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Oshiro A, Imanaga N, Terao N, Koizumi H. CHANGES IN SCLERAL THICKNESS IN THE ACUTE PHASE OF VOGT-KOYANAGI-HARADA DISEASE. Retina 2024; 44:1344-1350. [PMID: 39047128 DOI: 10.1097/iae.0000000000004129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/27/2024]
Abstract
PURPOSE To evaluate changes in scleral thickness in Vogt-Koyanagi-Harada (VKH) disease. METHODS This study included 34 eyes of 17 treatment-naïve patients with acute-phase VKH disease. Scleral thickness and the presence of ciliochoroidal effusion were examined using anterior segment optical coherence tomography at baseline and 1 week, 2 weeks, and 12 weeks after the start of corticosteroid treatment. Scleral thickness was measured 6 mm posterior to the scleral spur in four directions. RESULTS Twenty-eight eyes (82.4%) initially had ciliochoroidal effusion, but this rapidly decreased to nine eyes (26.5%) after 1 week. The sclera with ciliochoroidal effusion became thinner from baseline to 1 week at the superior (400.2 ± 46.9-353.5 ± 47.9 µm), temporal (428.4 ± 53.6-387.8 ± 56.1 µm), inferior (451.5 ± 71.0-400.5 ± 50.5 µm), and nasal (452.4 ± 78.0-407.6 ± 62.9 µm) points (P < 0.01 for all), and no further changes were observed. The sclera without ciliochoroidal effusion remained unchanged. CONCLUSION In VKH disease, eyes with ciliochoroidal effusion exhibited the maximum scleral thickness during the acute phase. This thickening responded rapidly to treatment and became thinner within 1 week. Inflammation in VKH disease may affect not only the choroid but also the sclera.
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Affiliation(s)
- Ayano Oshiro
- Department of Ophthalmology, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan
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Abstract
PURPOSE To evaluate thicknesses of sclera and lamina cribrosa (LC) in central retinal vein occlusion (CRVO). METHOD Thirty-two patients with CRVO (mean age 62.2 ± 11.6 years, women/men 18/14) and 35 age- and sex-matched healthy volunteers were included into the study. Scleral thickness was measured at scleral spur and at 1 to 3 mm from scleral spur in four quadrants (temporal, nasal, super, and inferior) using anterior segment optical coherence tomography. Lamina cribrosa was measured using optic disk enhanced depth imaging optical coherence tomography. RESULTS The sclera was thicker in affected eyes of the CRVO group than healthy subjects at scleral spur in four quadrants (738.7 ± 30.9 µm vs. 702 ± 30.8 µm in temporal, 700.4 ± 19.7 µm vs. 673 ± 13.7 µm in superior, 693 ± 19.3 µm vs. 665.3 ± 24.2 µm in nasal, 810.7 ± 28.9 µm vs. 784.5 ± 23.7 µm in inferior quadrants, respectively; P < 0.05 for all). Lamina cribrosa thickness in affected eyes of the CRVO group was significantly higher than that of healthy subjects (285.2 ± 12.7 µm vs. 266.4 ± 10.7 µm, respectively; P < 0.01). The correlation between scleral thickness and LC thickness was moderate at scleral spur of temporal and superior quadrants of affected eyes (r = 0.510 and r = 0.420, respectively). CONCLUSION Thicknesses of sclera and LC are increased in the CRVO, which may play a role in the pathogenesis of the disease.
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Conrady CD, Yeh S. A Review of Ocular Drug Delivery Platforms and Drugs for Infectious and Noninfectious Uveitis: The Past, Present, and Future. Pharmaceutics 2021; 13:1224. [PMID: 34452185 PMCID: PMC8399730 DOI: 10.3390/pharmaceutics13081224] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 08/03/2021] [Accepted: 08/05/2021] [Indexed: 12/11/2022] Open
Abstract
Uveitis refers to a broad group of inflammatory disorders of the eye that often require medical and surgical management to improve or stabilize vision and prevent vision-threatening pathological changes to the eye. Drug delivery to the eye to combat inflammation and subsequent complications from uveitic conditions is complex as there are multiple barriers to absorption limiting availability of the needed drug in the affected tissues. As such, there has been substantial interest in developing new drugs and drug delivery platforms to help reduce intraocular inflammation and its complications. In this review, we discuss the challenges of drug delivery, novel technologies recently approved for uveitis patient care and promising drug delivery platforms for uveitis and sequelae of ocular inflammation.
