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Kim YW, Sharpe GP, Siber J, Keßler R, Fischer J, Otto T, Chauhan BC. Critical Impact of Working Distance on OCT Imaging: Correction of Optical Distortion and Its Effects on Measuring Retinal Curvature. Invest Ophthalmol Vis Sci 2024; 65:10. [PMID: 39374011 DOI: 10.1167/iovs.65.12.10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/08/2024] Open
Abstract
Purpose To assess the impact of working distance (WD) on optical distortion in optical coherence tomography (OCT) imaging and to evaluate the effectiveness of optical distortion correction in achieving consistent retinal Bruch's membrane (BM) layer curvature, regardless of variations in WD. Methods Ten subjects underwent OCT imaging with four serial macular volume scans, each employing distinct WD settings adjusted by balancing the sample and reference arm of the OCT interferometer (eye length settings changed). Either of two types of 30° standard objectives (SOs) was used. A ray tracing model was used to correct optical distortion, and BM layer curvature (represented as the second derivative of the curve) was measured. Linear mixed effects (LME) modeling was used to analyze factors associated with BM layer curvature, both before and after distortion correction. Results WD exhibited significant associations with axial length (β = -1.35, P < 0.001), SO type (P < 0.001), and eye length settings (P < 0.001). After optical distortion correction, the mean ± SD BM layer curvature significantly increased from 16.80 ± 10.08 µm-1 to 49.31 ± 7.50 µm-1 (P < 0.001). The LME model showed a significant positive association between BM layer curvature and WD (β = 1.94, P < 0.001). After distortion correction, the percentage change in BM layer curvature due to a 1-mm WD alteration decreased from 9.75% to 0.25%. Conclusions Correcting optical distortion in OCT imaging significantly mitigates the influence of WD on BM layer curvature, enabling a more accurate analysis of posterior eye morphology, especially when variations in WD are unavoidable.
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Affiliation(s)
- Yong Woo Kim
- Department of Ophthalmology and Visual Sciences, Dalhousie University and Nova Scotia Health, Halifax, Nova Scotia, Canada
| | - Glen P Sharpe
- Department of Ophthalmology and Visual Sciences, Dalhousie University and Nova Scotia Health, Halifax, Nova Scotia, Canada
| | - Julia Siber
- Heidelberg Engineering GmbH, Heidelberg, Germany
| | - Ralf Keßler
- Heidelberg Engineering GmbH, Heidelberg, Germany
| | - Jörg Fischer
- Heidelberg Engineering GmbH, Heidelberg, Germany
| | - Tilman Otto
- Heidelberg Engineering GmbH, Heidelberg, Germany
| | - Balwantray C Chauhan
- Department of Ophthalmology and Visual Sciences, Dalhousie University and Nova Scotia Health, Halifax, Nova Scotia, Canada
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Lei S, Wu Y, Kou J, Chen Q, Liu L. The effect of individualized ocular refraction customized spectacle lenses on myopia control in schoolchildren: A 1-year randomised clinical trial. Ophthalmic Physiol Opt 2024; 44:1279-1289. [PMID: 38935437 DOI: 10.1111/opo.13354] [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: 02/09/2024] [Revised: 06/07/2024] [Accepted: 06/07/2024] [Indexed: 06/29/2024]
Abstract
PURPOSE The aim of this study was to investigate the effect of individualized ocular refraction customized (IORC) spectacle lenses with different actual amounts of peripheral myopic defocus (MD) on myopia control over 1 year. These lenses compensate for the original peripheral refraction via the free-form surface on the back of the lens. METHODS This 1-year, double-masked randomised clinical trial included 184 myopic schoolchildren aged 8-12 years. Participants were randomised to receive IORC lenses with high (IORC-H group, +4.50 D), medium (IORC-M group, +3.50 D) or low (IORC-L group, +2.50 D) MD or single-vision (SV) lenses. The spherical equivalent refractive error (SER) and axial length (AL) were measured at baseline and 6-monthly intervals. RESULTS After 1 year, the mean (SD) changes in SER were -0.18 (0.37), -0.36 (0.37), -0.52 (0.39) and -0.60 (0.42) D for the IORC-H, IORC-M, IORC-L and SV groups, respectively. Compared with the SV group, the effects of slowing myopia progression were 70%, 40% and 13% for the IORC-H (difference of 0.47 D, p < 0.001), IORC-M (difference of 0.32 D, p = 0.001) and IORC-L (difference of 0.15 D, p > 0.05) groups, respectively. The mean (SD) changes in AL were 0.12 (0.16), 0.23 (0.17), 0.29 (0.17) and 0.36 (0.17) mm for the IORC-H, IORC-M, IORC-L and SV groups, respectively. The axial elongation was 67%, 36% and 19% lower in the IORC-H (difference of 0.25 mm, p < 0.001), IORC-M (difference of 0.15 mm, p < 0.001) and IORC-L (difference of 0.10 mm, p = 0.04) groups, respectively, compared with the SV group. The IORC-H group exhibited significantly less axial elongation than the IORC-M and IORC-L groups (p = 0.01 and p < 0.001, respectively). CONCLUSION Compared with the IORC-M and IORC-L lenses, the IORC-H lens was found to have superior efficacy in inhibiting myopic progression and slowing eye growth in schoolchildren, with better myopia control efficacy in younger children.
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Affiliation(s)
- Si Lei
- Department of Ophthalmology, West China Hospital of Sichuan University, Chengdu, Sichuan, China
- Department of Optometry and Vision Science, West China School of Medicine, Sichuan University, Chengdu, Sichuan, China
| | - Ye Wu
- Department of Ophthalmology, West China Hospital of Sichuan University, Chengdu, Sichuan, China
- Department of Optometry and Vision Science, West China School of Medicine, Sichuan University, Chengdu, Sichuan, China
| | - Ji Kou
- Department of Ophthalmology, West China Hospital of Sichuan University, Chengdu, Sichuan, China
- Department of Optometry and Vision Science, West China School of Medicine, Sichuan University, Chengdu, Sichuan, China
| | - Qian Chen
- Center of Biostatistics, Design, Measurement and Evaluation, Department of Clinical Research Management, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Longqian Liu
- Department of Ophthalmology, West China Hospital of Sichuan University, Chengdu, Sichuan, China
- Department of Optometry and Vision Science, West China School of Medicine, Sichuan University, Chengdu, Sichuan, China
- Laboratory of Optometry and Vision Sciences, West China Hospital, Sichuan University, Chengdu, Sichuan, China
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Zheleznyak L, Liu C, Winter S. Chromatic cues for the sign of defocus in the peripheral retina. BIOMEDICAL OPTICS EXPRESS 2024; 15:5098-5114. [PMID: 39296412 PMCID: PMC11407258 DOI: 10.1364/boe.537268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2024] [Accepted: 07/28/2024] [Indexed: 09/21/2024]
Abstract
Detecting optical defocus at the retina is crucial for accurate accommodation and emmetropization. However, the optical characteristics of ocular defocus are not fully understood. To bridge this knowledge gap, we simulated polychromatic retinal image quality by considering both the monochromatic wavefront aberrations and chromatic aberrations of the eye, both in the fovea and the periphery (nasal visual field). Our study revealed two main findings: (1) chromatic and monochromatic aberrations interact to provide a signal to the retina (chromatic optical anisotropy) to discern positive from negative defocus and (2) that chromatic optical anisotropy exhibited notable differences among refractive error groups (myopes, emmetropes and hyperopes). These findings could enhance our understanding of the underlying mechanisms of defocus detection and their subsequent implications for myopia control therapies. Further research is needed to explore the retinal architecture's ability to utilize the optical signals identified in this study.
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Affiliation(s)
- Len Zheleznyak
- Clerio Vision, Inc., Rochester NY, USA
- Center for Visual Science, University of Rochester, Rochester, New York, USA
| | - Chang Liu
- The Institute of Optics, University of Rochester, Rochester, New York, USA
| | - Simon Winter
- Department of Biomedical Engineering, Wroclaw University of Science and Technology, Wroclaw, Poland
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Rozema JJ. Generalised models of the vertebrate eye. Ophthalmic Physiol Opt 2024. [PMID: 39137249 DOI: 10.1111/opo.13376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 07/27/2024] [Accepted: 07/31/2024] [Indexed: 08/15/2024]
Abstract
PURPOSE To present a set of closed-form analytical equations to create a consistent eye model balance based on clinically measured input parameters in a single step. These models complement the existing iterative approaches in the literature. METHODS Two different approaches are presented, both considering the cornea and lens as equivalent thin lenses. The first, called the Gaussian model, starts by defining the refractive error as the difference between the axial power (or dioptric distance) and the whole eye power, which can be expanded by filling in the formulas for each power. The resulting equation can be solved for either the refractive error, axial length, corneal power, lens power or the distance between the cornea and the lens as a function of the other four parameters. The second approach uses vergence calculations to provide alternative expressions, assuming that the refractive error is located at the corneal plane. Both models are explored for a biometric range typically found in adult human eyes. RESULTS The Gaussian and vergence models each instantly balance the input data into a working eye model over the human physiological range and far beyond as demonstrated in various examples. The equations of the Gaussian model are more complicated, while the vergence model experiences more singularities, albeit in trivial or highly unlikely parameter combinations. CONCLUSIONS The proposed equations form a flexible and robust platform to create eye models from clinical data. Possible applications lie in creating animal eye models or providing a generic reference for real biometric data and the relationships between the ocular dimensions.
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Affiliation(s)
- Jos J Rozema
- Visual Optics Lab Antwerp (VOLANTIS), Faculty of Medicine and Health Sciences, Antwerp University, Wilrijk, Belgium
- Department of Ophthalmology, Antwerp University Hospital, Edegem, Belgium
- Institute for Medical Informatics, Statistics, and Epidemiology (IMISE), Leipzig University, Leipzig, Germany
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Atchison DA, Charman WN. Optics of spectacle lenses intended to treat myopia progression. Optom Vis Sci 2024; 101:238-249. [PMID: 38857035 DOI: 10.1097/opx.0000000000002140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2024] Open
Abstract
SIGNIFICANCE This is a review of the optics of various spectacle lenses that have been used in myopia control over the last 60 years, with emphasis on approximately the last 15 years.Myopia has become an increasing health problem worldwide, particularly in some East Asian countries. This has led to many attempts to slow its progression in children and reduce its endpoint value. This review is concerned with the optics of spectacle lenses for use in myopia control, from bifocal lenses to multisegment and diffusion optics lenses. Treatments are based on theories of the onset or progression of myopia. These include the hypotheses that eye growth and myopia in susceptible children may be stimulated by (1) poor accommodation response and the consequent hyperopic defocus with near vision tasks, (2) relative hyperopic peripheral refraction, and (3) high retinal image contrast as occurs in urban environments. Using spectacle lenses to slow myopia progression has a history of about 60 years. The review is laid out in approximately the order in which different types of lenses have been introduced: bifocals, conventional progressive addition lenses, undercorrection with single-vision lenses, specialized progressive addition lenses, defocus-incorporated multiple segments, diffusion optics, and concentric bifocals. In the review, some of the lenses are combined with an eye model to determine refractive errors for peripheral vision for the stationary eye and for foveal vision for the rotating eye. Numbers are provided for the reported success of particular designs in retarding myopia progression, but this is not an epidemiological paper, and there is no critical review of the findings. Some of the recent treatments, such as multiple segments, appear to reduce the eye growth and myopia progression by better than 50% over periods of up to 2 years.
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Affiliation(s)
| | - W Neil Charman
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
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Liu F, Ye Y, Yang W, Wang J, Xu Y, Zhao Y, Li M, Chen Z, Shen Y, Li M, Zhou X. Quantitative Evaluation of the Topographical Maps of Three-Dimensional Choroidal Vascularity Index in Children With Different Degrees of Myopia. Invest Ophthalmol Vis Sci 2024; 65:14. [PMID: 38466287 DOI: 10.1167/iovs.65.3.14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2024] Open
Abstract
Purpose To investigate topographical maps of the three-dimensional choroidal vascularity index (3D-CVI) in children with different levels of myopia. Methods We enrolled 274 eyes from 143 children with various severity of myopia, including emmetropia (EM), low myopia (LM), and moderate-high myopia (MHM). The choroidal vessel volume (CVV), choroidal stroma volume (CSV), and 3D-CVI in different eccentricities (fovea, parafovea, and perifovea) and quadrants (nasal, temporal, superior, and inferior) were obtained from swept-source optical coherence tomography angiography (SS-OCTA) volume scans. All choroidal parameters were compared among groups, and the associated factors contributing to different 3D-CVIs were analyzed. Results Compared to the less myopic group, the more myopic group showed a significant decrease in CVV and CSV (MHM < LM < EM) and a significant increase in the 3D-CVI (MHM > LM > EM) in most areas (all P < 0.05). The nasal quadrant had the greatest 3D-CVI and lowest CSV and CVV, and vice versa in the temporal quadrant. The 3D-CVIs of the EM and LM groups gradually increased from the fovea to the perifovea, whereas the 3D-CVI of the MHM group first decreased and then increased. Regression analysis showed that axial length was an independent risk factor affecting foveal and parafoveal 3D-CVIs. Restricted cubic spline analysis revealed that the 3D-CVI increased with spherical equivalent (SE) when the SE was less than threshold and decreased when the SE was greater than threshold (SE thresholds for foveal, parafoveal, and perifoveal 3D-CVIs were -5.25 D, -5.125 D, and -2.00 D, respectively; all P < 0.05). Conclusions Children with myopia exhibited decreased CSV and CVV, increased 3D-CVIs, and altered 3D-CVI eccentricity characteristics (from the fovea to the perifovea). The quadratic relationship between the 3D-CVI and SE should be explored in longitudinal investigations.
