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Lai X, Liu X, Zeng T, Huang Y, Yang X. Comparison of visual outcomes and optical aberrations after SMILE with intraoperative Kappa angle adjustments between small and large Kappa angles. Sci Rep 2024; 14:14551. [PMID: 38914606 PMCID: PMC11196622 DOI: 10.1038/s41598-024-65366-w] [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: 09/16/2023] [Accepted: 06/19/2024] [Indexed: 06/26/2024] Open
Abstract
This study compares postoperative visual outcomes and optical aberrations after Small Incision Lenticule Extraction (SMILE) in patients with both small (S-Kappa: Kappa angle < 0.2 mm) and large Kappa (L-Kappa: Kappa angle ≥ 0.2 mm) angles. The evaluated aberrations include total higher-order aberrations (HOAs), horizontal coma (HC), vertical coma (VC), and spherical aberrations (SA), with procedures incorporating intraoperative Kappa angle adjustments. We retrospectively analyzed patient records undergoing SMILE utilizing linear mixed models (LMM). We assessed adjusted mean uncorrected distance visual acuity (UDVA), Strehl ratio (SR), total HOAs, VC, and SA at pupils of 3 mm and 6 mm for both S-Kappa and L-Kappa. The disparities between S-Kappa and L-Kappa were evaluated by LMM's adjusted mean differences. The differences in optical metrics were also assessed in eyes grouped by myopia levels: low, moderate, and high. A sensitivity analysis was conducted on a threshold of Kappa angle at 0.3 mm. Eight-five patients (169 eyes) were analyzed, and no significant pre-operative difference was found in UDVA (p = .222) or spherical equivalent (p = .433). Post-operative differences were found in SR at 3 mm pupil size (-0.06, p = .022), total HOA 3 mm (0.15, p = .022), HC 3 mm (0.04, p = .042), VC 3 mm and 6 mm (-0.08, p = .041; 0.04, p = .041). The stratified analysis for high myopia revealed significant differences in UDVA (-0.04, p = .037), HC 3 mm (0.07, p = .03), VC 6 mm (-0.21, p = .001), and SA 3 mm and 6 mm (0.07, p = .037; -0.09, p = .037). Sensitivity analysis showed no significant difference using a 0.3 mm Kappa threshold. While some optical aberrations exhibited statistical differences between S-Kappa and L-Kappa, their clinical significance is limited. Thus, a large Kappa angle might not substantially influence post-operative optical aberrations when intraoperative Kappa angle adjustments are implemented.
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Affiliation(s)
- Xiaojuan Lai
- Department of Ophthalmology, The Second People's Hospital of Yibin, Yi'bin, 644000, China
| | - Xi Liu
- Department of Ophthalmology, The Second People's Hospital of Yibin, Yi'bin, 644000, China.
| | - Tao Zeng
- Department of Ophthalmology, The Second People's Hospital of Yibin, Yi'bin, 644000, China
| | - Yi Huang
- Department of Ophthalmology, The Second People's Hospital of Yibin, Yi'bin, 644000, China
| | - Xin Yang
- The University of Alabama, Tuscaloosa, AL, 35487, USA
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Walther G, Meyer D, Richards J, Rickert M, Kollbaum P. On-eye centration of soft contact lenses. Ophthalmic Physiol Opt 2024; 44:737-745. [PMID: 38217323 DOI: 10.1111/opo.13278] [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: 10/04/2023] [Revised: 12/28/2023] [Accepted: 01/03/2024] [Indexed: 01/15/2024]
Abstract
PURPOSE To evaluate the relative positions of modern soft contact lenses (SCLs) relative to the limbus/cornea and the pupil. METHODS Sixty images of the anterior eyes of 101 subjects were acquired over 10 s while participants fixated the centre of the camera lens located 33 cm in front of the eye in a well-lit (300 lux) clinic. Custom validated image analysis software was used to locate the boundaries of the contact lenses, pupils and corneas (limbus). Horizontal and vertical relative positions of the contact lens, pupil and limbus were calculated from the fitted boundaries. RESULTS The mean (standard deviation) pupil and corneal diameters for all subjects were 3.84 mm, (0.83) and 11.97 mm (0.48), respectively. The mean [95% confidence interval] pupil centre was located 0.28 mm [0.26, 0.30] nasally and 0.07 mm [0.05, 0.10] superiorly to the corneal centre. Consistent with clinical observations, the contact lenses centred accurately relative to the corneal centre both nasally 0.04 mm [0.01, 0.07] and inferiorly -0.01 mm [-0.06, 0.03]. However, regardless of the eye, the contact lens was significantly (p < 0.001) decentred relative to the pupil centre both temporally -0.23 mm [-0.26, -0.20] and inferiorly -0.08 mm [-0.12, -0.04]. Decentration magnitudes were significantly correlated between the right and left eyes. CONCLUSIONS Spherical SCLs centred well on the cornea but temporally and inferiorly from the primary line of sight (pupil centre), due to the differences in the location of the pupil and corneal centres. Contrary to some previous reports, there was no evidence that lens optics or material affected lens centration significantly.
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Affiliation(s)
| | - Dawn Meyer
- Indiana University, Bloomington, Indiana, USA
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Davies LN, Biswas S, Bullimore M, Cruickshank F, Estevez JJ, Khanal S, Kollbaum P, Marcotte-Collard R, Montani G, Plainis S, Richdale K, Simard P, Wolffsohn JS. BCLA CLEAR presbyopia: Mechanism and optics. Cont Lens Anterior Eye 2024:102185. [PMID: 38796331 DOI: 10.1016/j.clae.2024.102185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2024]
Abstract
With over a billion adults worldwide currently affected, presbyopia remains a ubiquitous, global problem. Despite over a century of study, the precise mechanism of ocular accommodation and presbyopia progression remains a topic of debate. Accordingly, this narrative review outlines the lenticular and extralenticular components of accommodation together with the impact of age on the accommodative apparatus, neural control of accommodation, models of accommodation, the impact of presbyopia on retinal image quality, and both historic and contemporary theories of presbyopia.
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Affiliation(s)
- Leon N Davies
- School of Optometry, College of Health and Life Sciences, Aston University, Birmingham, UK.
| | - Sayantan Biswas
- School of Optometry, College of Health and Life Sciences, Aston University, Birmingham, UK
| | | | - Fiona Cruickshank
- Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology, Medicine and Health, University of Manchester, UK
| | - Jose J Estevez
- Caring Futures Institute, College of Nursing and Health Sciences, Optometry and Vision Science, Flinders University, Adelaide, Australia; Flinders Centre for Ophthalmology, Eye and Vision Research, Department of Ophthalmology, Flinders University, Adelaide, Australia
| | - Safal Khanal
- Department of Optometry and Vision Science, The University of Alabama at Birmingham, USA
| | | | | | | | - Sotiris Plainis
- Laboratory of Optics and Vision, School of Medicine, University of Crete, Greece
| | | | - Patrick Simard
- School of Optometry, Universite de Montreal, Montreal, Quebec, Canada
| | - James S Wolffsohn
- School of Optometry, College of Health and Life Sciences, Aston University, Birmingham, UK
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Onyszkiewicz M, Hilmers J, Rejdak R, Zrenner E, Straßer T. Effects of Miosis on the Visual Acuity Space under Varying Conditions of Contrast and Ambient Luminance in Presbyopia. J Clin Med 2024; 13:1209. [PMID: 38592033 PMCID: PMC10931829 DOI: 10.3390/jcm13051209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 02/15/2024] [Accepted: 02/16/2024] [Indexed: 04/10/2024] Open
Abstract
Background: Presbyopia is an age-related ocular condition, typically affecting individuals aged over 40 years, characterized by a gradual and irreversible decline in the eye's ability to focus on nearby objects. Correction methods for presbyopia encompass the use of corrective lenses, surgical interventions (corneal or lens based), and, more recently, the FDA-approved topical administration of 1.25% pilocarpine. While prior research has demonstrated the efficacy of daily pilocarpine eye drop application in enhancing near visual acuity by increasing the depth of focus leveraging the pinhole effect, limited knowledge exists regarding its influence on visual acuity under varying conditions of contrast and ambient luminance. Methods: This study aims to investigate the impact of these variables on visual acuity, employing the VA-CAL test, among 11 emmetropic and 11 presbyopic volunteers who reported subjective difficulties with near vision. This study includes evaluations under natural conditions with a pinhole occluder (diameter of 2 mm), and subsequent administration of 1% pilocarpine (Pilomann, Bausch + Lomb, Laval, Canada). Results: The VA-CAL results demonstrate the expected, statistically significant effects of contrast and ambient luminance on visual acuity in both emmetropic and presbyopic volunteers. Furthermore, in emmetropic individuals, the application of pilocarpine resulted in a statistically significant reduction in visual acuity. In contrast, presbyopes did not exhibit statistically significant differences in the visual acuity space under either the pinhole or pilocarpine conditions when compared to natural conditions. Conclusions: The pharmacological treatment of presbyopia with pilocarpine eye drops, intended to enhance near vision, does not adversely affect visual acuity in presbyopes. This suggests that pilocarpine may offer a viable alternative for individuals averse to wearing corrective eyewear.
