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Yang Z, Yang K, Li Z, Hu Y, Jiang J, Tang X, Zeng J, Wang M, Yang X. Using three-dimensional modelling of the anterior sclera to investigate the scleral profile in myopic eyes. Ophthalmic Physiol Opt 2024; 44:219-228. [PMID: 37811684 DOI: 10.1111/opo.13235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Revised: 09/06/2023] [Accepted: 09/12/2023] [Indexed: 10/10/2023]
Abstract
PURPOSE This study used three-dimensional (3D) modelling to investigate scleral profiles in myopic eyes and compare them with emmetropic eyes. METHODS In this prospective observational study, the eyes of 151 participants were analysed using the corneoscleral profile module (CSP) of the Pentacam HR. Non-rotationally symmetrical ellipsoids were fitted to the anterior scleral sagittal height. Three radii were analysed, namely the nasal-temporal (Rx), superior-inferior (Ry) and anterior-posterior (Rz) orientations. Additionally, the area index (AI) and aspherical parameters (Qxy, Qxz and Qyz) of the anterior sclera-fitted ellipsoid (ASFE) were quantified. RESULTS The findings showed an increase in Rx (-0.349 mm/D), Ry (-0.373 mm/D), Rz (-1.232 mm/D) and AI (-36.165 mm2 /D) with increasing myopia. From emmetropia to high myopia, the vertical and horizontal planes of the anterior sclera became increasingly prolate (emmetropia, Qxz: 0.02, Qyz: 0.01; low myopia, Qxz: -0.28, Qyz: -0.28; high myopia, Qxz: -0.41, Qyz: -0.43). There were no significant differences in the coronal plane across the three groups (H = 2.65, p = 0.27). The anterior scleral shape of high myopes in the horizontal and vertical planes was more prolate than that of emmetropes and low myopes (Qxz, high myopes vs. low myopes: p = 0.03, high myopes vs. emmetropes: p < 0.001; Qyz, high myopes vs. low myopes: p = 0.04, high myopes vs. emmetropes: p < 0.001). CONCLUSIONS As the degree of myopia increased, non-uniform anterior scleral enlargement was observed. These findings provide a better understanding of the anterior segment with varying degrees of myopia.
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Affiliation(s)
- Zhengfei Yang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - KaiQi Yang
- Faculty of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an, China
| | - Zhouyue Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Yin Hu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Jinyun Jiang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xianghua Tang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - JunWen Zeng
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Mengyi Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xiao Yang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
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Bandlitz S, Lagodny M, Kurz C, Wolffsohn JS. Anterior ocular surface sagittal height prediction. Ophthalmic Physiol Opt 2022; 42:1023-1031. [PMID: 35703419 DOI: 10.1111/opo.13017] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 05/16/2022] [Accepted: 05/16/2022] [Indexed: 11/29/2022]
Abstract
PURPOSE To investigate the validity of Placido-based corneal topography parameters to predict corneoscleral sagittal heights measured by Fourier-based profilometry at various diameters. METHODS Minimal (Minsag ), maximal (Maxsag ) sagittal height, toricity (Maxsag - Minsag ) and axis of the flattest meridian (Minsag ) of 36 subjects (mean age 25.4 SD ± 3.2 years; 21 female) were measured using the Eye Surface Profiler and analysed for diameters (chord length) of 8 to 16 mm (in 2-mm intervals). Furthermore, corneal central radii, corneal astigmatism, eccentricity and diameter were measured using the Keratograph 5 M. RESULTS Using multiple linear regression analysis, the best equation for predicting the sagittal heights for 8 mm (r2 = 0.95), and 10 mm (r2 = 0.93) diameters included corneal central radii and eccentricity. The best equation for predicting sagittal heights for 12 mm (r2 = 0.86), 14 mm (r2 = 0.78) and 16 mm (r2 = 0.65) diameters included corneal central radii, eccentricity and corneal diameter. Corneal astigmatism was significantly correlated with sagittal height toricity for 8 and 10 mm diameters (r2 = 0.50 and 0.29; p < 0.01), while no correlation was observed for 12, 14 and 16 mm diameters (p = 0.18 to p = 0.76). The axis of the flattest corneal meridian measured by Placido-based topography was significantly correlated with the axis of the flattest meridian measured by Fourier-based profilometry for 8, 10 and 12 mm diameters (r2 = 0.17 to 0.44; p < 0.05), while there was no correlation for 14 and 16 mm diameters (p = 0.48 and p = 0.75). For a typical soft contact lens diameter of 14 mm, 78% of the variance could be determined with a corneal topographer and 68% with keratometry and corneal diameter measurement. CONCLUSIONS The combination of corneal central radii, eccentricity and corneal diameter measured by Placido-based topography is a valid predictor of the corneoscleral sagittal height in healthy eyes. Scleral toricity and axis of the flattest meridian seem to be independent from Placido-based corneal parameters and requires additional measuring tools.
