1
|
Weisensee J, Ringhofer OM, Langenbucher A. Prediction of Visual Acuity in Pseudophakic Cataract Population Based on Residual Refraction. Curr Eye Res 2024; 49:1054-1060. [PMID: 38831678 DOI: 10.1080/02713683.2024.2359981] [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: 02/25/2024] [Revised: 05/06/2024] [Accepted: 05/21/2024] [Indexed: 06/05/2024]
Abstract
PURPOSE The purpose of the study was to design a simple, handy prediction for the effect of spherical and cylindrical refractive error on the visual acuity degradation at different distances and validate this model on a clinical dataset. METHODS This study examined 70 eyes from 35 patients' post-cataract surgery with aberration-free intraocular lenses. Biometric and corneal data were analysed, and subjective refraction and visual acuity were evaluated by two experienced optometrists. The study computed the spherical equivalent (SEQ), and defocus equivalent via vector addition (DEQ vec), as the sum of absolute values (DEQ abs). Predictive models were developed using univariate regression, with confidence intervals (BCa 95%) calculated through non-parametric bootstrapping (10,000 cycles). RESULTS Various calculated equivalents included -0.44 D for spherical equivalent (SEQ), 0.70 D for defocus equivalent based on vector calculation (DEQ vec), and 0.89 D for defocus equivalent based on absolute values (DEQ abs). Uncorrected and corrected visual acuity averaged 0.07 logMAR and -0.04 logMAR, respectively. The absolute defocus equivalent (DEQ abs) exhibited the smallest confidence interval (BCa 95%) at 0.07. CONCLUSION The defocus equivalent based on the addition of absolute values (DEQ abs) emerged as the most practical predictor for the described applications. Notably, it offers the advantage of easy calculability through a simple equation: VA loss = DEQ abs ⋅ 0.23. In 95% of cases, this predicted loss would have an accuracy of ±0.03 lines.
Collapse
Affiliation(s)
- Johannes Weisensee
- Department of Experimental Ophthalmology, Saarland University, Homburg, Saar, Germany
| | | | - Achim Langenbucher
- Department of Experimental Ophthalmology, Saarland University, Homburg, Saar, Germany
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
Wang Y, Liu Y, Zhu X, Zhou X, He JC, Qu X. Corneal and lenticular biometry in Chinese children with myopia. Clin Exp Optom 2023; 106:836-844. [PMID: 36045001 DOI: 10.1080/08164622.2022.2116269] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 08/15/2022] [Indexed: 10/14/2022] Open
Abstract
CLINICAL RELEVANCE The measurement and simulation of corneal and lenticular curvature radii using a single swept-source biometry device enables a more thorough evaluation of the shape and refractive power of the cornea and lens during emmetropization or myopia progression in children. BACKGROUND This study aimed to evaluate the distribution characteristics of corneal and lenticular parameters in Chinese children with myopia and explored their association with other ocular components. METHODS In this cross-sectional study, all ocular biometric parameters were measured using a Zeiss IOLMaster 700 Biometry. Simulations of the corneal and lenticular curvature radii were implemented using a customised MATLAB program based on cross-sectional swept-source optical coherence tomography images obtained from the same device. The associations of the calculated and simulated refractive powers of the cornea and lens with other ocular parameters were evaluated. RESULTS In total, 119 children with myopia were recruited. Boys had a deeper anterior chamber and longer axial length (AL) than girls, while girls had steeper anterior corneal and lenticular curvatures and greater corneal and lenticular power. Children aged 10 years and older showed a larger anterior lenticular radius of curvature (sRal) and less lenticular power (PL,OCT) than younger participants. There was a significant positive correlation between AL and the anterior corneal radius of curvature, regardless of sex or age. The sRal exhibited a significant increasing trend, and PL,OCT exhibited a declining trend with a longer AL only in children younger than 10 years. CONCLUSION AL is the most influential factor in the determination of spherical equivalent refractive error, while decreases in both corneal and crystalline lens power are significantly inversely correlated with axial elongation.