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Affiliation(s)
- Fang Liu
- Department of Ophthalmology and Optometry, Eye, Ear, Nose, and Throat Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Yuhao Ye
- Department of Ophthalmology and Optometry, Eye, Ear, Nose, and Throat Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Weiming Yang
- Department of Ophthalmology and Optometry, Eye, Ear, Nose, and Throat Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
- Department of Ophthalmology, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai, China
| | - Jing Wang
- Department of Ophthalmology and Optometry, Eye, Ear, Nose, and Throat Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Ye Xu
- Department of Ophthalmology and Optometry, Eye, Ear, Nose, and Throat Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Yu Zhao
- Department of Ophthalmology and Optometry, Eye, Ear, Nose, and Throat Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Meng Li
- Department of Ophthalmology and Optometry, Eye, Ear, Nose, and Throat Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Zhi Chen
- Department of Ophthalmology and Optometry, Eye, Ear, Nose, and Throat Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Yang Shen
- Department of Ophthalmology and Optometry, Eye, Ear, Nose, and Throat Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Meiyan Li
- Department of Ophthalmology and Optometry, Eye, Ear, Nose, and Throat Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Xingtao Zhou
- Department of Ophthalmology and Optometry, Eye, Ear, Nose, and Throat Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
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Debowy F, Pierscionek B. A comparative analysis of the influence of refractive error on image acuity using three eye models. Ophthalmic Physiol Opt 2024; 44:182-190. [PMID: 38009663 DOI: 10.1111/opo.13251] [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: 07/07/2023] [Revised: 10/31/2023] [Accepted: 10/31/2023] [Indexed: 11/29/2023]
Abstract
PURPOSE To analyse and compare image acuity for different refractive errors generated by either altering axial length or corneal curvature and using three human eye models with two pupil sizes. METHODS Three different eye models, Liou-Brennan, Goncharov and Navarro, were used. Simulations were made (using Ansys Zemax OpticStudio 22.3) for real pupil sizes of 3 and 6 mm with refractive errors ranging from -2 to +2 D in 0.25 D increments. Refractive errors were simulated by varying axial length or corneal curvature. Root mean square (RMS) values were used to determine image acuity. RESULTS For the 3-mm pupil, all models gave similar results, with the Navarro model having slightly higher RMS values for the emmetropic eye. For the 6-mm pupil, the Liou-Brennan and Goncharov eye models gave similar results, with RMS values lower than for the Navarro eye model. The highest RMS value was visible in the axial length-induced refractive errors. Refractive errors generated by altering corneal curvature give smaller RMS values than those generated by altering axial length. The axial length and corneal radius simulations indicate a wide spread of results for myopic, hyperopic and emmetropic eyes. There are multiple outcomes that give the same refractive error, even within a single-eye model. The axial length/corneal curvature ratio showed a higher ratio for myopes than hyperopes for every model. CONCLUSIONS The influence of refractive error on image acuity varied depending on the simulation method of refractive error and the model used. The origins of refractive error and the influence it has on image acuity need further investigation. As models become more sophisticated, personalised and biologically relevant, they will better represent the image acuity of the eye for varying refractive errors, ethnicities, ages and pupil sizes.
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Affiliation(s)
- Fabian Debowy
- Faculty of Health, Education Medicine and Social Care, Medical Technology Research Centre, Anglia Ruskin University, Cambridge, UK
| | - Barbara Pierscionek
- Faculty of Health, Education Medicine and Social Care, Medical Technology Research Centre, Anglia Ruskin University, Cambridge, UK
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Radhakrishnan H, Lam CSY, Charman WN. Multiple segment spectacle lenses for myopia control. Part 1: Optics. Ophthalmic Physiol Opt 2023; 43:1125-1136. [PMID: 37378657 DOI: 10.1111/opo.13191] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 05/27/2023] [Accepted: 06/10/2023] [Indexed: 06/29/2023]
Abstract
PURPOSE To understand and compare the optics of two multiple segment (MS) spectacle lenses (Hoya MiyoSmart and Essilor Stellest) designed to inhibit myopia progression in children. METHODS The optics of the two designs are presented, together with geometrical optics-based calculations to understand the impact of the lenses on the optics of the eye. Lenses were evaluated with three techniques: surface images, Twyman-Green interferometry and focimetry. The carrier lens powers and the spatial distribution, powers and forms of the lenslets were measured. RESULTS MS lenses as manufactured were found to match most of the design specifications provided by their manufacturers, although some apparent small discrepancies were found. The focimeter-measured power of the lenslets was approximately +3.50 D for the MiyoSmart and +4.00 D for the highly aspheric lenslets of the Stellest design. For both lens designs, image contrast would be expected to become modestly reduced in the focal planes of the distance-correcting carrier lenses. Images become much more degraded in the combined carrier-lenslet focal plane, due to the generation of multiple laterally displaced images formed by adjacent lenslets within the effective pupil. The exact effects observed depended on the effective pupil size and its location with respect to the lenslets, as well as the power and arrangement of the lenslets. CONCLUSION Wearing either of these lenses will produce broadly similar effects on retinal imagery.
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Affiliation(s)
- Hema Radhakrishnan
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Carly Siu Yin Lam
- Centre for Myopia Research, School of Optometry, The Hong Kong Polytechnic University, Hung Hom, Hong Kong
- Centre for Eye and Vision Research (CEVR), Hong Kong SAR, China
| | - W Neil Charman
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
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Pusti D, Degre Kendrick C, Wu Y, Ji Q, Jung HW, Yoon G. Widefield wavefront sensor for multidirectional peripheral retinal scanning. BIOMEDICAL OPTICS EXPRESS 2023; 14:4190-4204. [PMID: 37799675 PMCID: PMC10549753 DOI: 10.1364/boe.491412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 06/30/2023] [Accepted: 07/01/2023] [Indexed: 10/07/2023]
Abstract
The quantitative evaluation of peripheral ocular optics is essential in both myopia research and the investigation of visual performance in people with normal and compromised central vision. We have developed a widefield scanning wavefront sensor (WSWS) capable of multidirectional scanning while maintaining natural central fixation at the primary gaze. This Shack-Hartmann-based WSWS scans along any retinal meridian by using a unique scanning method that involves the concurrent operation of a motorized rotary stage (horizontal scan) and a goniometer (vertical scan). To showcase the capability of the WSWS, we tested scanning along four meridians including a 60° horizontal, 36° vertical, and two 36° diagonal scans, each completed within a time frame of 5 seconds.
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Affiliation(s)
- Dibyendu Pusti
- College of Optometry,
University of Houston, Houston, TX 77204, USA
- Flaum Eye Institute, University of Rochester, Rochester, NY 14623, USA
| | - Chloe Degre Kendrick
- College of Optometry,
University of Houston, Houston, TX 77204, USA
- Flaum Eye Institute, University of Rochester, Rochester, NY 14623, USA
| | - Yifei Wu
- Flaum Eye Institute, University of Rochester, Rochester, NY 14623, USA
| | - Qiuzhi Ji
- Institute of Optics, University of Rochester, Rochester, NY 14627, USA
- School of Optometry, Indiana University, Bloomington, IN 47405, USA
| | - Hae Won Jung
- College of Optometry,
University of Houston, Houston, TX 77204, USA
- Institute of Optics, University of Rochester, Rochester, NY 14627, USA
| | - Geunyoung Yoon
- College of Optometry,
University of Houston, Houston, TX 77204, USA
- Flaum Eye Institute, University of Rochester, Rochester, NY 14623, USA
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Chenguiti Y, Hamlaoui S, Baranton K, Otani S, Tartaglia EM. Modulation of cortical activity by spherical blur and its correlation with retinal defocus. Front Neurosci 2023; 17:1184381. [PMID: 37521696 PMCID: PMC10372438 DOI: 10.3389/fnins.2023.1184381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Accepted: 05/24/2023] [Indexed: 08/01/2023] Open
Abstract
Cortical activity, as recorded via electroencephalography, has been linked to the refractive error of an individual. It is however unclear which optical metric modulates this response. Here, we measured simultaneously the brain activity and the retinal defocus of a visual stimulus perceived through several values of spherical blur. We found that, contrary to the existing literature on the topic, the cortical response as a function of the overcorrections follows a sigmoidal shape rather than the classical bell shape, with the inflection point corresponding to the subjective refraction and to the stimulus being in focus on the retina. However, surprisingly, the amplitude of the cortical response does not seem to be a good indicator of how much the stimulus is in or out of focus on the retina. Nonetheless, the defocus is not equivalent to the retinal image quality, nor is an absolute predictor of the visual performance of an individual. Simulations of the retinal image quality seem to be a powerful tool to predict the modulation of the cortical response with the refractive error.
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Affiliation(s)
- Yannis Chenguiti
- Center of Innovation and Technologies Europe, Essilor International, SAS, Charenton-le-Pont, France
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
| | - Samy Hamlaoui
- Center of Innovation and Technologies Europe, Essilor International, SAS, Charenton-le-Pont, France
| | - Konogan Baranton
- Center of Innovation and Technologies Europe, Essilor International, SAS, Charenton-le-Pont, France
| | - Satoru Otani
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
| | - Elisa M. Tartaglia
- Center of Innovation and Technologies Europe, Essilor International, SAS, Charenton-le-Pont, France
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Tabernero J, Kallamata E, Velonias G, Vera-Diaz FA. Individualized modeling for the peripheral optics of the human myopic eye. BIOMEDICAL OPTICS EXPRESS 2023; 14:2726-2735. [PMID: 37342699 PMCID: PMC10278608 DOI: 10.1364/boe.489792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 05/04/2023] [Accepted: 05/04/2023] [Indexed: 06/23/2023]
Abstract
Individualized optical modelling of the eye is a useful tool to estimate optical properties of the eye from a set of geometrical parameters. In the context of myopia research, it is important to understand not only the on-axis (foveal) optical quality, but also the peripheral profile. This work describes a method to extend on-axis individualized eye modeling to the peripheral retina. Using measurements of corneal geometry, axial distances, and central optical quality from a group of young adults, a crystalline lens model was built to help reproduce the peripheral optical quality of the eye. Subsequent individualized eye models were generated from each of the 25 participants. These models were used to predict the individual peripheral optical quality over the central 40 degrees. Outcomes of the final model were then compared to the actual measurements of peripheral optical quality in these participants, measured with a scanning aberrometer. A high agreement was found between the final model and measured optical quality for the relative spherical equivalent and J0 astigmatism.
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Affiliation(s)
- Juan Tabernero
- Departamento de Electromagnetismo y Electrónica, Universidad de Murcia, Campus de Espinardo, Murcia, 30100, Spain
| | - Enian Kallamata
- New England College of Optometry, 424 Beacon Street, Boston, MA 02140, USA
| | - Gabriella Velonias
- New England College of Optometry, 424 Beacon Street, Boston, MA 02140, USA
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Wu RJ, Clark AM, Cox MA, Intoy J, Jolly PC, Zhao Z, Rucci M. High-resolution eye-tracking via digital imaging of Purkinje reflections. J Vis 2023; 23:4. [PMID: 37140912 PMCID: PMC10166114 DOI: 10.1167/jov.23.5.4] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2023] Open
Abstract
Reliably measuring eye movements and determining where the observer looks are fundamental needs in vision science. A classical approach to achieve high-resolution oculomotor measurements is the so-called dual Purkinje image (DPI) method, a technique that relies on the relative motion of the reflections generated by two distinct surfaces in the eye, the cornea and the back of the lens. This technique has been traditionally implemented in fragile and difficult to operate analog devices, which have remained exclusive use of specialized oculomotor laboratories. Here we describe progress on the development of a digital DPI, a system that builds on recent advances in digital imaging to enable fast, highly precise eye-tracking without the complications of previous analog devices. This system integrates an optical setup with no moving components with a digital imaging module and dedicated software on a fast processing unit. Data from both artificial and human eyes demonstrate subarcminute resolution at 1 kHz. Furthermore, when coupled with previously developed gaze-contingent calibration methods, this system enables localization of the line of sight within a few arcminutes.
