1
|
Strohmaier CA, Wanderer D, Zhang X, Agarwal D, Toomey CB, Wahlin K, Zhang HF, Stamer WD, Weinreb RN, McDonnell FS, Huang AS. Greater Outflow Facility Increase After Targeted Trabecular Bypass in Angiographically Determined Low-low Regions. Ophthalmol Glaucoma 2023; 6:570-579. [PMID: 37348815 PMCID: PMC10917462 DOI: 10.1016/j.ogla.2023.06.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 05/31/2023] [Accepted: 06/14/2023] [Indexed: 06/24/2023]
Abstract
PURPOSE To investigate the impact of trabecular bypass surgery targeted to angiographically determined high- vs. low-aqueous humor outflow areas on outflow facility (C) and intraocular pressure (IOP). DESIGN Ex vivo comparative study. SUBJECTS Postmortem ex vivo porcine and human eyes. METHODS Porcine (n = 14) and human (n = 13) whole globes were acquired. In both species, anterior segments were dissected, mounted onto a perfusion chamber, and perfused using Dulbecco's phosphate buffered solution containing glucose in a constant flow paradigm to achieve a stable baseline. Fluorescein was perfused into the anterior chamber and used to identify baseline segmental high- and low-flow regions of the conventional outflow pathways. The anterior segments were divided into 2 groups, and a 5 mm needle goniotomy was performed in either a high- or low-flow area. Subsequently, C and IOP were quantitatively reassessed and compared between surgery in baseline "high-flow" and "low-flow" region eyes followed by indocyanine green angiography. MAIN OUTCOME MEASURES Outflow facility. RESULTS In all eyes, high- and low-flow segments could be identified. Performing a 5-mm goniotomy increased outflow facility to a variable extent depending on baseline flow status. In the porcine high-flow group, C increased from 0.31 ± 0.09 to 0.39 ± 0.09 μL/mmHg/min (P = 0.12). In the porcine low-flow group, C increased from 0.29 ± 0.03 to 0.56 ± 0.10 μL/mmHg/min (P < 0.001). In the human high-flow group, C increased from 0.38 ± 0.20 to 0.41 ± 0.20 μL/mmHg/min (P = 0.02). In the human low-flow group, C increased from 0.25 ± 0.11 to 0.32 ± 0.11 μL/mmHg/min (<0.001). There was statistically significant greater increase in C for eyes where surgery was targeted to baseline low-flow regions in both porcine (0.07 ± 0.09 vs. 0.27 ± 0.13, P = 0.007 μL/mmHg/min, high vs low flow) and human eyes (0.03 ± 0.03 vs. 0.07 ± 0.02, P = 0.03 μL/mmHg/min, high vs. low flow). CONCLUSIONS Targeting surgery to low-flow areas of the trabecular meshwork yields higher overall facility increase and IOP reduction compared to surgery in high-flow areas. FINANCIAL DISCLOSURE(S) Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
Collapse
Affiliation(s)
- Clemens A Strohmaier
- Department of Ophthalmology and Optometry, Kepler University Hospital, Johannes Kepler University, Linz, Austria; The Viterbi Family Department of Ophthalmology, Hamilton Glaucoma Center, Shiley Eye Institute, University of California, San Diego, California.
| | - Daniel Wanderer
- The Viterbi Family Department of Ophthalmology, Hamilton Glaucoma Center, Shiley Eye Institute, University of California, San Diego, California
| | - Xiaowei Zhang
- The Viterbi Family Department of Ophthalmology, Hamilton Glaucoma Center, Shiley Eye Institute, University of California, San Diego, California
| | - Devansh Agarwal
- The Viterbi Family Department of Ophthalmology, Hamilton Glaucoma Center, Shiley Eye Institute, University of California, San Diego, California
| | - Christopher B Toomey
- The Viterbi Family Department of Ophthalmology, Hamilton Glaucoma Center, Shiley Eye Institute, University of California, San Diego, California
| | - Karl Wahlin
- The Viterbi Family Department of Ophthalmology, Hamilton Glaucoma Center, Shiley Eye Institute, University of California, San Diego, California
| | - Hao F Zhang
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois
| | - W Daniel Stamer
- Department of Biomedical Engineering, Duke University, Durham, North Carolina
| | - Robert N Weinreb
- The Viterbi Family Department of Ophthalmology, Hamilton Glaucoma Center, Shiley Eye Institute, University of California, San Diego, California
| | | | - Alex S Huang
- The Viterbi Family Department of Ophthalmology, Hamilton Glaucoma Center, Shiley Eye Institute, University of California, San Diego, California
| |
Collapse
|
2
|
Strohmaier CA, McDonnell FS, Zhang X, Wanderer D, Stamer WD, Weinreb RN, Huang AS. Differences in Outflow Facility Between Angiographically Identified High- Versus Low-Flow Regions of the Conventional Outflow Pathways in Porcine Eyes. Invest Ophthalmol Vis Sci 2023; 64:29. [PMID: 36939719 PMCID: PMC10043501 DOI: 10.1167/iovs.64.3.29] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2023] Open
Abstract
Purpose To investigate differences in outflow facility between angiographically determined high- and low-flow segments of the conventional outflow pathway in porcine eyes. Methods Porcine anterior segments (n = 14) were mounted in a perfusion chamber and perfused using Dulbecco's phosphate buffered solution with glucose. Fluorescein angiography was performed to determine high- and low-flow regions of the conventional outflow pathways. The trabecular meshwork (TM) was occluded using cyanoacrylate glue, except for residual 5-mm TM areas that were either high or low flow at baseline, designating these eyes as "residual high-flow" or "residual low-flow" eyes. Subsequently, outflow was quantitatively reassessed and compared between residual high-flow and residual low-flow eyes followed by indocyanine green angiography. Results Fluorescein aqueous angiography demonstrated high-flow and low-flow regions. Baseline outflow facilities were 0.320 ± 0.08 and 0.328 ± 0.10 µL/min/mmHg (P = 0.676) in residual high-flow and residual low-flow eyes before TM occlusion, respectively. After partial trabecular meshwork occlusion, outflow facility decreased to 0.209 ± 0.07 µL/min/mmHg (-32.66% ± 19.53%) and 0.114 ± 0.08 µL/min/mmHg (-66.57% ± 23.08%) in residual high- and low-flow eyes (P = 0.035), respectively. There was a significant difference in the resulting IOP increase (P = 0.034). Conclusions Angiographically determined high- and low-flow regions in the conventional outflow pathways differ in their segmental outflow facility; thus, there is an uneven distribution of local outflow facility across different parts of the TM.
Collapse
Affiliation(s)
- Clemens A Strohmaier
- Department of Ophthalmology and Optometry, Kepler University Hospital, Johannes Kepler University, Linz, Austria
- Hamilton Glaucoma Center, The Viterbi Family Department of Ophthalmology, Shiley Eye Institute, University of California, San Diego, California, United States
| | - Fiona S McDonnell
- Department of Ophthalmology, Duke University, Durham, North Carolina, United States
| | - Xiaowei Zhang
- Hamilton Glaucoma Center, The Viterbi Family Department of Ophthalmology, Shiley Eye Institute, University of California, San Diego, California, United States
| | - Daniel Wanderer
- Hamilton Glaucoma Center, The Viterbi Family Department of Ophthalmology, Shiley Eye Institute, University of California, San Diego, California, United States
| | - W Daniel Stamer
- Department of Ophthalmology, Duke University, Durham, North Carolina, United States
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, United States
| | - Robert N Weinreb
- Hamilton Glaucoma Center, The Viterbi Family Department of Ophthalmology, Shiley Eye Institute, University of California, San Diego, California, United States
| | - Alex S Huang
- Hamilton Glaucoma Center, The Viterbi Family Department of Ophthalmology, Shiley Eye Institute, University of California, San Diego, California, United States
| |
Collapse
|
3
|
Trabeculopuncture as a predictive test of distal outflow resistance in canal-based surgery. Sci Rep 2022; 12:10584. [PMID: 35732782 PMCID: PMC9218089 DOI: 10.1038/s41598-022-13990-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 05/31/2022] [Indexed: 11/16/2022] Open
Abstract
We investigated whether trabeculopuncture (TP) could detect distal outflow resistance to predict the outcome of canal-based glaucoma surgery such as ab interno trabeculectomy (AIT). These procedures have a high utilization in open angle glaucoma, but fail in eyes with an unidentified distal outflow resistance. We assigned 81 porcine eyes to two groups: trial (n = 42) and control (n = 39). At 24 h, four YAG-laser trabeculopunctures were placed nasally, followed by a 180° AIT at the same site at 48 h. The proportion of TP responders between both AIT groups was compared. Histology and outflow canalograms were determined. Both post-TP and post-AIT IOPs were lower than baseline IOP (p = 0.015 and p < 0.01, respectively). The success rates of TP and AIT were 69% and 85.7%, respectively. Sensitivity and specificity values of TP as predictive test for AIT success were 77.7% and 83.3%, respectively. The positive and negative predictive values were 96.6% and 38.5%, respectively. We conclude that a 10% reduction in IOP after TP can be used as a predictor for the success (> 20% IOP decrease) of 180° AIT in porcine eyes.