Collapse
Affiliation(s)
- Yuliang Wang
- Department of Ophthalmology and Vision Science, Eye & ENT Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia, Fudan University, Shanghai, China
- Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
| | - Yujia Liu
- Department of Ophthalmology and Vision Science, Eye & ENT Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia, Fudan University, Shanghai, China
- Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
| | - Xingxue Zhu
- Department of Ophthalmology and Vision Science, Eye & ENT Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia, Fudan University, Shanghai, China
- Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
| | - Xingtao Zhou
- Department of Ophthalmology and Vision Science, Eye & ENT Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia, Fudan University, Shanghai, China
- Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
| | - Ji C He
- Department of Vision Sciences, New England College of Optometry, Boston, MA, USA
| | - Xiaomei Qu
- Department of Ophthalmology and Vision Science, Eye & ENT Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia, Fudan University, Shanghai, China
- Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
| |
Collapse
|
4
|
Ferraro G, Gigante Y, Pitea M, Mautone L, Ruocco G, Di Angelantonio S, Leonetti M. A model eye for fluorescent characterization of retinal cultures and tissues. Sci Rep 2023; 13:10983. [PMID: 37415074 PMCID: PMC10326009 DOI: 10.1038/s41598-023-37806-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 06/28/2023] [Indexed: 07/08/2023] Open
Abstract
Many human neural or neurodegenerative diseases strongly affect the ocular and retinal environment showing peculiar alterations which can be employed as specific disease biomarkers. The noninvasive optical accessibility of the retina makes the ocular investigation a potentially competitive strategy for screening, thus the development of retinal biomarkers is rapidly growing. Nevertheless, a tool to study and image biomarkers or biological samples in a human-like eye environment is still missing. Here we report on a modular and versatile eye model designed to host biological samples, such as retinal cultures differentiated from human induced pluripotent stem cells and ex-vivo retinal tissue, but also suited to host any kind of retinal biomarkers. We characterized the imaging performance of this eye model on standard biomarkers such as Alexa Fluor 532 and Alexa Fluor 594.
Collapse
Affiliation(s)
- G Ferraro
- Center for Life Nano- & Neuro-Science , Istituto Italiano di Tecnologia, Viale Regina Elena, 291, 00161, Rome, Italy
- D-Tails s.r.l. BCorp, Via di Torre Rossa, 66, 00165, Rome, Italy
| | - Y Gigante
- Center for Life Nano- & Neuro-Science , Istituto Italiano di Tecnologia, Viale Regina Elena, 291, 00161, Rome, Italy
- D-Tails s.r.l. BCorp, Via di Torre Rossa, 66, 00165, Rome, Italy
| | - M Pitea
- Center for Life Nano- & Neuro-Science , Istituto Italiano di Tecnologia, Viale Regina Elena, 291, 00161, Rome, Italy
- D-Tails s.r.l. BCorp, Via di Torre Rossa, 66, 00165, Rome, Italy
| | - L Mautone
- Center for Life Nano- & Neuro-Science , Istituto Italiano di Tecnologia, Viale Regina Elena, 291, 00161, Rome, Italy
- Department of Physiology and Pharmacology "V. Erspamer", Sapienza University, Piazzale Aldo Moro 5, 00185, Rome, Italy
| | - G Ruocco
- Center for Life Nano- & Neuro-Science , Istituto Italiano di Tecnologia, Viale Regina Elena, 291, 00161, Rome, Italy
- Dipartimento di Fisica, Sapienza University, Piazzale Aldo Moro, 5, 00185, Rome, Italy
| | - S Di Angelantonio
- Center for Life Nano- & Neuro-Science , Istituto Italiano di Tecnologia, Viale Regina Elena, 291, 00161, Rome, Italy.
- D-Tails s.r.l. BCorp, Via di Torre Rossa, 66, 00165, Rome, Italy.
- Department of Physiology and Pharmacology "V. Erspamer", Sapienza University, Piazzale Aldo Moro 5, 00185, Rome, Italy.
| | - M Leonetti
- Center for Life Nano- & Neuro-Science , Istituto Italiano di Tecnologia, Viale Regina Elena, 291, 00161, Rome, Italy.
- D-Tails s.r.l. BCorp, Via di Torre Rossa, 66, 00165, Rome, Italy.
- Institute of Nanotechnology, Soft and Living Matter Laboratory, Consiglio Nazionale delle Ricerche (CNR-NANOTEC), Piazzale Aldo Moro 5, 00185, Rome, Italy.
| |
Collapse
|
5
|
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.
