptures diagnosed by ultrasound. Typical sonographic findings were illustrated.
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Affiliation(s)
| | - TT Wong
- Tuen Mun Hospital, Department of Diagnostic Radiology, Tsing Chung Koon Road, Tuen Mun, N.T., Hong Kong
| | - MK Yuen
- Tuen Mun Hospital, Department of Diagnostic Radiology, Tsing Chung Koon Road, Tuen Mun, N.T., Hong Kong
| | - CW Kam
- Tuen Mun Hospital, Department of Diagnostic Radiology, Tsing Chung Koon Road, Tuen Mun, N.T., Hong Kong
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Wong OF, Lam TSK, Wong TT, Fung HT. An Uncommon Cause of Deep Vein Thrombosis: Mycotic Aneurysm Secondary to Salmonella Arteritis. HONG KONG J EMERG ME 2017. [DOI: 10.1177/102490790901600411] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Mycotic aneurysm is an uncommon surgical emergency with high mortality. Endovascular infection due to salmonella is the commonest cause of intra-abdominal mycotic aneurysm. We report a rare presentation of mycotic aneurysm in a 78-year-old man who presented to the accident and emergency department with deep vein thrombosis due to compression of the iliac vein by a mycotic aneurysm arising from the internal iliac artery and an adjacent abscess. A comprehensive review of the aetiology, clinical presentation and management of mycotic aneurysm secondary to salmonella arteritis is presented.
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Joseph RR, Tan DWN, Ramon MRM, Natarajan JV, Agrawal R, Wong TT, Venkatraman SS. Characterization of liposomal carriers for the trans-scleral transport of Ranibizumab. Sci Rep 2017; 7:16803. [PMID: 29196745 PMCID: PMC5711922 DOI: 10.1038/s41598-017-16791-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 11/13/2017] [Indexed: 01/04/2023] Open
Abstract
Age-related macular degeneration (AMD) is a leading cause of blindness in the modern world. The standard treatment regimen for neovascular AMD is the monthly/bimonthly intravitreal injection of anti-VEGF agents such as ranibizumab or aflibercept. However, these repeated invasive injections can lead to sight-threatening complications. Sustained delivery by encapsulation of the drug in carriers is a way to reduce the frequency of these injections. Liposomes are biocompatible, non-toxic vesicular nanocarriers, which can be used to encapsulate therapeutic agents to provide sustained release. The protein encapsulation was performed by a modified dehydration-rehydration (DRV) method. The liposomes formed were characterized for size, zeta potential, encapsulation efficiency, stability, in vitro release, and ex vivo release profiles. In addition, the localization of the liposomes themselves was studied ex vivo. Entrapment-efficiency of ranibizumab into 100-nm liposomes varied from 14.7 to 57.0%. Negatively-charged liposomes prepared from DPPC-DPPG were found to have the slowest release with a low initial burst release compared to the rest of liposomal formulations. The ex vivo protein release was found to slower than the in vitro protein release for all samples. In conclusion, the DPPC-DPPG liposomes significantly improved the encapsulation and release profile of ranibizumab.
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Affiliation(s)
- Rini Rachel Joseph
- School of Materials Science and Engineering, Nanyang Technological University, Singapore, Singapore
| | - Dulcia Wei Ni Tan
- School of Materials Science and Engineering, Nanyang Technological University, Singapore, Singapore
| | - Moreno Raja Miguel Ramon
- School of Materials Science and Engineering, Nanyang Technological University, Singapore, Singapore
| | - Jayaganesh V Natarajan
- School of Materials Science and Engineering, Nanyang Technological University, Singapore, Singapore
| | - Rupesh Agrawal
- National Healthcare Group Eye Institute, Tan Tock Seng Hospital, Singapore, Singapore
| | - Tina T Wong
- School of Materials Science and Engineering, Nanyang Technological University, Singapore, Singapore.
- Singapore National Eye Centre, Singapore, Singapore.
- Ocular Drug Delivery Group, Singapore Eye Research Institute, Singapore, Singapore.
| | - Subbu S Venkatraman
- School of Materials Science and Engineering, Nanyang Technological University, Singapore, Singapore.