Collapse
|
4
|
Effects of Ripasudil on Open-Angle Glaucoma after Circumferential Suture Trabeculotomy Ab Interno. J Clin Med 2021; 10:jcm10030401. [PMID: 33494305 PMCID: PMC7864492 DOI: 10.3390/jcm10030401] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Revised: 01/17/2021] [Accepted: 01/18/2021] [Indexed: 11/18/2022] Open
Abstract
We evaluated the effects of ripasudil on the distal aqueous outflow tract in patients with open-angle glaucoma (OAG) who underwent a 360° suture trabeculotomy ab interno followed by ripasudil treatment beginning 1 month postoperatively. We compared 27 of these patients, by using propensity score analysis, with 27 patients in a matched control group who had no ripasudil treatment. We assessed the changes in the mean intraocular pressure (IOP) and the relationship between the IOP changes and background factors. All eyes had a complete 360° Schlemm’s canal incision and phacoemulsification. The mean IOP at 1 and 3 months after ripasudil administration were significantly reduced by −1.7 ± 1.9 mmHg (p < 0.0001) and −1.3 ± 2.3 mmHg (p = 0.0081) in the ripasudil group, respectively, but IOP in the control group was not significantly reduced. The IOP reduction was significantly associated with the IOP before ripasudil treatment (p < 0.001). In conclusion, the use of ripasudil for patients with OAG after circumferential incision of the Schlemm’s canal produced significant IOP reductions. Ripasudil may affect the distal outflow tract, thereby leading to the IOP reduction.
Collapse
|
5
|
Intraocular Pressure After Cataract Surgery Combined With Ab Interno Trabeculectomy Versus Trabecular Micro-bypass Stent: An Intrasubject Same-surgeon Comparison. J Glaucoma 2021; 29:773-782. [PMID: 32404618 DOI: 10.1097/ijg.0000000000001547] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
PRECIS Combining Trabectome or iStent with phacoemulsification equally reduces intraocular pressure (IOP) and IOP-lowering medication burden during a 24-month follow-up, with a possible advantage to the Trabectome in the early postoperative period. PURPOSE Intrasubject same-surgeon comparison between phacoemulsification combined with Trabectome (Phaco/Trabectome) versus one first-generation iStent (Phaco/iStent). SETTINGS Private glaucoma and cataract practice. DESIGN This is a retrospective interventional case series. METHODS Data collected at 3 to 4 and 20 to 24 hours and up to 30 months following Phaco/Trabectome in 1 eye and Phaco/iStent in the contralateral eye in patients with bilateral visually-significant cataract and open-angle glaucoma. Evaluations included IOP, intraocular pressure-lowering medications (IOPmeds), visual acuity, and complications. RESULTS Forty-five patients (90 eyes) were identified (age 76.5, 57 to 95 y). At 3 to 4 hours, IOP was above baseline in 12 and 13 eyes following Phaco/Trabectome and Phaco/iStent, respectively, but the degree of IOP elevation was smaller (P=0.048) following Phaco/Trabectome: 4.3 mm Hg, 2.0 to 6.6 mm Hg (95% confidence interval) versus Phaco/iStent: 8.7 mm Hg, 3.8 to 13.6 mm Hg. At 20 to 24 hours, compared with baseline, IOP was significantly lower after Phaco/Trabectome (P=0.004) but not after Phaco/iStent (P=0.14) although the rate of hyphema was higher following Phaco/Trabectome (12/45 vs. 2/45 eyes, P=0.007). IOP reduction from baseline at 3 to 4 hours was significantly larger (P=0.020) in the 21 eyes with hyphema: -3.9, -6.4 to -1.4 versus the 69 eyes without hyphema: -0.3, -2.0 to +1.4. At 1, 6, 12, and 24 months, IOP and number of IOPmeds were similar and significantly lower compared with baseline following either procedure. No complications were encountered in either group. CONCLUSIONS Combined phacoemulsification with either Trabectome or first-generation iStent similarly lowers IOP and IOPmeds burden at 1, 6, 12, and 24 months following surgery. The Trabectome may have an advantage in lowering IOP faster and lessening the degree of IOP elevations in the early postoperative period.
Collapse
|
6
|
Exact matching of trabectome-mediated ab interno trabeculectomy to conventional trabeculectomy with mitomycin C followed for 2 years. Graefes Arch Clin Exp Ophthalmol 2020; 259:963-970. [PMID: 33263824 PMCID: PMC8016747 DOI: 10.1007/s00417-020-05031-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 11/16/2020] [Accepted: 11/23/2020] [Indexed: 10/30/2022] Open
Abstract
PURPOSE We used exact matching for a highly balanced comparison of ab interno trabeculectomy (AIT) with the trabectome to trabeculectomy with mitomycin C (TRAB). METHODS A total of 5485 patients who underwent AIT were exact-matched to 196 TRAB patients by baseline intraocular pressure (IOP), number of glaucoma medications, and glaucoma type. Nearest-neighbor-matching was applied to age. Success was defined as a final IOP of less than 21 mmHg, IOP reduction of at least 20% reduction from baseline, and no secondary surgical interventions. Outcomes were measured at 1, 3, 6, 12, 18, and 24 months. RESULTS A total of 165 AIT could be matched to 165 TRAB. The mean baseline IOP was 22.3 ± 5.6 mmHg, and the baseline number of glaucoma medications was 2.7 ± 1.1 in both groups. At 24 months, IOP was reduced to 15.8 ± 5.2 mmHg in AIT and 12.4 ± 4.7 mmHg in TRAB. IOP was lower than baseline at all visits (p < 0.01) and lower in TRAB than AIT (p < 0.01). Glaucoma medications were reduced to 2.1 ± 1.3 in AIT and 0.2 ± 0.8 in TRAB. Compared to baseline, patients used fewer drops postoperatively (p < 0.01) and more infrequently in TRAB than in AIT (p > 0.01). Secondary surgical interventions had the highest impact on success and became necessary in 15 AIT and 59 TRAB patients. Thirty-two challenging events occurred in TRAB and none in AIT. CONCLUSION Both AIT and TRAB reduced IOP and medications. This reduction was more significant in TRAB but at the expense of four times as many secondary interventions.
Collapse
|
7
|
Al Yousef Y, Strzalkowska A, Hillenkamp J, Rosentreter A, Loewen NA. Comparison of a second-generation trabecular bypass (iStent inject) to ab interno trabeculectomy (Trabectome) by exact matching. Graefes Arch Clin Exp Ophthalmol 2020; 258:2775-2780. [PMID: 32960322 PMCID: PMC7677264 DOI: 10.1007/s00417-020-04933-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 09/07/2020] [Accepted: 09/10/2020] [Indexed: 11/28/2022] Open
Abstract
Purpose To achieve a highly balanced comparison of trabecular bypass stenting (IS2, iStent inject) with ab interno trabeculectomy (T, Trabectome) by exact matching. Methods Fifty-three IS2 eyes were matched to 3446 T eyes. Patients were matched using exact matching by baseline intraocular pressure (IOP), the number of glaucoma medications, and glaucoma type, and using nearest neighbor matching by age. Individuals without a close match were excluded. All surgeries were combined with phacoemulsification. Results A total of 78 eyes (39 in each group) could be matched as exact pairs with a baseline IOP of 18.3 ± 5.1 mmHg and glaucoma medications of 2.7 ± 1.2 in each. IOP in IS2 was reduced to 14.6 ± 4.2 mmHg at 3 months and in T to a minimum of 13.1 ± 3.2 mmHg at 1 month. In IS2, IOP began to rise again at 6 months, eventually exceeding baseline. At 24 months, IOP in IS2 was 18.8 ± 9.0 mmHg and in T 14.2 ± 3.5 mmHg. IS2 had a higher average IOP than T at all postoperative visits (p < 0.05 at 1, 12, 18 months). Glaucoma medications decreased to 2.0 ± 1.5 in IS2 and to 1.5 ± 1.4 in T. Conclusion T resulted in a larger and sustained IOP reduction compared with IS2 where a rebound occurred after 6 months to slightly above preoperative values.