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Affiliation(s)
- Maksymilian Onyszkiewicz
- Institute for Ophthalmic Research, University of Tuebingen, 72076 Tuebingen, Germany; (M.O.); (E.Z.)
- Chair and Department of General and Pediatric Ophthalmology, Medical University of Lublin, 20-059 Lublin, Poland
| | - Julian Hilmers
- Institute for Ophthalmic Research, University of Tuebingen, 72076 Tuebingen, Germany; (M.O.); (E.Z.)
- STZ Eyetrial, University Eye Hospital Tuebingen, 72076 Tuebingen, Germany;
| | - Robert Rejdak
- STZ Eyetrial, University Eye Hospital Tuebingen, 72076 Tuebingen, Germany;
| | - Eberhart Zrenner
- Institute for Ophthalmic Research, University of Tuebingen, 72076 Tuebingen, Germany; (M.O.); (E.Z.)
- University Eye Hospital Tuebingen, 72076 Tuebingen, Germany
| | - Torsten Straßer
- Institute for Ophthalmic Research, University of Tuebingen, 72076 Tuebingen, Germany; (M.O.); (E.Z.)
- Chair and Department of General and Pediatric Ophthalmology, Medical University of Lublin, 20-059 Lublin, Poland
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Manzanera S, Artal P. Stability of the retinal image under normal viewing conditions and the implications for neural adaptation. Sci Rep 2024; 14:2280. [PMID: 38280921 PMCID: PMC10821888 DOI: 10.1038/s41598-024-52612-4] [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: 11/07/2023] [Accepted: 01/21/2024] [Indexed: 01/29/2024] Open
Abstract
Previous studies have demonstrated that the visual system adapts to the specific aberration pattern of an individual's eye. Alterations to this pattern can lead to reduced visual performance, even when the Root Mean Square (RMS) of the wavefront error remains constant. However, it is well-established that ocular aberrations are dynamic and can change with factors such as pupil size and accommodation. This raises an intriguing question: can the neural system adapt to continuously changing aberration patterns? To address this question, we measured the ocular aberrations in four subjects under various natural viewing conditions, which included changes in accommodative state and pupil size. We subsequently computed the associated Point Spread Functions (PSFs). For each subject, we examined the stability in the orientation of the PSFs and analyzed the cross-correlation between different PSFs. These findings were then compared to the characteristics of a distribution featuring PSF shapes akin to random variations. Our results indicate that the changes observed in the PSFs are not substantial enough to produce a PSF shape distribution resembling random variations. This lends support to the notion that neural adaptation is indeed a viable mechanism even in response to continuously changing aberration patterns.
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Affiliation(s)
- Silvestre Manzanera
- Laboratorio de Óptica, Universidad de Murcia, Campus de Espinardo (Edificio 34), 30100, Murcia, Spain
| | - Pablo Artal
- Laboratorio de Óptica, Universidad de Murcia, Campus de Espinardo (Edificio 34), 30100, Murcia, Spain.
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Shetty N, Shetty R, Ranade R, Narasimhan R, Artal P, Nuijts RMMA, Sinha Roy A. Using adaptive optics to optimize the spherical aberration of eyes implanted with EDOF and enhanced monofocal intraocular lenses. J Cataract Refract Surg 2024; 50:30-36. [PMID: 37732726 DOI: 10.1097/j.jcrs.0000000000001315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 09/08/2023] [Indexed: 09/22/2023]
Abstract
PURPOSE To assess the effect of change in ocular spherical aberration (SA) with adaptive optics on visual acuity (VA) at different defocus after implantation of extended depth-of-focus (EDOF) and enhanced monofocal intraocular lenses (IOLs). SETTINGS Narayana Nethralaya Eye Hospital, Bangalore, India. DESIGN Prospective, longitudinal, observational. METHODS 80 eyes (40 patients) that had cataract surgery were included in the study. 40 eyes were implanted with Eyhance EDOF IOLs and the remaining with Vivity EDOF IOLs. Baseline ocular aberrations were measured with a visual adaptive optics aberrometer, then the optimal SA was determined by increasing it in steps of -0.01 μm up to -0.1 μm until the maximum improvement in near distance VA was observed for a given eye. Then the defocus curve for each eye was measured after modifying the ocular SA by magnitude equal to optimal SA. RESULTS Most of the eyes accepted a negative induced SA of -0.05 μm (Eyhance group: 67.6%; Vivity group, 45.2%). In the Eyhance group (dominant eyes), VA improved at -2 diopters (D) ( P < .02) only and degraded at 0 D, +0.5 D, and +1 D defocus ( P < .05). In the Vivity group, the VA remained unchanged at all defocus ( P > .05). In the Eyhance group (nondominant eyes), VA improved at -3.5 D defocus only and degraded at +1.5 D and +2 D defocus ( P < .05). In the Vivity group, VA improved at -2.5 D defocus ( P < .05) only. CONCLUSIONS A negative induced SA of -0.05 μm in implanted eyes was optimal for a slight improvement in distance-corrected near and intermediate VA without any significant decrease in baseline distance-corrected VA.
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Affiliation(s)
- Naren Shetty
- From the Department of Cataract Surgery, Narayana Nethralaya Eye Hospital, Bangalore, India (N. Shetty, Ranade); Department of Cornea and Refractive Surgery, Narayana Nethralaya Eye Hospital, Bangalore, India (R. Shetty, Ranade); Imaging, Biomechanics and Mathematical Modelling Solutions Lab, Narayana Nethralaya Foundation, Bangalore, India (Narasimhan, Roy); Laboratorio de Óptica, Instituto Universitario de Investigación en Óptica y Nanofísica, Universidad de Murcia, Spain (Artal); University Eye Clinic Maastricht, Maastricht University Medical Center (MUMC+), Maastricht, the Netherlands (Nuijts)
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Kusada N, Yokoi N, Sotozono C. Association between Corneal Higher-Order Aberrations Evaluated with a Videokeratographer and Corneal Surface Abnormalities in Dry Eye. Diagnostics (Basel) 2023; 13:3319. [PMID: 37958214 PMCID: PMC10647685 DOI: 10.3390/diagnostics13213319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Revised: 10/23/2023] [Accepted: 10/25/2023] [Indexed: 11/15/2023] Open
Abstract
Analysis of higher-order aberrations (HOAs) is one reported method for evaluating dry eye disease (DED)-related loss of visual function. Tear film (TF) instability and corneal epithelial damage (CED) are both reportedly responsible for HOAs in DED, although, to the best of our knowledge, there are no reported methods that allow concurrent evaluation of their effects. In this study, we used a videokeratographer (VK) to continuously measure HOAs in DED after eye opening and investigated factors of ocular surface abnormalities that determine HOAs. This study involved 96 DED cases that underwent DED symptom assessment with a questionnaire and examination of tear volume, TF abnormalities (i.e., TF lipid-layer interference grades and spreading grades, and non-invasive breakup time and fluorescein breakup time), and CED, and their correlation with HOAs evaluated via VK. The results show that HOAs at 1 or 2 s after eye opening can reflect TF instability and CED within the central 4-millimeter-diameter area of the optical zone in DED eyes concurrently. This finding may be useful for the rapid and non-invasive detection and evaluation of degraded visual function in DED cases with a variety of clinical features.
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Affiliation(s)
| | - Norihiko Yokoi
- Department of Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan; (N.K.); (C.S.)