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Affiliation(s)
- Ruei-Jr Wu
- Department of Brain & Cognitive Sciences and Center for Visual Science, University of Rochester, 310 Meliora Hall, Rochester, NY, USA
| | - Ashley M Clark
- Department of Brain & Cognitive Sciences and Center for Visual Science, University of Rochester, 310 Meliora Hall, Rochester, NY, USA
| | - Michele A Cox
- Department of Brain & Cognitive Sciences and Center for Visual Science, University of Rochester, 310 Meliora Hall, Rochester, NY, USA
| | - Janis Intoy
- Department of Brain & Cognitive Sciences and Center for Visual Science, University of Rochester, 310 Meliora Hall, Rochester, NY, USA
| | - Paul C Jolly
- Department of Brain & Cognitive Sciences and Center for Visual Science, University of Rochester, 310 Meliora Hall, Rochester, NY, USA
| | - Zhetuo Zhao
- Department of Brain & Cognitive Sciences and Center for Visual Science, University of Rochester, 310 Meliora Hall, Rochester, NY, USA
| | - Michele Rucci
- Department of Brain & Cognitive Sciences and Center for Visual Science, University of Rochester, 310 Meliora Hall, Rochester, NY, USA
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Lacort M, Pérez-Gracia J, Ares J, Remón L. Optical Quality Variation of Different Intraocular Lens Designs in a Model Eye: Lens Placed Correctly and in an Upside-Down Position. Ophthalmic Res 2023; 66:757-766. [PMID: 36716717 DOI: 10.1159/000528504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 11/28/2022] [Indexed: 02/01/2023]
Abstract
INTRODUCTION Intraocular lenses (IOLs) may lose their optical quality if they are not correctly placed inside the capsular bag once implanted. One possible malpositioning of the IOL could be the implantation in an upside-down position. In this work, three aspheric IOLs with different spherical aberration (SA) have been designed and numerically tested to analyse the optical quality variation with the IOL flip, and misalignments, using a theoretical model eye. METHODS Using the commercial optical design software OSLO, the effect of decentration and tilt was evaluated by numerical ray tracing in two conditions: in their designed position and flipped with respect to the planned position (IOL is implanted upside down). The theoretical model eye used was the Atchison model eye. Seven IOL designs of +27.00 diopters were used: a lens with negative SA to correct the corneal SA, a lens to partially correct the corneal SA, and a lens to not add any SA to the cornea (aberration-free IOL). These lenses were designed with the aspherical surface located on the anterior and posterior IOL surface. A lens with no aspherical surfaces was also included. For the optical quality analysis, the modulation transfer function (MTF) was used, together with the Zernike wavefront aberration coefficients of defocus, astigmatism, and primary coma. RESULTS Off-centring and tilting the IOL reduced overall MTF values and increased wavefront aberration errors. With the IOL correctly positioned within the capsular bag, an aberration-free IOL is the best choice for maintaining optical quality. When the IOL is flipped inside the capsular bag, the optical quality changes, with the aberration-free IOL and the IOL without aspheric surfaces providing the worst results. With the lens in an upside-down position, an IOL design to partially correct corneal SA shows the best optical quality results in decentration and tilt, in terms of MTF and wavefront aberrations. CONCLUSION The aberration-free IOL is the best choice when minimal postoperative errors of decentration or tilt are predicted. With IOL flip, the negative SA lens design is the best choice, regarding the root mean square wavefront aberrations. However, in a proper IOL implantation, the IOL designed to partially compensate the corneal SA including asphericity on its posterior surface is the better possible option, even in the presence of decentration or tilt.
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Affiliation(s)
- Marta Lacort
- Departamento de Física Aplicada, Universidad de Zaragoza, Zaragoza, Spain
| | - Jesús Pérez-Gracia
- Departamento de Física Aplicada, Universidad de Zaragoza, Zaragoza, Spain
| | - Jorge Ares
- Departamento de Física Aplicada, Universidad de Zaragoza, Zaragoza, Spain
| | - Laura Remón
- Departamento de Física Aplicada, Universidad de Zaragoza, Zaragoza, Spain
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Huang X, Anderson T, Dubra A. Retinal magnification factors at the fixation locus derived from schematic eyes with four individualized surfaces. BIOMEDICAL OPTICS EXPRESS 2022; 13:3786-3808. [PMID: 35991930 PMCID: PMC9352277 DOI: 10.1364/boe.460553] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 05/20/2022] [Accepted: 05/23/2022] [Indexed: 05/02/2023]
Abstract
Retinal magnification factors (RMFs) allow the conversion of angles to lengths in retinal images. In this work, we propose paraxial and non-paraxial RMF calculation methods that incorporate the individual topography and separation of the anterior and posterior surfaces of the cornea and crystalline lens, assuming homogeneous ocular media. Across 34 eyes, the two RMF methods differ by 0.1% on average, due to surface tilt, decenter, and lack of rotational symmetry in the non-paraxial modeling, which results in up to 2.2% RMF variation with retinal meridian. Differences with widely used individualized RMF calculation methods are smallest for eyes with ∼24 mm axial length, and as large as 7.5% in a 29.7 mm long eye (15D myope). To better model the capture of retinal images, we propose the tracing of chief rays, instead of the scaling of posterior nodal or principal distances often used in RMF definitions. We also report that RMF scale change is approximately proportional to both refractive error and axial separation between the ophthalmoscope's exit pupil and the eye's entrance pupil, resulting in RMF changes as large as 13% for a 1cm displacement in a 15D myopic eye. Our biometry data shows weak correlation and statistical significance between surface radii and refractive error, as well as axial length, whether considering all eyes in the study, or just the high myopes, defined as those with refractive error sphere equivalent ≤ -4D. In contrast, vitreous thicknesses show a strong correlation (r ≤ -0.92) and significance (p ≤ 10-13) with refractive error when considering all eyes or just high myopes (r ≤ -0.95; p ≤ 10-5). We also found that potential RMF change with depth of cycloplegia and/or residual accommodation is smaller than 0.2%. Finally, we propose the reporting of individual ocular biometry data and a detailed RMF calculation method description in scientific publications to facilitate the comparison of retinal imaging biomarker data across studies.
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Affiliation(s)
- Xiaojing Huang
- Institute of Optics, University of Rochester, Rochester, NY 14620, USA
- Byers Eye Institute, Stanford University, Palo Alto, CA 94303, USA
| | | | - Alfredo Dubra
- Byers Eye Institute, Stanford University, Palo Alto, CA 94303, USA
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Myopia: Mechanisms and Strategies to Slow Down Its Progression. J Ophthalmol 2022; 2022:1004977. [PMID: 35747583 PMCID: PMC9213207 DOI: 10.1155/2022/1004977] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 05/29/2022] [Indexed: 12/15/2022] Open
Abstract
This topical review aimed to update and clarify the behavioral, pharmacological, surgical, and optical strategies that are currently available to prevent and reduce myopia progression. Myopia is the commonest ocular abnormality; reinstated interest is associated with high and increasing prevalence, especially but not, in the Asian population and progressive nature in children. The growing global prevalence seems to be associated with both genetic and environmental factors such as spending more time indoor and using digital devices, particularly during the coronavirus disease 2019 pandemic. Various options have been assessed to prevent or reduce myopia progression in children. In this review, we assess the effects of several types of measures, including spending more time outdoor, optical interventions such as the bifocal/progressive spectacle lenses, soft bifocal/multifocal/extended depth of focus/orthokeratology contact lenses, refractive surgery, and pharmacological treatments. All these options for controlling myopia progression in children have various degrees of efficacy. Atropine, orthokeratology/peripheral defocus contact and spectacle lenses, bifocal or progressive addition spectacles, and increased outdoor activities have been associated with the highest, moderate, and lower efficacies, respectively.
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Espinosa J, Pérez J, Villanueva A. Prediction of Subjective Refraction From Anterior Corneal Surface, Eye Lengths, and Age Using Machine Learning Algorithms. Transl Vis Sci Technol 2022; 11:8. [PMID: 35404439 PMCID: PMC9034724 DOI: 10.1167/tvst.11.4.8] [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] [Indexed: 11/24/2022] Open
Abstract
Purpose To develop a machine learning regression model of subjective refractive prescription from minimum ocular biometry and corneal topography features. Methods Anterior corneal surface parameters (Zernike coefficients and keratometry), axial length, anterior chamber depth, and age were posed as features to predict subjective refractions. Measurements from 355 eyes were split into training (75%) and test (25%) sets. Different machine learning regression algorithms were trained by 10-fold cross-validation, optimized, and tested. A neighborhood component analysis provided features’ normalized weights in predictions. Results Gaussian process regression algorithms provided the best models with mean absolute errors of around 1.00 diopters (D) in the spherical component and 0.15 D in the astigmatic components. Conclusions The normalized weights showed that subjective refraction can be predicted by only keratometry, age, and axial length. Increasing the topographic description detail of the anterior corneal surface implied by a high-order Zernike decomposition versus adjustment to a spherocylindrical surface is not reflected as improved subjective refraction prediction, which is poor, mainly in the spherical component. However, the highest achievable accuracy differs by only 0.75 D from that of other works with a more exhaustive eye refractive elements description. Although the chosen parameters may have not been the most efficient, applying machine learning and big data to predict subjective refraction can be risky and impractical when evaluating a particular subject at statistical extremes. Translational Relevance This work evaluates subjective refraction prediction by machine learning from the anterior corneal surface and ocular biometry. It shows the minimum biometric information required and the highest achievable accuracy. RESUMEN Objetivo El desarrollo de un modelo de regresión de aprendizaje automático prescripción refractiva subjetiva a partir de las características mínimas de la biometría ocular y la superficie corneal. Métodos Los parámetros de la superficie corneal anterior (coeficientes de Zernike y queratometría), además de longitudes axiales y de cámara anterior, edades y las refracciones subjetivas no ciclopléjicas de 355 ojos se dividieron en un conjunto de entrenamiento (75%) y otro de test (25%) y se entrenaron diferentes algoritmos de regresión de aprendizaje automático mediante validación cruzada 10 veces, se optimizaron y se probaron sobre el conjunto test. Resultados Los algoritmos de regresión del proceso gaussiano proporcionaron los mejores modelos con un error absoluto medio fue de alrededor de 1.00 D en el componente esférico y de 0.25 D en los componentes astigmáticos. Conclusiones Los pesos normalizados mostraron que la refracción subjetiva puede predecirse utilizando únicamente la queratometría, la edad y la longitud axial como características. El aumento del detalle de la descripción topográfica de la superficie corneal anterior que supone una descomposición de Zernike de alto orden frente al ajuste a una superficie esferocilíndrica realizado por queratometría no se refleja en una mejora de la predicción de la refracción subjetiva, que es pobre, en cualquier caso, principalmente en el componente esférico. Sin embargo, la máxima precisión alcanzada difiere en sólo 0,75 D de la de otros trabajos con una descripción más exhaustiva de los elementos refractivos del ojo. De todos modos, el aprendizaje automático y los datos masivos aplicados a la predicción de la refracción subjetiva pueden ser arriesgados y poco prácticos cuando se evalúa a un sujeto concreto en los extremos estadísticos, aunque los parámetros elegidos puedan no haber sido los más ineficaces. Relevancia Traslativa El trabajo evalúa la predicción de la refracción subjetiva mediante aprendizaje automático a partir de la superficie corneal anterior y la biometría ocular, mostrando la mínima información biométrica requerida y la máxima precisión alcanzable.
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Affiliation(s)
- Julián Espinosa
- IUFACyT, Universidad de Alicante, San Vicente del Raspeig, Spain.,Departamento de Óptica, Farmacología y Anatomía, Universidad de Alicante, San Vicente del Raspeig, Spain
| | - Jorge Pérez
- IUFACyT, Universidad de Alicante, San Vicente del Raspeig, Spain.,Departamento de Óptica, Farmacología y Anatomía, Universidad de Alicante, San Vicente del Raspeig, Spain
| | - Asier Villanueva
- IUFACyT, Universidad de Alicante, San Vicente del Raspeig, Spain
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17
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Pérez-Gracia J, Ares J, Ávila FJ, Remón L. Effect of decentration, tilt and rotation on the optical quality of various toric intraocular lens designs: a numerical and experimental study. BIOMEDICAL OPTICS EXPRESS 2022; 13:1948-1967. [PMID: 35519245 PMCID: PMC9045935 DOI: 10.1364/boe.447045] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 02/21/2022] [Accepted: 02/26/2022] [Indexed: 06/12/2023]
Abstract
Toric intraocular lenses (T-IOLs) may lose their optical quality if they are not correctly positioned inside the capsular bag once implanted. In this work, T-IOLs with cylinder powers of +1.50, +4.50 and +7.50 D and differing degrees of spherical aberration have been designed, manufactured and tested in vitro using a commercial optical bench that complies with the requirements of standard ISO 11979-2. Moreover, the effect of tilt and rotation on optical quality was assessed by means of numerical ray tracing on an astigmatic eye model, while the effect of decentration was evaluated numerically and experimentally.