Collapse
Affiliation(s)
- Yousef Al Yousef
- Department of Ophthalmology, University of Würzburg, Josef-Schneider-Straße, 11 97080, Würzburg, Germany
| | - Alicja Strzalkowska
- Department of Ophthalmology, University of Würzburg, Josef-Schneider-Straße, 11 97080, Würzburg, Germany
| | - Jost Hillenkamp
- Department of Ophthalmology, University of Würzburg, Josef-Schneider-Straße, 11 97080, Würzburg, Germany
| | - André Rosentreter
- Department of Ophthalmology, University Witten/Herdecke, Wuppertal, Germany
| | - Nils A Loewen
- Department of Ophthalmology, University of Würzburg, Josef-Schneider-Straße, 11 97080, Würzburg, Germany.
| |
Collapse
|
8
|
Esfandiari H, Taubenslag K, Shah P, Goyal S, Weiner AJ, Severson ML, Weiner A, Grover DS, Bussel II, Loewen NA. Two-year data comparison of ab interno trabeculectomy and trabecular bypass stenting using exact matching. J Cataract Refract Surg 2020; 45:608-614. [PMID: 31030775 DOI: 10.1016/j.jcrs.2018.12.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2018] [Revised: 12/09/2018] [Accepted: 12/10/2018] [Indexed: 11/25/2022]
Abstract
PURPOSE To create a balanced comparison of ab interno trabeculectomy (AIT) (Trabectome) and trabecular bypass stenting (TBS) (iStent). SETTING Eye and Ear Institute, Pittsburgh, Pennsylvania, Ross Eye Institute, Buffalo, New York, and Glaucoma Associates of Texas, Dallas, USA. DESIGN Retrospective case series. METHODS The primary outcome measure was an unmedicated intraocular pressure (IOP) of 21 mm Hg or less and the secondary measure was an unmedicated IOP reduction of 20% or more at 2 years. Patients were matched by baseline IOP, number of glaucoma medications, and glaucoma type using exact matching and by age using nearest neighbor matching. Individuals without a close match were excluded. All surgeries were combined with phacoemulsification. RESULTS One hundred fifty-four AIT eyes and 110 TBS eyes were analyzed. Forty-eight AIT patients were exactly matched with 48 TBS patients. Both groups had a mean baseline IOP of 15.3 mm Hg ± 3.1 (SD). At 24 months, the mean IOP was 13.9 ± 3.3 mm Hg in AIT patients and 16.8 ± 2.8 mm Hg in TBS patients and the mean number of medications was 0.7 ± 1.0 and 1.7 ± 1.2, respectively (both P = .04). At 24 months, the IOP was 21 mm Hg or less without medications in 53% of AIT patients and 16.6% of TBS patients (P < .05). At that time, 17.6% of patients in the AIT group but no patient in the TBS group had an IOP reduction of 20% or more without medication. CONCLUSION An exact matching comparison of AIT and TBS showed greater IOP reduction with fewer medications after AIT.
Collapse
Affiliation(s)
- Hamed Esfandiari
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pennsylvania, USA
| | - Kenneth Taubenslag
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pennsylvania, USA
| | - Priyal Shah
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pennsylvania, USA
| | - Swati Goyal
- Eye Q Superspeciality Eye Hospital, Gurgaon, India
| | - Adam J Weiner
- Beaumont Eye Institute, Oakland University William Beaumont School of Medicine, Royal Oak, Michigan, USA
| | - Melissa L Severson
- Department of Ophthalmology and Ira G. Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo/State University of New York, USA
| | - Asher Weiner
- Department of Ophthalmology and Ira G. Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo/State University of New York, USA
| | | | - Igor I Bussel
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pennsylvania, USA
| | - Nils A Loewen
- Department of Ophthalmology, University of Würzburg, Würzburg, Germany.
| |
Collapse
|
9
|
Evaluation of Blood-filling Patterns in Schlemm Canal for Trabectome Surgery. J Glaucoma 2020; 29:1101-1105. [PMID: 32890107 DOI: 10.1097/ijg.0000000000001646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PRéCIS:: Regardless of the blood-filling patterns in Schlemm canal (SC) before the trabecular meshwork (TM) ablation, the trabectome surgery, combined with phacoemulsification, is effective for mild to moderate primary open-angle glaucoma patients. PURPOSE The purpose of this study was to evaluate the association between trabectome surgery outcomes and the blood filling patterns in SC before TM ablation. MATERIALS AND METHODS This retrospective cohort study included 105 eyes of 84 Japanese primary open-angle glaucoma patients who had undergone trabectome surgery in combination with cataract surgery. Provocative gonioscopy was performed before TM ablation to classify the blood filling patterns in SC into 3 groups: no filling (group 1); patchy/irregular filling (group 2); and complete filling (group 3). The subjects were divided into 3 groups according to the blood filling patterns and the trabectome surgery outcomes were compared, including intraocular pressure (IOP), the percentage reduction in IOP, surgical success rate, and the number of glaucoma medications. Success was defined by IOP ≤15 mm Hg and a >20% reduction in IOP with/without glaucoma medication, and without additional glaucoma surgery after trabectome surgery combined with cataract surgery. RESULTS Twenty-four eyes were assigned to group 1, 48 to group 2, and 33 to group 3. Between-group analyses showed no significant intergroup differences in age (P=0.213), preoperative mean deviation (P=0.505), preoperative and postoperative IOP (P=0.941 and 0.458, respectively), preoperative and postoperative number of glaucoma medications (P=0.805 and 0.077, respectively), percentage IOP reduction (P=0.256), and success rates (P=0.540). CONCLUSION Trabectome surgery is effective for mild to moderate primary open-angle glaucoma patients, independent of the blood-filling patterns in SC before the TM ablation.
Collapse
|
10
|
Aqueous outflow imaging techniques and what they tell us about intraocular pressure regulation. Eye (Lond) 2020; 35:216-235. [PMID: 32826996 DOI: 10.1038/s41433-020-01136-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 07/19/2020] [Accepted: 08/07/2020] [Indexed: 02/06/2023] Open
Abstract
Recent advances in the medical and surgical management of open-angle glaucoma have increased the number of treatment options available. Several new intraocular pressure (IOP)-lowering treatments target the conventional aqueous outflow (AO) system. However, success rates are variable and outcomes in individual patients are often difficult to predict. Variable treatment responses remain unexplained and highlight deficiencies in our current understanding of AO regulation and IOP homeostasis. Imaging is often relied upon to confirm diagnoses and monitor treatment responses in other ocular and systemic pathologies. As yet no suitable AO imaging tool has been developed to fulfil this role in glaucoma. A variety of imaging techniques have been used to study the AO tracts of humans and animals in ex vivo and in vivo eyes. In this review, results from novel imaging techniques that assess aqueous drainage through the episcleral venous system are considered and we argue these provide new insights into AO regulation. We suggest that the ability to objectively measure AO responses to interventions would be a significant clinical advance, and we have demonstrated that this can be achieved with direct visualisation of aqueous drainage. We predict that the evolution of AO imaging technology will continue to reveal critical components of AO and IOP regulation, and that personalised IOP-lowering treatment in glaucoma care may well become a reality in the near future.
Collapse
|
11
|
Loewen RT, Waxman S, Wang C, Atta S, Chen S, Watkins SC, Watson AM, Loewen NA. 3D-Reconstruction of the human conventional outflow system by ribbon scanning confocal microscopy. PLoS One 2020; 15:e0232833. [PMID: 32421732 PMCID: PMC7233539 DOI: 10.1371/journal.pone.0232833] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2019] [Accepted: 04/22/2020] [Indexed: 11/19/2022] Open
Abstract
PURPOSE The risk for glaucoma is driven by the microanatomy and function of the anterior segment. We performed a computation-intense, high-resolution, full-thickness ribbon-scanning confocal microscopy (RSCM) of the outflow tract of two human eyes. We hypothesized this would reveal important species differences when compared to existing data of porcine eyes, an animal that does not spontaneously develop glaucoma. METHODS After perfusing two human octogenarian eyes with lectin-fluorophore conjugate and optical clearance with benzyl alcohol benzyl benzoate (BABB), anterior segments were scanned by RSCM and reconstructed in 3D for whole-specimen rendering. Morphometric analyses of the outflow tract were performed for the trabecular meshwork (TM), limbal, and perilimbal outflow structures and compared to existing porcine data. RESULTS RSCM provided high-resolution data for IMARIS-based surface reconstruction of outflow tract structures in 3D. Different from porcine eyes with an abundance of highly interconnected, narrow, and short collector channels (CCs), human eyes demonstrated fewer CCs which had a 1.5x greater cross-sectional area (CSA) and 2.6x greater length. Proximal CC openings at the level of Schlemm's canal (SC) had a 1.3x larger CSA than distal openings into the scleral vascular plexus (SVP). CCs were 10.2x smaller in volume than the receiving SVP vessels. Axenfeld loops, projections of the long ciliary nerve, were also visualized. CONCLUSION In this high-resolution, volumetric RSCM analysis, human eyes had far fewer outflow tract vessels than porcine eyes. Human CCs spanned several clock-hours and were larger than in porcine eyes. These species differences may point to factors downstream of the TM that increase our vulnerability to glaucoma.