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Sánchez RF, Puertas FJ, Issolio LA. Modulation transfer function formula for different age ranges. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2023; 40:1979-1985. [PMID: 37855554 DOI: 10.1364/josaa.494721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 09/19/2023] [Indexed: 10/20/2023]
Abstract
The modulation transfer function (MTF) is one of the most complete tools to study the optical performance of the eye. We present the average radial MTF profiles measured in 68 subjects grouped in six age ranges (from 20 to 80 years) and a general formula to estimate the radial profile of human MTF as a function of pupil size and age. The mean MTF for each age group was fitted to an analytical expression to compute two parameters related to aging. The proposed formula fitted reasonably well to experimental data available in previous works and predicted the average changes with aging of different optical quality parameters obtained from MTF.
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Fasoula NA, Xie Y, Katsouli N, Reidl M, Kallmayer MA, Eckstein HH, Ntziachristos V, Hadjileontiadis L, Avgerinos DV, Briasoulis A, Siasos G, Hosseini K, Doulamis I, Kampaktsis PN, Karlas A. Clinical and Translational Imaging and Sensing of Diabetic Microangiopathy: A Narrative Review. J Cardiovasc Dev Dis 2023; 10:383. [PMID: 37754812 PMCID: PMC10531807 DOI: 10.3390/jcdd10090383] [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: 05/31/2023] [Revised: 08/21/2023] [Accepted: 08/25/2023] [Indexed: 09/28/2023] Open
Abstract
Microvascular changes in diabetes affect the function of several critical organs, such as the kidneys, heart, brain, eye, and skin, among others. The possibility of detecting such changes early enough in order to take appropriate actions renders the development of appropriate tools and techniques an imperative need. To this end, several sensing and imaging techniques have been developed or employed in the assessment of microangiopathy in patients with diabetes. Herein, we present such techniques; we provide insights into their principles of operation while discussing the characteristics that make them appropriate for such use. Finally, apart from already established techniques, we present novel ones with great translational potential, such as optoacoustic technologies, which are expected to enter clinical practice in the foreseeable future.
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Affiliation(s)
- Nikolina-Alexia Fasoula
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, 85764 Neuherberg, Germany; (N.-A.F.); (Y.X.); (N.K.); (V.N.)
- Chair of Biological Imaging at the Central Institute for Translational Cancer Research (TranslaTUM), School of Medicine, Technical University of Munich, 81675 Munich, Germany
| | - Yi Xie
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, 85764 Neuherberg, Germany; (N.-A.F.); (Y.X.); (N.K.); (V.N.)
- Chair of Biological Imaging at the Central Institute for Translational Cancer Research (TranslaTUM), School of Medicine, Technical University of Munich, 81675 Munich, Germany
| | - Nikoletta Katsouli
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, 85764 Neuherberg, Germany; (N.-A.F.); (Y.X.); (N.K.); (V.N.)
- Chair of Biological Imaging at the Central Institute for Translational Cancer Research (TranslaTUM), School of Medicine, Technical University of Munich, 81675 Munich, Germany
| | - Mario Reidl
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, 85764 Neuherberg, Germany; (N.-A.F.); (Y.X.); (N.K.); (V.N.)
- Chair of Biological Imaging at the Central Institute for Translational Cancer Research (TranslaTUM), School of Medicine, Technical University of Munich, 81675 Munich, Germany
| | - Michael A. Kallmayer
- Department for Vascular and Endovascular Surgery, Klinikum rechts der Isar, Technical University of Munich (TUM), 81675 Munich, Germany; (M.A.K.); (H.-H.E.)
| | - Hans-Henning Eckstein
- Department for Vascular and Endovascular Surgery, Klinikum rechts der Isar, Technical University of Munich (TUM), 81675 Munich, Germany; (M.A.K.); (H.-H.E.)
| | - Vasilis Ntziachristos
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, 85764 Neuherberg, Germany; (N.-A.F.); (Y.X.); (N.K.); (V.N.)
- Chair of Biological Imaging at the Central Institute for Translational Cancer Research (TranslaTUM), School of Medicine, Technical University of Munich, 81675 Munich, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, 80336 Munich, Germany
| | - Leontios Hadjileontiadis
- Department of Biomedical Engineering, Healthcare Engineering Innovation Center (HEIC), Khalifa University, Abu Dhabi P.O. Box 127788, United Arab Emirates;
- Department of Electrical and Computer Engineering, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
| | | | - Alexandros Briasoulis
- Aleksandra Hospital, National and Kapodistrian University of Athens Medical School, 11527 Athens, Greece;
| | - Gerasimos Siasos
- Sotiria Hospital, National and Kapodistrian University of Athens Medical School, 11527 Athens, Greece;
| | - Kaveh Hosseini
- Cardiac Primary Prevention Research Center, Cardiovascular Disease Research Institute, Tehran University of Medical Sciences, Tehran 1411713138, Iran;
| | - Ilias Doulamis
- Department of Surgery, The Johns Hopkins Hospital, School of Medicine, Baltimore, MD 21287, USA;
| | | | - Angelos Karlas
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, 85764 Neuherberg, Germany; (N.-A.F.); (Y.X.); (N.K.); (V.N.)
- Chair of Biological Imaging at the Central Institute for Translational Cancer Research (TranslaTUM), School of Medicine, Technical University of Munich, 81675 Munich, Germany
- Department for Vascular and Endovascular Surgery, Klinikum rechts der Isar, Technical University of Munich (TUM), 81675 Munich, Germany; (M.A.K.); (H.-H.E.)
- DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, 80336 Munich, Germany
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10
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Baur ID, Auffarth GU, Khoramnia R, Łabuz G. Spherical Aberration of Astigmatic Corneas in a Cataract Population. J Refract Surg 2023; 39:532-538. [PMID: 37578181 DOI: 10.3928/1081597x-20230717-01] [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: 08/15/2023]
Abstract
PURPOSE To study the distribution of spherical aberration (SA) in astigmatic corneas in a cataract population and the relationship between magnitude of corneal astigmatism and fourth-order corneal SA. METHODS Data routinely collected using a Scheimpflug camera (Pentacam; Oculus Optikgeräte GmbH) were retrospectively analyzed. Patients with a minimum age of 60 years were included. Total corneal SA (from anterior and posterior corneal surface) was obtained for a 6-mm cor-neal area aligned with the pupil center. Exclusion criteria were insufficient measurement quality, total deviation index (Belin/Ambrósio Deviation) greater than 1.60, and corneal thickness at the thinnest point of less than 490 μm. One eye per patient was chosen randomly. Eyes were divided into low (≤ 1.00 diopters [D]), moderate (> 1.00 to ≤ 2.00 D), and high (> 2.00 D) astigmatism groups according to the Scheimpflug measurements. RESULTS A total of 528 eyes were included in this analysis. Low astigmatism was found in 129 patients, moderate astigmatism in 265 patients, and high astigmatism in 134 patients. Mean astigmatism was 0.68 ± 0.24, 1.45 ± 0.28, and 2.91 ± 0.95 D in the low, moderate, and high astigmatism groups, respectively. Mean corneal SA in patients with moderate and high astigmatism was higher than in the low astigmatism group. The difference reached the significance level for the comparison of low and high astigmatism groups (P = .023). The fourth-order SA increased gradually with the magnitude of astigmatism with a slope of 0.015. CONCLUSIONS SA was significantly larger in the cataract population with high corneal astigmatism. The increase of positive sign SA with the magnitude of astigmatism suggests that patients with moderate to high astigmatism may benefit more from intraocular lenses with negative sign SA correction. [J Refract Surg. 2023;39(8):532-538.].
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Leroux C, Ouadi S, Leahy C, Marc I, Fontvieille C, Bardin F. Absolute prediction of relative changes in contrast sensitivity with aberrations using a single metric of retinal image quality. BIOMEDICAL OPTICS EXPRESS 2023; 14:3203-3212. [PMID: 37497514 PMCID: PMC10368034 DOI: 10.1364/boe.487217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 05/09/2023] [Accepted: 05/10/2023] [Indexed: 07/28/2023]
Abstract
Metrics of retinal image quality predict optimal refractive corrections and correlate with visual performance. To date, they do not predict absolutely the relative change in visual performance when aberrations change and therefore need to be a-posteriori rescaled to match relative measurements. Here we demonstrate that a recently proposed metric can be used to predict, in an absolute manner, changes in contrast sensitivity measurements with Sloan letters when aberrations change. Typical aberrations of young and healthy eyes (for a 6 mm pupil diameter) were numerically introduced, and we measured the resulting loss in contrast sensitivity of subjects looking through a 2 mm diameter pupil. Our results suggest that the metric can be used to corroborate measurements of visual performance in clinical practice, thereby potentially improving patient follow-ups.