Collapse
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
| |
Collapse
|
6
|
Oltrup T, Bende T, Al-Mohamedi H, Cayless A, Bende M, Leitritz MA, Bartz Schmidt KU. Comparison of spherical and aspherical intraocular lenses with decentration and tilt error using a physical model of human contrast vision and an image quality metric. Z Med Phys 2021; 31:316-326. [PMID: 33612389 DOI: 10.1016/j.zemedi.2021.01.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 01/22/2021] [Accepted: 01/26/2021] [Indexed: 01/19/2023]
Abstract
PURPOSE In this study, two intraocular lenses (spherical IOL SA60AT and aspherical IOL SN60WF) are examined in an eye model under conditions of misalignment (defocus, decentration and tilt). The lenses are rated using the contrast sensitivity function (CSF) based on Barten's physical model. The square root integral (SQRI) method is used as a quality criterion comparable to the subjective image quality assessment of the human eye. METHODS The IOLs to be tested are decentered from 0 to 1mm and tilted from -5 to +5 degrees in the Navarro eye model (optimized for far-point 6m and pupil aperture 3mm). The defocus of the IOLs is ±0.1mm at the anterior chamber depth (ACD). The optical modulation transfer function (MTF) is simulated with a ray tracing program. The SQRI is calculated using this MTF and the Barten CSF model (for in-focus at aperture 3 and 4.5mm and for defocus at 3mm). RESULTS With increasing decentration, the spherical IOL shows a significantly smaller loss of quality for both apertures compared to the aspherical lens. With an aperture of 4.5mm, the image quality of the aspherical IOL is better for small decentration and tilt. The loss of quality of the spherical IOL increases with increasing tilt in both directions. In contrast, the image quality of the aspherical IOL is reduced under decentration for certain tilt values. For ACD-0.1mm, both IOLs behave similarly to the in-focus situation. For ACD+0.1mm, the influence of tilt without decentration is small for both IOLs. With increasing decentration, the quality loss of the aspherical IOL is similar to that in-focus and greater than that of the spherical lens. CONCLUSION In general, under the same conditions the spherical SA60AT displays a lower tolerance in loss of quality of subjective vision with lens alignment errors, in comparison to the aspherical SN60WF, limited by certain combinations of decentration and tilt according to this study. This study shows a way to evaluate IOLs based on the subjective visual performance of the eye.
Collapse
Affiliation(s)
- Theo Oltrup
- Div. Exp. Ophthalmic Surgery and Refractive Surgery, Department of Ophthalmology, University Tuebingen, Germany.
| | - Thomas Bende
- Div. Exp. Ophthalmic Surgery and Refractive Surgery, Department of Ophthalmology, University Tuebingen, Germany
| | - Haroun Al-Mohamedi
- Div. Exp. Ophthalmic Surgery and Refractive Surgery, Department of Ophthalmology, University Tuebingen, Germany
| | - Alan Cayless
- School of Physical Sciences, Open University, Milton Keynes, United Kingdom
| | - Marvin Bende
- Div. Exp. Ophthalmic Surgery and Refractive Surgery, Department of Ophthalmology, University Tuebingen, Germany
| | - Martin A Leitritz
- Div. Exp. Ophthalmic Surgery and Refractive Surgery, Department of Ophthalmology, University Tuebingen, Germany
| | - Karl-Ulrich Bartz Schmidt
- Div. Exp. Ophthalmic Surgery and Refractive Surgery, Department of Ophthalmology, University Tuebingen, Germany
| |
Collapse
|
7
|
Fernández J, Rodríguez-Vallejo M, Martínez J, Burguera N, Piñero DP. Prediction of Visual Acuity and Contrast Sensitivity From Optical Simulations With Multifocal Intraocular Lenses. J Refract Surg 2020; 35:789-795. [PMID: 31830295 DOI: 10.3928/1081597x-20191024-01] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 10/23/2019] [Indexed: 11/20/2022]
Abstract
PURPOSE To evaluate whether the prediction of visual performance based on the modulation transfer function area (MTFa) calculated with optical simulations is better correlated with visual acuity or contrast sensitivity obtained from defocus curves in patients implanted with a trifocal intraocular lens. METHODS Biometric eye data from 43 patients were used to create a mean eye model. A trifocal intraocular lens with a power obtained from the mean of the eyes implanted was incorporated into the model and the MTFa was calculated at the 11 defocus planes corresponding the 11 defocus locations measured in clinical practice. Simulations were conducted for pupil diameters of 2.5, 3, 3.5, and 4 mm. The MTFa correlation with visual acuity and contrast sensitivity was evaluated with the mean obtained after stratification of the clinical sample in four groups according to the previous pupil diameters. RESULTS A linear model predicted the visual acuity and contrast sensitivity from MTFa with similar accuracy to nonlinear models, with R2 approximately 0.50 for visual acuity and approximately 0.42 for contrast sensitivity. A change of -0.01 logMAR and -0.02 logC was produced per unit of MTFa for visual acuity and contrast sensitivity, respectively. The mean difference between the visual acuity and contrast sensitivity obtained from the model and that measured in clinical practice was close to zero, but the bias varied depending on the defocus lens used, with higher deviation at -0.50 and -3.00 diopters of defocus. CONCLUSIONS The MTFa obtained from optical simulations can be used to predict the mean visual acuity and contrast sensitivity consistently, with contrast sensitivity being more sensitive but with higher bias. [J Refract Surg. 2019;35(12):789-795.].