Collapse
Affiliation(s)
- Ralitsa T. Loewen
- Department of Ophthalmology, University of Würzburg, Würzburg, Germany
| | - Susannah Waxman
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Chao Wang
- Department of Ophthalmology, University of Würzburg, Würzburg, Germany
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Cellular Biology, Center for Biologic Imaging, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Sarah Atta
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Si Chen
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Simon C. Watkins
- Department of Cellular Biology, Center for Biologic Imaging, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Alan M. Watson
- Department of Cellular Biology, Center for Biologic Imaging, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Nils A. Loewen
- Department of Ophthalmology, University of Würzburg, Würzburg, Germany
| |
Collapse
|
12
|
Chen S, Waxman S, Wang C, Atta S, Loewen R, Loewen NA. Dose-dependent effects of netarsudil, a Rho-kinase inhibitor, on the distal outflow tract. Graefes Arch Clin Exp Ophthalmol 2020; 258:1211-1216. [PMID: 32372330 PMCID: PMC7237522 DOI: 10.1007/s00417-020-04691-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 03/24/2020] [Accepted: 04/07/2020] [Indexed: 12/15/2022] Open
Abstract
PURPOSE To characterize the effects of netarsudil on the aqueous humor outflow tract distal to the trabecular meshwork (TM). We hypothesized that netarsudil increases outflow facility in eyes with and without circumferential ab interno trabeculectomy (AIT) that removes the TM. METHODS Sixty-four porcine anterior segment cultures were randomly assigned to groups with (n = 32) and without circumferential AIT (n = 32). Cultures were exposed to 0.1, 1, and 10 μM netarsudil (N = 8 eyes per concentration). For each concentration, IOP and vessel diameters were compared with their respective pretreatment baselines. Outflow tract vessel diameters were assessed by spectral-domain optical coherence tomography (SDOCT) and rendered in 4D (XYZ time series). RESULTS Netarsudil at 1 μM reduced IOP both in eyes with TM (- 0.60 ± 0.24 mmHg, p = 0.01) and in eyes without TM (- 1.79 ± 0.42 mmHg, p < 0.01). At this concentration, vessels of the distal outflow tract dilated by 72%. However, at 0.1 μM netarsudil elevated IOP in eyes with TM (1.59 ± 0.36 mmHg, p < 0.001) as well as in eyes without TM (0.23 ± 0.32 mmHg, p < 0.001). Vessels of the distal outflow tract constricted by 31%. Similarly, netarsudil at a concentration of 10 μM elevated IOP both in eyes with TM (1.91 ± 0.193, p < 0.001) and in eyes without TM (3.65 ± 0.86 mmHg, p < 0.001). At this concentration, outflow tract vessels constricted by 27%. CONCLUSION In the porcine anterior segment culture, the dose-dependent IOP changes caused by netarsudil matched the diameter changes of distal outflow tract vessels. Hyper- and hypotensive properties of netarsudil persisted after TM removal.
Collapse
Affiliation(s)
- Si Chen
- Department of Ophthalmology, University of Würzburg, Josef-Schneider-Straße 11, 97080, Würzburg, Germany.,Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.,Department of Ophthalmology, Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Susannah Waxman
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Chao Wang
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.,Department of Ophthalmology, Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Sarah Atta
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Ralitsa Loewen
- Department of Ophthalmology, University of Würzburg, Josef-Schneider-Straße 11, 97080, Würzburg, Germany.,Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Nils A Loewen
- Department of Ophthalmology, University of Würzburg, Josef-Schneider-Straße 11, 97080, Würzburg, Germany. .,Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
| |
Collapse
|
13
|
Xin C, Wang H, Wang N. Minimally Invasive Glaucoma Surgery: What Do We Know? Where Should We Go? Transl Vis Sci Technol 2020; 9:15. [PMID: 32821487 PMCID: PMC7401977 DOI: 10.1167/tvst.9.5.15] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 12/02/2019] [Indexed: 12/17/2022] Open
Abstract
With the arrival of a plethora of new and revolving minimally invasive glaucoma surgery techniques, glaucoma specialists currently are fortunate to have various surgical options that aim to recovery of the function of the aqueous outflow system in different ways. Meanwhile, the aqueous outflow system has become the hot point of researching. In ARVO 2019, a special interest group session was held on new perspectives on minimally invasive glaucoma surgery. Ten surgeons, clinical professors, and experimental scientists were invited to report their latest studies and discussed on five hot topics in this special interest group. This review summarizes the special interest group session and posts the issues of greatest concern, providing insight to the aqueous outflow system and areas that require further study.
Collapse
Affiliation(s)
- Chen Xin
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Huangzhou Wang
- Ophthalmology Department, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Ningli Wang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| |
Collapse
|
14
|
Wang C, Dang Y, Shah P, Esfandiari H, Hong Y, Loewen RT, Waxman S, Atta S, Xia X, Loewen NA. Intraocular pressure reduction in a pigmentary glaucoma model by Goniotome Ab interno trabeculectomy. PLoS One 2020; 15:e0231360. [PMID: 32298335 PMCID: PMC7162452 DOI: 10.1371/journal.pone.0231360] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 03/21/2020] [Indexed: 01/08/2023] Open
Abstract
PURPOSE To investigate whether microsurgical excision of trabecular meshwork (TM) in an ex vivo pigmentary glaucoma model can normalize the hypertensive phenotype. METHODS Eight eyes of a porcine pigmentary glaucoma model underwent 90° of microsurgical TM excision with an aspirating dual-blade (Goniotome (G)). 24 hours later, additional 90° of TM were removed. Anterior segments with sham surgeries served as the control (C). Outflow facility and intraocular pressure (IOP) were analyzed. Histology with hematoxylin and eosin (H&E) was obtained. RESULTS After the first 90° TM excision, IOP was significantly lower in G (10.2±2.4 mmHg, n = 7) than C (20.0±2.0mmHg, n = 8, P<0.01). Outflow facility in G (0.38±0.07 μl/min/mmHg) was higher than C (0.16±0.02 μl/min/mmHg, P<0.01). After the second 90° TM excision, IOP in G (6.46±0.81 mmHg, n = 7) was significantly lower than C (20.3±1.7 mmHg, n = 8, P<0.001), while the outflow facility in G (0.50±0.05 μl/min/mmHg, n = 7) was higher than C (0.16±0.01 μl/min/mmHg, n = 8, P<0.001). Compared to the first excision, excision of an additional 90° did not change of IOP (P = 0.20) or outflow facility (P = 0.17) further. CONCLUSIONS Excision of 90° of TM in a pigmentary glaucoma model using an aspirating dual-blade decreased IOP and increased outflow facility.
Collapse
Affiliation(s)
- Chao Wang
- Department of Ophthalmology, University of Würzburg, Würzburg, Germany
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Department of Ophthalmology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, United States of America
| | - Yalong Dang
- Department of Ophthalmology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, United States of America
| | - Priyal Shah
- Department of Ophthalmology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, United States of America
| | - Hamed Esfandiari
- Department of Ophthalmology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, United States of America
| | - Ying Hong
- Department of Ophthalmology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, United States of America
- Department of Ophthalmology, Peking University Third Hospital, Beijing, China
| | - Ralitsa T. Loewen
- Department of Ophthalmology, University of Würzburg, Würzburg, Germany
- Department of Ophthalmology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, United States of America
| | - Susannah Waxman
- Department of Ophthalmology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, United States of America
| | - Sarah Atta
- Department of Ophthalmology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, United States of America
| | - Xiaobo Xia
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Nils A. Loewen
- Department of Ophthalmology, University of Würzburg, Würzburg, Germany
| |
Collapse
|
15
|
Similar Performance of Trabectome and Ahmed Glaucoma Devices in a Propensity Score-matched Comparison. J Glaucoma 2019; 27:490-495. [PMID: 29613976 DOI: 10.1097/ijg.0000000000000960] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To apply propensity score matching to Ahmed glaucoma drainage implants (AGI) to trabectome-mediated ab interno trabeculectomy (AIT). Recent data suggest that AIT can produce results similar to AGI traditionally reserved for more severe glaucoma. METHODS AGI and AIT patients with at least 1 year of follow-up were included. The primary outcome measures were intraocular pressure (IOP), glaucoma medications, and a Glaucoma Index (GI) score. GI reflected glaucoma severity based on visual field, the number of preoperative medications, and preoperative IOP. Score matching used a genetic algorithm consisting of age, sex, type of glaucoma, concurrent phacoemulsification, baseline number of medications, and baseline IOP. Patients without a close match were excluded. RESULTS Of 152 patients, 34 AIT patients were matched to 32 AGI patients. Baseline characteristics including ethnicity, IOP, the number of medications, glaucoma type, the degree of visual field loss and GI were not significantly different between AIT and AGI. AIT had a preoperative IOP of 23.6±8.1 mm Hg compared with 26.5+10.6 mm Hg for AGI. At 12 months, the mean IOP was 15.0±9 mm Hg for AIT versus 15.0±4 mm Hg for AGI (P=0.8), whereas the number of drops was 2.3±2.2 for AIT versus 3.6±1.3 for AGI (P=0.016). Only 6 AIT patients (17.6%) required further surgery within the first 12 months versus 9 (28%) for AGI. Success, defined as IOP<21 mm Hg, <20% reduction and no reoperation, was achieved in 76% of AIT versus 69% of AGI (P=0.48). Complications occurred in 13% of AGI and 0.8% of AIT. CONCLUSIONS A propensity score-matched comparison of AIT and AGI showed an equivalent IOP reduction through 1 year. Surprisingly, the AGI group required more glaucoma medications than the AIT group at 6 and 12 months.