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Affiliation(s)
- Charles Leroux
- Laboratoire MIPA, Université de Nîmes, Sites des Carmes, Nîmes, 30000, France
| | - Sarah Ouadi
- Laboratoire MIPA, Université de Nîmes, Sites des Carmes, Nîmes, 30000, France
| | - Conor Leahy
- Carl Zeiss Meditec, Inc., 5300 Central Parkway, Dublin, CA 94568, USA
| | - Isabelle Marc
- Euromov Digital Health in Motion, Univ Montpellier, IMT Mines Ales, Alès, France
| | | | - Fabrice Bardin
- Laboratoire MIPA, Université de Nîmes, Sites des Carmes, Nîmes, 30000, France
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Nepita I, Raimondi R, Piazza S, Diaspro A, Vidal-Aroca F, Surdo S, Romano MR. Optical-Quality Assessment of a Miniaturized Intraocular Telescope. J Clin Med 2023; 12:jcm12103375. [PMID: 37240481 DOI: 10.3390/jcm12103375] [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: 03/12/2023] [Revised: 04/20/2023] [Accepted: 05/05/2023] [Indexed: 05/28/2023] Open
Abstract
Age-related macular degeneration (AMD) causes severe vision impairments, including blindness. An option to improve vision in AMD patients is through intraocular lenses and optics. Among others, implantable miniaturized telescopes, which direct light to healthy lateral regions of the retina, can be highly effective in improving vision in AMD patients. Yet, the quality of the restored vision might be sensitive to the optical transmission and aberrations of the telescope. To shed light on these points, we studied the in vitro optical performance of an implantable miniaturized telescope, namely, the SING IMT™ (Samsara Vision Ltd., Far Hills, NJ, USA) designed to improve vision in patients affected by late-stage AMD. Specifically, we measured the optical transmission in the spectral range 350-750 nm of the implantable telescope with a fiber-optic spectrometer. Wavefront aberrations were studied by measuring the wavefront of a laser beam after passing through the telescope and expanding the measured wavefront into a Zernike polynomial basis. Wavefront concavity indicated that the SING IMT™ behaves as a diverging lens with a focal length of -111 mm. The device exhibited even optical transmission in the whole visible spectrum and effective curvature suitable for retinal images magnification with negligible geometrical aberrations. Optical spectrometry and in vitro wavefront analysis provide evidence supporting the feasibility of miniaturized telescopes as high-quality optical elements and a favorable option for AMD visual impairment treatments.
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Affiliation(s)
- Irene Nepita
- Nanoscopy, Istituto Italiano di Tecnologia, Via E. Melen 83, 16152 Genova, Italy
- Genoa Instruments s.r.l., Via E. Melen 83, 16152 Genoa, Italy
| | - Raffaele Raimondi
- Department of Biomedical Sciences, Humanitas University, 20090 Milano, Italy
| | - Simonluca Piazza
- Nanoscopy, Istituto Italiano di Tecnologia, Via E. Melen 83, 16152 Genova, Italy
- Genoa Instruments s.r.l., Via E. Melen 83, 16152 Genoa, Italy
| | - Alberto Diaspro
- Nanoscopy, Istituto Italiano di Tecnologia, Via E. Melen 83, 16152 Genova, Italy
- DIFILAB, Department of Physics, University of Genoa, 16146 Genoa, Italy
| | | | - Salvatore Surdo
- Genoa Instruments s.r.l., Via E. Melen 83, 16152 Genoa, Italy
- Dipartimento di Ingegneria dell'Informazione, Università di Pisa, 56122 Pisa, Italy
| | - Mario R Romano
- Department of Biomedical Sciences, Humanitas University, 20090 Milano, Italy
- Eye Center, Humanitas Gavazzeni-Castelli, 24128 Bergamo, Italy
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13
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Csoba I, Kunkli R. Rendering algorithms for aberrated human vision simulation. Vis Comput Ind Biomed Art 2023; 6:5. [PMID: 36930412 PMCID: PMC10023823 DOI: 10.1186/s42492-023-00132-9] [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: 08/08/2022] [Accepted: 03/06/2023] [Indexed: 03/18/2023] Open
Abstract
Vision-simulated imagery-the process of generating images that mimic the human visual system-is a valuable tool with a wide spectrum of possible applications, including visual acuity measurements, personalized planning of corrective lenses and surgeries, vision-correcting displays, vision-related hardware development, and extended reality discomfort reduction. A critical property of human vision is that it is imperfect because of the highly influential wavefront aberrations that vary from person to person. This study provides an overview of the existing computational image generation techniques that properly simulate human vision in the presence of wavefront aberrations. These algorithms typically apply ray tracing with a detailed description of the simulated eye or utilize the point-spread function of the eye to perform convolution on the input image. Based on the description of the vision simulation techniques, several of their characteristic features have been evaluated and some potential application areas and research directions have been outlined.
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Affiliation(s)
- István Csoba
- Faculty of Informatics, University of Debrecen, Debrecen 4028, Hungary. .,Doctoral School of Informatics, University of Debrecen, Debrecen 4028, Hungary.
| | - Roland Kunkli
- Faculty of Informatics, University of Debrecen, Debrecen 4028, Hungary
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14
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Goswami S, Bharadwaj SR. Impact of temporal fluctuations in optical defocus on visual acuity: Empirical results and modeling outcomes. J Vis 2023; 23:14. [PMID: 36971683 PMCID: PMC10064932 DOI: 10.1167/jov.23.3.14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023] Open
Abstract
Optical defocus in human eyes is seldom steady during naturalistic steady-state viewing. It fluctuates by 0.3 to 0.5 diopters (D) from accommodative microfluctuations and by 1.5 to 2.5 D in dysfunctions such as spasm of near reflex, both with ≤2 Hz low-pass frequency spectra. This study observed losses in monocular visual acuity of cyclopleged adults who encountered varying amplitude (0.25-2.0 D) and temporal frequency (0.25-2.0 Hz) combinations of sinusoidal defoci induced using an electrically tunable lens. Visual acuity, recorded for 300-ms flashes of Sloan optotype presentation using the method of constant stimuli, deteriorated with defocus amplitude at a rate steeper for lower than higher temporal frequencies. A template matching model of acuity, incorporating optical and neural low-pass filters, neural noise, and a cross-correlated decision operator, showed the best match with empirical data when acuity was governed by the minimum defocus available during optotype display. This criterion minimized acuity loss for higher temporal frequencies due to the increased probability of zero-defocus encounters within the presentation duration. Other decision criteria such as defocus averaging across the entire or parts of the presentation duration yielded less satisfactory results. These results imply that vision loss in humans encountering broadband time-varying defocus is dictated by the dominant low frequencies, with higher frequencies largely compensated using the least defocus decision strategy.
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Affiliation(s)
- Sabyasachi Goswami
- Brien Holden Institute of Optometry and Vision Sciences, L V Prasad Eye Institute, Hyderabad, Telangana, India
- Prof Brien Holden Eye Research Centre, Hyderabad Eye Research Foundation, L V Prasad Eye Institute, Hyderabad, Telangana, India
| | - Shrikant R Bharadwaj
- Brien Holden Institute of Optometry and Vision Sciences, L V Prasad Eye Institute, Hyderabad, Telangana, India
- Prof Brien Holden Eye Research Centre, Hyderabad Eye Research Foundation, L V Prasad Eye Institute, Hyderabad, Telangana, India
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15
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Recep ÖF, Kocabas DO, Kiziltoprak H, Ozulken K. Effects on Wavefront Aberration after Short-term Wear of Senofilcon A Photochromic Contact Lens. Klin Monbl Augenheilkd 2022. [PMID: 36347502 DOI: 10.1055/a-1973-8904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND To assess the variability in wavefront aberrations with short-term wear of photochromic senofilcon A contact lenses in both its activated and inactive states. METHODS AND MATERIAL In this cross-sectional study, 20 participants who had previously used soft contact lenses were enrolled. Corneal aberrometry measurements were performed on each subject, without contact lenses, using Sirius Scheimpflug-Placido topography. The photochromic lenses were illuminated using a blue-violet light (λ max = 420 nm) so as to provoke an activated state, and measurements were taken with the lenses inserted, in both states. The root mean square (RMS) of the aberrations was calculated, and the higher- and lower-order aberrations, astigmatism, coma, spherical aberration, and trefoil measurements were evaluated using a 5.0-mm pupil diameter. RESULTS The average contact lens sphere power was - 2.33 ± 1.07 D. The mean refractive errors with contact lens wear were 0.07 ± 0.18 D for the sphere and - 0.26 ± 0.15 D for the cylinder. The mean RMS values for all the corneal aberrations showed no statistically significant differences with and without contact lenses (p > 0.05). In a bivariate correlation analysis, there was a positive correlation between contact lens sphere power and coma (vertical and horizontal) in the activated state (r = 0.455, p = 0.44 and r = 0.495, p = 0.27, respectively). CONCLUSION The photochromic contact lenses did not influence ocular aberration during short-term wear, even when the photochromatic additive was activated. This property may help to provide more comfortable vision with lens wear. This finding needs to be verified by further studies.