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18
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Automatic compensation enhances the orientation perception in chronic astigmatism. Sci Rep 2022; 12:3710. [PMID: 35260694 PMCID: PMC8904485 DOI: 10.1038/s41598-022-07788-y] [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: 09/03/2021] [Accepted: 02/24/2022] [Indexed: 11/10/2022] Open
Abstract
Astigmatism is a prevalent optical problem in which two or more focal points blur the retinal image at a particular meridian. Although many features of astigmatic vision, including orientation perception, are impaired at the retinal image level, the visual system appears to partly restore perceptual impairment after an extended period of astigmatism. However, the mechanism of orientation perception restoration in chronic astigmatism has not yet been clarified. We investigated the notable reduction of perceptual error in chronic astigmatism by comparing the orientation perception of a chronic astigmatism group with the perception of a normal-vision group, in which astigmatism was transiently induced. We found that orientation perception in the chronic group was more accurate than in the normal vision group. Interestingly, the reduction of perceptual errors was automatic; it remained even after the optical refractive errors were fully corrected, and the orientation perception was much more stable across different orientations, despite the uneven noise levels of the retinal images across meridians. We provide here a mechanistic explanation for how the compensation of astigmatic orientation perception occurred, using neural adaptation to the biased distribution of orientations.
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Debellemanière G, Dubois M, Gauvin M, Wallerstein A, Brenner LF, Rampat R, Saad A, Gatinel D. The PEARL-DGS Formula: The Development of an Open-source Machine Learning-based Thick IOL Calculation Formula. Am J Ophthalmol 2021; 232:58-69. [PMID: 33992611 DOI: 10.1016/j.ajo.2021.05.004] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Revised: 04/30/2021] [Accepted: 05/02/2021] [Indexed: 11/19/2022]
Abstract
PURPOSE To describe an open-source, reproducible, step-by-step method to design sum-of-segments thick intraocular lens (IOL) calculation formulas, and to evaluate a formula built using this methodology. DESIGN Retrospective, multicenter case series METHODS: A set of 4242 eyes implanted with Finevision IOLs (PhysIOL, Liège, Belgium) was used to devise the formula design process and build the formula. A different set of 677 eyes from the same center was kept separate to serve as a test set. The resulting formula was evaluated on the test set as well as another independent data set of 262 eyes. RESULTS The lowest standard deviation (SD) of prediction errors on Set 1 were obtained with the PEARL-DGS formula (±0.382 D), followed by K6 and Olsen (±0.394 D), EVO 2.0 (±0.398 D), RBF 3.0, and BUII (±0.402 D). The formula yielding the lowest SD on Set 2 was the PEARL-DGS (±0.269 D), followed by Olsen (±0.272 D), K6 (±0.276 D), EVO 2.0 (±0.277 D), and BUII (±0.301 D). CONCLUSION Our methodology achieved an accuracy comparable to other state-of-the-art IOL formulas. The open-source tools provided in this article could allow other researchers to reproduce our results using their own data sets, with other IOL models, population settings, biometric devices, and measured, rather than calculated, posterior corneal radius of curvature or sum-of-segments axial lengths.
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Affiliation(s)
- Guillaume Debellemanière
- From the Department of Ophthalmology, Rothschild Foundation Hospital, Paris, France (D.G., D.M., R.R., S.A.,G.D.)
| | - Mathieu Dubois
- From the Department of Ophthalmology, Rothschild Foundation Hospital, Paris, France (D.G., D.M., R.R., S.A.,G.D.)
| | - Mathieu Gauvin
- Department of Ophthalmology and Visual Sciences, McGill University, Montreal, Quebec, Canada (G.M., W.A.); LASIK MD, Montreal, Quebec, Canada (G.M., W.A.)
| | - Avi Wallerstein
- Department of Ophthalmology and Visual Sciences, McGill University, Montreal, Quebec, Canada (G.M., W.A.); LASIK MD, Montreal, Quebec, Canada (G.M., W.A.)
| | | | - Radhika Rampat
- From the Department of Ophthalmology, Rothschild Foundation Hospital, Paris, France (D.G., D.M., R.R., S.A.,G.D.)
| | - Alain Saad
- From the Department of Ophthalmology, Rothschild Foundation Hospital, Paris, France (D.G., D.M., R.R., S.A.,G.D.)
| | - Damien Gatinel
- From the Department of Ophthalmology, Rothschild Foundation Hospital, Paris, France (D.G., D.M., R.R., S.A.,G.D.).
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20
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Customized eye modeling for optical quality assessment in myopic femto-LASIK surgery. Sci Rep 2021; 11:16049. [PMID: 34362982 PMCID: PMC8346559 DOI: 10.1038/s41598-021-95730-z] [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: 04/04/2021] [Accepted: 07/27/2021] [Indexed: 02/07/2023] Open
Abstract
Refractive surgery is recognized as an effective method for myopia treatment, but it can induce night vision disturbances such as glare. We present an eye modeling method for the optical quality assessment in response to the structural changes in the eyes by femto-LASIK surgery. Customized eye models were built from the measurements of 134 right eyes pre- and post-operatively. Optical performance was evaluated using spot diagrams, point spread functions (PSFs), modulation transfer functions (MTFs), and chromatic aberrations at various fields (0°-30°), different pupil diameters (2-6 mm), and initial myopias (- 1.25 to - 10.5 D). Pupil size and initial myopia are the two major factors that affect visual performance of post-operative eyes. The results of spot diagrams, PSFs, and MTFs indicated that post-operative visual performance deteriorated as the visual field and pupil size increased, and it was significantly influenced by initial myopia. Post-operative chromatic aberrations were also affected by initial myopia. As pupil size increased, the post-operative longitudinal chromatic aberrations tended to decrease slightly, while the transverse chromatic aberrations remained similar. The use of eye modeling for refractive surgery assessment could possibly provide a more personalized surgical approach, could improve the prediction accuracy of refractive surgery outcomes, and promote the invention and development of better surgical methods.
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21
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Li Q, Fang F. Retinal contour modelling to reproduce two-dimensional peripheral spherical equivalent refraction. BIOMEDICAL OPTICS EXPRESS 2021; 12:3948-3964. [PMID: 34457391 PMCID: PMC8367254 DOI: 10.1364/boe.426413] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/13/2021] [Accepted: 05/16/2021] [Indexed: 05/17/2023]
Abstract
Reproduction of the peripheral spherical equivalent refraction (SER) in the eye model is critical for investigations in myopia control. Based on the derivation of a linear relationship between SER and the vergence of the wavefront at exit pupil center, a computing method is proposed to locate the retinal points to reproduce the two-dimensional (2D) distribution of SER. The method is validated by reproducing SER maps measured on both emmetropic and myopic eyes in a realistic eye model based on measurement data. By fitting the retinal points to a general ellipsoid, the limited capability of the general ellipsoid model in reproducing the 2D map of SER is calculated and compared with original data. The high accuracy in SER reproduction and low time-cost of the proposed retinal-locating method can help significantly improve the precision and accuracy of customized wide-angle eye modelling.
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Affiliation(s)
- Qing Li
- Center of Micro/Nano Manufacturing Technology (MNMT-Dublin), University College Dublin, Dublin 4, Ireland
| | - Fengzhou Fang
- Center of Micro/Nano Manufacturing Technology (MNMT-Dublin), University College Dublin, Dublin 4, Ireland
- State Key Laboratory of Precision Measuring Technology and Instruments, Laboratory of Micro/Nano Manufacturing Technology (MNMT), Tianjin University, Tianjin 300072, China
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22
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Smiddy WE, Kapitanski L, Flynn HW. Can the Macula be Attached if View Is Obscured by a Bullous Retinal Detachment? A Mathematical Consideration. Transl Vis Sci Technol 2021; 10:13. [PMID: 34003993 PMCID: PMC8054619 DOI: 10.1167/tvst.10.4.13] [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] [Indexed: 11/26/2022] Open
Abstract
Purpose The purpose of this study was to determine if it is possible for the macula to remain attached if a bullous retinal detachment blocks the examiner's view to the macula. Methods A mathematical analysis compared the arc length of the attached retina versus the length of a detached retina necessary to obscure the macula (hang over the visual axis). The shape (oblate ellipsoid) and dimensions of the retina were based on a published study. The complete path of the hanging retina was calculated as a static catenary so as to depict the lowest possible position (“worst case scenario”). Results The measured and calculated angle between the fovea and ora serrata was 105 degrees. When considering a catenary shape of the hanging retina, the macula could, mathematically, still be attached despite the retina hanging down 1.03 mm below the visual axis for an emmetropic eye. The maximal distance calculated was 1.095 mm for a −12 diopter (D) myopic eye. Conclusions If the macular center cannot be viewed due to a bullous superior retinal detachment hanging into the examiner's view, it is unlikely but possible that the macula remains attached. If the view is obscured by at least 1 mm below the fovea, it is not mathematically possible for the fovea to be attached. Translational Relevance The status of the macula being detached is subject to mathematical constraints, which, explored herein, offer a higher certainty of clinical decision making that could inform management for better clinical results.
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Affiliation(s)
- William E Smiddy
- Department of Ophthalmology, University of Miami Miller School of Medicine, Bascom Palmer Eye Institute, Miami, FL, USA
| | - Lev Kapitanski
- Department of Mathematics, University of Miami, Miami, FL, USA
| | - Harry W Flynn
- Department of Ophthalmology, University of Miami Miller School of Medicine, Bascom Palmer Eye Institute, Miami, FL, USA
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23
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Józwik A, Asejczyk-Widlicka M, Kurzynowski P, Pierscionek BK. How a dynamic optical system maintains image quality: Self-adjustment of the human eye. J Vis 2021; 21:6. [PMID: 33656560 PMCID: PMC7938001 DOI: 10.1167/jov.21.3.6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The eyeball is continually subjected to forces that cause alterations to its shape and dimensions, as well as to its optical components. Forces that induce accommodation result in an intentional change in focus; others, such as the effect of intraocular pressure fluctuations, are more subtle. Although the mechanical properties of the eyeball and its components permit mediation of such subtle forces, the concomitant optical changes are not detected by the visual system. Optical self-adjustment is postulated as the mechanism that maintains image quality. The purpose of this study was to investigate how self-adjustment occurs by using an optical model of the eyeball and to test the requisite optical and biometric conditions.
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Affiliation(s)
- Agnieszka Józwik
- Department of Optics and Photonics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wroclaw, Poland.,
| | - Magdalena Asejczyk-Widlicka
- Department of Optics and Photonics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wroclaw, Poland.,
| | - Piotr Kurzynowski
- Department of Optics and Photonics, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wroclaw, Poland.,
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Hashemi H, Nabovati P, Aghamirsalim M, Mahboubipour H, Yekta A, Khabazkhoob M. Corneal asphericity and related factors in the geriatric population: A population-based study. Ophthalmic Physiol Opt 2021; 41:691-701. [PMID: 33998696 DOI: 10.1111/opo.12831] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Accepted: 03/08/2021] [Indexed: 11/28/2022]
Abstract
PURPOSE To determine the distribution of the corneal asphericity coefficient (Q value) and related factors in an Iranian geriatric population. METHODS This population-based study was conducted in 2019 in Tehran, using stratified multistage random cluster sampling. The study population was ≥60 years of age. Participants underwent corneal imaging using a Pentacam HR. Mean keratometry, corneal astigmatism, central corneal thickness, anterior chamber depth and the overall anterior and posterior Q values (for 8 mm chord diameter) were recorded. Axial length measurements were performed using the IOL Master 500. RESULTS 2457 eyes of 2457 individuals were analysed. The mean age was 67.3 ± 5.82 years and 1479 (60.2%) were female. The mean Q value for the anterior corneal surface was -0.35 ± 0.17 (95% CI: -0.35 to -0.34). The anterior Q value showed a statistically significant inverse relationship with axial length and mean keratometry, and a significant direct association with anterior chamber depth and corneal astigmatism. The mean posterior Q value was -0.41 ± 0.15 (95% CI: -0.42 to -0.40). The posterior Q value had a significant direct relationship with age, anterior chamber depth, mean keratometry and corneal astigmatism. CONCLUSION The corneal Q values in this geriatric Iranian population were more negative than the values reported in most previous studies. Corneal asphericity was greater affected by ocular biometry and corneal curvature than demographic factors and refractive status.