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Affiliation(s)
- Stefan Bandlitz
- Höhere Fachschule für Augenoptik Köln (Cologne School of Optometry), Cologne, Germany.,School of Life and Health Sciences, Aston University, Birmingham, UK
| | - Matthias Lagodny
- Höhere Fachschule für Augenoptik Köln (Cologne School of Optometry), Cologne, Germany
| | - Corinna Kurz
- Höhere Fachschule für Augenoptik Köln (Cologne School of Optometry), Cologne, Germany
| | - James S Wolffsohn
- School of Life and Health Sciences, Aston University, Birmingham, UK
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Macedo-de-Araújo RJ, Fadel D, Barnett M. How Can We Best Measure the Performance of Scleral Lenses? Current Insights. CLINICAL OPTOMETRY 2022; 14:47-65. [PMID: 35418790 PMCID: PMC9000539 DOI: 10.2147/opto.s284632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 03/24/2022] [Indexed: 06/14/2023]
Abstract
Scleral lenses (SLs) present several unique advantageous characteristics for patients. As these lenses are mainly fitted in severely diseased eyes, a thorough evaluation of the ocular surface before and after SL fitting and the on-eye SL fitting evaluation are essential and help minimize potential physiological complications. This review will explore the current and emerging techniques and instrumentation to best measure SL performance ensuring optimal lens fitting, visual quality, comfort and physiological responses, highlighting some potential complications and follow-up recommendations. A single physician could perform the great majority of evaluations. Still, the authors consider that the assessment of SL fitting should be a collaborative and multidisciplinary job, involving contact lens practitioners, ophthalmologists and the industry. This publication has reviewed the most up-to-date work and listed the most used techniques; however, the authors encourage the development of more evidence-based recommendations for SL clinical practice.
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Affiliation(s)
- Rute J Macedo-de-Araújo
- Clinical & Experimental Optometry Research Laboratory (CEORLab), Physics Centre of Minho and Porto Universities (CF-UM-UP), University of Minho, Braga, Portugal
| | | | - Melissa Barnett
- Davis Eye Center, University of California, Sacramento, CA, USA
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García de Oteyza G, Álvarez de Toledo J, Barraquer RI, Kling S. Refractive changes of a new asymmetric intracorneal ring segment with variable thickness and base width: A 2D finite-element model. PLoS One 2021; 16:e0257222. [PMID: 34525102 PMCID: PMC8443075 DOI: 10.1371/journal.pone.0257222] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Accepted: 08/25/2021] [Indexed: 12/02/2022] Open
Abstract
PURPOSE To evaluate the local geometric effects of a unilateral intrastromal ring segment with a combined variation of ring thickness and base width in a finite element simulation, and to compare it against the isolated effect of thickness or base width variation alone. METHODS A two-dimensional finite-element model of a transversely isotropic cornea was created assuming either axisymmetric stress or plane strain condition. The model geometry was composed of a three-layered corneal tissue (epithelium, anterior and posterior stroma) fixed at the limbus. The implantation of a triangular-shape asymmetric ring segment with varying ring thickness (150 to 300 μm) and base width (600 to 800 μm) was simulated. Also, changes induced by thickness or base width alone were studied and compared their combined effect in the asymmetric ring segment. Geometrical deformation of the simulated cornea and sagittal curvature were the main parameters of study. RESULTS Increasing ring thickness and base width along the arc of the asymmetric ring segment produced a more pronounced flattening in this part of the ring. The asymmetric design did find a good balance between maximizing corneal flattening at one end and minimizing it at the other end, compared to the isolated effect of ring thickness and width. Ring thickness was the most robust parameter in flattening both, the central and peripheral cornea. CONCLUSION The finite-element model permitted a theoretical study of corneal deformation undergoing implantation of realistic and hypothetical ring geometries. Intracorneal asymmetric ring segments with varying thickness and base width can be a good alternative in corneas with asymmetric keratoconus phenotypes.