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Affiliation(s)
- Christopher D. Conrady
- Department of Ophthalmology and Visual Sciences, Truhlsen Eye Center, University of Nebraska Medical Center, Omaha, NE 68105, USA
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, MI 48105, USA
| | - Steven Yeh
- Department of Ophthalmology and Visual Sciences, Truhlsen Eye Center, University of Nebraska Medical Center, Omaha, NE 68105, USA
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Walker MK, Schornack MM, Vincent SJ. Anatomical and physiological considerations in scleral lens wear: Conjunctiva and sclera. Cont Lens Anterior Eye 2020; 43:517-528. [PMID: 32624363 DOI: 10.1016/j.clae.2020.06.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 06/17/2020] [Accepted: 06/18/2020] [Indexed: 12/20/2022]
Abstract
While scleral lenses have been fitted using diagnostic lenses or impression moulding techniques for over a century, recent advances in anterior segment imaging such as optical coherence tomography and corneo-scleral profilometry have significantly improved the current understanding of the anatomy of the anterior eye including the morphometry of the conjunctiva, sclera, and corneo-scleral junction, as well as the ocular surface shape and elevation. These technological advances in ocular imaging along with continual improvements and innovations in scleral lens design and manufacturing have led to a global increase in scleral lens prescribing. This review provides a comprehensive overview of the conjunctiva and sclera in the context of modern scleral lens practice, including anatomical variations in healthy and diseased eyes, the physiological impact of scleral lens wear, potential fitting challenges, and current approaches to lens modifications in order to minimise lens-induced complications and adverse ocular effects. Specific topics requiring further research are also discussed.
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Affiliation(s)
- Maria K Walker
- University of Houston College of Optometry, The Ocular Surface Institute, Houston, USA
| | | | - Stephen J Vincent
- Queensland University of Technology (QUT), Centre for Vision and Eye Research, School of Optometry and Vision Science, Contact Lens and Visual Optics Laboratory, Institute of Health and Biomedical Innovation, Queensland, Australia.
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Buckhurst HD, Gilmartin B, Lam A, Cubbidge RP, Logan NS. In vivo measures of anterior scleral resistance in humans with rebound tonometry. Ophthalmic Physiol Opt 2020; 40:472-481. [PMID: 32495401 DOI: 10.1111/opo.12695] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 04/10/2020] [Accepted: 04/14/2020] [Indexed: 11/30/2022]
Abstract
PURPOSE To measure regional variations in anterior scleral resistance (ASR) using a ballistic rebound tonometer (RBT) and examine whether the variations are significantly affected by ethnicity and refractive error (RE). METHODS ASR was measured using a RBT (iCare TA01) following calibration against the biomechanical properties of agarose biogels. Eight scleral regions (nasal, temporal, superior, inferior, inferior-nasal, inferior-temporal, superior-nasal and superior-temporal) were measured at locations 4mm from the limbus. Subjects were 130 young adults comprising three ethnic groups whose RE distributions [MSE (D) ± S.D.] incorporated individuals categorised as without-myopia (NM; MSE ≥ -0.50) and with-myopia (WM; MSE < -0.50); British-White (BW): 26 NM + 0.52 ± 1.15D; 22 WM -3.83 ± 2.89D]; British-South-Asian (BSA): [9 NM + 0.49 ± 1.06D; 11 WM -5.07 ± 3.76D; Hong-Kong-Chinese (HKC): [11 NM + 0.39 ± 0.66D; 49 WM -4.46 ± 2.70D]. Biometric data were compiled using cycloplegic open-field autorefraction and the Zeiss IOLMaster. Two- and three-way repeated measures analysis of variances (anovas) tested regional differences for RBT values across both refractive status and ethnicity whilst stepwise forward multiple linear regression was used as an exploratory test. RESULTS Significant regional variations in ASR were identified for the BW, BSA and HKC (p < 0.001) individuals; superior-temporal region showed the lowest levels of resistance whilst the inferior-nasal region the highest. Compared to the BW and BSA groups, the HKC subjects displayed a significant increase in mean resistance for each respective region (p < 0.001). With the exception of the inferior region, ethnicity was found to be the chief predictor for variation in the scleral RBT values for all other regions. Mean RE group differences were insignificant. CONCLUSIONS The novel application of RBT to the anterior sclera confirm regional variation in ASR. Greater ASR amongst the HKC group than the BW and BSA individuals suggests that ethnic differences in anterior scleral biomechanics may exist.