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Ozdemir S, Wu HK, Finkelstein EA, Wong TT. Parents' views on their children's use of eye drops and willingness to accept a new sustained-release subconjunctival injection. Clin Ophthalmol 2017; 11:1903-1909. [PMID: 29123377 PMCID: PMC5661848 DOI: 10.2147/opth.s141851] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Aim The objectives of this study were to explore parents’ views about their children’s use of regular eye drops and whether they would consider a sustained-release subconjunctival injection as a replacement for daily drops. Methods A survey was conducted with 134 parents of children with chronic eye diseases at the Singapore National Eye Centre. Parents were asked their views about their children’s use of eye drops and were then presented with a discrete choice experiment that, via a series of trade-off tasks, allowed for estimating demand for a series of hypothetical subconjunctival injections that varied along product features, including interval between administrations, risk of complications, out-of-pocket cost and whether it is recommended by the patient’s treating physician. Results Results showed that the vast majority of parents did not find administration of eye drops to be inconvenient (78%) nor did children complain about using daily eye drops (78%). Furthermore, only about half of parents whose child missed doses stated concerns about the consequences of non-compliance. The discrete choice experiment revealed that only one in five parents would consider a subconjunctival injection for their children. These parents tended to be more concerned about the consequences of non-compliance with eye drops, had children who administered the drops themselves or had other chronic disease requiring regular medication. Among these parents, risk of complications had the largest effect on injection uptake. Conclusion This study shows that parents do not find administration of daily eye drops to be a significant burden. As a result, most would not consider a subconjunctival injection unless risk of complications was extremely small.
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Affiliation(s)
- Semra Ozdemir
- Signature Program in Health Services and Systems Research, Duke-NUS Medical School Singapore
| | - Hong King Wu
- Signature Program in Health Services and Systems Research, Duke-NUS Medical School Singapore
| | - Eric A Finkelstein
- Signature Program in Health Services and Systems Research, Duke-NUS Medical School Singapore
| | - Tina T Wong
- Glaucoma Department, Singapore National Eye Centre, Singapore
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Foo VHX, Tan SEM, Chen DZ, Perera SA, Sabayanagam C, Fenwick EK, Wong TT, Lamoureux EL. Areas and factors associated with patients' dissatisfaction with glaucoma care. Clin Ophthalmol 2017; 11:1849-1857. [PMID: 29075097 PMCID: PMC5648314 DOI: 10.2147/opth.s138668] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVE The aim of this study was to evaluate patients' dissatisfaction with overall and specific aspects of a tertiary glaucoma service and to determine their independent factors, including intraocular pressure (IOP) and visual acuity (VA). METHODS Patients, aged ≥21 years, from a specialist glaucoma service in a tertiary eye hospital in Singapore for at least 6 months, were recruited for this cross-sectional study between March and June 2014. All consenting patients completed a 7-area glaucoma-specific satisfaction questionnaire and one item related to satisfaction with overall glaucoma care. We determined the top three areas of dissatisfaction and overall dissatisfaction with the glaucoma service. We also explored the independent factors associated with overall and specific areas of patients' dissatisfaction with their glaucoma care, including VA and IOP by using logistic regression models. RESULTS Of the 518 patients recruited, 438 (84.6%) patients completed the study. Patients' dissatisfaction with the overall glaucoma service was 7.5%. The three areas of glaucoma service with the highest dissatisfaction rates were as follows: 1) explanation of test results (24.8%); 2) explanation of glaucoma complications (23.7%); and 3) advice on managing glaucoma (23.5%). Patients who were dissatisfied with the overall service had a worse mean VA compared with satisfied patients (logarithm of the minimum angle of resolution =0.41±0.43 vs 0.27±0.49, p=0.005), whereas mean IOP remained well-controlled in both the groups (13.55±2.46 mmHg vs 14.82±2.86 mmHg, p=0.014). In adjusted models, factors associated with overall dissatisfaction with glaucoma care included a pre-university education and above (odds ratio [OR] =8.06, 95% CI =1.57-41.27) and lower IOP (OR =0.83, 95% CI =0.71-0.98). CONCLUSION Although less than one tenth of glaucoma patients were dissatisfied with the overall glaucoma service, one in four patients were dissatisfied with three specific aspects of care. A lower IOP, ironically, and education level were associated with overall dissatisfaction. Improving patients' understanding of glaucoma test results, glaucoma complications, and disease management may increase patient satisfaction levels.