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Affiliation(s)
- Gonzalo García de Oteyza
- Clínica Oftalmológica García de Oteyza, Barcelona, Spain
- Escuela de Doctorado, Universidad Autónoma de Barcelona (UAB), Barcelona, Spain
| | | | - Rafael I. Barraquer
- Centro de Oftalmología Barraquer, Barcelona, Spain
- Universitat Internacional de Catalunya (UIC), Barcelona, Spain
| | - Sabine Kling
- Department of Information Technology and Electrical Engineering, OPTIC Team, Computer-assisted Applications in Medicine Group, ETH Zurich, Zurich, Switzerland
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Vanhonsebrouck E, Consejo A, Coucke PJ, Leroy BP, Kreps EO. The corneoscleral shape in Marfan syndrome. Acta Ophthalmol 2021; 99:405-410. [PMID: 32996688 DOI: 10.1111/aos.14636] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 07/07/2020] [Accepted: 09/02/2020] [Indexed: 12/12/2022]
Abstract
PURPOSE To investigate the corneoscleral shape in Marfan syndrome (MFS) patients. METHODS Thirty eyes of 15 participants with molecularly proven MFS were included in this prospective, cross-sectional study. Optical biometry, Scheimpflug imaging, and corneoscleral topography (Eye Surface Profiler) were performed in all patients. Topographic data were compared to data from controls (25 emmetropes and 17 myopes). The raw three-dimensional anterior height data from MFS eyes and control eyes were exported for further analysis. Custom-made software was used to demarcate the limbal radius and to calculate the sagittal height in different concentric annuli centred at the corneal apex, placed in a pupil plane, for the central cornea (0-4 mm radius), peripheral cornea (4-6 mm radius) and sclera (6-8 mm radius) and the corneoscleral asymmetry. RESULTS Marfan syndrome (MFS) eyes had significantly lower values of mean sagittal height compared to non-MFS eyes in all three annuli (central cornea, corneal periphery and sclera (independent t-test, p < 0.01 except for the inferior area of the scleral radius: p > 0.05). The sclera was significantly more asymmetric in MFS eyes compared to myopes (independent t-test, p < 0.01 for both eyes), but similar to emmetropes (independent t-test, p = 0.17 and p = 0.93 for right and left eyes, respectively). In MFS eyes, scleral asymmetry was not found to be correlated with axial length (Pearson correlation coefficient, r < 0.30, p > 0.05). CONCLUSION The peripheral cornea and sclera of Marfan syndrome patients have a significantly different shape compared to healthy controls.
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Affiliation(s)
| | - Alejandra Consejo
- Institute of Physical Chemistry Polish Academy of Sciences Warsaw Poland
| | - Paul J. Coucke
- Center for Medical Genetics Ghent University Hospital Ghent Belgium
| | - Bart P. Leroy
- Department of Ophthalmology Ghent University Hospital Ghent Belgium
- Center for Medical Genetics Ghent University Hospital Ghent Belgium
- Division of Ophthalmology & Center for Cellular & Molecular Therapeutics Children’s Hospital of Philadelphia Philadelphia USA
| | - Elke O. Kreps
- Department of Ophthalmology Ghent University Hospital Ghent Belgium
- Faculty of Medical Sciences Antwerp University Antwerp Belgium
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6
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The corneoscleral shape in keratoconus patients with and without specialty lens wear. Cont Lens Anterior Eye 2021; 44:101343. [DOI: 10.1016/j.clae.2020.06.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Revised: 05/25/2020] [Accepted: 06/03/2020] [Indexed: 12/30/2022]
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Corneoscleral Topography Measured with Fourier-based Profilometry and Scheimpflug Imaging. Optom Vis Sci 2021; 97:766-774. [PMID: 32941338 DOI: 10.1097/opx.0000000000001572] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