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Affiliation(s)
- Hassan Hashemi
- Noor Research Center for Ophthalmic Epidemiology, Noor Eye Hospital, Tehran, Iran
| | - Payam Nabovati
- Department of Optometry, School of Rehabilitation Sciences, Rehabilitation Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Mohamadreza Aghamirsalim
- Translational Ophthalmology Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | | | - Abbasali Yekta
- Department of Optometry, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mehdi Khabazkhoob
- Department of Basic Sciences, School of Nursing and Midwifery, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Bao J, Yang A, Huang Y, Li X, Pan Y, Ding C, Lim EW, Zheng J, Spiegel DP, Drobe B, Lu F, Chen H. One-year myopia control efficacy of spectacle lenses with aspherical lenslets. Br J Ophthalmol 2021; 106:1171-1176. [PMID: 33811039 PMCID: PMC9340037 DOI: 10.1136/bjophthalmol-2020-318367] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 02/28/2021] [Accepted: 03/01/2021] [Indexed: 01/23/2023]
Abstract
Aims To evaluate the 1-year efficacy of two new myopia control spectacle lenses with lenslets of different asphericity. Methods One hundred seventy schoolchildren aged 8–13 years with myopia of −0.75 D to −4.75 D were randomised to receive spectacle lenses with highly aspherical lenslets (HAL), spectacle lenses with slightly aspherical lenslets (SAL), or single-vision spectacle lenses (SVL). Cycloplegic autorefraction (spherical equivalent refraction (SER)), axial length (AL) and best-corrected visual acuity (BCVA) were measured at baseline and 6-month intervals. Adaptation and compliance questionnaires were administered during all visits. Results After 1 year, the mean changes in the SER (±SE) and AL (±SE) in the SVL group were −0.81±0.06 D and 0.36±0.02 mm. Compared with SVL, the myopia control efficacy measured using SER was 67% (difference of 0.53 D) for HAL and 41% (difference of 0.33 D) for SAL, and the efficacy measured using AL was 64% (difference of 0.23 mm) for HAL and 31% (difference of 0.11 mm) for SAL (all p<0.01). HAL resulted in significantly greater myopia control than SAL for SER (difference of 0.21 D, p<0.001) and AL (difference of 0.12 mm, p<0.001). The mean BCVA (−0.01±0.1 logMAR, p=0.22) and mean daily wearing time (13.2±2.6 hours, p=0.26) were similar among the three groups. All groups adapted to their lenses with no reported adverse events, complaints or discomfort. Conclusions Spectacle lenses with aspherical lenslets effectively slow myopia progression and axial elongation compared with SVL. Myopia control efficacy increased with lenslet asphericity. Trial registration number ChiCTR1800017683.
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Affiliation(s)
- Jinhua Bao
- Eye Hospital and School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China.,Wenzhou Medical University-Essilor International Research Center (WEIRC), Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Adeline Yang
- Wenzhou Medical University-Essilor International Research Center (WEIRC), Wenzhou Medical University, Wenzhou, Zhejiang, China.,R&D AMERA, Essilor International, Singapore
| | - Yingying Huang
- Eye Hospital and School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China.,Wenzhou Medical University-Essilor International Research Center (WEIRC), Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xue Li
- Eye Hospital and School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China.,Wenzhou Medical University-Essilor International Research Center (WEIRC), Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Yiguo Pan
- Eye Hospital and School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China.,Wenzhou Medical University-Essilor International Research Center (WEIRC), Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Chenglu Ding
- Eye Hospital and School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China.,Wenzhou Medical University-Essilor International Research Center (WEIRC), Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Ee Woon Lim
- Wenzhou Medical University-Essilor International Research Center (WEIRC), Wenzhou Medical University, Wenzhou, Zhejiang, China.,R&D AMERA, Essilor International, Singapore
| | - Jingwei Zheng
- Eye Hospital and School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Daniel P Spiegel
- Wenzhou Medical University-Essilor International Research Center (WEIRC), Wenzhou Medical University, Wenzhou, Zhejiang, China.,R&D AMERA, Essilor International, Singapore
| | - Björn Drobe
- Wenzhou Medical University-Essilor International Research Center (WEIRC), Wenzhou Medical University, Wenzhou, Zhejiang, China.,R&D AMERA, Essilor International, Singapore
| | - Fan Lu
- Eye Hospital and School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China .,Wenzhou Medical University-Essilor International Research Center (WEIRC), Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Hao Chen
- Eye Hospital and School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China .,Wenzhou Medical University-Essilor International Research Center (WEIRC), Wenzhou Medical University, Wenzhou, Zhejiang, China
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26
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Rozema JJ. Estimating principal plane positions for ocular power calculations in children and adults. Ophthalmic Physiol Opt 2021; 41:409-413. [PMID: 33399238 DOI: 10.1111/opo.12781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 12/01/2020] [Accepted: 12/01/2020] [Indexed: 11/28/2022]
Abstract
PURPOSE To develop an age-dependent model to estimate the positions of the ocular and lenticular principal planes (pps) for use in ocular and axial power calculations. METHODS Ocular power of the eye (Peye ) and axial power (Pax ) were calculated based on previously published average data of the ocular biometry and refraction in newborn infants, children and adults, as well as the associated pp positions. Next, regressions of the pp positions were made as a function of the logarithm of age, which were subsequently used to estimate Peye and Pax . These regression-based estimates were compared with the original data for validation. Finally, this procedure was repeated using the Atchison myopic eye model to determine the influence of myopia on the regression estimates. RESULTS In adults, the corneal pps almost coincide at 0.058 mm in front of the cornea. The first lenticular pp position relative to the corneal apex is described by the equation: 5.809 - 0.697·exp(-0.211·Age) (r2 = 0.96), and the second lenticular pp by 6.026 - 0.684·exp(-0.232·Age) (r2 = 0.95). The first ocular pp position relative to the corneal apex is at 0.293·exp(-0.232·Age) - 2.2·10-3 ·Age + 1.723 (r2 = 0.99) and the second ocular pp is located at 0.392·exp(-0.181·Age) - 2.4·10-3 ·Age + 2.093 (r2 = 0.99). Estimates of Peye and Pax derived from these regressions led to minor differences from the original values (0.00 ± 0.06D and 0.00 ± 0.10D, respectively). These errors were not affected by ocular refraction between -10D and 0D, with errors of + 0.12 ± 0.00D and -0.02 ± 0.05D for Peye and Pax , respectively. CONCLUSION The proposed regression models of the pp positions are sufficiently accurate to estimate Peye and Pax reliably. Interestingly, although the adult lens undergoes considerable physiological changes, its pps remain fixed with respect to the corneal apex.
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Affiliation(s)
- Jos J Rozema
- Visual Optics Lab Antwerp (VOLANTIS), Department of Ophthalmology, Antwerp University Hospital, Edegem, Belgium.,Department of Medicine and Health Sciences, Antwerp University, Wilrijk, Belgium
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Motwani M. Analysis and Causation of All Inaccurate Outcomes After WaveLight Contoura LASIK with LYRA Protocol. Clin Ophthalmol 2020; 14:3841-3854. [PMID: 33223821 PMCID: PMC7672711 DOI: 10.2147/opth.s267091] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 09/03/2020] [Indexed: 11/23/2022] Open
Abstract
Purpose This study analyzes every eye that had an outcome greater than 0.25D of sphere or astigmatism from planned goal after treatment with WaveLight Contoura with LYRA Protocol. Methods The study included 266 consecutive eyes treated with LASIK Contoura using the LYRA Protocol. All LASIK procedures were performed on the WaveLight EX500 excimer laser. Flaps were created with either the Alcon WaveLight FS200 femtosecond laser or the Moria M2 microkeratome. Eyes that were off by >0.25 diopters (D) sphere or cylinder from the targeted goal within 3 months after surgery were identified and analyzed for cause. Topographical, higher-order aberration, and epithelial maps were created. Results Causes for inaccurate outcomes were biomechanical corneal change from LASK flap creation (9.78% of total eyes), pre-operative epithelial compensation of corneal higher-order aberration (4.1% of total eyes), changes to lamellar corneal tension from laser ablation causing a hyperopic shift (1.9% of total eyes), epithelial thickening over the ablation area post-operatively causing a refractive change (1.5% of total eyes), and posterior astigmatism (0.75%). Conclusion The causes of the majority of inaccurate outcomes have not been properly defined and must be incorporated into further improving outcomes. Current and planned advances in technology do not address the majority of these causes.
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Montesano G, Ometto G, Hogg RE, Rossetti LM, Garway-Heath DF, Crabb DP. Revisiting the Drasdo Model: Implications for Structure-Function Analysis of the Macular Region. Transl Vis Sci Technol 2020; 9:15. [PMID: 32974087 PMCID: PMC7490226 DOI: 10.1167/tvst.9.10.15] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 08/13/2020] [Indexed: 02/07/2023] Open
Abstract
Purpose To provide a consistent implementation of a retinal ganglion cell (RGC) displacement model proposed by Drasdo et al. for macular structure-function analysis, customizable by axial length (AL). Methods The effect of axial length on the shape of the inner retina was measured on 235 optical coherence tomography (OCT) scans from healthy eyes, to provide evidence for geometric scaling of structures with eye size. Following this assumption, we applied the Drasdo model to map perimetric stimuli on the radially displaced RGCs using two different methods: Method 1 only displaced the center of the stimuli; Method 2 applied the displacement to every point on the edge of the stimuli. We compared the accuracy of the two methods by calculating, for each stimulus, the number of expected RGC receptive fields and the number RGCs calculated from the histology map, expected to be equivalent. The same calculation was repeated on RGC density maps derived from 28 OCT scans from 28 young healthy subjects (age < 40 years) to confirm our results on clinically available measurements. Results The size of the retinal structures significantly increased with AL (P < 0.001) and was well predicted by geometric scaling. Method 1 systematically underestimated the RGC counts by as much as 60%. No bias was observed with Method 2. Conclusions The Drasdo model can effectively account for AL assuming geometric scaling. Method 2 should be used for structure-function analyses. Translational Relevance We developed a free web App in Shiny R to make our results available for researchers.
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Affiliation(s)
- Giovanni Montesano
- City, University of London-Optometry and Visual Sciences, London, UK.,NIHR Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK
| | - Giovanni Ometto
- City, University of London-Optometry and Visual Sciences, London, UK.,NIHR Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK
| | - Ruth E Hogg
- Centre for Public Health, Queen's University Belfast, Block B, Royal Hospital, Grosvenor Road, Belfast, Northern Ireland
| | | | - David F Garway-Heath
- NIHR Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK
| | - David P Crabb
- City, University of London-Optometry and Visual Sciences, London, UK
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Queirós A, Pereira-da-Mota AF, Costa J, Amorim-de-Sousa A, Fernandes PRB, González-Méijome JM. Retinal Response of Low Myopes during Orthokeratology Treatment. J Clin Med 2020; 9:E2649. [PMID: 32824056 PMCID: PMC7463747 DOI: 10.3390/jcm9082649] [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: 07/15/2020] [Revised: 08/05/2020] [Accepted: 08/10/2020] [Indexed: 11/16/2022] Open
Abstract
The aim of this study was to evaluate the changes in retinal activity during orthokeratology (OK) treatment in 20 myopic eyes. Pattern electroretinography (PERG) and visual evoked potential (VEP) were assessed with the RETI-port/scan21 (Roland Consult, Wiesbaden, Germany). Measurements were taken at baseline (BL) and 1 night (1N), 15 nights (15N), 30 nights (30N), and 60 nights (60N) of OK lens wear. Repeated measures analysis of variance (ANOVA) and the Friedman test were used. Twenty eyes (23.20 ± 3.46 years, 70% female) with visual acuity ≤ 0.00 logMAR in post-treatment showed that despite a slight increase in retinal and cortical response amplitude, observed with both PERG and VEP, respectively, immediately after the initial treatment, these differences found were not statistically significant during the 60 days of OK treatment, despite a statistically significant increase in N95 response with PERG. This shows that retinal and cortical visual-related electrical activity is maintained or slightly increased during OK treatment.
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Affiliation(s)
- António Queirós
- Clinical & Experimental Optometry Research Lab (CEORLab), Center of Physics, School of Science, University of Minho, Gualtar, 4710-057 Braga, Portugal; (A.F.P.-d.-M.); (J.C.); (A.A.-d.-S.); (P.R.B.F.); (J.M.G.-M.)