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Affiliation(s)
- Hetal D Buckhurst
- Eye and Vision Research Group, School of Health Professions, Faculty of Health, Plymouth University, Plymouth, UK
| | | | - Andrew Lam
- School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong
| | | | - Nicola S Logan
- School of Life & Health Sciences, Aston University, Birmingham, UK
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Woodman-Pieterse EC, Read SA, Collins MJ, Alonso-Caneiro D. Anterior scleral thickness changes with accommodation in myopes and emmetropes. Exp Eye Res 2018; 177:96-103. [DOI: 10.1016/j.exer.2018.07.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2018] [Revised: 06/07/2018] [Accepted: 07/20/2018] [Indexed: 11/24/2022]
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Scleral changes with accommodation. Ophthalmic Physiol Opt 2017; 37:263-274. [DOI: 10.1111/opo.12377] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 02/21/2017] [Indexed: 11/26/2022]
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Anterior eye tissue morphology: Scleral and conjunctival thickness in children and young adults. Sci Rep 2016; 6:33796. [PMID: 27646956 PMCID: PMC5028711 DOI: 10.1038/srep33796] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Accepted: 09/01/2016] [Indexed: 12/11/2022] Open
Abstract
The sclera and conjunctiva form part of the eye's tough, protective outer coat, and play important roles in the eye's mechanical protection and immune defence, as well as in determining the size and shape of the eye globe. Advances in ocular imaging technology now allow these tissues in the anterior eye to be imaged non-invasively and with high resolution, however there is a paucity of data examining the dimensions of these tissues in paediatric populations. In this study, we have used optical coherence tomography (OCT) imaging to examine the normal in vivo thickness profile of the anterior sclera and overlying conjunctiva in 111 healthy young participants, including a large proportion of paediatric subjects. We demonstrate that the thickness of the anterior sclera varies significantly with measurement location and meridian. Tissue thickness also varied significantly with age, with younger subjects exhibiting significantly thinner scleras and significantly greater conjunctival thickness. Males were also found to exhibit significantly greater scleral thickness. Refractive error however was not significantly associated with either scleral or conjunctival thickness in this population. These findings provide new data describing the normative dimensions of anterior eye tissues in children and the factors that can influence these dimensions in young populations.
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Read SA, Alonso-Caneiro D, Free KA, Labuc-Spoors E, Leigh JK, Quirk CJ, Yang ZYL, Vincent SJ. Diurnal variation of anterior scleral and conjunctival thickness. Ophthalmic Physiol Opt 2016; 36:279-89. [PMID: 26931410 DOI: 10.1111/opo.12288] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 01/25/2016] [Indexed: 11/30/2022]
Abstract
PURPOSE To examine whether anterior scleral and conjunctival thickness undergoes significant diurnal variation over a 24-h period. METHODS Nineteen healthy young adults (mean age 22 ± 2 years) with minimal refractive error (mean spherical equivalent refraction -0.08 ± 0.39 D), had measures of anterior scleral and conjunctival thickness collected using anterior segment optical coherence tomography (AS-OCT) at seven measurement sessions over a 24-h period. The thickness of the temporal anterior sclera and conjunctiva were determined at six locations (each separated by 0.5 mm) at varying distances from the scleral spur (SS) for each subject at each measurement session. RESULTS Both the anterior sclera and conjunctiva were found to undergo significant diurnal variations in thickness over a 24-h period (both p < 0.01). The sclera and conjunctiva exhibited a similar pattern of diurnal change, with a small magnitude thinning observed close to midday, and a larger magnitude thickening observed in the early morning immediately after waking. The amplitude of diurnal thickness change was larger in the conjunctiva (mean amplitude 69 ± 29 μm) compared to the sclera (21 ± 8 μm). The conjunctiva exhibited its smallest magnitude of change at the SS location (mean amplitude 56 ± 17 μm) whereas the sclera exhibited its largest magnitude of change at this location (52 ± 21 μm). CONCLUSIONS This study provides the first evidence of diurnal variations occurring in the thickness of the anterior sclera and conjunctiva. Studies requiring precise measures of these anatomical layers should therefore take time of day into consideration. The majority of the observed changes occurred in the early morning immediately after waking and were of larger magnitude in the conjunctiva compared to the sclera. Thickness changes at other times of the day were of smaller magnitude and generally not statistically significant.