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Affiliation(s)
| | | | - David Ziyou Chen
- Department of Ophthalmology, National University of Singapore and National University Health System, Singapore
| | - Shamira A Perera
- Singapore National Eye Centre, Singapore.,Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Charumathi Sabayanagam
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.,Centre for Quantitative Medicine, Duke-NUS Medical School, Singapore
| | - Eva Katie Fenwick
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.,Centre for Quantitative Medicine, Duke-NUS Medical School, Singapore
| | - Tina T Wong
- Singapore National Eye Centre, Singapore.,Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.,Centre for Quantitative Medicine, Duke-NUS Medical School, Singapore
| | - Ecosse L Lamoureux
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.,Centre for Quantitative Medicine, Duke-NUS Medical School, Singapore.,Centre for Eye Research Australia, University of Melbourne, Melbourne, VIC, Australia
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Verma S, Nongpiur ME, Oo HH, Atalay E, Goh D, Wong TT, Perera SA, Aung T. Plateau Iris Distribution Across Anterior Segment Optical Coherence Tomography Defined Subgroups of Subjects With Primary Angle Closure Glaucoma. Invest Ophthalmol Vis Sci 2017; 58:5093-5097. [PMID: 28986594 DOI: 10.1167/iovs.17-22364] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose We previously identified three distinct subgroups of patients with primary angle closure glaucoma (PACG) based on anterior segment optical coherence tomography (ASOCT) imaging. Group 1 was characterized by a large iris area with deepest anterior chambers, group 2 by a large lens vault (LV) and shallow anterior chamber depth (ACD), and group 3 displayed intermediate values across iris area, LV, and ACD. The purpose of the present study was to determine the distribution of plateau iris in these subgroups using ultrasound biomicroscopy (UBM) features. Methods UBM images of the 210 subjects who were previously enrolled for the ASOCT subgrouping analysis and had undergone laser peripheral iridotomy were assessed and graded by a single glaucoma fellowship trained clinician. Plateau iris was defined as the presence of all the following UBM criteria in at least two quadrants: anteriorly directed ciliary body, absent ciliary sulcus, iris angulation, flat iris plane, and iridoangle touch. Results Of 210 subjects, 23 were excluded due to poor-quality images. Based on standardized UBM criteria, the overall prevalence of plateau iris was 36.9% (n = 187). The proportion of plateau iris was similar across the three groups (subgroup 1:35.4% (n = 29); subgroup 2:39.0% (n = 32); subgroup 3:34.8% (n = 8), P = 0.87). On multiple logistic regression analysis, iris thickness at 750 μm from the scleral spur (IT750) was the only variable associated with plateau iris (odds ratio: 1.5/100 μm increase in iris thickness [IT], P = 0.04). Conclusions The proportion of plateau iris was similar across the three ASOCT-based PACG subgroups and more than one-third of subjects with PACG were diagnosed with plateau iris based on standardized UBM criteria. In addition, we noted that eyes with increased peripheral IT have an increased likelihood of plateau iris.