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Motwani M. Biomechanical Changes to the Cornea from LASIK Flap Creation Resulting in Inaccurate Ablations and Suboptimal Refractive Outcomes with Topographic-Guided Ablation. Clin Ophthalmol 2020; 14:2319-2327. [PMID: 32848360 PMCID: PMC7429235 DOI: 10.2147/opth.s263896] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 07/23/2020] [Indexed: 01/10/2023] Open
Abstract
Purpose This study documents a biomechanical corneal change related to corneal flap creation in certain patients leading to an irregular ablation pattern and an inaccurate refractive outcome. Methods This retrospective study included consecutive eyes treated with primary LASIK Contoura using the LYRA Protocol. All LASIK procedures were performed on the WaveLight EX500 excimer laser. Flaps were created with either the Alcon WaveLight FS200 femtosecond laser or the Moria M2 microkeratome. Eyes that were off by greater than or equal to 0.50 diopters (D) sphere or cylinder from the targeted goal within 3 months after surgery were identified. Topographical, higher order aberration, and epithelial maps were created. Of these eyes, approximately 10% of eyes were found to have undergone a biomechanical change upon flap creation that led to an inaccurate outcome. Results Six representative cases are presented that demonstrate the biomechanical change, outcomes, and treatment. All patients demonstrated an elliptical, irregular ablation pattern on post-operative topography, lateralized the thinnest point of the cornea relative to the corneal apex on Pentacam pachymetry maps, and irregular corneal epithelial thickening at the periphery of the elliptical ablation. Conclusion A biomechanical change during flap creation can occur in certain types of corneas during LASIK flap creation and subsequent treatment with topographic-guided ablation leading to an irregular ablation and suboptimal refractive outcomes.
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Wu JY, Kim J. Prescription AR: a fully-customized prescription-embedded augmented reality display. OPTICS EXPRESS 2020; 28:6225-6241. [PMID: 32225876 DOI: 10.1364/oe.380945] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
In this paper, we present a fully-customized AR display design that considers the user's prescription, interpupillary distance, and taste of fashion. A free-form image combiner embedded inside the prescription lens provides augmented images onto the vision-corrected real world. The optics was optimized for each prescription level, which can reduce the mass production cost while satisfying the user's taste. The foveated optimization method was applied which distributes the pixels in accordance with human visual acuity. Our design can cover myopia, hyperopia, astigmatism, and presbyopia, and allows the eye-contact interaction with privacy protection. A 169g dynamic prototype showed a 40° × 20° virtual image with a 23 cpd resolution at center field and 6 mm × 4 mm eye-box, with the vision-correction and varifocal (0.5-3m) capability.
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Fernández J, Rodríguez-Vallejo M, Martínez J, Tauste A, Piñero DP. Patient selection to optimize near vision performance with a low-addition trifocal lens. JOURNAL OF OPTOMETRY 2020; 13:50-58. [PMID: 31680039 PMCID: PMC6951843 DOI: 10.1016/j.optom.2019.06.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 05/31/2019] [Accepted: 06/26/2019] [Indexed: 06/10/2023]
Abstract
PURPOSE To assess the impact of ocular biometric variables on the visual performance achieved with a low addition trifocal intraocular lens (MIOL). METHODS Retrospective observational study including 34 eyes. Preoperative measured variables included mean corneal power (Km), corneal regular astigmatism (RA), anterior chamber depth (ACD), axial length (AXL), total irregular astigmatism (IA), spherical aberration (SA) and distance from pupil center to vertex normal (µ). Same variables were retrieved from the three month visit follow-up in addition to the actual lens position (ALP), the calculated effective addition (EA), the IOL centration from vertex normal (d), and the visual acuity defocus curve. The area under the defocus curve was computed along the total curve (TAUC) and ranges for far (FAUC), intermediate (IAUC) and near vision (NAUC). The sample was split in two groups of 17 eyes with TAUCs above and below the mean, and the differences among groups for different ocular parameters were assessed. RESULTS The group of eyes above TAUC of 2.03 logMAR*m-1 showed significantly lower Km and greater AXL and SA. Km was negatively correlated with TAUC and NAUC. NAUC was negatively correlated with IA and positively with d. A multiple lineal regression model including Km, d, and IA predicted NAUC (r-square = 34%). No significant differences between IA and SA were found between preoperative and postoperative values but µ significantly decreased after surgery. CONCLUSIONS The mean corneal power, irregular astigmatism, and centration from vertex normal should be considered for optimizing the near visual performance with this MIOL.
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Affiliation(s)
- Joaquín Fernández
- Department of Ophthalmology (Qvision), Vithas Virgen del Mar Hospital, 04120, Almería, Spain
| | | | - Javier Martínez
- Department of Ophthalmology (Qvision), Vithas Virgen del Mar Hospital, 04120, Almería, Spain
| | - Ana Tauste
- Department of Ophthalmology (Qvision), Vithas Virgen del Mar Hospital, 04120, Almería, Spain
| | - David P Piñero
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain; Department of Ophthalmology (IMQO-Oftalmar), Vithas Medimar International Hospital, Alicante, Spain
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Gifford KL, Gifford P, Hendicott PL, Schmid KL. Stability of peripheral refraction changes in orthokeratology for myopia. Cont Lens Anterior Eye 2019; 43:44-53. [PMID: 31796369 DOI: 10.1016/j.clae.2019.11.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 11/18/2019] [Accepted: 11/18/2019] [Indexed: 12/15/2022]
Abstract
PURPOSE Orthokeratology (OK) is known to alter relative peripheral refraction (RPR) with this presumed to be its key myopia control mechanism. A prospective, longitudinal study was performed to examine stability of OK-induced RPR changes in myopic children and young adults. METHODS RPR of twelve children (C)(8-16 years) and eight adults (A)(18-29 years) with spherical equivalent refraction of -0.75 to -5.00D were measured unaided and while wearing single vision soft contact lenses (SCL). Measurements were repeated after 1, 6 and 12 months of OK wear. RPR was measured using an open-field Shin Nippon SRW-5000 autorefractor at 10, 20 and 30 degrees nasally (N) and temporally (T), converted into power vectors M, J0 and J45. On-axis refractions and axial lengths (IOL Master) were also measured. RESULTS Compared to the unaided state, 1-month of OK wear shifted the RPR in the myopic direction at 30 T (C: p = 0.023; A:, p = 0.002) and 30 N (C&A, p = 0.003) and was stable thereafter, with similar changes compared to SCL wear. J0 showed a myopic shift in comparison to both unaided and SCL correction in children but not adults, and J45 did not change in either group. The on-axis OK correction was predictive of the RPR shift in both children and adults at 30 T (C: r=-0.58, p = 0.029; A: r=-0.92, p < 0.001) and 30 N (C: r=-0.60, p = 0.024; A: r=-0.74, p = 0.013) with symmetry of RPR shifts (C: r = 0.67, p = 0.008; A: r = 0.85, p = 0.004). No relationships between changes in RPR and axial length were found after twelve months of OK wear; level of myopia was stable in both groups. CONCLUSION Relative to both unaided and single vision SCL correction, OK shifted the RPR in the myopic direction; the RPR was stable from 1 to 12 months. The RPR shift in OK wear varied with the degree of myopia but was not correlated with myopia progression.
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Affiliation(s)
- Kate L Gifford
- School of Optometry and Vision Science, and Institute of Health and Biomedical Innovation, Faculty of Health, Queensland University of Technology, 60 Musk Avenue, Kelvin Grove QLD 4059 Australia.
| | - Paul Gifford
- School of Optometry and Vision Science, Faculty of Science, University of New South Wales, Rupert Myers Building, Barker Street, Kensington NSW 2033 Australia
| | - Peter L Hendicott
- School of Optometry and Vision Science, and Institute of Health and Biomedical Innovation, Faculty of Health, Queensland University of Technology, 60 Musk Avenue, Kelvin Grove QLD 4059 Australia
| | - Katrina L Schmid
- School of Optometry and Vision Science, and Institute of Health and Biomedical Innovation, Faculty of Health, Queensland University of Technology, 60 Musk Avenue, Kelvin Grove QLD 4059 Australia
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Suliman A, Rubin A. A review of higher order aberrations of the human eye. AFRICAN VISION AND EYE HEALTH 2019. [DOI: 10.4102/aveh.v78i1.501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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Wildsoet CF, Chia A, Cho P, Guggenheim JA, Polling JR, Read S, Sankaridurg P, Saw SM, Trier K, Walline JJ, Wu PC, Wolffsohn JS. IMI - Interventions Myopia Institute: Interventions for Controlling Myopia Onset and Progression Report. Invest Ophthalmol Vis Sci 2019; 60:M106-M131. [PMID: 30817829 DOI: 10.1167/iovs.18-25958] [Citation(s) in RCA: 217] [Impact Index Per Article: 43.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Myopia has been predicted to affect approximately 50% of the world's population based on trending myopia prevalence figures. Critical to minimizing the associated adverse visual consequences of complicating ocular pathologies are interventions to prevent or delay the onset of myopia, slow its progression, and to address the problem of mechanical instability of highly myopic eyes. Although treatment approaches are growing in number, evidence of treatment efficacy is variable. This article reviews research behind such interventions under four categories: optical, pharmacological, environmental (behavioral), and surgical. In summarizing the evidence of efficacy, results from randomized controlled trials have been given most weight, although such data are very limited for some treatments. The overall conclusion of this review is that there are multiple avenues for intervention worthy of exploration in all categories, although in the case of optical, pharmacological, and behavioral interventions for preventing or slowing progression of myopia, treatment efficacy at an individual level appears quite variable, with no one treatment being 100% effective in all patients. Further research is critical to understanding the factors underlying such variability and underlying mechanisms, to guide recommendations for combined treatments. There is also room for research into novel treatment options.
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Affiliation(s)
- Christine F Wildsoet
- Berkeley Myopia Research Group, School of Optometry and Vision Science Program, University of California Berkeley, Berkeley, California, United States
| | - Audrey Chia
- Singapore Eye Research Institute and Singapore National Eye Center, Singapore
| | - Pauline Cho
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong
| | - Jeremy A Guggenheim
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom
| | - Jan Roelof Polling
- Erasmus MC Department of Ophthalmology, Rotterdam, The Netherlands.,HU University of Applied Sciences, Optometry and Orthoptics, Utrecht, The Netherlands
| | - Scott Read
- School of Optometry and Vision Science and Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia
| | - Padmaja Sankaridurg
- Brien Holden Vision Institute and School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
| | - Seang-Mei Saw
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore
| | - Klaus Trier
- Trier Research Laboratories, Hellerup, Denmark
| | - Jeffrey J Walline
- The Ohio State University College of Optometry, Columbus, Ohio, United States
| | - Pei-Chang Wu
- Department of Ophthalmology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - James S Wolffsohn
- Ophthalmic Research Group, Aston University, Birmingham, United Kingdom
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Abstract
The aperture stop of the iris is subject to refraction by the cornea, and thus an outside observer sees a virtual image: the “entrance pupil” of the eye. When viewed off-axis, the entrance pupil has an elliptical form. The precise appearance of the entrance pupil is a consequence of the anatomical and optical properties of the eye, and the relative positions of the eye and the observer. This paper presents a ray traced model eye that provides the parameters of the entrance pupil ellipse for an observer at an arbitrary location. The model is able to reproduce empirical measurements of the shape of the entrance pupil with good accuracy. I demonstrate that accurate specification of the entrance pupil of a stationary eye requires modeling of corneal refraction, the misalignment of the visual and optical axes, and the non-circularity of the aperture stop. The model, including a three-dimensional ray tracing function through quadric surfaces, is implemented in open-source MATLAB code.
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Affiliation(s)
- Geoffrey K Aguirre
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.
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Liu Y, Wang Y. Optical quality comparison between laser ablated myopic eyes with centration on coaxially sighted corneal light reflex and on entrance pupil center. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2019; 36:B103-B109. [PMID: 31044979 DOI: 10.1364/josaa.36.00b103] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 02/24/2019] [Indexed: 06/09/2023]
Abstract
This paper aims to compare the image quality between centration on the coaxially sighted corneal light reflex (CSCLR) and on the entrance pupil center (EPC). Myopic laser ablation was simulated on eye models, and the optical performances were compared. Centration on the EPC leads to higher wavefront aberrations and lower modulation transfer function. The two centration methods give nearly identical retinal images for angle kappa less than 5°. Because of less tissue removal, centration on the EPC is probably preferable for angle kappa less than 5°, but CSCLR centration may be preferable for angle kappa larger than 5°. The degree of tilt of the post-surgery anterior corneal surface explains the differences between the two methods.