Collapse
|
16
|
Waxman S, Wang C, Dang Y, Hong Y, Esfandiari H, Shah P, Lathrop KL, Loewen RT, Loewen NA. Structure-Function Changes of the Porcine Distal Outflow Tract in Response to Nitric Oxide. Invest Ophthalmol Vis Sci 2019; 59:4886-4895. [PMID: 30347083 PMCID: PMC6181305 DOI: 10.1167/iovs.18-24943] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Purpose To correlate outflow function and outflow tract vessel diameter changes induced by nitric oxide (NO). Methods In a porcine anterior segment perfusion model, the effects of a nitric oxide donor (100 μM DETA-NO) on outflow facility were compared with controls (n = 8 per group) with trabecular meshwork (TM) and after circumferential ab interno trabeculectomy (AIT). Outflow structures were assessed with spectral-domain optical coherence tomography (SD-OCT) before and after NO, or an NO synthase inhibitor (100 μM L-NAME) and the vasoconstrictor, endothelin-1 (100 pg/mL ET-1). Scans were processed with a custom macroscript and aligned for automated reslicing and quantification of cross-sectional outflow tract areas (CSA). Results The facility increased after DETA-NO (Δ of 0.189 ± 0.081 μL/min·mm Hg, P = 0.034) and AIT (Δ of 0.251 ± 0.094 μL/min·mm Hg, P = 0.009), respectively. Even after AIT, DETA-NO increased the facility by 61.5% (Δ of 0.190 ± 0.074 μL/min·mm Hg, P = 0.023) and CSA by 13.9% (P < 0.001). L-NAME + ET-1 decreased CSA by -8.6% (P < 0.001). NO increased the diameter of focal constrictions 5.0 ± 3.8-fold. Conclusions NO can dilate vessels of the distal outflow tract and increase outflow facility in a TM-independent fashion. There are short, focally constricting vessel sections that display large diameter changes and may have a substantial impact on outflow.
Collapse
Affiliation(s)
- Susannah Waxman
- Department of Ophthalmology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, United States
| | - Chao Wang
- Department of Ophthalmology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, United States.,Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha, Hunan, China.,The Third Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Yalong Dang
- Department of Ophthalmology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, United States
| | - Ying Hong
- Department of Ophthalmology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, United States.,Department of Ophthalmology, Peking University Third Hospital, Beijing, China
| | - Hamed Esfandiari
- Department of Ophthalmology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, United States
| | - Priyal Shah
- Department of Ophthalmology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, United States
| | - Kira L Lathrop
- Department of Ophthalmology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, United States
| | - Ralitsa T Loewen
- Department of Ophthalmology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, United States
| | - Nils A Loewen
- Department of Ophthalmology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, United States
| |
Collapse
|
17
|
Outflow facility and extent of angle closure in a porcine model. Graefes Arch Clin Exp Ophthalmol 2019; 257:1239-1245. [PMID: 30944988 DOI: 10.1007/s00417-019-04279-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 01/29/2019] [Accepted: 02/15/2019] [Indexed: 12/19/2022] Open
Abstract
PURPOSE To establish the extent of anterior chamber angle circumference needed to maintain a physiological outflow facility (C). This could create a model to investigate focal outflow regulation. METHODS Twenty anterior segments of porcine eyes were assigned to five groups, each with a different degree of cyanoacrylate-mediated angle closure: 90° (n = 4), 180° (n = 4), 270° (n = 4), 360° (n = 4), and four unoccluded control eyes. The outflow facility was measured at baseline, 3, 12, 24, and 36 h after angle closure. Outflow patterns were evaluated with canalograms and the histomorphology was compared. RESULTS Baseline outflow facilities of the five groups were similar (F = 0.922, p = 0.477). Occlusion of 360° induced a significant decrease in facility from baseline at all time-points (p ≤ 0.023 at 3, 12, 24, and 36 h). However, no difference from baseline was found in any of the partially occluded (0-270°) groups (F ≥ 0.067, p ≥ 0.296 at 3, 12, 24, and 36 h). The canalograms confirmed the extent of occlusion with flow through the unblocked regions. Histology revealed no adverse effects of blockage on the TM or aqueous plexus in the unoccluded angle portions. The unoccluded TM appeared normal. CONCLUSION Cyanoacrylate-mediated angle occlusion created a reproducible angle closure model. Ninety degrees of unoccluded anterior chamber angle circumference was sufficient to maintain physiological outflow. This model may help understand how outflow can be regulated in healthy, nonglaucomatous TM.
Collapse
|
18
|
Waxman S, Loewen RT, Dang Y, Watkins SC, Watson AM, Loewen NA. High-Resolution, Three-Dimensional Reconstruction of the Outflow Tract Demonstrates Segmental Differences in Cleared Eyes. Invest Ophthalmol Vis Sci 2019; 59:2371-2380. [PMID: 29847643 PMCID: PMC5939687 DOI: 10.1167/iovs.17-23075] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Purpose The rate of conventional aqueous humor outflow is the highest nasally. We hypothesized that this is reflected in regionally different outflow structures and analyzed the entire limbus by high-resolution, full-thickness ribbon-scanning confocal microscopy (RSCM). Methods We perfused pig eyes by anterior chamber cannulation with eight lectin-fluorophore conjugates, followed by optical clearance with benzyl alcohol benzyl benzoate (BABB). RSCM and advanced analysis software (Imaris) were used to reconstruct a three-dimensional (3D), whole-specimen rendering of the perilimbal outflow structures. We performed morphometric analyses of the outflow tract from the level of the trabecular meshwork (TM) to the scleral vascular plexus (SVP). Results Except for pigmented structures, BABB cleared the entire eye. Rhodamine-conjugated Glycine max agglutinin (soybean [SBA]) labeled the outflow tract evenly and retained fluorescence for months. RSCM produced terabyte-sized files allowing for in silico dissection of outflow tract vessels at a high resolution and in 3D. Networks of interconnected lumens were traced from the TM to downstream drainage structures. The collector channel (CC) volumes were 10 times smaller than the receiving SVP vessels, the largest of which were in the inferior limbus. Proximal CC diameters were up to four times the size of distal diameters and more elliptical at their proximal ends. The largest CCs were found in the superonasal and inferonasal quadrants where the highest outflow occurs. Conclusion RSCM of cleared eyes enabled high-resolution, volumetric analysis of the outflow tract. The proximal structures had greater diameters nasally, whereas the SVP was larger in the inferior limbus.
Collapse
Affiliation(s)
- Susannah Waxman
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Ralitsa T Loewen
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Yalong Dang
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Simon C Watkins
- Center for Biologic Imaging and the Department of Cellular Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Alan M Watson
- Center for Biologic Imaging and the Department of Cellular Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Nils A Loewen
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| |
Collapse
|
19
|
Huang AS, Penteado RC, Papoyan V, Voskanyan L, Weinreb RN. Aqueous Angiographic Outflow Improvement after Trabecular Microbypass in Glaucoma Patients. Ophthalmol Glaucoma 2018; 2:11-21. [PMID: 31595267 DOI: 10.1016/j.ogla.2018.11.010] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Purpose To study changes in aqueous humor outflow (AHO) patterns after trabecular micro-bypass (TMB) in glaucoma patients using intraoperative sequential aqueous angiography. Design Prospective comparative case series. Subjects Fifteen subjects (14 with glaucoma and 1 normal). Methods Sequential aqueous angiography (Spectralis HRA+OCT; Heidelberg Engineering) was performed on fourteen glaucoma patients undergoing routine TMB (iStent Inject; Glaukos Corporation) and cataract surgery and one normal patient undergoing cataract surgery alone. Indocyanine green (ICG) aqueous angiography established initial baseline nasal angiographic AHO patterns. Two TMB stents were placed in regions of baseline low or high angiographic AHO in each eye (n = 2 eyes with enough space to place two stents in both low angiographic regions; n = 8 eyes with two stents both placed in high angiographic regions; n = 4 eyes with enough space to place one stent in a low angiographic region and the other stent in a high angiographic region). Subsequent fluorescein aqueous angiography was utilized to query alterations to angiographic AHO patterns. Main Outcome Measure Angiographic signal and patterns before and after TMB. Results At baseline, all eyes showed segmental angiographic AHO patterns. Focused on the nasal hemisphere of each eye, for each stent TMB in initially low ICG angiographic signal regions showed transient or persistently improved fluorescein angiographic signal (11.2-fold; p = 0.014). TMB in initially high ICG signal regions led to faster development of fluorescein angiographic patterns (3.1-fold; p = 0.02). Conclusion TMB resulted in different patterns of aqueous angiographic AHO improvement whose further understanding may advance basic knowledge of AHO and possibly enhance intraocular pressure reduction after glaucoma surgery in the future.