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Affiliation(s)
- Scott A Read
- Contact Lens and Visual Optics Laboratory, School of Optometry and Vision Science, Queensland University of Technology, Brisbane, Australia
| | - David Alonso-Caneiro
- Contact Lens and Visual Optics Laboratory, School of Optometry and Vision Science, Queensland University of Technology, Brisbane, Australia
| | - Kelly A Free
- Contact Lens and Visual Optics Laboratory, School of Optometry and Vision Science, Queensland University of Technology, Brisbane, Australia
| | - Elspeth Labuc-Spoors
- Contact Lens and Visual Optics Laboratory, School of Optometry and Vision Science, Queensland University of Technology, Brisbane, Australia
| | - Jaron K Leigh
- Contact Lens and Visual Optics Laboratory, School of Optometry and Vision Science, Queensland University of Technology, Brisbane, Australia
| | - Charlotte J Quirk
- Contact Lens and Visual Optics Laboratory, School of Optometry and Vision Science, Queensland University of Technology, Brisbane, Australia
| | - Zoe Y-L Yang
- Contact Lens and Visual Optics Laboratory, School of Optometry and Vision Science, Queensland University of Technology, Brisbane, Australia
| | - Stephen J Vincent
- Contact Lens and Visual Optics Laboratory, School of Optometry and Vision Science, Queensland University of Technology, Brisbane, Australia
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Buckhurst HD, Gilmartin B, Cubbidge RP, Logan NS. Measurement of Scleral Thickness in Humans Using Anterior Segment Optical Coherent Tomography. PLoS One 2015. [PMID: 26218188 PMCID: PMC4517791 DOI: 10.1371/journal.pone.0132902] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Anterior segment optical coherent tomography (AS-OCT, Visante; Zeiss) is used to examine meridional variation in anterior scleral thickness (AST) and its association with refractive error, ethnicity and gender. Scleral cross-sections of 74 individuals (28 males; 46 females; aged between 18-40 years (27.7±5.3)) were sampled twice in random order in 8 meridians: [superior (S), inferior (I), nasal (N), temporal (T), superior-temporal (ST), superior-nasal (SN), inferior-temporal (IT) and inferior-nasal (IN)]. AST was measured in 1mm anterior-to-posterior increments (designated the A-P distance) from the scleral spur (SS) over a 6mm distance. Axial length and refractive error were measured with a Zeiss IOLMaster biometer and an open-view binocular Shin-Nippon autorefractor. Intra- and inter-observer variability of AST was assessed for each of the 8 meridians. Mixed repeated measures ANOVAs tested meridional and A-P distance differences in AST with refractive error, gender and ethnicity. Only right eye data were analysed. AST (mean±SD) across all meridians and A-P distances was 725±46 μm. Meridian SN was the thinnest (662±57 μm) and I the thickest (806±60 μm). Significant differences were found between all meridians (p<0.001), except S:ST, IT:IN, IT:N and IN:N. Significant differences between A-P distances were found except between SS and 6 mm and between 2 and 4 mm. AST measurements at 1mm (682±48 μm) were the thinnest and at 6mm (818±49 μm) the thickest (p<0.001); a significant interaction occurred between meridians and A-P distances (p<0.001). AST was significantly greater (p<0.001) in male subjects but no significant differences were found between refractive error or ethnicity. Significant variations in AST occur with regard to meridian and distance from the SS and may have utility in selecting optimum sites for pharmaceutical or surgical intervention.
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Affiliation(s)
- Hetal D. Buckhurst
- Plymouth University, School of Health Professions, Peninsula Allied Health Centre, Derriford Road, Plymouth, United Kingdom
- * E-mail:
| | - Bernard Gilmartin
- Aston University, School of Life & Health Sciences, Birmingham, United Kingdom
| | - Robert P. Cubbidge
- Aston University, School of Life & Health Sciences, Birmingham, United Kingdom
| | - Nicola S Logan
- Aston University, School of Life & Health Sciences, Birmingham, United Kingdom
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Ebneter A, Häner NU, Zinkernagel MS. Metrics of the normal anterior sclera: imaging with optical coherence tomography. Graefes Arch Clin Exp Ophthalmol 2015; 253:1575-80. [PMID: 26067393 PMCID: PMC4548011 DOI: 10.1007/s00417-015-3072-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Revised: 05/17/2015] [Accepted: 05/25/2015] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND To investigate anterior scleral thickness in a cohort of healthy subjects using enhanced depth imaging anterior segment optical coherence tomography. METHODS Observational case series. The mean scleral thickness in the inferonasal, inferotemporal, superotemporal, and superonasal quadrant was measured 2 mm from the scleral spur on optical coherence tomography in healthy volunteers. RESULTS Fifty-three eyes of 53 Caucasian patients (25 male and 28 female) with an average age of 48.6 years (range: 18 to 92 years) were analysed. The mean scleral thickness was 571 μm (SD 84 μm) in the inferonasal quadrant, 511 μm (SD 80 μm) in the inferotemporal quadrant, 475 (SD 81 μm) in the superotemporal, and 463 (SD 64 μm) in the superonasal quadrant. The mean scleral thickness was significantly different between quadrants (p < 0.0001, repeated measures one-way ANOVA). The association between average scleral thickness and age was statistically significant (p < 0.0001, Pearson r = 0.704). CONCLUSIONS Enhanced depth imaging optical coherence tomography revealed the detailed anatomy of the anterior sclera and enabled non-invasive measurements of scleral thickness in a non-contact approach. The anterior scleral thickness varies significantly between quadrants, resembling the spiral of Tillaux. An association of increasing scleral thickness with age was found.