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Ji Q, Yoo YS, Alam H, Yoon G. Through-focus optical characteristics of monofocal and bifocal soft contact lenses across the peripheral visual field. Ophthalmic Physiol Opt 2019; 38:326-336. [PMID: 29691930 DOI: 10.1111/opo.12452] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Accepted: 03/15/2018] [Indexed: 12/17/2022]
Abstract
PURPOSE To characterise the impact of monofocal soft contact lens (SCL) and bifocal SCLs on refractive error, depth of focus (DoF) and orientation of blur in the peripheral visual field. METHODS Monofocal and two bifocal SCLs, Acuvue Bifocal (AVB, Johnson & Johnson) and Misight Dual Focus (DF, CooperVision) with +2.0 D add power were modelled using a ray tracing program (ZEMAX) based on their power maps. These SCLs were placed onto the anterior corneal surface of the simulated Atchison myopic eye model to correct for -3.0 D spherical refractive error at the fovea. To quantify through-focus retinal image quality, defocus from -3.5 D to 1.5 D in 0.5 D steps was induced at each horizontal eccentricity from 0 to 40° in 10° steps. Wavefront aberrations were computed for each visual eccentricity and defocus. The retinal images were simulated using a custom software program developed in Matlab (The MathWorks) by convolving the point spread function calculated from the aberration with a reference image. The convolved images were spatially filtered to match the spatial resolution limit of each peripheral eccentricity. Retinal image quality was then quantified by the 2-D cross-correlation between the filtered convolved retinal images and the reference image. Peripheral defocus, DoF and orientation of blur were also estimated. RESULTS In comparison with the monofocal SCL, the bifocal SCLs degraded retinal image quality while DoF was increased at fovea. From 10 to 20°, a relatively small amount of myopic shift (less than 0.3 D) was induced by bifocal SCLs compared with monofocal. DoF was also increased with bifocal SCLs at peripheral vision of 10 and 20°. The trend of myopic shift became less consistent at larger eccentricity, where at 30° DF showed a 0.75 D myopic shift while AVB showed a 0.2 D hyperopic shift and both AVB and DF exhibited large relative hyperopic defocus at 40°. The anisotropy in orientation of blur was found to increase and change its direction through focus beyond central vision. This trend was found to be less dominant with bifocal SCLs compared to monofocal SCL. CONCLUSIONS Bifocal SCLs have a relatively small impact on myopic shift in peripheral refractive error while DoF is increased significantly. We hypothetically suggest that a mechanism underlying myopia control with these bifocal or multifocal contact lenses is an increase in DoF and a decrease in anisotropy of peripheral optical blur.
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Affiliation(s)
- Qiuzhi Ji
- Flaum Eye Institute, The Institute of Optics, Center for Visual Science, University of Rochester, Rochester, USA
| | - Young-Sik Yoo
- Flaum Eye Institute, The Institute of Optics, Center for Visual Science, University of Rochester, Rochester, USA.,Department of Convergence Medical Science, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Hira Alam
- Flaum Eye Institute, The Institute of Optics, Center for Visual Science, University of Rochester, Rochester, USA.,Department of Biology, University of Rochester, Rochester, USA
| | - Geunyoung Yoon
- Flaum Eye Institute, The Institute of Optics, Center for Visual Science, University of Rochester, Rochester, USA
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Li Q, Fang F. Advances and challenges of soft contact lens design for myopia control. APPLIED OPTICS 2019; 58:1639-1656. [PMID: 30874202 DOI: 10.1364/ao.58.001639] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Myopia has shown a rapid increase during the past decades around the world, posing great threat to ocular health. Myopia is mostly attributed to an overgrowth of the axial length of the eye, which is an abnormal growth of the sclera that is attributed to a series of environmental and genetic factors and their interactions. Soft contact lenses have the potential to be an ideal method of correction for slowing myopic progression. This paper serves as a comprehensive review of the state of the art in the field of soft contact lens design for myopia control. The knowledge gaps are identified in designing the contact lenses and potential challenges are also presented that could be faced in future development.
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Zapata-Díaz JF, Radhakrishnan H, Charman WN, López-Gil N. Accommodation and age-dependent eye model based on in vivo measurements. JOURNAL OF OPTOMETRY 2019; 12:3-13. [PMID: 29573985 PMCID: PMC6318498 DOI: 10.1016/j.optom.2018.01.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 01/09/2018] [Accepted: 01/20/2018] [Indexed: 06/02/2023]
Abstract
PURPOSE To develop a flexible model of the average eye that incorporates changes with age and accommodation in all optical parameters, including entrance pupil diameter, under photopic, natural, environmental conditions. METHODS We collated retrospective in vivo measurements of all optical parameters, including entrance pupil diameter. Ray-tracing was used to calculate the wavefront aberrations of the eye model as a function of age, stimulus vergence and pupil diameter. These aberrations were used to calculate objective refraction using paraxial curvature matching. This was also done for several stimulus positions to calculate the accommodation response/stimulus curve. RESULTS The model predicts a hyperopic change in distance refraction as the eye ages (+0.22D every 10 years) between 20 and 65 years. The slope of the accommodation response/stimulus curve was 0.72 for a 25 years-old subject, with little change between 20 and 45 years. A trend to a more negative value of primary spherical aberration as the eye accommodates is predicted for all ages (20-50 years). When accommodation is relaxed, a slight increase in primary spherical aberration (0.008μm every 10 years) between 20 and 65 years is predicted, for an age-dependent entrance pupil diameter ranging between 3.58mm (20 years) and 3.05mm (65 years). Results match reasonably well with studies performed in real eyes, except that spherical aberration is systematically slightly negative as compared with the practical data. CONCLUSIONS The proposed eye model is able to predict changes in objective refraction and accommodation response. It has the potential to be a useful design and testing tool for devices (e.g. intraocular lenses or contact lenses) designed to correct the eye's optical errors.
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Affiliation(s)
- Juan F Zapata-Díaz
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Hema Radhakrishnan
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, United Kingdom
| | - W Neil Charman
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Norberto López-Gil
- Facultad de Óptica y Optometría, Universidad de Murcia, 30100 Murcia, Spain.
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Nadeem Akram M, Baraas RC, Baskaran K. Improved wide-field emmetropic human eye model based on ocular wavefront measurements and geometry-independent gradient index lens. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2018; 35:1954-1967. [PMID: 30461856 DOI: 10.1364/josaa.35.001954] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
There is a need to better understand the peripheral optics of the human eye and their correction. Current eye models have some limitations to accurately predict the wavefront errors for the emmetropic eye over a wide field. The aim here was to develop an anatomically correct optical model of the human eye that closely reproduces the wavefront of an average Caucasian-only emmetropic eye across a wide visual field. Using an optical design program, a schematic eye was constructed based on ocular wavefront measurements of the right eyes of thirty healthy young emmetropic individuals over a wide visual field (from 40° nasal to 40° temporal and up to 20° inferior field). Anatomical parameters, asymmetries, and dispersion properties of the eye's different optical components were taken into account. A geometry-independent gradient index model was employed to better represent the crystalline lens. The RMS wavefront error, wavefront shapes, dominant Zernike coefficients, nasal-temporal asymmetries, and dispersion properties of the developed schematic eye closely matched the corresponding measured values across the visual field. The developed model can help in the design of wide-field ophthalmic instruments and is useful in the study and simulations of the peripheral optics of the human eye.
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Abstract
Contact lenses have been a common means of vision correction for more than half a century. Recent developments have raised the possibility that the next few decades will see a considerable broadening of the range of applications for contact lenses, with associated expansions in the number and type of individuals who consider them a valuable option. The novel applications of contact lenses include treatment platforms for myopic progression, biosensors, and ocular drug delivery. Orthokeratology has shown the most consistent treatment for myopia control with the least side effects. Recent work has resulted in commercialization of a device to monitor intraocular pressure for up to 24 hours, and extensive efforts are underway to develop a contact lens sensor capable of continuous glucose tear film monitoring for the management of diabetes. Other studies on drug-eluting contact lenses have focused on increasing the release duration through molecular imprinting, use of vitamin E, and increased drug binding to polymers by sandwiching a poly (lactic-co-glycolic acid) layer in the lens. This review demonstrates the potential for contact lenses to provide novel opportunities for refractive management, diagnosis, and management of diseases.
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Rodriguez-Vallejo M, Montagud D, Monsoriu JA, Ferrando V, Furlan WD. Relative Peripheral Myopia Induced by Fractal Contact Lenses. Curr Eye Res 2018; 43:1514-1521. [PMID: 30089428 DOI: 10.1080/02713683.2018.1507043] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
PURPOSE To assess the peripheral refraction induced by Fractal Contact Lenses (FCLs) in myopic eyes by means of a two-dimensional Relative Peripheral Refractive Error (RPRE) map. MATERIALS AND METHODS This study involved 26 myopic subjects ranging from -0.50 D to -7.00 D. FCLs prototypes were custom-manufactured and characterized. Corneal topographies were taken in order to assess correlations between corneal asphericity and lens decentration. Two-dimensional RPREs were measured with an open-field autorefractor at 67 points, covering the central 60 × 30 degrees of the visual field. The bidimensional RPRE vector components: M, J0 and J45 of the difference between the values obtained with and without the FCLs in the eye were obtained. Additionally, the FCL-induced peripheral refraction in tangential and sagittal planes was computed along the horizontal meridian. RESULTS Induced by the FCLs, significant differences for all vector components were found in the peripheral retina. FCLs were decentered a mean of 0.7 ± 0.19 mm to the temporal cornea. The two-dimensional RPRE maps manifested the FCLs decentration. In particular, M varied asymmetrically between nasal and temporal retina after fitting the FCLs with a significant increment of the myopic shift beyond 10º (p < 0.05). No correlations were found between the amount of lens decentration and the asphericity of the cornea along temporal and nasal sides. However, significant correlations were found between the corneal asphericity and vector components of the RPRE in naked eyes. FCLs produced an increasing myopic shift in tangential and sagittal power errors along the horizontal meridian. CONCLUSIONS As predicted by ray-tracing simulations, FCLs fitted in myopic eyes produce a myopic shift of the RPRE. The two-dimensional RPRE maps show information about the lens performance that is hidden in the conventional one-dimensional meridional representations.
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Affiliation(s)
| | - Diego Montagud
- b Centro de Tecnologías Físicas , Universitat Politècnica de València , Valencia , Spain
| | - Juan A Monsoriu
- b Centro de Tecnologías Físicas , Universitat Politècnica de València , Valencia , Spain
| | - Vicente Ferrando
- c Departamento de Óptica , Universitat de València , Burjassot , Spain
| | - Walter D Furlan
- c Departamento de Óptica , Universitat de València , Burjassot , Spain
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Group Analysis of Q Values Calculated with Tangential Radius of Curvature from Human Anterior Corneal Surface. J Ophthalmol 2018; 2018:7263564. [PMID: 29850210 PMCID: PMC5932450 DOI: 10.1155/2018/7263564] [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: 10/03/2017] [Accepted: 01/31/2018] [Indexed: 11/18/2022] Open
Abstract
Objective To calculate the Q values from the human anterior corneal surface with the tangential radius of curvature and analyze its distribution characteristics in different age and refractive status groups. Methods Tangential power maps of the anterior cornea from Orbscan II were acquired for 201 subjects' right eyes. They were divided into groups of adults and children and then divided further into subgroups according to the refraction status. The Q values of each semimeridian were calculated by the tangential radius with a linear regression equation. The Q value distribution in both the nasal cornea and temporal cornea were analyzed. Results The mean temporal Q values of the emmetropia group of adults and all children's groups were significantly different from the mean nasal Q value. The mean nasal corneal Q values were more negative in children. The adult group showed differences only in the low myopia group. The mean Q value of the nasal cornea among different refractive groups of children was significantly different, and so was the temporal cornea between the adult myopia and emmetropia group. Conclusion The method using the tangential radius of curvature combined with linear regression to obtain anterior surface Q values for both adults and children was stable and reliable. When we analyzed the anterior corneal Q value, area division was necessary.