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Affiliation(s)
| | | | - Hasan Kiziltoprak
- Ophthalmology, Adıyaman University Training and Research Hospital, Adıyaman, Turkey
| | - Kemal Ozulken
- Ophthalmology, TOBB Economics and Technology University Faculty of Medicine, Ankara, Turkey
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16
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Miyanishi Y, Sahin E, Gotchev A. Optical modelling of an accommodative light field display system and prediction of human eye responses. OPTICS EXPRESS 2022; 30:37193-37212. [PMID: 36258312 DOI: 10.1364/oe.458651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 09/08/2022] [Indexed: 06/16/2023]
Abstract
The spatio-angular resolution of a light field (LF) display is a crucial factor for delivering adequate spatial image quality and eliciting an accommodation response. Previous studies have modelled retinal image formation with an LF display and evaluated whether accommodation would be evoked correctly. The models were mostly based on ray-tracing and a schematic eye model, which pose computational complexity and inaccurately represent the human eye population's behaviour. We propose an efficient wave-optics-based framework to model the human eye and a general LF display. With the model, we simulated the retinal point spread function (PSF) of a point rendered by an LF display at various depths to characterise the retinal image quality. Additionally, accommodation responses to the rendered point were estimated by computing the visual Strehl ratio based on the optical transfer function (VSOTF) from the PSFs. We assumed an ideal LF display that had an infinite spatial resolution and was free from optical aberrations in the simulation. We tested points rendered at 0-4 dioptres of depths having angular resolutions of up to 4x4 viewpoints within a pupil. The simulation predicted small and constant accommodation errors, which contradict the findings of previous studies. An evaluation of the optical resolution on the retina suggested a trade-off between the maximum achievable resolution and the depth range of a rendered point where in-focus resolution is kept high. The proposed framework can be used to evaluate the upper bound of the optical performance of an LF display for realistically aberrated eyes, which may help to find an optimal spatio-angular resolution required to render a high quality 3D scene.
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17
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Devi P, Kumar P, Marella BL, Bharadwaj SR. Impact of Degraded Optics on Monocular and Binocular Vision: Lessons from Recent Advances in Highly-Aberrated Eyes. Semin Ophthalmol 2022; 37:869-886. [PMID: 35786147 DOI: 10.1080/08820538.2022.2094711] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
PURPOSE Optical imperfections of the eye, characterized by higher-order wavefront aberrations, are exaggerated in corneal disease (e.g., keratoconus) and iatrogeny (e.g., keratorefractive surgery for myopia correction, keratoplasty for optical clarity restoration). This article reviews the recent advances on this topic for a comprehensive understanding of how optical degradations in disease models impact retinal image quality and monocular and binocular visual performance. METHODS Published literature over the last decade on retinal image quality and/or monocular and binocular visual functions with corneal irregularity was reviewed based on their relevance to the current topic, study population and strength of study design. The literature was summarized into four themes: 1) wavefront errors and retinal image quality of highly aberrated eyes, 2) monocular and binocular vision loss consequent to degraded optics and visual strategies to optimize performance, 3) impact of optical correction modalities on visual performance and 4) implications for clinical management of patients. RESULTS Across the 46 articles reviewed, the results clearly indicated that an increase in higher-order aberrations across these conditions had a significant negative impact on the patient's retinal image quality, and monocular and binocular visual functions. Interocular differences in retinal image quality deteriorated visual performance more than an overall worsening of image quality bilaterally. Minimizing optical degradation using rigid contact lenses and adaptive optics technology significantly improves retinal image quality and monocular and binocular vision, but performance remains sub-optimal relative to age-similar healthy controls. CONCLUSION Corneal disease and iatrogeny are useful models to understand the impact of optical degradation on retinal image quality and visual performance. Clinical management will greatly benefit from equalizing retinal image quality of both eyes of these patients. Future studies that deepen our understanding of the structure-function relation in these conditions are desirable for advancing vision science in this area and for developing novel clinical management strategies.
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Affiliation(s)
- Preetirupa Devi
- Brien Holden Institute of Optometry and Vision Sciences, L V Prasad Eye Institute, Hyderabad, India.,Prof Brien Holden Eye Research Centre, L V Prasad Eye Institute, Hyderabad, India.,School of Health Sciences, Division of Optometry and Visual Sciences, City, University of London, London, UK
| | - Preetam Kumar
- Brien Holden Institute of Optometry and Vision Sciences, L V Prasad Eye Institute, Hyderabad, India.,Prof Brien Holden Eye Research Centre, L V Prasad Eye Institute, Hyderabad, India.,School of Health Sciences, Division of Optometry and Visual Sciences, City, University of London, London, UK
| | - Bhagya Lakshmi Marella
- Brien Holden Institute of Optometry and Vision Sciences, L V Prasad Eye Institute, Hyderabad, India.,Prof Brien Holden Eye Research Centre, L V Prasad Eye Institute, Hyderabad, India.,School of Health Sciences, Division of Optometry and Visual Sciences, City, University of London, London, UK
| | - Shrikant R Bharadwaj
- Brien Holden Institute of Optometry and Vision Sciences, L V Prasad Eye Institute, Hyderabad, India.,Prof Brien Holden Eye Research Centre, L V Prasad Eye Institute, Hyderabad, India
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18
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Cense B, Maddipatla R, Cervantes Lozano FJ, Joo C. Two concepts for ultra-high-resolution polarization-sensitive optical coherence tomography with a single camera. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2022; 39:1295-1308. [PMID: 36215616 DOI: 10.1364/josaa.458631] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 06/12/2022] [Indexed: 06/16/2023]
Abstract
Two designs with a multiplexed superluminescent diode for ultra-high-resolution spectral-domain polarization-sensitive optical coherence tomography (UHR-PS-OCT) are introduced. In the first design, a Wollaston prism separates orthogonal polarization states next to each other on one linescan camera; the other design uses a beam displacer to separate orthogonal states onto two lines of a linescan camera with multiple rows of detectors. The coherence lengths measured with the two systems were 3.6 µm and 2.9 µm (n=1.38), respectively. Measurements were collected from the fovea of a healthy subject, a healthy subject with astigmatism, and a patient with central serous retinopathy (CSR). A single volumetric scan provides double pass retardance induced by the retinal nerve fiber layer birefringence (RNFL) and its birefringence, the cumulative double pass retardance induced by the Henle fiber layer, and the retardance that is induced by the retinal pigment epithelium-Bruch's membrane complex. The high axial resolution in UHR-PS-OCT is particularly helpful for the measurements of thin retinal tissue, such as the RNFL in the fovea, where birefringence values of around 1°/µm were found. Tilting of the retina due to a CSR or by off centering the imaging beam in the pupil causes an artificial increase in the double pass retardance induced by the RNFL and Henle fiber layer.