Collapse
|
8
|
Lian T, MacKenzie KJ, Brainard DH, Cottaris NP, Wandell BA. Ray tracing 3D spectral scenes through human optics models. J Vis 2019; 19:23. [PMID: 31658357 DOI: 10.1167/19.12.23] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Scientists and engineers have created computations and made measurements that characterize the first steps of seeing. ISETBio software integrates such computations and data into an open-source software package. The initial ISETBio implementations modeled image formation (physiological optics) for planar or distant scenes. The ISET3d software described here extends that implementation, simulating image formation for three-dimensional scenes. The software system relies on a quantitative computer graphics program that ray traces the scene radiance through the physiological optics to the retinal irradiance. We describe and validate the implementation for several model eyes. Then, we use the software to quantify the impact of several physiological optics parameters on three-dimensional image formation. ISET3d is integrated with ISETBio, making it straightforward to convert the retinal irradiance into cone excitations. These methods help the user compute the predictions of optics models for a wide range of spatially rich three-dimensional scenes. They can also be used to evaluate the impact of nearby visual occlusion, the information available to binocular vision, or the retinal images expected from near-field and augmented reality displays.
Collapse
Affiliation(s)
- Trisha Lian
- Department of Electrical Engineering, Stanford University, Palo Alto, CA, USA
| | | | - David H Brainard
- Department of Psychology, University of Pennsylvania, Pennsylvania, PA, USA
| | - Nicolas P Cottaris
- Department of Psychology, University of Pennsylvania, Pennsylvania, PA, USA
| | - Brian A Wandell
- Department of Psychology, Stanford University, Palo Alto, CA, USA
| |
Collapse
|
9
|
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.
Collapse
|
10
|
Esteve-Taboada JJ, Montés-Micó R, Ferrer-Blasco T. Schematic eye models to mimic the behavior of the accommodating human eye. J Cataract Refract Surg 2018; 44:627-641. [PMID: 29891156 DOI: 10.1016/j.jcrs.2018.02.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 02/23/2018] [Accepted: 02/28/2018] [Indexed: 11/19/2022]
Abstract
A simplified version of the human eye is known as a schematic eye model. Since the first attempts in the middle of the 19th century, numerous approaches describing new schematic eye models have been introduced. Some are able to describe the accommodation ability of the human eye. Accommodated schematic eyes could be of great interest because they explain the functionality of the human eye and they are easy to use for research purposes. Purposes include the design and testing of multifocal ophthalmic intraocular lenses, the evaluation of the effect of optical aberrations on retinal image quality, and the study of the optical performance of the eye at different distances after some refractive surgical procedures. This paper reviews and summarizes the most important features and details of accommodated schematic eye models that have been proposed in the past years.
Collapse
Affiliation(s)
- José J Esteve-Taboada
- From the Department of Optics and Optometry and Vision Sciences, University of Valencia, Valencia, Spain
| | - Robert Montés-Micó
- From the Department of Optics and Optometry and Vision Sciences, University of Valencia, Valencia, Spain.
| | - Teresa Ferrer-Blasco
- From the Department of Optics and Optometry and Vision Sciences, University of Valencia, Valencia, Spain
| |
Collapse
|
11
|
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.
Collapse
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
| |
Collapse
|
12
|
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.