SIGNIFICANCE Precise measurement of corneoscleral topography makes a valuable contribution to the understanding of anterior eye anatomy and supports the fitting process of contact lenses. Sagittal height data, determined by newer noninvasive techniques, are particularly useful for initial scleral lens selection. PURPOSE The purpose of this study was to investigate the agreement and repeatability of Fourier-based profilometry and Scheimpflug imaging, in the measurement of sagittal height and toricity of the corneoscleral region. METHODS Minimal (Minsag), maximal (Maxsag) sagittal height, toricity (Maxsag - Minsag), and the maximum possible measurement zone diameter of 38 subjects were compared using the Eye Surface Profiler (ESP; Eagle Eye, Houten, the Netherlands) and the corneoscleral profile module of the Pentacam (Oculus, Wetzlar, Germany) at two different sessions. Correlations between the instruments were analyzed using the Pearson coefficient. Differences between sessions and instruments were analyzed using Bland-Altman and paired t tests. RESULTS For an equal chord length, the measurement with Pentacam was significantly greater for Minsag (344 μm; 95% confidence interval [CI], 322 to 364 μm; P < .001) and significantly greater for Maxsag (280 μm; 95% CI, 256 to 305 μm; P < .001), but significantly smaller for toricity (-63 μm; 95% CI, -95 to -31 μm; P < .001). Maximum possible measurement zone diameter with ESP (16.4 ± 1.3 mm) was significantly greater than with Pentacam (14.8 ± 1.1 mm) (P < .001). Repeated measurements from session 1 and session 2 were not significantly different for Pentacam and ESP (P = .74 and P = .64, respectively). The 95% CIs around differences indicate good repeatability for Pentacam (mean difference, -0.9 μm; 95% CI, -6.7 to 4.8 μm) and ESP (4.6 μm; -22.4 to 31.6). CONCLUSIONS Although both instruments deliver useful data especially for the fitting of scleral and soft contact lenses, the sagittal height and the toricity measurements cannot be considered as interchangeable.
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Barnett M, Courey C, Fadel D, Lee K, Michaud L, Montani G, van der Worp E, Vincent SJ, Walker M, Bilkhu P, Morgan PB. CLEAR - Scleral lenses. Cont Lens Anterior Eye 2021; 44:270-288. [PMID: 33775380 DOI: 10.1016/j.clae.2021.02.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 02/01/2021] [Indexed: 12/25/2022]
Abstract
Scleral lenses were the first type of contact lens, developed in the late nineteenth century to restore vision and protect the ocular surface. With the advent of rigid corneal lenses in the middle of the twentieth century and soft lenses in the 1970's, the use of scleral lenses diminished; in recent times there has been a resurgence in their use driven by advances in manufacturing and ocular imaging technology. Scleral lenses are often the only viable form of contact lens wear across a range of clinical indications and can potentially delay the need for corneal surgery. This report provides a brief historical review of scleral lenses and a detailed account of contemporary scleral lens practice including common indications and recommended terminology. Recent research on ocular surface shape is presented, in addition to a comprehensive account of modern scleral lens fitting and on-eye evaluation. A range of optical and physiological challenges associated with scleral lenses are presented, including options for the clinical management of a range of ocular conditions. Future applications which take advantage of the stability of scleral lenses are also discussed. In summary, this report presents evidence-based recommendations to optimise patient outcomes in modern scleral lens practice.
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Affiliation(s)
- Melissa Barnett
- University of California, Davis Eye Center, Sacramento, CA, United States.