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19
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Barbero S, Bradley A, López-Gil N, Rubinstein J, Thibos L. Catastrophe optics theory unveils the localised wave aberration features that generate ghost images. Ophthalmic Physiol Opt 2022; 42:1074-1091. [PMID: 35620968 PMCID: PMC9543491 DOI: 10.1111/opo.13008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 04/29/2022] [Accepted: 04/29/2022] [Indexed: 12/19/2022]
Abstract
Monocular polyplopia (ghost or multiple images) is a serious visual impediment for some people who report seeing two (diplopia), three (triplopia) or even more images. Polyplopia is expected to appear if the point spread function (PSF) has multiple intensity cores (a dense concentration of a large portion of the radiant flux contained in the PSF) relatively separated from each other, each of which contributes to a distinct image. We present a theory that assigns these multiple PSF cores to specific features of aberrated wavefronts, thereby accounting optically for the perceptual phenomenon of monocular polyplopia. The theory provides two major conclusions. First, the most likely event giving rise to multiple PSF cores is the presence of hyperbolic, or less probably elliptical, umbilic caustics (using the terminology of catastrophe optics). Second, those umbilic caustics formed on the retinal surface are associated with certain points of the wave aberration function, called cusps of Gauss, where the gradient of a curvature function vanishes. However, not all cusps of Gauss generate those umbilic caustics. We also provide necessary conditions for those cusps of Gauss to be fertile. To show the potential of this theoretical framework for understanding the nature and origin of polyplopia, we provide specific examples of ocular wave aberration functions that induce diplopia and triplopia. The polyplopia effects in these examples are illustrated by depicting the multi-core PSFs and the convolved retinal images for clinical letter charts, both through computer simulations and through experimental recording using an adaptive optics set-up. The number and location of cores in the PSF is thus a potentially useful metric for the existence and severity of polyplopia in spatial vision. These examples also help explain why physiological pupil constriction might reduce the incidence of ghosting and multiple images of daily objects that affect vision with dilated pupils. This mechanistic explanation suggests a possible role for optical phase-masking as a clinical treatment for polyplopia and ghosting.
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Affiliation(s)
| | - Arthur Bradley
- School of Optometry, Indiana University, Bloomington, Indiana, USA
| | - Norberto López-Gil
- Instituto Universitario de Investigación en Envejecimiento, Universidad de Murcia, Murcia, Spain
| | | | - Larry Thibos
- School of Optometry, Indiana University, Bloomington, Indiana, USA
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20
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Singh V, Burge J, Brainard DH. Equivalent noise characterization of human lightness constancy. J Vis 2022; 22:2. [PMID: 35394508 PMCID: PMC8994201 DOI: 10.1167/jov.22.5.2] [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: 12/03/2022] Open
Abstract
A goal of visual perception is to provide stable representations of task-relevant scene properties (e.g. object reflectance) despite variation in task-irrelevant scene properties (e.g. illumination and reflectance of other nearby objects). To study such stability in the context of the perceptual representation of lightness, we introduce a threshold-based psychophysical paradigm. We measure how thresholds for discriminating the achromatic reflectance of a target object (task-relevant property) in rendered naturalistic scenes are impacted by variation in the reflectance functions of background objects (task-irrelevant property), using a two-alternative forced-choice paradigm in which the reflectance of the background objects is randomized across the two intervals of each trial. We control the amount of background reflectance variation by manipulating a statistical model of naturally occurring surface reflectances. For low background object reflectance variation, discrimination thresholds were nearly constant, indicating that observers’ internal noise determines threshold in this regime. As background object reflectance variation increases, its effects start to dominate performance. A model based on signal detection theory allows us to express the effects of task-irrelevant variation in terms of the equivalent noise, that is relative to the intrinsic precision of the task-relevant perceptual representation. The results indicate that although naturally occurring background object reflectance variation does intrude on the perceptual representation of target object lightness, the effect is modest – within a factor of two of the equivalent noise level set by internal noise.
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Affiliation(s)
- Vijay Singh
- Department of Physics, North Carolina Agricultural and Technical State University, Greensboro, NC, USA.,Computational Neuroscience Initiative, University of Pennsylvania, Philadelphia, PA, USA.,
| | - Johannes Burge
- Computational Neuroscience Initiative, University of Pennsylvania, Philadelphia, PA, USA.,Department of Psychology, University of Pennsylvania, Philadelphia, PA, USA.,Neuroscience Graduate Group, University of Pennsylvania, Philadelphia, PA, USA.,Bioengineering Graduate Group, University of Pennsylvania, Philadelphia, PA, USA.,
| | - David H Brainard
- Computational Neuroscience Initiative, University of Pennsylvania, Philadelphia, PA, USA.,Department of Psychology, University of Pennsylvania, Philadelphia, PA, USA.,Neuroscience Graduate Group, University of Pennsylvania, Philadelphia, PA, USA.,Bioengineering Graduate Group, University of Pennsylvania, Philadelphia, PA, USA.,
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21
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Leroux CE, Bouchet E, Espinasse P, Fontvieille C, Bardin F. Correlation between Contrast Sensitivity and Modulation Transfer Functions. Optom Vis Sci 2021; 98:1263-1269. [PMID: 34510142 DOI: 10.1097/opx.0000000000001795] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
SIGNIFICANCE Previous studies found no correlation between visual acuity and optical quality in a population of young subjects with good vision. Using sinusoidal gratings, we systematically investigate the correlation between contrast sensitivity and optical quality as a function of spatial frequency. PURPOSE This study describes the correlation between the contrast sensitivity function (CSF) and the modulation transfer function (MTF) in a sample of young and informed subjects. Our results are compared with prior studies on the correlation between visual acuity and metrics of image quality. We also compare our results with previous studies that compare the CSF, the MTF, and the neural contrast sensitivity function (NCSF). METHODS The CSF of 28 informed subjects is measured in photopic conditions. The polychromatic MTF is computed from the measurements of monochromatic aberrations. The (CSF, MTF) correlation is estimated as the Pearson correlation coefficient, at each spatial frequency. The NCSF of each subject is estimated as the ratio of CSF to MTF. RESULTS We obtain high correlation coefficients (0.8) in the range of spatial frequencies of 3 to 6 cycles per degree, which also corresponds to high NCSF. Correlation decreases with increasing spatial frequency in the range of 6 to 18 cycles per degree (down to 0.0 at 18 cycles per degree). In that range, optical and neural contrast sensitivities are both approximately reduced by factor 4. CONCLUSIONS In our sample of young subjects with good vision, the CSF with sinusoidal gratings better differentiates eyes of good optical quality at intermediate spatial frequencies (3 to 6 cycles per degree) than at higher spatial frequencies (12 to 18 cycles per degree). At the highest tested spatial frequency of sinusoidal gratings (18 cycles per degree), there is no significant correlation between optical quality and contrast sensitivity.
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Affiliation(s)
| | - Elise Bouchet
- Laboratoire Mathématiques Informatique Physique et Applications, Université de Nîmes, Nîmes Cedex, France
| | - Pauline Espinasse
- Laboratoire Mathématiques Informatique Physique et Applications, Université de Nîmes, Nîmes Cedex, France
| | - Christophe Fontvieille
- Laboratoire Mathématiques Informatique Physique et Applications, Université de Nîmes, Nîmes Cedex, France
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22
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Georgiev S, Kumar A, Findl O, Hirnschall N, Niederleithner M, Kendrisic M, Drexler W, Leitgeb RA. Digital ocular swept source optical coherence aberrometry. BIOMEDICAL OPTICS EXPRESS 2021; 12:6762-6779. [PMID: 34858679 PMCID: PMC8606149 DOI: 10.1364/boe.430596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 08/09/2021] [Accepted: 08/11/2021] [Indexed: 06/13/2023]
Abstract
Ocular aberrometry is an essential technique in vision science and ophthalmology. We demonstrate how a phase-sensitive single mode fiber-based swept source optical coherence tomography (SS-OCT) setup can be employed for quantitative ocular aberrometry with digital adaptive optics (DAO). The system records the volumetric point spread function at the retina in a de-scanning geometry using a guide star pencil beam. Succeeding test-retest repeatability assessment with defocus and astigmatism analysis on a model eye within ± 3 D dynamic range, the feasibility of technique is demonstrated in-vivo at a B-scan rate of >1 kHz in comparison with a commercially available aberrometer.