Collapse
Affiliation(s)
- Alex S Huang
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Rafaella C Penteado
- Hamilton Glaucoma Center, Shiley Eye Institute, and Department of Ophthalmology University of California, San Diego, CA, USA
| | - Vahan Papoyan
- Department of Ophthalmology, Yerevan State Medical University, Ophthalmological Center after S.V. Malayan
| | - Lilit Voskanyan
- Department of Ophthalmology, Yerevan State Medical University, Ophthalmological Center after S.V. Malayan
| | - Robert N Weinreb
- Hamilton Glaucoma Center, Shiley Eye Institute, and Department of Ophthalmology University of California, San Diego, CA, USA
| |
Collapse
|
20
|
Dang Y, Wang C, Shah P, Waxman S, Loewen RT, Loewen NA. RKI-1447, a Rho kinase inhibitor, causes ocular hypotension, actin stress fiber disruption, and increased phagocytosis. Graefes Arch Clin Exp Ophthalmol 2018; 257:101-109. [PMID: 30456419 DOI: 10.1007/s00417-018-4175-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 10/17/2018] [Accepted: 10/25/2018] [Indexed: 01/08/2023] Open
Abstract
PURPOSE This study investigated the hypotensive effect of RKI-1447, a Rho kinase inhibitor, in a porcine ex vivo pigmentary glaucoma model. METHODS Twenty-eight porcine anterior chambers were perfused with medium supplemented with 1.67 × 107 pigment particles/ml for 48 h before treatment with RKI-1447 (n = 16) or vehicle control (n = 12). Intraocular pressure (IOP) was recorded and outflow facility was calculated. Primary trabecular meshwork cells were exposed to RKI-1447 or vehicle control; effects on the cytoskeleton, motility, and phagocytosis were evaluated. RESULT Compared to baseline, the perfusion of pigment caused a significant increase in IOP in the RKI-1447 group (P = 0.003) at 48 h. Subsequent treatment with RKI-1447 significantly reduced IOP from 20.14 ± 2.59 to 13.38 ± 0.91 mmHg (P = 0.02). Pigment perfusion reduced the outflow facility from 0.27 ± 0.03 at baseline to 0.18 ± 0.02 at 48 h (P < 0.001). This was partially reversed with RKI-1447. RKI-1447 caused no apparent histological changes in the micro- or macroscopic TM appearance. RKI-1447-treated primary TM cells showed significant disruption of the actin cytoskeleton both in the presence and absence of pigment (P < 0.001) but no effect on TM migration was observed. Pigment-treated TM cells exhibited a reduction in TM phagocytosis, which RKI-1447 reversed. CONCLUSION RKI-1447 significantly reduces IOP by disrupting TM stress fibers and increasing TM phagocytosis. These features may make it useful for the treatment of secondary glaucomas with an increased phagocytic load.
Collapse
Affiliation(s)
- Yalong Dang
- Department of Ophthalmology, University of Pittsburgh School of Medicine, 203 Lothrop St, Suite 819, Pittsburgh, PA, 15213, USA
| | - Chao Wang
- Department of Ophthalmology, University of Pittsburgh School of Medicine, 203 Lothrop St, Suite 819, Pittsburgh, PA, 15213, USA.,Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China
| | - Priyal Shah
- Department of Ophthalmology, University of Pittsburgh School of Medicine, 203 Lothrop St, Suite 819, Pittsburgh, PA, 15213, USA.,Institute of Ophthalmology and Visual Science, Rutgers New Jersey Medical School, Newark, NJ, USA
| | - Susannah Waxman
- Department of Ophthalmology, University of Pittsburgh School of Medicine, 203 Lothrop St, Suite 819, Pittsburgh, PA, 15213, USA
| | - Ralitsa T Loewen
- Department of Ophthalmology, University of Pittsburgh School of Medicine, 203 Lothrop St, Suite 819, Pittsburgh, PA, 15213, USA
| | - Nils A Loewen
- Department of Ophthalmology, University of Pittsburgh School of Medicine, 203 Lothrop St, Suite 819, Pittsburgh, PA, 15213, USA.
| |
Collapse
|
21
|
Dang Y, Wang C, Shah P, Waxman S, Loewen RT, Hong Y, Esfandiari H, Loewen NA. Outflow enhancement by three different ab interno trabeculectomy procedures in a porcine anterior segment model. Graefes Arch Clin Exp Ophthalmol 2018; 256:1305-1312. [PMID: 29721662 PMCID: PMC7804591 DOI: 10.1007/s00417-018-3990-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 03/29/2018] [Accepted: 04/11/2018] [Indexed: 12/11/2022] Open
Abstract
PURPOSE To evaluate three different microincisional ab interno trabeculectomy procedures in a porcine eye perfusion model. METHODS In perfused porcine anterior segments, 90° of trabecular meshwork (TM) was ablated using the Trabectome (T; n = 8), Goniotome (G; n = 8), or Kahook device (K; n = 8). After 24 h, additional 90° of TM was removed. Intraocular pressure (IOP) and outflow facility were measured at 5 and 10 μl/min perfusion to simulate an elevated IOP. Structure and function were assessed with canalograms and histology. RESULTS At 5 μl/min infusion rate, T resulted in a greater IOP reduction than G or K from baseline (76.12% decrease versus 48.19% and 47.96%, P = 0.013). IOP reduction between G and K was similar (P = 0.420). Removing another 90° of TM caused an additional IOP reduction only in T and G but not in K. Similarly, T resulted in the largest increase in outflow facility at 5 μl/min compared with G and K (first ablation, 3.41 times increase versus 1.95 and 1.87; second ablation, 4.60 versus 2.50 and 1.74) with similar results at 10 μl/min (first ablation, 3.28 versus 2.29 and 1.90 (P = 0.001); second ablation, 4.10 versus 3.01 and 2.01 (P = 0.001)). Canalograms indicated circumferential flow beyond the ablation endpoints. CONCLUSIONS T, G, and K significantly increased the outflow facility. In this model, T had a larger effect than G and K.
Collapse
Affiliation(s)
- Yalong Dang
- Department of Ophthalmology, University of Pittsburgh School of Medicine, 203 Lothrop St, Suite 819, Pittsburgh, PA, 15213, USA
| | - Chao Wang
- Department of Ophthalmology, University of Pittsburgh School of Medicine, 203 Lothrop St, Suite 819, Pittsburgh, PA, 15213, USA
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China
| | - Priyal Shah
- Department of Ophthalmology, University of Pittsburgh School of Medicine, 203 Lothrop St, Suite 819, Pittsburgh, PA, 15213, USA
- Institute of Ophthalmology and Visual Science, Rutgers New Jersey Medical School, Newark, NJ, USA
| | - Susannah Waxman
- Department of Ophthalmology, University of Pittsburgh School of Medicine, 203 Lothrop St, Suite 819, Pittsburgh, PA, 15213, USA
| | - Ralitsa T Loewen
- Department of Ophthalmology, University of Pittsburgh School of Medicine, 203 Lothrop St, Suite 819, Pittsburgh, PA, 15213, USA
| | - Ying Hong
- Department of Ophthalmology, University of Pittsburgh School of Medicine, 203 Lothrop St, Suite 819, Pittsburgh, PA, 15213, USA
| | - Hamed Esfandiari
- Department of Ophthalmology, University of Pittsburgh School of Medicine, 203 Lothrop St, Suite 819, Pittsburgh, PA, 15213, USA
| | - Nils A Loewen
- Department of Ophthalmology, University of Pittsburgh School of Medicine, 203 Lothrop St, Suite 819, Pittsburgh, PA, 15213, USA.
| |
Collapse
|
22
|
Yoshikawa M, Akagi T, Uji A, Nakanishi H, Kameda T, Suda K, Ikeda HO, Tsujikawa A. Pilot study assessing the structural changes in posttrabecular aqueous humor outflow pathway after trabecular meshwork surgery using swept-source optical coherence tomography. PLoS One 2018; 13:e0199739. [PMID: 29953502 PMCID: PMC6023224 DOI: 10.1371/journal.pone.0199739] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 06/13/2018] [Indexed: 11/19/2022] Open
Abstract
This study evaluated the morphological change in aqueous humor outflow (AHO) pathways using swept-source optical coherence tomography (SS-OCT) volumetric scans in glaucoma patients before and after glaucoma surgery. In this prospective observational case series, 15 eyes (13 patients) with glaucoma were treated with 120-degree Trabectome or 360-degree suture trabeculotomy and followed up for 3 months. B-scan images of the posttrabecular AHO pathway were reconstructed and the pathway areas were evaluated, before and after surgery. Changes in posttrabecular AHO pathway were qualitatively classified as “increased”, “non-significant change”, and “decreased” on reconstructed B-scan images. Quantitative measurements of the posttrabecular AHO pathway areas were performed pre- and postoperatively. Factors associated with both qualitative and quantitative changes in AHO pathway were investigated. From 30 regions (15 nasal and 15 temporal regions) in the 15 eyes, AHO pathways were analyzable in 20 regions pre- and postoperatively. Qualitative assessments of the pathway changes were “increased” in 8 regions, “non-significant change” in 9 regions, and “decreased” in 3 regions. Quantitative assessments of the average pathway area did not change significantly (from 3155±1633 pixels preoperatively to 3212±1684 pixels postoperatively, P = 0.50). All parameters relating to intraocular pressure changes or the surgical location were not associated with postoperative AHO pathway change. The intrascleral AHO pathway could be well visualized in glaucoma patients pre- and postoperatively using swept-source optical coherence tomography. However, structural changes in the AHO pathway assessed by SS-OCT were not significant after trabecular-targeted glaucoma surgery. Functional assessments of AHO are needed in future studies.