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Affiliation(s)
- Andreas Ebneter
- Department of Ophthalmology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland,
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Georgalas I, Koutsandrea C, Papaconstantinou D, Mpouritis D, Petrou P. Scleral melt following Retisert intravitreal fluocinolone implant. DRUG DESIGN DEVELOPMENT AND THERAPY 2014; 8:2373-5. [PMID: 25489235 PMCID: PMC4257017 DOI: 10.2147/dddt.s66634] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Intravitreal fluocinolone acetonide implant (Retisert) has a high potency, a low solubility, and a very short duration of action in the systemic circulation, enabling the steroid pellet to be small and reducing the risk of systemic side effects. Scleral melt has not been reported as a possible complication of Retisert implant. The authors describe the occurrence of scleral melt 18 months after the implantation of fluocinolone acetonide implant in a 42-year-old Caucasian woman. To the authors' knowledge, this is the first report of this possible complication.
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Affiliation(s)
- Ilias Georgalas
- Ophthalmology Department, University of Athens, Athens, Greece
| | | | | | | | - Petros Petrou
- Ophthalmology Department, University of Athens, Athens, Greece ; Moorfields Eye Hospital, London, UK
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14
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Fusco S, Ullrich F, Pokki J, Chatzipirpiridis G, Özkale B, Sivaraman KM, Ergeneman O, Pané S, Nelson BJ. Microrobots: a new era in ocular drug delivery. Expert Opin Drug Deliv 2014; 11:1815-26. [DOI: 10.1517/17425247.2014.938633] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Stefano Fusco
- Institute of Robotics and Intelligent Systems, ETH Zurich,
Tannenstrasse 3, Zurich, 8037, Switzerland
| | - Franziska Ullrich
- Institute of Robotics and Intelligent Systems, ETH Zurich,
Tannenstrasse 3, Zurich, 8037, Switzerland
| | - Juho Pokki
- Institute of Robotics and Intelligent Systems, ETH Zurich,
Tannenstrasse 3, Zurich, 8037, Switzerland
| | - George Chatzipirpiridis
- Institute of Robotics and Intelligent Systems, ETH Zurich,
Tannenstrasse 3, Zurich, 8037, Switzerland
| | - Berna Özkale
- Institute of Robotics and Intelligent Systems, ETH Zurich,
Tannenstrasse 3, Zurich, 8037, Switzerland
| | - Kartik M Sivaraman
- Institute of Robotics and Intelligent Systems, ETH Zurich,
Tannenstrasse 3, Zurich, 8037, Switzerland
| | - Olgaç Ergeneman
- Institute of Robotics and Intelligent Systems, ETH Zurich,
Tannenstrasse 3, Zurich, 8037, Switzerland
| | - Salvador Pané
- Institute of Robotics and Intelligent Systems, ETH Zurich,
Tannenstrasse 3, Zurich, 8037, Switzerland
| | - Bradley J Nelson
- Institute of Robotics and Intelligent Systems, ETH Zurich,
Tannenstrasse 3, Zurich, 8037, Switzerland
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Abstract
Purpose To obtain information about scleral thickness in different ocular regions and its associations. Methods The histomorphometric study included 238 human globes which had been enucleated because of choroidal melanomas or due to secondary angle-closure glaucoma. Using light microscopy, anterior-posterior pupil-optic nerve sections were measured. Results In the non-axially elongated group (axial length ≤26 mm), scleral thickness decreased from the limbus (0.50±0.11 mm) to the ora serrata (0.43±0.14 mm) and the equator (0.42±0.15 mm), and then increased to the midpoint between posterior pole and equator (0.65±0.15 mm) and to the posterior pole (0.94±0.18 mm), from where it decreased to the peri-optic nerve region (0.86±0.21 mm) and finally the peripapillary scleral flange (0.39±0.09 mm). Scleral thickness was significantly lower in the axially elongated group (axial length >26 mm) than in the non-axially elongated group for measurements taken at and posterior to the equator. Scleral thickness measurements of the posterior pole and of the peripapillary scleral flange were correlated with lamina