Collapse
|
13
|
Di Y, Li MY, Qiao T, Lu N. Edge detection and mathematic fitting for corneal surface with Matlab software. Int J Ophthalmol 2017; 10:336-342. [PMID: 28393021 DOI: 10.18240/ijo.2017.03.02] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 12/08/2016] [Indexed: 11/23/2022] Open
Abstract
AIM To select the optimal edge detection methods to identify the corneal surface, and compare three fitting curve equations with Matlab software. METHODS Fifteen subjects were recruited. The corneal images from optical coherence tomography (OCT) were imported into Matlab software. Five edge detection methods (Canny, Log, Prewitt, Roberts, Sobel) were used to identify the corneal surface. Then two manual identifying methods (ginput and getpts) were applied to identify the edge coordinates respectively. The differences among these methods were compared. Binomial curve (y=Ax2+Bx+C), Polynomial curve [p(x)=p1xn+p2xn-1 +....+pnx+pn+1] and Conic section (Ax2+Bxy+Cy2+Dx+Ey+F=0) were used for curve fitting the corneal surface respectively. The relative merits among three fitting curves were analyzed. Finally, the eccentricity (e) obtained by corneal topography and conic section were compared with paired t-test. RESULTS Five edge detection algorithms all had continuous coordinates which indicated the edge of the corneal surface. The ordinates of manual identifying were close to the inside of the actual edges. Binomial curve was greatly affected by tilt angle. Polynomial curve was lack of geometrical properties and unstable. Conic section could calculate the tilted symmetry axis, eccentricity, circle center, etc. There were no significant differences between 'e' values by corneal topography and conic section (t=0.9143, P=0.3760 >0.05). CONCLUSION It is feasible to simulate the corneal surface with mathematical curve with Matlab software. Edge detection has better repeatability and higher efficiency. The manual identifying approach is an indispensable complement for detection. Polynomial and conic section are both the alternative methods for corneal curve fitting. Conic curve was the optimal choice based on the specific geometrical properties.
Collapse
Affiliation(s)
- Yue Di
- Department of Ophthalmology, Shanghai Children's Hospital, Shanghai Jiaotong University, Shanghai 200062, China
| | - Mei-Yan Li
- Department of Ophthalmology, Eye & ENT Hospital Fudan Unversity, Fenyang Road 83, Shanghai 200031, China
| | - Tong Qiao
- Department of Ophthalmology, Shanghai Children's Hospital, Shanghai Jiaotong University, Shanghai 200062, China
| | - Na Lu
- Department of Radiology, Huashan Hospital North, Fudan University, 108 Luxiang Road, Shanghai 201907, China
| |
Collapse
|
14
|
Corcoran A, Muyo G, van Hemert J, Gorman A, Harvey AR. Application of a wide-field phantom eye for optical coherence tomography and reflectance imaging. JOURNAL OF MODERN OPTICS 2015; 62:1828-1838. [PMID: 26740737 PMCID: PMC4685623 DOI: 10.1080/09500340.2015.1045309] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Accepted: 04/20/2015] [Indexed: 05/18/2023]
Abstract
Optical coherence tomography (OCT) and reflectance imaging are used in clinical practice to measure the thickness and transverse dimensions of retinal features. The recent trend towards increasing the field of view (FOV) of these devices has led to an increasing significance of the optical aberrations of both the human eye and the device. We report the design, manufacture and application of the first phantom eye that reproduces the off-axis optical characteristics of the human eye, and allows the performance assessment of wide-field ophthalmic devices. We base our design and manufacture on the wide-field schematic eye, [Navarro, R. J. Opt. Soc. Am. A, 1985,2.] as an accurate proxy to the human eye and enable assessment of ophthalmic imaging performance for a [Formula: see text] external FOV. We used multi-material 3D-printed retinal targets to assess imaging performance of the following ophthalmic instruments: the Optos 200Tx, Heidelberg Spectralis, Zeiss FF4 fundus camera and Optos OCT SLO and use the phantom to provide an insight into some of the challenges of wide-field OCT.