Collapse
Affiliation(s)
- Munemitsu Yoshikawa
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Tadamichi Akagi
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
- * E-mail:
| | - Akihito Uji
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Hideo Nakanishi
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Takanori Kameda
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Kenji Suda
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Hanako Ohashi Ikeda
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Akitaka Tsujikawa
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| |
Collapse
|
23
|
Dang Y, Waxman S, Wang C, Loewen RT, Sun M, Loewen NA. A porcine ex vivo model of pigmentary glaucoma. Sci Rep 2018; 8:5468. [PMID: 29615741 PMCID: PMC5882895 DOI: 10.1038/s41598-018-23861-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 03/16/2018] [Indexed: 11/11/2022] Open
Abstract
Pigment dispersion can lead to pigmentary glaucoma, a poorly understood condition of younger myopic eyes with fluctuating high intraocular pressure. It has been difficult to investigate its pathogenesis without a model similar to human eyes in size and behavior. Here we present a porcine ex vivo model that recreates several features of pigmentary glaucoma, including intraocular hypertension, accumulation of pigment in the trabecular meshwork, and declining phagocytosis. We found that trabecular meshwork cells regulate outflow, form actin stress fibers, and have a decreased phagocytic activity. Gene expression microarrays and a pathway analysis of TM monolayers as well as ex vivo anterior segment perfusion cultures indicated that RhoA plays a central role in regulating the cytoskeleton, motility, and phagocytosis in the trabecular meshwork, providing new insights and targets to investigate in pigmentary glaucoma.
Collapse
Affiliation(s)
- Yalong Dang
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, United States of America
| | - Susannah Waxman
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, United States of America
| | - Chao Wang
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, United States of America
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha, China
| | - Ralitsa T Loewen
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, United States of America
| | - Ming Sun
- Department of Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, United States of America
| | - Nils A Loewen
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, United States of America.
| |
Collapse
|
24
|
Wecker T, van Oterendorp C, Reichardt W. Functional assessment of the aqueous humour distal outflow pathways in bovine eyes using time-of-flight magnetic resonance tomography. Exp Eye Res 2017; 166:168-173. [PMID: 29074388 DOI: 10.1016/j.exer.2017.10.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 10/16/2017] [Accepted: 10/16/2017] [Indexed: 11/29/2022]
Abstract
The major part of the aqueous humor leaves the eye through the "conventional outflow pathway", consisting of the trabecular meshwork, Schlemm's canal, collector channels, an intrasceral plexus and the episcleral veins. While the trabecular meshwork is well characterized, little is known about anatomical and functional features of the peripheral outflow tract beyond Schlemm's canal. The emergence of minimally-invasive glaucoma surgery directly targeting the outflow resistance in the trabecular meshwork has elicited growing interest in these structures. We used time-of-flight magnetic resonance imaging in ex vivo bovine eyes to map fluid flow under physiological conditions. We were able to identify the peripheral outflow vessels solely by the signal detected from the fluid flow inside their lumina. A question of clinical relevance is, whether localized opening of the trabecular meshwork leads to only localized or to a 360° increase in intrascleral flow. To address this, a goniotomy ab interno was performed in 3 eyes and the flow signal intensity was quantified sectorially. A significant increase in fluid flow was observed in the sector distal to the goniotomy (p = 0.0005) but not in the other sectors (p = 0.1). As a proof of concept we demonstrated that TOF-MRI based detection of flow in the peripheral aqueous outflow tract is feasible. The functional link observed between trabecular meshwork sectors and their distal outflow tract sectors may be relevant for minimally-invasive glaucoma surgery in humans.
Collapse
Affiliation(s)
- Thomas Wecker
- Eye Center, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Germany; Wecker Eye Center, Heilbronn, Germany.
| | | | - Wilfried Reichardt
- Medical Physics, Department of Radiology, Faculty of Medicine, University of Freiburg, Germany; German Consortium for Translational Cancer Research (DKTK), Heidelberg, Germany; German Cancer Research Center (DKFZ), Heidelberg, Germany
| |
Collapse
|
25
|
Huang AS, Francis BA, Weinreb RN. Structural and functional imaging of aqueous humour outflow: a review. Clin Exp Ophthalmol 2017; 46:158-168. [PMID: 28898516 DOI: 10.1111/ceo.13064] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 09/06/2017] [Indexed: 01/15/2023]
Abstract
Maintaining healthy aqueous humour outflow (AHO) is important for intraocular cellular health and stable vision. Impairment of AHO can lead to increased intraocular pressure, optic nerve damage and concomitant glaucoma. An improved understanding of AHO will lead to improved glaucoma surgeries that enhance native AHO as well as facilitate the development of AHO-targeted pharmaceuticals. Recent AHO imaging has evolved to live human assessment and has focused on the structural evaluation of AHO pathways and the functional documentation of fluid flow. Structural AHO evaluation is predominantly driven by optical coherence tomography, and functional evaluation of flow is performed using various methods, including aqueous angiography. Advances in structural and functional evaluation of AHO are reviewed with discussion of strengths, weaknesses and potential future directions.
Collapse
Affiliation(s)
- Alex S Huang
- Doheny Eye Institute, Los Angeles, California, USA.,Doheny Eye Centers, Department of Ophthalmology, David Geffen School of Medicine at University of California, Los Angeles, California, USA
| | - Brian A Francis
- Doheny Eye Institute, Los Angeles, California, USA.,Doheny Eye Centers, Department of Ophthalmology, David Geffen School of Medicine at University of California, Los Angeles, California, USA
| | - Robert N Weinreb
- Shiley Eye Institute and Hamilton Glaucoma Center, Department of Ophthalmology, University of California, San Diego, California, USA
| |
Collapse
|
26
|
Kostanyan T, Shazly T, Kaplowitz KB, Wang SZ, Kola S, Brown EN, Loewen NA. Longer-term Baerveldt to Trabectome glaucoma surgery comparison using propensity score matching. Graefes Arch Clin Exp Ophthalmol 2017; 255:2423-2428. [PMID: 28944413 DOI: 10.1007/s00417-017-3804-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 08/08/2017] [Accepted: 09/12/2017] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To apply propensity score matching to compare Baerveldt glaucoma drainage implant (BGI) to Trabectome-mediated ab interno trabeculectomy (AIT). Recent data suggests that AIT can produce results similar to BGI which is traditionally reserved for more severe glaucoma. METHODS BGI and AIT patients with at least 1 year of follow-up were included. The primary outcome measures were intraocular pressure (IOP), number of glaucoma medications, and a Glaucoma Index (GI) score. GI reflected glaucoma severity based on visual field, the number of preoperative medications, and preoperative IOP. Score matching used a genetic algorithm consisting of age, gender, type of glaucoma, concurrent phacoemulsification, baseline number of medications, and baseline IOP. Patients with neovascular glaucoma, with prior glaucoma surgery, or without a close match were excluded. RESULTS Of 353 patients, 30 AIT patients were matched to 29 BGI patients. Baseline characteristics including, IOP, the number of glaucoma medications, type of glaucoma, the degree of VF loss and GI were not significantly different between AIT and BGI. BGI had a preoperative IOP of 21.6 ± 6.3 mmHg compared to 21.5 ± 7.4 for AIT on 2.8 ± 1.1 medications and 2.5 ± 2.3 respectively. At 30 months, the mean IOP was 15.0 ± 3.9 mmHg for AIT versus 15.0 ± 5.7 mmHg for BGI (p > 0.05), while the number of drops was 1.5 ± 1.3 for AIT (change: p = 0.001) versus 2.4 ± 1.2 for BGI (change: p = 0.17; AIT vs BGI: 0.007). Success, defined as IOP < 21 mmHg, < 20% reduction and no reoperation, was achieved at 1 year in 56% of AIT versus 55% of BGI (p > 0.05) and 50% versus 52% at 2.5 years. CONCLUSIONS A propensity score matched comparison of AIT and BGI demonstrated a similar IOP reduction through 1 year. AIT required fewer medications.
Collapse
Affiliation(s)
- Tigran Kostanyan
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Tarek Shazly
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Kevin B Kaplowitz
- Department of Ophthalmology, VA Loma Linda, Loma Linda University, Loma Linda, CA, USA
| | - Steven Z Wang
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Sushma Kola
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Eric N Brown
- Department of Ophthalmology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Nils A Loewen
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, USA. .,Department of Ophthalmology, School of Medicine, University of Pittsburgh, 203 Lothrop St, Pittsburgh, PA, 15213, USA.
| |
Collapse
|
27
|
Adjunctive Imaging for Canal-based Glaucoma Surgery. Int Ophthalmol Clin 2017; 57:73-84. [PMID: 28885248 DOI: 10.1097/iio.0000000000000199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
28
|
Dang Y, Waxman S, Wang C, Jensen A, Loewen RT, Bilonick RA, Loewen NA. Freeze-thaw decellularization of the trabecular meshwork in an ex vivo eye perfusion model. PeerJ 2017; 5:e3629. [PMID: 28828244 PMCID: PMC5560227 DOI: 10.7717/peerj.3629] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 07/10/2017] [Indexed: 12/13/2022] Open
Abstract
Objective The trabecular meshwork (TM) is the primary substrate of outflow resistance in glaucomatous eyes. Repopulating diseased TM with fresh, functional TM cells might be a viable therapeutic approach. Decellularized TM scaffolds have previously been produced by ablating cells with suicide gene therapy or saponin, which risks incomplete cell removal or dissolution of the extracellular matrix, respectively. We hypothesized that improved trabecular meshwork cell ablation would result from freeze-thaw cycles compared to chemical treatment. Materials and Methods We obtained 24 porcine eyes from a local abattoir, dissected and mounted them in an anterior segment perfusion within two hours of sacrifice. Intraocular pressure (IOP) was recorded continuously by a pressure transducer system. After 72 h of IOP stabilization, eight eyes were assigned to freeze-thaw (F) ablation (−80 °C × 2), to 0.02% saponin (S) treatment, or the control group (C), respectively. The TM was transduced with an eGFP expressing feline immunodeficiency viral (FIV) vector and tracked via fluorescent microscopy to confirm ablation. Following treatment, the eyes were perfused with standard tissue culture media for 180 h. TM histology was assessed by hematoxylin and eosin staining. TM viability was evaluated by a calcein AM/propidium iodide (PI) assay. The TM extracellular matrix was stained with Picro Sirius Red. We measured IOP and modeled it with a linear mixed effects model using a B-spline function of time with five degrees of freedom. Results F and S experienced a similar IOP reduction of 30% from baseline (P = 0.64). IOP reduction of about 30% occurred in F within 24 h and in S within 48 h. Live visualization of eGFP demonstrated that F conferred a complete ablation of all TM cells and only a partial ablation in S. Histological analysis and Picro Sirius staining confirmed that no TM cells survived in F while the extracellular matrix remained. The viability assay showed very low PI and no calcein staining in F in contrast to many PI-labeled, dead TM cells and calcein-labeled viable TM cells in S. Conclusion We developed a rapid TM ablation method that uses cyclic freezing that is free of biological or chemical agents and able to produce a decellularized TM scaffold with preserved TM extracellular matrix in an organotypic perfusion culture.