cribrosa thickness measurements. Scleral thickness measurements at any location of examination were not significantly (all P>0.10) correlated with corneal thickness measurements. Scleral thickness was statistically independent of age, gender and presence of glaucoma. Conclusions In non-axially elongated eyes, the sclera was thickest at the posterior pole, followed by the peri-optic nerve region, the midpoint between posterior pole and equator, the limbus, the ora serrata, the equator and finally the peripapillary scleral flange. In axially elongated eyes, scleral thinning occurred at and posterior to the equator, being more marked closer to the posterior pole and the longer the axial length was. Within the anterior and posterior segment respectively, scleral thickness measurements were correlated with each other. Posterior scleral thickness was correlated with lamina cribrosa thickness. Scleral thickness measurements at any location of examination were not significantly correlated with corneal thickness or with age, gender and presence of absolute secondary angler-closure glaucoma.
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Affiliation(s)
- Sujiv Vurgese
- Department of Ophthalmology, Medical Faculty Mannheim, Ruprecht-Karls-University Heidelberg, Heidelberg, Germany
| | - Songhomitra Panda-Jonas
- Department of Ophthalmology, Medical Faculty Mannheim, Ruprecht-Karls-University Heidelberg, Heidelberg, Germany
| | - Jost B. Jonas
- Department of Ophthalmology, Medical Faculty Mannheim, Ruprecht-Karls-University Heidelberg, Heidelberg, Germany
- * E-mail:
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16
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Current world literature. Curr Opin Ophthalmol 2011; 22:523-9. [PMID: 22005482 DOI: 10.1097/icu.0b013e32834cb7d7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Patel H, Gilmartin B, Cubbidge RP, Logan NS. In vivo measurement of regional variation in anterior scleral resistance to Schiotz indentation. Ophthalmic Physiol Opt 2011; 31:437-43. [PMID: 21504438 DOI: 10.1111/j.1475-1313.2011.00840.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
PURPOSE Recent studies indicate that ocular and scleral rigidity is pertinent to our understanding of glaucoma, age related macular degeneration and the development and pathogenesis of myopia. The principal method of measuring ocular rigidity is by extrapolation of data from corneal indentation tonometry (K(o) ) using Friedenwald's transformation algorithms. Using scleral indentation (Schiotz tonometry) we assess whether regional variations in resistance to indentation occur in vivo across the human anterior globe directly, with reference to the deflection of Schiotz scale readings. METHODS Data were collected from both eyes of 26 normal young adult subjects with a range of refractive error (mean spherical equivalent ± S.D. of -1.77 D ± 3.28 D, range -10.56 to +4.38 D). Schiotz tonometry (5.5 g & 7.5 g) was performed on the cornea and four scleral quadrants; supero-temporal (ST) and -nasal (SN), infero-temporal (IT) and -nasal (IN) approximately 8 mm posterior to the limbus. RESULTS Values of K(o) (mm(3) )(-1) were consistent with those previously reported (mean 0.0101 ± 0.0082, range 0.0019-0.0304). In regards to the sclera, significant differences (p < 0.001) were found across quadrants with indentation readings for both loads between means for the cornea and ST; ST and SN; ST and IT, ST and IN. Mean (±S.D.) scale readings for 5.5 g were: cornea 5.93 ± 1.14, ST 8.05 ± 1.58, IT 7.03 ± 1.86, SN 6.25 ± 1.10, IN 6.02 ± 1.49; and 7.5 g: cornea 9.26 ± 1.27, ST 11.56 ± 1.65, IT 10.31 ± 1.74, SN 9.91 ± 1.20, IN 9.50 ± 1.56. CONCLUSIONS Significant regional variation was found in the resistance of the anterior sclera to indentation produced by the Schiotz tonometer.
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Affiliation(s)
- Hetal Patel
- Ophthalmic Research Group, School of Life & Health Sciences, Aston University, Birmingham, UK.
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