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Affiliation(s)
- Stefan Georgiev
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria
- Vienna Institute for Research in Ocular Surgery, Hanusch Hospital, Vienna, Austria
- Contributed equally
| | - Abhishek Kumar
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria
- Wavesense Engineering GmbH, Vienna, Austria
- Contributed equally
| | - Oliver Findl
- Vienna Institute for Research in Ocular Surgery, Hanusch Hospital, Vienna, Austria
| | - Nino Hirnschall
- Vienna Institute for Research in Ocular Surgery, Hanusch Hospital, Vienna, Austria
| | - Michael Niederleithner
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria
| | - Milana Kendrisic
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria
| | - Wolfgang Drexler
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria
| | - Rainer A. Leitgeb
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria
- Christian Doppler Laboratory for Innovative Optical Imaging and Its Translation to Medicine, Medical University of Vienna, Waehringer Guertel 18-20 A-1090 Vienna, Austria
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23
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Chakravarthula P, Zhang Z, Tursun O, Didyk P, Sun Q, Fuchs H. Gaze-Contingent Retinal Speckle Suppression for Perceptually-Matched Foveated Holographic Displays. IEEE TRANSACTIONS ON VISUALIZATION AND COMPUTER GRAPHICS 2021; 27:4194-4203. [PMID: 34449368 DOI: 10.1109/tvcg.2021.3106433] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Computer-generated holographic (CGH) displays show great potential and are emerging as the next-generation displays for augmented and virtual reality, and automotive heads-up displays. One of the critical problems harming the wide adoption of such displays is the presence of speckle noise inherent to holography, that compromises its quality by introducing perceptible artifacts. Although speckle noise suppression has been an active research area, the previous works have not considered the perceptual characteristics of the Human Visual System (HVS), which receives the final displayed imagery. However, it is well studied that the sensitivity of the HVS is not uniform across the visual field, which has led to gaze-contingent rendering schemes for maximizing the perceptual quality in various computer-generated imagery. Inspired by this, we present the first method that reduces the "perceived speckle noise" by integrating foveal and peripheral vision characteristics of the HVS, along with the retinal point spread function, into the phase hologram computation. Specifically, we introduce the anatomical and statistical retinal receptor distribution into our computational hologram optimization, which places a higher priority on reducing the perceived foveal speckle noise while being adaptable to any individual's optical aberration on the retina. Our method demonstrates superior perceptual quality on our emulated holographic display. Our evaluations with objective measurements and subjective studies demonstrate a significant reduction of the human perceived noise.
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24
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Tamura M, Moriguchi Y, Yeh SY, Matsumoto A, Shibutani M, Asao T, Mino T, Nakanishi M, Kubota A, Akiba M. Sensorless astigmatism correction using a variable cross-cylinder for high lateral resolution optical coherence tomography in a human retina. APPLIED OPTICS 2021; 60:9553-9559. [PMID: 34807099 DOI: 10.1364/ao.441646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 09/30/2021] [Indexed: 06/13/2023]
Abstract
High lateral resolution (∼5µm) optical coherence tomography (OCT) that employs a variable cross-cylinder (VCC) to compensate for astigmatism is presented for visualizing minute structures of the human retina. The VCC and its sensorless optimization process enable ocular astigmatism correction of up to -5.0 diopter within a few seconds. VCC correction has been proven to increase the signal-to-noise ratio and lateral resolution using a model eye. This process is also validated using the human eye by visualizing the capillary network and human cone mosaic. The proposed method is applicable to existing OCT, making high lateral resolution OCT practical in clinical settings.
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25
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Zhong Y, Zhu Y, Wang W, Wang K, Liu X, Yao K. Femtosecond laser-assisted cataract surgery versus conventional phacoemulsification: comparison of internal aberrations and visual quality. Graefes Arch Clin Exp Ophthalmol 2021; 260:901-911. [PMID: 34636992 DOI: 10.1007/s00417-021-05441-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 10/01/2021] [Accepted: 10/01/2021] [Indexed: 01/19/2023] Open
Abstract
PURPOSE To compare the internal aberrations and optical quality after femtosecond laser-assisted cataract surgery (FLACS) and conventional phacoemulsification cataract surgery (CPCS). METHODS This study included patients who received FLACS or CPCS from January 2016 to July 2019. Postoperative examinations included wavefront measurements under pupil diameters of 3.0 mm and 5.0 mm, intraocular lens (IOL) decentration, visual acuity (VA), and refractive outcomes. Visual quality was measured with Strehl ratio and modulation transfer function (MTF). Subgroup analyses were conducted based on monofocal or multifocal-extended depth of focus (EDOF) IOL. RESULTS The study consisted of 221 eyes (105 eyes in FLACS and 116 eyes in CPCS). With a pupil diameter of 5.0 mm, FLACS demonstrated a significantly lower root mean square of total internal aberration (P = 0.004), higher order aberrations (HOAs) (P = 0.034), tilt (P = 0.049), coma (P = 0.004), and spherical aberration (P = 0.014). IOL tilt was found to be positively correlated with total internal aberration (P < 0.001), HOAs (P < 0.001), and coma (P < 0.001). The FLACS group presented significantly smaller IOL decentration than the CPCS group (P < 0.001), but there were no significant differences in terms of VA and refractive outcomes between groups. In the multifocal-EDOF subgroup, Strehl ratio and MTF values were significantly higher in the femtosecond group with a 3.0-mm pupil. CONCLUSION FLACS induced significantly lower values of IOL tilt, decentration, and internal aberrations compared with the CPCS group with a pupil diameter of 5.0 mm, while no significant differences were found in the VA or optical quality over long-term observation. TRIAL REGISTRATION This trial was registered at www.chictr.org.cn (registration number ChiCTR2000038965).
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Affiliation(s)
- Yueyang Zhong
- Eye Center of the Second Affiliated Hospital, School of Medicine, Zhejiang University, No. 88 Jiefang Road, Hangzhou, 310009, Zhejiang Province, China
| | - Yanan Zhu
- Eye Center of the Second Affiliated Hospital, School of Medicine, Zhejiang University, No. 88 Jiefang Road, Hangzhou, 310009, Zhejiang Province, China
| | - Wei Wang
- Eye Center of the Second Affiliated Hospital, School of Medicine, Zhejiang University, No. 88 Jiefang Road, Hangzhou, 310009, Zhejiang Province, China
| | - Kai Wang
- Eye Center of the Second Affiliated Hospital, School of Medicine, Zhejiang University, No. 88 Jiefang Road, Hangzhou, 310009, Zhejiang Province, China
| | - Xin Liu
- Eye Center of the Second Affiliated Hospital, School of Medicine, Zhejiang University, No. 88 Jiefang Road, Hangzhou, 310009, Zhejiang Province, China
| | - Ke Yao
- Eye Center of the Second Affiliated Hospital, School of Medicine, Zhejiang University, No. 88 Jiefang Road, Hangzhou, 310009, Zhejiang Province, China.
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Simulations of Decentration and Tilt of a Supplementary Sulcus-Fixated Intraocular Lens in a Polypseudophakic Combination Using Ray-Tracing Software. PHOTONICS 2021. [DOI: 10.3390/photonics8080309] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
This study aimed to assess image quality after the tilt and decentration of supplementary intraocular lenses (IOLs) in a two-lens configuration. One was designed for sulcus fixation with a nominal power range of 1D–10D and was combined with a capsular fixation 20D IOL. The optical performance of a ray-tracing model was tested under IOL misalignment through the area under the modulation transfer function (MTFa) and wave aberrations. Tilting by 10° resulted in a 4% reduction of the MTFa for a 10D IOL as compared to 9% for the 20D lens. The two models demonstrated good tolerance to a 1 mm decentration; as for the 10D sulcus-fixated lens, the MTFa loss was 2%, and 4% for the capsular fixation lens. Coma and astigmatism increased three- and four-fold, respectively, after a 10° tilt compared to the aberration level induced by the 1 mm decentration. Both analyses showed a trend towards a lower MTF impact and fewer optical errors with decreasing nominal power. In conclusion, when misaligned, low-power sulcus-fixated IOLs might retain their good optical quality. An extreme tilt of 10° has a more detrimental effect on the IOL performance than a 1 mm decentration. The proper alignment of a high-power capsular fixation lens is important in achieving a desirable postoperative outcome.
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Visual image quality after small-incision lenticule extraction compared with that of spectacles and contact lenses. J Cataract Refract Surg 2021; 47:731-740. [PMID: 33181632 DOI: 10.1097/j.jcrs.0000000000000501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 10/28/2020] [Indexed: 11/25/2022]
Abstract
PURPOSE To assess the influence of small-incision lenticule extraction (SMILE) for high myopia on the visual image quality assessed by the logarithm of the visual Strehl ratio (logVSX) and put this into a clinical context by pairwise comparing the logVSX of postoperative eyes with those of myopic controls wearing spectacles and/or contact lenses. SETTING University hospital. DESIGN Prospective and cross-sectional clinical study. METHODS Patients with a myopic spherical equivalent of at least 6.00 diopters treated with SMILE aimed at emmetropia and correspondingly myopic controls corrected with spectacles and/or contact lenses were included. The logVSX calculation was divided into habitual logVSX based on the wavefront aberration measurement directly and optimal logVSX calculated in a theoretical through-focus experiment to obtain the best-achievable logVSX. RESULTS A total of 117 eyes of 61 patients and 64 eyes of 34 myopic controls were included. SMILE did not affect the habitual logVSX but worsened the optimal logVSX (P < .001). The postoperative habitual logVSX was statistically significantly worse compared with contact lenses (P = .002). The postoperative optimal logVSX was significantly worse compared with both spectacles (P < .01) and contact lenses (P = .003). There was no statistically significant difference in habitual or optimal logVSX between spectacles and contact lenses. CONCLUSIONS SMILE for high myopia does not affect the habitual logVSX but decreases the optimal logVSX slightly. The postoperative habitual logVSX is worse than for contact lenses but not spectacles, and the postoperative optimal logVSX is worse than for both contact lenses and spectacles. There is no statistically significant difference in either habitual or optimal logVSX between spectacles and contact lenses.