| | | | | | - Karen Lee
- University of Houston, College of Optometry, Houston, TX, United States
| | | | - Giancarlo Montani
- Università del Salento, Dipartimento di Matematica e Fisica CERCA, Lecce, Italy
| | - Eef van der Worp
- Eye-Contact-Lens Research & Education, Amsterdam, NL, Netherlands
| | - 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, Brisbane, Australia
| | - Maria Walker
- University of Houston, College of Optometry, Houston, TX, United States
| | - Paramdeep Bilkhu
- School of Optometry & Vision Science, Aston University, Birmingham, United Kingdom
| | - Philip B Morgan
- Eurolens Research, Division of Pharmacy and Optometry, University of Manchester, Manchester, United Kingdom
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Bataille L, Piñero DP. Characterization of the geometric properties of the sclero-conjunctival structure: a review. Int J Ophthalmol 2020; 13:1484-1492. [PMID: 32953590 DOI: 10.18240/ijo.2020.09.22] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 07/06/2020] [Indexed: 12/27/2022] Open
Abstract
To revise the peer-reviewed literature on geometric properties of the scleral-conjunctival structure in order to define their clinical relevance and the potential relationship between their changes and myopia development or progression. A bibliographic search focused on the study of the geometry of conjunctiva and/or sclera as well as those studies evaluating the relationship between geometric changes in the scleral-conjunctival structure and myopia was carried out. Several studies have been performed with different diagnostic technologies, including optical coherence tomography, profilometry and Scheimpflug imaging, to detect geometric changes of the scleral-conjunctival tissue in different physiological conditions of the eye, after use of contact lenses and in different ocular pathologies. Likewise, these technologies have been shown to be a valuable clinical tool to optimize scleral contact lens fitting. Future studies should investigate new potential clinical applications of such technologies, including the evaluation of anterior scleral changes related to myopia, as well as to define standardized clinical standard operating procedures for obtaining accurate and reproducible clinical measurement of the scleral-conjunctival morphology.
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Affiliation(s)
- Laurent Bataille
- Research and Development Department, VISSUM, Alicante 03016, Spain.,Group of Optics and Visual Perception, Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante 03690, Spain
| | - David P Piñero
- Group of Optics and Visual Perception, Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante 03690, Spain
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Scleral shape and its correlation with corneal parameters in keratoconus. Cont Lens Anterior Eye 2020; 44:101366. [DOI: 10.1016/j.clae.2020.08.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 08/21/2020] [Accepted: 08/26/2020] [Indexed: 11/19/2022]
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Anterior eye shape in emmetropes, low to moderate myopes, and high myopes. Cont Lens Anterior Eye 2020; 44:101361. [DOI: 10.1016/j.clae.2020.08.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Revised: 08/11/2020] [Accepted: 08/11/2020] [Indexed: 12/13/2022]
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12
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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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Abstract
PRéCIS:: The ultrasound ciliary plasty (UCP) procedure affects corneal parameters, although the effect is transient. Ultrasound energy affects the sclera, leading to induced astigmatism. The area of energy application correlates with the astigmatism axis. PURPOSE To assess the postoperative corneal topography for 1 year after UCP. MATERIALS AND METHODS In total, 78 patients with primary and secondary refractory glaucoma were enrolled in the study. The primary outcome measures were the corneal parameters obtained with anterior segment swept-source optical coherence tomography. Intraocular pressure, number of antiglaucoma medications, and best-corrected logMAR visual acuities were analyzed as secondary outcome measures. Measurements were performed preoperatively and at 1 week, and 1, 3, 6, and 12 months postoperatively. A total of 39 patients (39 eyes) completed the follow-up period of 12 months. RESULTS There was a significant difference in the anterior/posterior steep/flat keratometry and anterior/posterior astigmatism values immediately after UCP. However, 3 months postoperatively these parameters returned to their initial values and there were no significant differences noted. The mean±SD values of anterior astigmatism preoperatively and at 1 week, and 1, 3, 6, and 12 months postoperatively were 1.12±0.66 D, 2.17±0.91 D (P<0.001), 2.05±0.93 D (P<0.001), 1.55±0.75 D (P=0.004), 1.31±0.70 D (P=0.024), and 1.20±0.73 D (P=0.406), respectively. The astigmatism axis tended to approach 90 degrees meridian with a significant difference 1 week postoperatively. Central and minimal corneal thickness remained unchanged, whereas the intraocular pressure and the number of antiglaucoma medications decreased significantly. CONCLUSIONS UCP influenced the corneal topography parameters in the immediate postoperative period; however, with time, all parameters returned to their initial values.