Collapse
Affiliation(s)
- Anthony Corcoran
- Physics and Astronomy Department, University of Glasgow, Glasgow, Scotland
| | - Gonzalo Muyo
- Research Department, Optos PLC, Dunfermline, Scotland
| | | | | | - Andrew R. Harvey
- Physics and Astronomy Department, University of Glasgow, Glasgow, Scotland
| |
Collapse
|
15
|
Rodriguez-Vallejo M, Benlloch J, Pons A, Monsoriu JA, Furlan WD. The effect of fractal contact lenses on peripheral refraction in myopic model eyes. Curr Eye Res 2014; 39:1151-60. [PMID: 24749733 DOI: 10.3109/02713683.2014.903498] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE To test multizone contact lenses in model eyes: Fractal Contact Lenses (FCLs), designed to induce myopic peripheral refractive error (PRE). METHODS Zemax ray-tracing software was employed to simulate myopic and accommodation-dependent model eyes fitted with FCLs. PRE, defined in terms of mean sphere M and 90°-180° astigmatism J180, was computed at different peripheral positions, ranging from 0 to 35° in steps of 5°, and for different pupil diameters (PDs). Simulated visual performance and changes in the PRE were also analyzed for contact lens decentration and model eye accommodation. For comparison purposes, the same simulations were performed with another commercially available contact lens designed for the same intended use: the Dual Focus (DF). RESULTS PRE was greater with FCL than with DF when both designs were tested for a 3.5 mm PD, and with and without decentration of the lenses. However, PRE depended on PD with both multizone lenses, with a remarkable reduction of the myopic relative effect for a PD of 5.5 mm. The myopic PRE with contact lenses decreased as the myopic refractive error increased, but this could be compensated by increasing the power of treatment zones. A peripheral myopic shift was also induced by the FCLs in the accommodated model eye. In regard to visual performance, a myopia under-correction with reference to the circle of least confusion was obtained in all cases for a 5.5 mm PD. The ghost images, generated by treatment zones of FCL, were dimmer than the ones produced with DF lens of the same power. CONCLUSIONS FCLs produce a peripheral myopic defocus without compromising central vision in photopic conditions. FCLs have several design parameters that can be varied to obtain optimum results: lens diameter, number of zones, addition and asphericity; resulting in a very promising customized lens for the treatment of myopia progression.
Collapse
|
16
|
Ribeiro F, Castanheira-Dinis A, Dias JM. Refractive error assessment: influence of different optical elements and current limits of biometric techniques. J Refract Surg 2013; 29:206-12. [PMID: 23446018 DOI: 10.3928/1081597x-20130129-07] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Accepted: 12/20/2012] [Indexed: 11/20/2022]
Abstract
PURPOSE To identify and quantify sources of error on refractive assessment using exact ray tracing. METHODS The Liou-Brennan eye model was used as a starting point and its parameters were varied individually within a physiological range. The contribution of each parameter to refractive error was assessed using linear regression curve fits and Gaussian error propagation analysis. A MonteCarlo analysis quantified the limits of refractive assessment given by current biometric measurements. RESULTS Vitreous and aqueous refractive indices are the elements that influence refractive error the most, with a 1% change of each parameter contributing to a refractive error variation of +1.60 and -1.30 diopters (D), respectively. In the phakic eye, axial length measurements taken by ultrasound (vitreous chamber depth, lens thickness, and anterior chamber depth [ACD]) were the most sensitive to biometric errors, with a contribution to the refractive error of 62.7%, 14.2%, and 10.7%, respectively. In the pseudophakic eye, vitreous chamber depth showed the highest contribution at 53.7%, followed by postoperative ACD at 35.7%. When optic measurements were considered, postoperative ACD was the most important contributor, followed by anterior corneal surface and its asphericity. A MonteCarlo simulation showed that current limits of refractive assessment are 0.26 and 0.28 D for the phakic and pseudophakic eye, respectively. CONCLUSIONS The most relevant optical elements either do not have available measurement instruments or the existing instruments still need to improve their accuracy. Ray tracing can be used as an optical assessment technique, and may be the correct path for future personalized refractive assessment.