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Affiliation(s)
- Sushma Verma
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Monisha E Nongpiur
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.,Duke-NUS Medical School, Singapore
| | - Hnin H Oo
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Eray Atalay
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - David Goh
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Tina T Wong
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Shamira A Perera
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Tin Aung
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.,Duke-NUS Medical School, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
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Liu YC, Ng AHC, Ng XW, Yan P, Venkatraman SS, Mehta JS, Wong TT. Evaluation of a Sustained-Release Prednisolone Acetate Biodegradable Subconjunctival Implant in a Non-Human Primate Model. Transl Vis Sci Technol 2017; 6:9. [PMID: 29046829 PMCID: PMC5629924 DOI: 10.1167/tvst.6.5.9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 07/22/2017] [Indexed: 11/24/2022] Open
Abstract
PURPOSE We evaluate the toxicity and plasma toxicokinetic (TK) profile of a biodegradable subconjunctival microrod for sustained prednisolone acetate (PA) release over 12 weeks in a non-human primate model. METHODS The biodegradable copolymer poly(l-lactide-co-ε-caprolactone) (PLC) and 40-wt% PA microrods were used and fashioned into 8 and 16 mm lengths. Twelve monkeys were divided into two treatment groups of PA-loaded and blank microrods, with six monkeys each receiving either 8- or 16-mm microrods subconjunctively implanted into both eyes. TK and hematology parameters were analyzed. Ophthalmic clinical evaluation, including slit-lamp and ophthalmoscopy examinations, was performed. RESULTS Over the study period of 12 weeks, the mean area under the plasma concentration-time curve was 45.7% higher, and the maximum plasma concentration was 17.2% lower for the animals treated with 40-wt% PA 16-mm microrods compared to 8-mm microrods (251.44 versus 172.54 hours × nanograms per milliliter and 8.53 versus 10.30 ng/mL, respectively). The PA release was significantly below the levels of assumed toxicity. There was no significant difference in the time to reach maximum concentration between the 8- and 16-mm microrod groups (7.33 and 8 hours; P = 0.421). Findings from clinical evaluation, hematology, and histopathology showed no ocular side effects and no significant adverse systemic effects. CONCLUSION The PA biodegradable microrods demonstrated safe toxicokinetics even with the larger size implant containing a higher amount of drug. The PA implant may be considered as a safe alternative to the application of topical PA eyedrops. TRANSLATIONAL RELEVANCE The results provide the evidence of the safety of implanting a steroid delivery system subconjunctively, offering an alternative to topical PA eyedrops.
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Affiliation(s)
- Yu-Chi Liu
- Tissue Engineering and Stem Cell Group, Singapore Eye Research Institute, Singapore.,Department of Corneal and External Eye Disease, Singapore National Eye Centre, Singapore.,Department of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore
| | - Anthony Herr Cheun Ng
- School of Materials Science and Engineering, Nanyang Technological University, Singapore
| | - Xu Wen Ng
- School of Materials Science and Engineering, Nanyang Technological University, Singapore
| | - Peng Yan
- School of Materials Science and Engineering, Nanyang Technological University, Singapore
| | - Subbu S Venkatraman
- School of Materials Science and Engineering, Nanyang Technological University, Singapore
| | - Jodhbir S Mehta
- Tissue Engineering and Stem Cell Group, Singapore Eye Research Institute, Singapore.,Department of Corneal and External Eye Disease, Singapore National Eye Centre, Singapore.,Department of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore.,School of Materials Science and Engineering, Nanyang Technological University, Singapore
| | - Tina T Wong
- Department of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore.,School of Materials Science and Engineering, Nanyang Technological University, Singapore.,Ocular Therapeutics and Drug Delivery Group, Singapore Eye Research Institute, Singapore.,Department of Glaucoma, Singapore National Eye Centre, Singapore
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Abstract
Sustained-release drug delivery systems that replace the need for daily glaucoma medications will improve outcomes for those who are nonadherent and reduce the inconvenience of having to take medications on a recurring basis.The objective is to estimate uptake (i.e., demand) for a new technology that delivers sustained-release glaucoma medication and to investigate how uptake varies by product attributes, physician recommendations, peer adoption (i.e., percentage of patients seen in a clinic using the new technology), and patient characteristics.In a web-enabled discrete-choice experiment survey, glaucoma patients in the United States were asked to choose between continuing eye drop use or purchasing the new delivery system. In a cross-sectional web-enabled survey, ophthalmologists were asked their likelihood of recommending the new technology based on product and patient characteristics.Study participants were 500 glaucoma patients who were on topical administration of daily eye drops and 155 ophthalmologists who practice in the US.Main outcomes were predicted uptake for patients and likelihood of recommending a new drug delivery system for ophthalmologists. Logistic models were used to analyze the choice data.Uptake was estimated to be 18% at an annual cost of $1000 and to be 24% when the cost was $500. A physician's recommendation increased uptake by 6% to 12%, whereas an increase in peer adoption from 5% to 50% increased uptake by 3% to 7%. Patients aged ≥ 65 and those with lower income were more likely to remain on eye drops. Physicians were more likely to recommend a product if the interval between administrations is 6 months or longer and when long-term safety and efficacy data are available. They were less likely to recommend it to patients with lower income and no adherence problems.Results suggest a significant interest in an injectable solution or other sustained-release alternatives to daily eye drops. However, in this survey, patient uptake was greatly influenced by out-of-pocket cost and the interval between treatment administrations. Few physicians were willing to recommend sustained-release technology if the treatment interval was less than 3 months.