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14
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Analysis of macular curvature in normal eyes using swept-source optical coherence tomography. Jpn J Ophthalmol 2020; 64:180-186. [DOI: 10.1007/s10384-020-00721-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 12/27/2019] [Indexed: 12/15/2022]
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15
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Consejo A, Rozema JJ. In vivo anterior scleral morphometry, axial length and myopia. Cont Lens Anterior Eye 2020; 43:21-25. [DOI: 10.1016/j.clae.2018.10.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 10/26/2018] [Accepted: 10/26/2018] [Indexed: 12/01/2022]
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Abass A, Lopes BT, Eliasy A, Salomao M, Wu R, White L, Jones S, Clamp J, Ambrósio R, Elsheikh A. Artefact-free topography based scleral-asymmetry. PLoS One 2019; 14:e0219789. [PMID: 31348792 PMCID: PMC6660081 DOI: 10.1371/journal.pone.0219789] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 07/01/2019] [Indexed: 12/18/2022] Open
Abstract
PURPOSE To present a three-dimensional non-parametric method for detecting scleral asymmetry using corneoscleral topography data that are free of edge-effect artefacts. METHODS The study included 88 participants aged 23 to 65 years (37.7±9.7), 47 women and 41 men. The eye topography data were exported from the Eye Surface Profiler software in MATLAB binary data container format then processed by custom built MATLAB codes entirely independent from the profiler software. Scleral asymmetry was determined initially from the unprocessed topography before being determined again after removing the edge-effect noise. Topography data were levelled around the limbus, then edge-effect was eliminated using a robust statistical moving median technique. In addition to comparing raw elevation data, scleral elevation was also compared through fitting a sphere to every single scleral surface and determining the relative elevation from the best-fit sphere reference surface. RESULTS When considering the averaged raw topography elevation data in the scleral section of the eye at radius 8 mm, the average raw elevations of the right eyes' sclera were -1.5±1.77, -1.87±2.12, -1.36±1.82 and -1.57±1.87 mm. In the left eyes at the same radius the average raw elevations were -1.62±1.78, -1.82±2.07, -1.28±1.76 and -1.68±1.93 mm. While, when considering the average raw elevation of the sclera after removing the edge effect, the average raw elevations of the right eyes were -3.71±0.25, -4.06±0.23, -3.95±0.19 and -3.95±0.23 mm. In the left eyes at the same radius the average raw elevations were -3.71±0.19, -3.97±0.22, -3.96±0.19 and -3.96±0.18 mm in the nasal, temporal, superior and inferior sides respectively. Maximum raw elevation asymmetry in the averaged scleral raw elevation was 1.6647±0.9015 mm in right eyes and 1.0358±0.6842 mm in left eyes, both detected at -38° to the nasal side. Best-fit sphere-based relative elevation showed that sclera is more elevated in three main meridians at angles -40°, 76°, and 170° in right eyes and -40°, 76°, and 170° in left eyes, all measured from the nasal meridian. Maximum recorded relative elevation asymmetries were 0.0844±0.0355 mm and 0.068±0.0607 mm at angular positions 76° and 63.5° for right and left eyes in turn. CONCLUSIONS It is not possible to use corneoscleral topography data to predict the scleral shape without considering a method of removing the edge-effect from the topography data. The nasal side of the sclera is higher than the temporal side, therefore, rotationally symmetric scleral contact lenses are more likely to be translated towards the temporal side. The scleral shape is best described by levelled raw elevation rather than relative elevation.