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Remón L, Siedlecki D, Cabeza-Gil I, Calvo B. Influence of material and haptic design on the mechanical stability of intraocular lenses by means of finite-element modeling. JOURNAL OF BIOMEDICAL OPTICS 2018; 23:1-10. [PMID: 29508566 DOI: 10.1117/1.jbo.23.3.035003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 02/12/2018] [Indexed: 06/08/2023]
Abstract
Intraocular lenses (IOLs) are used in the cataract treatment for surgical replacement of the opacified crystalline lens. Before being implanted they have to pass the strict quality control to guarantee a good biomechanical stability inside the capsular bag, avoiding the rotation, and to provide a good optical quality. The goal of this study was to investigate the influence of the material and haptic design on the behavior of the IOLs under dynamic compression condition. For this purpose, the strain-stress characteristics of the hydrophobic and hydrophilic materials were estimated experimentally. Next, these data were used as the input for a finite-element model (FEM) to analyze the stability of different IOL haptic designs, according to the procedure described by the ISO standards. Finally, the simulations of the effect of IOL tilt and decentration on the optical performance were performed in an eye model using a ray-tracing software. The results suggest the major importance of the haptic design rather than the material on the postoperative behavior of an IOL. FEM appears to be a powerful tool for numerical studies of the biomechanical properties of IOLs and it allows one to help in the design phase to the manufacturers.
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Affiliation(s)
- Laura Remón
- Universidad de Zaragoza, Departamento de Física Aplicada, Facultad de Ciencias, Zaragoza, España
| | - Damian Siedlecki
- Wroclaw University of Science and Technology, Visual Optics Group, Department of Optics and Photonic, Poland
| | - Iulen Cabeza-Gil
- Universidad de Zaragoza, Escuela de Ingeniería y Arquitectura (EINA), Aragón Institute of Engineerin, España
| | - Begoña Calvo
- Universidad de Zaragoza, Escuela de Ingeniería y Arquitectura (EINA), Aragón Institute of Engineerin, España
- Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Spain
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Faria-Ribeiro M, Amorim-de-Sousa A, González-Méijome JM. Predicted accommodative response from image quality in young eyes fitted with different dual-focus designs. Ophthalmic Physiol Opt 2018; 38:309-316. [PMID: 29383756 DOI: 10.1111/opo.12443] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 12/01/2017] [Indexed: 12/22/2022]
Abstract
PURPOSE To investigate the separated and combined influences of inner zone (IZ) diameter and effective add power of dual-focus contact lenses (CL) in the image quality at distance and near viewing, in a functional accommodating model eye. METHODS Computational wave-optics methods were used to define zonal bifocal pupil functions, representing the optic zones of nine dual-focus centre-distance CLs. The dual-focus pupil functions were defined having IZ diameters of 2.10 mm, 3.36 mm and 4.00 mm, with add powers of 1.5 D, 2.0 D and 2.5 D (dioptres), for each design, that resulted in a ratio of 64%/36% between the distance and treatment zone areas, bounded by a 6 mm entrance pupil. A through-focus routine was implemented in MATLAB to simulate the changes in image quality, calculated from the Visual Strehl ratio, as the eye with the dual-focus accommodates, from 0 to -3.00 D target vergences. Accommodative responses were defined as the changes in the defocus coefficient, combined with a change in fourth and sixth order spherical aberration, which produced a peak in image quality at each target vergence. RESULTS Distance viewing image quality was marginally affected by IZ diameter but not by add power. Near image quality obtained when focussing the image formed by the near optics was only higher by a small amount compared to the other two IZ diameters. The mean ± standard deviation values obtained with the three adds were 0.28 ± 0.02, 0.23 ± 0.02 and 0.22 ± 0.02, for the small, medium and larger IZ diameters, respectively. On the other hand, near image quality predicted by focussing the image formed by the distance optics was considerably lower relatively to the other two IZ diameters. The mean ± standard deviation values obtained with the three adds were 0.15 ± 0.01, 0.38 ± 0.00 and 0.54 ± 0.01, for the small, medium and larger IZ diameters, respectively. CONCLUSIONS During near viewing through dual-focus CLs, image quality depends on the diameter of the most inner zone of the CL, while add power only affects the range of clear focus when focussing the image formed by the CL near optics. When only image quality gain is taken into consideration, medium and large IZ diameters designs are most likely to promote normal accommodative responses driven by the CL distance optics, while a smaller IZ diameter design is most likely to promote a reduced accommodative response driven by the dual-focus CL near optics.
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Affiliation(s)
- Miguel Faria-Ribeiro
- Clinical & Experimental Optometry Research Lab (CEORLab), Center of Physics, University of Minho, Braga, Portugal
| | - Ana Amorim-de-Sousa
- Clinical & Experimental Optometry Research Lab (CEORLab), Center of Physics, University of Minho, Braga, Portugal
| | - José M González-Méijome
- Clinical & Experimental Optometry Research Lab (CEORLab), Center of Physics, University of Minho, Braga, Portugal
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Bakaraju RC, Ehrmann K, Ho A. Extended depth of focus contact lenses vs. two commercial multifocals: Part 1. Optical performance evaluation via computed through-focus retinal image quality metrics. JOURNAL OF OPTOMETRY 2018; 11:10-20. [PMID: 28606456 PMCID: PMC5777930 DOI: 10.1016/j.optom.2017.04.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 02/12/2017] [Accepted: 04/21/2017] [Indexed: 05/20/2023]
Abstract
PURPOSE To compare the computed optical performance of prototype lenses designed using deliberate manipulation of higher-order spherical aberrations to extend depth-of-focus (EDOF) with two commercial multifocals. METHODS Emmetropic, presbyopic, schematic eyes were coupled with prototype EDOF and commercial multifocal lenses (Acuvue Oasys for presbyopia, AOP, Johnson & Johnson & Air Optix Aqua multifocal, AOMF, Alcon). For each test configuration, the through-focus retinal image quality (TFRIQ) values were computed over 21 vergences, ranging from -0.50 to 2.00D, in 0.125D steps. Analysis was performed considering eyes with three different inherent aberration profiles: five different pupils and five different lens decentration levels. RESULTS Except the LOW design, the AOP lenses offered 'bifocal' like TFRIQ performance. Lens performance was relatively independent to pupil and aberrations but not centration. Contrastingly, AOMF demonstrated distance centric performance, most dominant in LOW followed by MED and HIGH designs. AOMF lenses were the most sensitive to pupil, aberrations and centration. The prototypes demonstrated a 'lift-off' in the TFRIQ performance, particularly at intermediate and near, without trading performance at distance. When compared with AOP and AOMF, EDOF lenses demonstrated reduced sensitivity to pupil, aberrations and centration. CONCLUSION With the through focus retinal image quality as the gauge of optical performance, we demonstrated that the prototype EDOF designs were less susceptible to variations in pupil, inherent ocular aberrations and decentration, compared to the commercial designs. To ascertain whether these incremental improvements translate to a clinically palpable outcome requires investigation through human trials.
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Affiliation(s)
- Ravi C Bakaraju
- Brien Holden Vision Institute, Sydney, Australia; School of Optometry and Vision Science, University of New South Wales, Sydney, Australia.
| | - Klaus Ehrmann
- Brien Holden Vision Institute, Sydney, Australia; School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
| | - Arthur Ho
- Brien Holden Vision Institute, Sydney, Australia; School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
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Jiménez JR, Alarcón A, Anera RG, Jiménez Del Barco L. Q-optimized Algorithms: Theoretical Analysis of Factors Influencing Visual Quality After Myopic Corneal Refractive Surgery. J Refract Surg 2017; 32:612-7. [PMID: 27598731 DOI: 10.3928/1081597x-20160531-01] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Accepted: 05/03/2016] [Indexed: 11/20/2022]
Abstract
PURPOSE To model the effect of pupil size, optical zone, and initial myopic level on the retinal image quality after Q-optimized myopic corneal refractive surgery. METHODS Different Q-optimized and paraxial Munnerlyn algorithms were tested using a schematic myopic eye model to analyze the optical quality of the final retinal image for initial myopic errors from -1.00 to -7.00 diopters (D). Different optical zones (5.5, 6, and 6.5 mm in diameter) and two pupil diameters (5 and 7 mm, mesopic-scotopic conditions) were included in the comparison. Modulation transfer function (MTF) and area under the MTF from 0 to 60 cycles per degree (MTFa) were calculated by ray tracing to evaluate this retinal image quality. RESULTS The Q-optimized algorithm with Q = -0.45 provided the highest MTF and MTFa results for myopic corrections less than -5.00 D. For refractive errors greater than -5.00 D, Q = -0.26 provided the highest MTF and MTFa results. CONCLUSIONS Q-optimized algorithms improve the visual outcomes with respect to the paraxial Munnerlyn algorithm for myopic corneal surgery. The results show that the Q value that optimizes the results of the Q-optimized algorithm depends on the degree of myopia to correct and the size of the pupil. [J Refract Surg. 2016;32(9):612-617.].
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Osuagwu UL, Suheimat M, Atchison DA. Peripheral aberrations in adult hyperopes, emmetropes and myopes. Ophthalmic Physiol Opt 2017; 37:151-159. [PMID: 28211176 DOI: 10.1111/opo.12354] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 12/22/2016] [Indexed: 11/29/2022]
Abstract
PURPOSE To determine differences in peripheral aberrations in hyperopic, emmetropic and myopic groups. METHODS Cycloplegic peripheral aberrations for 5 mm pupils were measured at 39 locations across 42° × 32° of right eye visual fields with a COAS-HD Hartmann-Shack aberrometer in nine hyperopes (mean age 29 ± 5 years, spherical equivalent refraction M + 1.47 ± 0.58 D), 20 emmetropes (28 ± 7 years, +0.06 ± 0.36 D) and 20 myopes (27 ± 6 years, -2.55 ± 1.82 D). Relative peripheral refraction error RPRE and 3rd-4th order Zernike coefficients were compared between the groups. RESULTS Hyperopes and emmetropes had relative peripheral myopia across the visual field, with considerable nasal-temporal asymmetry for both groups and superior-inferior asymmetry for hyperopes. Myopes had minimal RPRE along the horizontal meridian, but myopic RPRE along the vertical meridian which was less than the other groups. There was little difference between groups in astigmatic components or higher-order Zernike coefficients, except for fourth-order spherical aberration which was more positive in hyperopes than in both emmetropes (mean difference ±95% CI = +0.05 ± 0.05 μm, p = 0.03) and myopes (+0.07 ± 0.04 μm, p = 0.003). Coma changed rapidly across the visual field with similar rates for all groups. CONCLUSIONS Hyperopes and emmetropes had greater relative peripheral myopia than myopes. There was asymmetry in RPRE along the vertical meridian for hyperopes which was not present in the emmetropes, suggesting there may be asymmetries in peripheral eye length along the vertical meridian for the former. Higher-order aberrations were affected by field eccentricity, but refractive error affected only the spherical aberration coefficient, which was more positive for hyperopes than for other groups.
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Affiliation(s)
- Uchechukwu L Osuagwu
- Institute of Health & Biomedical Innovation and School of Optometry & Vision Sciences, Queensland University of Technology, Brisbane, Australia
| | - Marwan Suheimat
- Institute of Health & Biomedical Innovation and School of Optometry & Vision Sciences, Queensland University of Technology, Brisbane, Australia
| | - David A Atchison
- Institute of Health & Biomedical Innovation and School of Optometry & Vision Sciences, Queensland University of Technology, Brisbane, Australia
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Changes in Peripheral Refraction, Higher-Order Aberrations, and Accommodative Lag With a Radial Refractive Gradient Contact Lens in Young Myopes. Eye Contact Lens 2017; 42:380-387. [PMID: 26808699 DOI: 10.1097/icl.0000000000000222] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
PURPOSE To evaluate changes in the peripheral refraction (PR), visual quality, and accommodative lag with a novel soft radial refractive gradient (SRRG) experimental contact lens that produces peripheral myopic defocus. METHODS 59 myopic right eyes were fitted with the lens. The PR was measured up to 30° in the nasal and temporal horizontal visual fields and compared with values obtained without the lens. The accommodative lag was measured monocularly using the distance-induced condition method at 40 cm, and the higher-order aberrations (HOAs) of the entire eye were obtained for 3- and 5-mm pupils by aberrometry. Visual performance was assessed through contrast sensitivity function (CSF). RESULTS With the lens, the relative PR became significantly less hyperopic from 30° to 15° temporally and 30° nasally in the M and J0 refractive components (P<0.05). Cylinder foci showed significant myopization from 30° to 15° temporally and 30° to 25° nasally (P<0.05). The HOAs increased significantly, the CSF decreased slightly but reached statistical significance for 6 and 12 cycles per degree (P<0.05), and the accommodative lag decreased significantly with the SRRG lens (P=0.0001). There was a moderate correlation between HOAs and CSF at medium and high spatial frequencies. CONCLUSION The SRRG lens induced a significant change in PR, particularly in the temporal retina. Tangential and sagittal foci changed significantly in the peripheral nasal and temporal retina. The decreased accommodative lag and increased HOAs particularly in coma-like aberration may positively affect myopia control. A longitudinal study is needed to confirm this potential.
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