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Affiliation(s)
- Semra Ozdemir
- Health Services and Systems Research Programme, Duke-NUS Medical School
| | - Tina T. Wong
- Glaucoma Department, Singapore National Eye Centre, Singapore
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48
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Seet LF, Toh LZ, Chu SWL, Finger SN, Chua JLL, Wong TT. Upregulation of distinct collagen transcripts in post-surgery scar tissue: a study of conjunctival fibrosis. Dis Model Mech 2017; 10:751-760. [PMID: 28331057 PMCID: PMC5483006 DOI: 10.1242/dmm.028555] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 03/09/2017] [Indexed: 01/07/2023] Open
Abstract
Excessive accumulation of collagen is often used to assess the development of fibrosis. This study aims to identify collagen genes that define fibrosis in the conjunctiva following glaucoma filtration surgery (GFS). Using the mouse model of GFS, we have identified collagen transcripts that were upregulated in the fibrotic phase of wound healing via RNA-seq. The collagen transcripts that were increased the most were encoded by Col8a1, Col11a1 and Col8a2. Further analysis of the Col8a1, Col11a1 and Col8a2 transcripts revealed their increase by 67-, 54- and 18-fold, respectively, in the fibrotic phase, compared with 12-fold for Col1a1, the most commonly evaluated collagen gene for fibrosis. However, only type I collagen was significantly upregulated at the protein level in the fibrotic phase. Type VIII and type I collagens colocalized in fibrous structures and in ACTA2-positive pericytes, and appeared to compensate for each other in expression levels. Type XI collagen showed low colocalization with both type VIII and type I collagens but can be found in association with macrophages. Furthermore, we show that both mouse and human conjunctival fibroblasts expressed elevated levels of the most highly expressed collagen genes in response to TGFβ2 treatment. Importantly, conjunctival tissues from individuals whose GF surgeries have failed due to scarring showed 3.60- and 2.78-fold increases in type VIII and I collagen transcripts, respectively, compared with those from individuals with no prior surgeries. These data demonstrate that distinct collagen transcripts are expressed at high levels in the conjunctiva after surgery and their unique expression profiles may imply differential influences on the fibrotic outcome. Summary: As well as providing an objective quantitative measure, distinct collagen genes may further aid in the characterization and definition of the development of fibrosis.