Collapse
Affiliation(s)
- Yalong Dang
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PAUnited States of America
| | - Susannah Waxman
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PAUnited States of America
| | - Chao Wang
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PAUnited States of America.,Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha, China
| | - Adrianna Jensen
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PAUnited States of America
| | - Ralitsa T Loewen
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PAUnited States of America
| | - Richard A Bilonick
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PAUnited States of America
| | - Nils A Loewen
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PAUnited States of America
| |
Collapse
|
29
|
Wang C, Dang Y, Waxman S, Xia X, Weinreb RN, Loewen NA. Angle stability and outflow in dual blade ab interno trabeculectomy with active versus passive chamber management. PLoS One 2017; 12:e0177238. [PMID: 28486513 PMCID: PMC5423641 DOI: 10.1371/journal.pone.0177238] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 04/24/2017] [Indexed: 11/30/2022] Open
Abstract
Purpose To compare intraoperative angle stability and postoperative outflow of two ab interno trabeculectomy devices that excise the trabecular meshwork with or without active aspiration and irrigation. We hypothesized that anterior segment optical coherence tomography (AS-OCT) allows for a quantitative comparison of intraoperative angle stability in a microincisional glaucoma surgery (MIGS) pig eye training model. Methods Twelve freshly enucleated porcine eyes were measured with AS-OCT at baseline, at the beginning of the procedure and at its conclusion to determine the anterior chamber depth (ACD) and the nasal angle α in degrees. The right and left eye of pairs were randomly assigned to an active dual blade goniectome (aDBG) and a passive dual blade goniectome (pDBG) group, respectively. The aDBG had irrigation and aspiration ports while the pDBG required surgery under viscoelastic. We performed the procedures using our MIGS training system with a standard, motorized ophthalmic operating microscope. We estimated outflow by obtaining canalograms with fluorescent spheres. Results In aDBG, the nasal angle remained wide open during the procedure at above 90° and did not change towards the end (100±10%, p = 0.9). In contrast, in pDBG, ACD decreased by 51±19% to 21% below baseline (p<0.01) while the angle progressively narrowed by 40±12% (p<0.001). Canalograms showed a similar extent of access to the outflow tract with the aDBG and the pDBG (p = 0.513). The average increase for the aDBG in the superonasal and inferonasal quadrants was between 27 to 31% and for the pDBG between 15 to 18%. Conclusion AS-OCT demonstrated that active irrigation and aspiration improved anterior chamber maintenance and ease of handling with the aDBG in this MIGS training model. The immediate postoperative outflow was equally good with both devices.
Collapse
Affiliation(s)
- Chao Wang
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Yalong Dang
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Susannah Waxman
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Xiaobo Xia
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Robert N. Weinreb
- Shiley Eye Institute, Hamilton Glaucoma Center and Department of Ophthalmology, University of California San Diego, La Jolla, California, United States of America
| | - Nils A. Loewen
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- * E-mail:
| |
Collapse
|
30
|
Dang Y, Waxman S, Wang C, Parikh HA, Bussel II, Loewen RT, Xia X, Lathrop KL, Bilonick RA, Loewen NA. Rapid learning curve assessment in an ex vivo training system for microincisional glaucoma surgery. Sci Rep 2017; 7:1605. [PMID: 28487512 PMCID: PMC5431621 DOI: 10.1038/s41598-017-01815-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 04/12/2017] [Indexed: 11/17/2022] Open
Abstract
Increasing prevalence and cost of glaucoma have increased the demand for surgeons well trained in newer, microincisional surgery. These procedures occur in a highly confined space, making them difficult to learn by observation or assistance alone as is currently done. We hypothesized that our ex vivo outflow model is sensitive enough to allow computing individual learning curves to quantify progress and refine techniques. Seven trainees performed nine trabectome-mediated ab interno trabeculectomies in pig eyes (n = 63). An expert surgeon rated the procedure using an Operating Room Score (ORS). The extent of outflow beds accessed was measured with canalograms. Data was fitted using mixed effect models. ORS reached a half-maximum on an asymptote after only 2.5 eyes. Surgical time decreased by 1.4 minutes per eye in a linear fashion. The ablation arc followed an asymptotic function with a half-maximum inflection point after 5.3 eyes. Canalograms revealed that this progress did not correlate well with improvement in outflow, suggesting instead that about 30 eyes are needed for true mastery. This inexpensive pig eye model provides a safe and effective microsurgical training model and allows objective quantification of outcomes for the first time.
Collapse
Affiliation(s)
- Yalong Dang
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Susannah Waxman
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Chao Wang
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
- The Third Xiangya Hospital of Central South University, Changsha, Hunan, China
- Xiangya School of Medicine, Central South University, Changsha, Hunan, China
| | - Hardik A Parikh
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Igor I Bussel
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Ralitsa T Loewen
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Xiaobo Xia
- Department of Ophthalmology, Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Kira L Lathrop
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Richard A Bilonick
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Nils A Loewen
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States.
| |
Collapse
|
31
|
Fallano K, Bussel I, Kagemann L, Lathrop KL, Loewen N. Training strategies and outcomes of ab interno trabeculectomy with the trabectome. F1000Res 2017; 6:67. [PMID: 28529695 PMCID: PMC5428488 DOI: 10.12688/f1000research.10236.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/20/2017] [Indexed: 11/05/2023] Open
Abstract
Plasma-mediated ab interno trabeculectomy with the trabectome was first approved by the US Food and Drug Administration in 2004 for use in adult and pediatric glaucomas. Since then, increased clinical experience and updated outcome data have led to its expanded use, including a range of glaucomas and angle presentations, previously deemed to be relatively contraindicated. The main benefits are a high degree of safety, ease, and speed compared to traditional filtering surgery and tube shunts. The increasing burden of glaucoma and expanding life expectancy has resulted in demand for well-trained surgeons. In this article, we discuss the results of trabectome surgery in standard and nonstandard indications. We present training strategies of the surgical technique that include a pig eye model, and visualization exercises that can be performed before and at the conclusion of standard cataract surgery in patients who do not have glaucoma. We detail the mechanism of enhancing the conventional outflow pathway and describe methods of visualization and function testing.
Collapse
Affiliation(s)
- Katherine Fallano
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Igor Bussel
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Larry Kagemann
- Food and Drug Administration, Silver Springs, MS, USA
- Department of Ophthalmology, New York University School of Medicine, New York, NY, USA
| | - Kira L. Lathrop
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Nils Loewen
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| |
Collapse
|
32
|
Fallano K, Bussel I, Kagemann L, Lathrop KL, Loewen N. Training strategies and outcomes of ab interno trabeculectomy with the trabectome. F1000Res 2017; 6:67. [PMID: 28529695 PMCID: PMC5428488 DOI: 10.12688/f1000research.10236.2] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/26/2017] [Indexed: 01/15/2023] Open
Abstract
Plasma-mediated ab interno trabeculectomy with the trabectome was first approved by the US Food and Drug Administration in 2004 for use in adult and pediatric glaucomas. Since then, increased clinical experience and updated outcome data have led to its expanded use, including a range of glaucomas and angle presentations, previously deemed to be relatively contraindicated. The main benefits are a high degree of safety, ease, and speed compared to traditional filtering surgery and tube shunts. The increasing burden of glaucoma and expanding life expectancy has resulted in demand for well-trained surgeons. In this article, we discuss the results of trabectome surgery in standard and nonstandard indications. We present training strategies of the surgical technique that include a pig eye model, and visualization exercises that can be performed before and at the conclusion of standard cataract surgery in patients who do not have glaucoma. We detail the mechanism of enhancing the conventional outflow pathway and describe methods of visualization and function testing.
Collapse
Affiliation(s)
- Katherine Fallano
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Igor Bussel
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Larry Kagemann
- Food and Drug Administration, Silver Springs, MS, USA
- Department of Ophthalmology, New York University School of Medicine, New York, NY, USA
| | - Kira L. Lathrop
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Nils Loewen
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| |
Collapse
|