Collapse
|
17
|
Optical Performance of Multifocal Soft Contact Lenses via a Single-Pass Method. Optom Vis Sci 2012; 89:1107-18. [DOI: 10.1097/opx.0b013e318264f3e9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
|
18
|
Gillner M, Langenbucher A, Eppig T. [Investigation of the theoretical image quality of aspheric intraocular lenses by decentration. Hoya AF-1 iMics1 und Zeiss ASPHINA(TM) (Invent ZO)]. Ophthalmologe 2012; 109:263-70. [PMID: 22447423 DOI: 10.1007/s00347-011-2517-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND The image quality of aberration correcting aspherical intraocular lenses (IOLs) depends on the centration in the eye. Aberration correcting IOLs of the second generation are claimed to be more robust to decentration. In this study the image quality of such IOLs was analyzed with decentration values of up to 1 mm. MATERIALS AND METHODS In this study two aberration correction IOLs of the second generation were compared in a model eye. The IOLs were decentered for two pupil diameters (3.0 and 4.5 mm) in a range of ± 1 mm relative to the line of sight in 50 µm steps and the modulation transfer function was calculated. The results were compared for different spatial frequencies and visual acuities. RESULTS The analyzed IOLs are superior to the spherical IOL in a decentration range from -0.45 mm to 0.60 mm (30 CPD, cycles per degree) for both pupil diameters. Especially for the greater pupil diameter the lenses show tolerance of image quality to lens decentration. CONCLUSIONS Both IOLs show only a slight decrease in image quality with decentration and the range of tolerable decentration is increased compared to aspherical IOLs of the first generation.
Collapse
Affiliation(s)
- M Gillner
- Institut für Medizinische Physik, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91052 Erlangen.
| | | | | |
Collapse
|
19
|
Bakaraju RC, Ehrmann K, Falk D, Ho A, Papas E. Physical human model eye and methods of its use to analyse optical performance of soft contact lenses. OPTICS EXPRESS 2010; 18:16868-16882. [PMID: 20721079 DOI: 10.1364/oe.18.016868] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
A bench-top physical model eye that closely replicates both anatomical and optical properties of an average human eye was designed and constructed. The cornea was sourced from a flouro-polymer with refractive index (RI) of 1.376 and crystalline lenses were made of Boston RGP polymers, EO and Equalens II, with an equivalent RI of 1.429 and 1.423 respectively. These materials served to make crystalline lens components of different age groups and accommodative states. De-Ionized water, with RI of 1.334 represented both aqueous and vitreous humor. The complementary metal-oxide sensor of a PixelLink digital camera with a resolution of 5MP and a 2.2 microm pixel pitch, hosted on a motor-base, served as the 'acting' retina. The translation and rotary functions of the motor-base facilitated the simulation of different states of ametropia and assessment of peripheral visual function, respectively. We validated one of its configurations to suit normal viewing conditions and results from the on and off-axis optical quality measurements are presented. As a demonstration of potential practical uses, several corrective soft contact lenses were placed on the model eye and their optical performance evaluated.
Collapse
|
20
|
Ale J, Manns F, Ho A. Evaluation of the performance of accommodating IOLs using a paraxial optics analysis. Ophthalmic Physiol Opt 2010; 30:132-42. [PMID: 20444117 DOI: 10.1111/j.1475-1313.2009.00694.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE We employed an analytical approach to evaluate the key parameters for the potential design optimisation of accommodating intra-ocular lenses (AIOL) and to use these parameters to predict their accommodative performance. METHODS Paraxial thin-lens equations to predict the accommodative performances of single-element (1E) and two-element (2E) AIOLs were developed. 2E-AIOLs with either mobile front or back lens elements were analysed as well as 1E-AIOL for their accommodative performance. A paraxial model including key ocular components (corneal surfaces, pupil and retina) as well as AIOL was used to evaluate the key control parameters and optimal design configurations. A range of variants of the model, representing varying powers of front and back optical elements and with either front or back optical element mobile was tested. RESULTS Optimal accommodative performance of 2E-AIOL is governed by the power combinations of its optical elements; design variants with higher positive front element power produced greater accommodative efficacy, while mobility of the front element contributed more to the accommodative performance than the back element. The performance of 1E-AIOL is primarily governed by the power of the AIOL; the higher the AIOL power, the better the accommodative performance. CONCLUSIONS From an accommodative performance standpoint, the optimal design of 2E-AIOL should comprise a high plus power front element. Considering the maximum potential amounts of element translation available clinically, 2E-AIOLs are predicted to offer higher accommodative performance compared to 1E-AIOL.
Collapse
Affiliation(s)
- Jit Ale
- Institute for Eye Research, University of New South Wales, Barker Street, Sydney, NSW 2052, Australia.
| | | | | |
Collapse
|