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Affiliation(s)
- Li-Fong Seet
- Ocular Therapeutics and Drug Delivery, Singapore Eye Research Institute, 20 College Road, Singapore 169856 .,Duke-NUS Medical School, 8 College Road, Singapore 169857.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, 5 Lower Kent Ridge Rd, National University Hospital, Singapore 119074
| | - Li Zhen Toh
- Ocular Therapeutics and Drug Delivery, Singapore Eye Research Institute, 20 College Road, Singapore 169856
| | - Stephanie W L Chu
- Ocular Therapeutics and Drug Delivery, Singapore Eye Research Institute, 20 College Road, Singapore 169856
| | - Sharon N Finger
- Ocular Therapeutics and Drug Delivery, Singapore Eye Research Institute, 20 College Road, Singapore 169856
| | - Jocelyn L L Chua
- Glaucoma Service, Singapore National Eye Centre, 11 Third Hospital Avenue, Singapore 168751
| | - Tina T Wong
- Ocular Therapeutics and Drug Delivery, Singapore Eye Research Institute, 20 College Road, Singapore 169856 .,Duke-NUS Medical School, 8 College Road, Singapore 169857.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, 5 Lower Kent Ridge Rd, National University Hospital, Singapore 119074.,Glaucoma Service, Singapore National Eye Centre, 11 Third Hospital Avenue, Singapore 168751.,School of Materials Science and Engineering, Nanyang Technological University, 11 Faculty Ave, Singapore 639977
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49
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Ho H, Htoon HM, Yam GHF, Toh LZ, Lwin NC, Chu S, Lee YS, Wong TT, Seet LF. Altered Anterior Segment Biometric Parameters in Mice Deficient in SPARC. ACTA ACUST UNITED AC 2017; 58:386-393. [DOI: 10.1167/iovs.16-20261] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
| | | | - Gary Hin-Fai Yam
- Singapore Eye Research Institute, Singapore 3Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 4Duke-NUS Medical School Singapore, Singapore
| | | | | | | | | | - Tina T. Wong
- Singapore National Eye Centre, Singapore 2Singapore Eye Research Institute, Singapore 3Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 4Duke-NUS Medical School Singapore, Singapore 5School of Materials Science and Engineering, Nanyang Technological University, Singapore
| | - Li-Fong Seet
- Singapore Eye Research Institute, Singapore 3Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 4Duke-NUS Medical School Singapore, Singapore
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Huang OS, Mehta JS, Htoon HM, Tan DT, Wong TT. Incidence and Risk Factors of Elevated Intraocular Pressure Following Deep Anterior Lamellar Keratoplasty. Am J Ophthalmol 2016; 170:153-160. [PMID: 27519560 DOI: 10.1016/j.ajo.2016.07.025] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2016] [Revised: 07/27/2016] [Accepted: 07/30/2016] [Indexed: 11/16/2022]
Abstract
PURPOSE To report the incidence and risk factors of elevated IOP following deep anterior lamellar keratoplasty (DALK). DESIGN A retrospective case series. METHODS A retrospective study investigating the 5-year incidence of raised IOP following DALK cases performed from 2004 to 2008 in a tertiary center. Patients with less than 6 months of follow-up were excluded. Elevated IOP was defined as IOP >21 mm Hg. RESULTS An episode of elevated IOP occurred in 36.1% of cases (44/122 cases), 11.4% (n = 5) occurring within the first week. The average duration of raised IOP was 48.9 (SD: 65.5) days. Causes included pupil block from air, swollen grafts, and corticosteroid response. Surgical intervention to lower IOP was required in 3 cases (6.8%). In multivariate analyses, the use of Olopatadine 0.1% or cyclosporine eye drops before DALK (OR = 14.51, 95% CI = 1.43-147.23) and use of topical prednisolone acetate 1% compared with dexamethasone 0.1% post DALK (OR = 4.79, 95% CI = 0.73-31.52) were associated with higher rates of elevated IOP post DALK. At 5 years post DALK, 3 of 71 cases (4.48%) developed de novo glaucomatous field defects, and 1 case with pre-existing glaucoma had progression of glaucomatous field defect. CONCLUSIONS DALK was associated with a significant incidence of transiently elevated IOP postoperatively, but had a low incidence of de novo glaucoma at 5 years in our study. Risk factors for raised IOP post DALK included the use of topical prednisolone acetate 1% compared with dexamethasone 0.1%, and the use of Olopatadine 0.1% or any concentration of cyclosporine eye drops prior to DALK.
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Affiliation(s)
| | - Jodhbir S Mehta
- Singapore National Eye Centre, Singapore; Singapore Eye Research Institute, Singapore; Ophthalmology Academic Clinical Program, Duke-NUS Graduate Medical School, Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Hla M Htoon
- Singapore Eye Research Institute, Singapore; Ophthalmology Academic Clinical Program, Duke-NUS Graduate Medical School, Singapore
| | - Donald T Tan
- Singapore National Eye Centre, Singapore; Singapore Eye Research Institute, Singapore; Ophthalmology Academic Clinical Program, Duke-NUS Graduate Medical School, Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Tina T Wong
- Singapore National Eye Centre, Singapore; Singapore Eye Research Institute, Singapore; Ophthalmology Academic Clinical Program, Duke-NUS Graduate Medical School, Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
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