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Affiliation(s)
- Ahmed Abass
- School of Engineering, University of Liverpool, Liverpool, United Kingdom
- * E-mail:
| | - Bernardo T. Lopes
- School of Engineering, University of Liverpool, Liverpool, United Kingdom
- Federal University of São Paulo, São Paulo, Brazil
| | - Ashkan Eliasy
- School of Engineering, University of Liverpool, Liverpool, United Kingdom
| | | | - Richard Wu
- Central Taiwan University of Science and Technology, Taichung, Taiwan
- Pacific University, College of Optometry, Forest Grove, Oregon, United States of America
| | - Lynn White
- UltraVision CLPL, Leighton Buzzard, United Kingdom
| | - Steve Jones
- School of Engineering, University of Liverpool, Liverpool, United Kingdom
| | - John Clamp
- UltraVision CLPL, Leighton Buzzard, United Kingdom
| | - Renato Ambrósio
- Federal University of São Paulo, São Paulo, Brazil
- Federal University of the State of Rio de Janeiro, RJ, Brazil
| | - Ahmed Elsheikh
- School of Engineering, University of Liverpool, Liverpool, United Kingdom
- National Institute for Health Research (NIHR) Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, United Kingdom
- School of Biological Science and Biomedical Engineering, Beihang University, Beijing, China
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17
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Geometrical characterization of the corneo-scleral transition in normal patients with Fourier domain optical coherence tomography. Int Ophthalmol 2019; 39:2603-2609. [DOI: 10.1007/s10792-019-01109-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 04/29/2019] [Indexed: 11/26/2022]
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18
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Characterization of Corneoscleral Geometry Using Fourier Transform Profilometry in the Healthy Eye. Eye Contact Lens 2019; 45:201-207. [DOI: 10.1097/icl.0000000000000560] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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19
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Macedo-de-Araújo RJ, van der Worp E, González-Méijome JM. In vivo assessment of the anterior scleral contour assisted by automatic profilometry and changes in conjunctival shape after miniscleral contact lens fitting. JOURNAL OF OPTOMETRY 2019; 12:131-140. [PMID: 30393001 PMCID: PMC6449784 DOI: 10.1016/j.optom.2018.10.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 09/17/2018] [Accepted: 10/01/2018] [Indexed: 06/08/2023]
Abstract
PURPOSE To compare the shape of the anterior sclera of candidates to scleral lens (ScCL) fitting with regular and irregular corneas and analyze the changes induced in the shape of the sclero-conjunctiva after ScCL wear. METHODS Thirty-five eyes of 18 subjects (19 eyes with irregular corneas and 16 with regular corneas) were consecutively recruited. Three measures of sclero-conjunctival shape were taken with Eye Surface Profiler (ESP, Eaglet Eye, Houten, The Netherlands). Tangent angles and ocular sagittal heights (OC-SAG) were analyzed at different chords from 13 to 17mm in the nasal, temporal, superior and inferior regions. The 19 eyes with irregular cornea were selected to wear ScCL and the changes in their sclero-conjunctival surface parameters were compared before and after 3h of lens wear. RESULTS Irregular corneas showed higher OC-SAG values than regular corneas in all the chords analyzed, with statistical significant differences in the temporal region. Regarding tangent angles, regular corneas showed lower values (flatter surface), with statistical significant differences at 8 and 8.50mm on the nasal and 8.50mm on the temporal region. Some changes were seen in sclero-conjuctival shape after short-term ScCL wear. There was an augment in OC-SAG after 3h of scleral lens wear and a reduction on tangent angles, namely on the nasal region at 7.5mm and 8.00mm chord lengths, which is coincidental with the landing zone of ScCL. CONCLUSIONS ESP shows mild differences in scleral shape between eyes with regular and irregular corneas. ESP might be valuable in quantifying the mechanical impact of the ScCL on the anterior eye surface.
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Affiliation(s)
| | - Eef van der Worp
- Eye-Contact-Lens Research & Education, Amsterdam, The Netherlands
| | - José Manuel González-Méijome
- Clinical & Experimental Optometry Research Lab (CEORLab), Center of Physics, University of Minho, Braga, Portugal
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20
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Consejo A, Behaegel J, Van Hoey M, Iskander DR, Rozema JJ. Scleral asymmetry as a potential predictor for scleral lens compression. Ophthalmic Physiol Opt 2018; 38:609-616. [DOI: 10.1111/opo.12587] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 10/16/2018] [Indexed: 12/26/2022]
Affiliation(s)
- Alejandra Consejo
- Department of Ophthalmology; Antwerp University Hospital; Edegem Belgium
- Department of Medicine and Health Sciences; University of Antwerp; Antwerp Belgium
- Department of Biomedical Engineering; Wroclaw University of Science and Technology; Wroclaw Poland
| | - Joséphine Behaegel
- Department of Medicine and Health Sciences; University of Antwerp; Antwerp Belgium
- Department of Ophthalmology; Brussels University Hospital; Jette Belgium
| | - Maarten Van Hoey
- Department of Ophthalmology; Antwerp University Hospital; Edegem Belgium
| | - D Robert Iskander
- Department of Biomedical Engineering; Wroclaw University of Science and Technology; Wroclaw Poland
| | - Jos J Rozema
- Department of Ophthalmology; Antwerp University Hospital; Edegem Belgium
- Department of Medicine and Health Sciences; University of Antwerp; Antwerp Belgium
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