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Abstract
Early detection and monitoring are critical to the diagnosis and management of glaucoma, a progressive optic neuropathy that causes irreversible blindness. Optical coherence tomography (OCT) has become a commonly utilized imaging modality that aids in the detection and monitoring of structural glaucomatous damage. Since its inception in 1991, OCT has progressed through multiple iterations, from time-domain OCT, to spectral-domain OCT, to swept-source OCT, all of which have progressively improved the resolution and speed of scans. Even newer technological advancements and OCT applications, such as adaptive optics, visible-light OCT, and OCT-angiography, have enriched the use of OCT in the evaluation of glaucoma. This article reviews current commercial and state-of-the-art OCT technologies and analytic techniques in the context of their utility for glaucoma diagnosis and management, as well as promising future directions. Expected final online publication date for the Annual Review of Vision Science, Volume 7 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Alexi Geevarghese
- Department of Ophthalmology, NYU Langone Health, NYU Grossman School of Medicine, New York, NY 10016, USA;
| | - Gadi Wollstein
- Department of Ophthalmology, NYU Langone Health, NYU Grossman School of Medicine, New York, NY 10016, USA; .,Department of Biomedical Engineering, NYU Tandon School of Engineering, Brooklyn, New York 11201, USA.,Center for Neural Science, NYU College of Arts and Sciences, New York, NY 10003, USA
| | - Hiroshi Ishikawa
- Department of Ophthalmology, NYU Langone Health, NYU Grossman School of Medicine, New York, NY 10016, USA; .,Department of Biomedical Engineering, NYU Tandon School of Engineering, Brooklyn, New York 11201, USA
| | - Joel S Schuman
- Department of Ophthalmology, NYU Langone Health, NYU Grossman School of Medicine, New York, NY 10016, USA; .,Department of Biomedical Engineering, NYU Tandon School of Engineering, Brooklyn, New York 11201, USA.,Center for Neural Science, NYU College of Arts and Sciences, New York, NY 10003, USA.,Department of Physiology and Neuroscience, NYU Langone Health, NYU Grossman School of Medicine, New York, NY 10016, USA
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Optimization of Virtual Shack-Hartmann Wavefront Sensing. SENSORS 2021; 21:s21144698. [PMID: 34300438 PMCID: PMC8309488 DOI: 10.3390/s21144698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 07/02/2021] [Accepted: 07/06/2021] [Indexed: 11/17/2022]
Abstract
Virtual Shack–Hartmann wavefront sensing (vSHWS) can flexibly adjust parameters to meet different requirements without changing the system, and it is a promising means for aberration measurement. However, how to optimize its parameters to achieve the best performance is rarely discussed. In this work, the data processing procedure and methods of vSHWS were demonstrated by using a set of normal human ocular aberrations as an example. The shapes (round and square) of a virtual lenslet, the zero-padding of the sub-aperture electric field, sub-aperture number, as well as the sequences (before and after diffraction calculation), algorithms, and interval of data interpolation, were analyzed to find the optimal configuration. The effect of the above optimizations on its anti-noise performance was also studied. The Zernike coefficient errors and the root mean square of the wavefront error between the reconstructed and preset wavefronts were used for performance evaluation. The performance of the optimized vSHWS could be significantly improved compared to that of a non-optimized one, which was also verified with 20 sets of clinical human ocular aberrations. This work makes the vSHWS’s implementation clearer, and the optimization methods and the obtained results are of great significance for its applications.
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Karkhanis MU, Ghosh C, Banerjee A, Hasan N, Likhite R, Ghosh T, Kim H, Mastrangelo CH. Correcting Presbyopia With Autofocusing Liquid-Lens Eyeglasses. IEEE Trans Biomed Eng 2021; 69:390-400. [PMID: 34232861 DOI: 10.1109/tbme.2021.3094964] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
OBJECTIVE Presbyopia, an age-related ocular disorder, is characterized by the loss in the accommodative abilities of the human eye. Conventional methods of correcting presbyopia divide the field of view, thereby resulting in significant vision impairment. We demonstrate the design, assembly and evaluation of autofocusing eyeglasses for restoration of accommodation without dividing the field of view. METHODS The adaptive optics eyeglasses comprise of two variable-focus liquid lenses, a time-of-flight range sensor and low-power, dual microprocessor control electronics, housed within an ergonomic frame. Subject-specific accommodation deficiency models were utilized to demonstrate high-fidelity accommodative correction. The abilities of this system to reduce accommodation deficiency, its power consumption, response time, optical performance and MTF were evaluated. RESULTS Average corrected accommodation deficiencies for 5 subjects ranged from -0.021 D to 0.016 D. Each accommodation correction calculation was performed in ∼67 ms which consumed 4.86 mJ of energy. The optical resolution of the system was 10.5 cycles/degree, and featured a restorative accommodative range of 4.3 D. This system was capable of running for up to 19 hours between charge cycles and weighed ∼132 g. CONCLUSION The design, assembly and performance of an autofocusing eyeglasses system to restore accommodation in presbyopes has been demonstrated. SIGNIFICANCE The new autofocusing eyeglasses system presented in this article has the potential to restore pre-presbyopic levels of accommodation in subjects diagnosed with presbyopia.
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Afsharan H, Hackmann MJ, Wang Q, Navaeipour F, Jayasree SVK, Zawadzki RJ, Silva D, Joo C, Cense B. Polarization properties of retinal blood vessel walls measured with polarization sensitive optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2021; 12:4340-4362. [PMID: 34457418 PMCID: PMC8367251 DOI: 10.1364/boe.426079] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 05/23/2021] [Accepted: 05/27/2021] [Indexed: 05/08/2023]
Abstract
A new method based on polarization-sensitive optical coherence tomography (PS-OCT) is introduced to determine the polarization properties of human retinal vessel walls, in vivo. Measurements were obtained near the optic nerve head of three healthy human subjects. The double pass phase retardation per unit depth (DPPR/UD), which is proportional to the birefringence, is higher in artery walls, presumably because of the presence of muscle tissue. Measurements in surrounding retinal nerve fiber layer tissue yielded lower DPPR/UD values, suggesting that the retinal vessel wall tissue near the optic nerve is not covered by retinal nerve fiber layer tissue (0.43°/µm vs. 0.77°/µm, respectively). Measurements were obtained from multiple artery-vein pairs, to quantify the different polarization properties. Measurements were taken along a section of the vessel wall, with changes in DPPR/UD up to 15%, while the vessel wall thickness remained relatively constant. A stationary scan pattern was applied to determine the influence of involuntary eye motion on the measurement, which was significant. Measurements were also analyzed by two examiners, with high inter-observer agreement. The measurement repeatability was determined with measurements that were acquired during multiple visits. An improvement in accuracy can be achieved with an ultra-broad-bandwidth PS-OCT system since it will provide more data points in-depth, which reduces the influence of discretization and helps to facilitate better fitting of the birefringence data.
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Affiliation(s)
- Hadi Afsharan
- Optical+Biomedical Engineering Laboratory, Department of Electrical, Electronic and Computer Engineering, The University of Western Australia, Perth WA 6009, Australia
| | - Michael J. Hackmann
- Optical+Biomedical Engineering Laboratory, Department of Electrical, Electronic and Computer Engineering, The University of Western Australia, Perth WA 6009, Australia
- School of Human Sciences, The University of Western Australia, Crawley 6009, WA, Australia
| | - Qiang Wang
- Optical+Biomedical Engineering Laboratory, Department of Electrical, Electronic and Computer Engineering, The University of Western Australia, Perth WA 6009, Australia
| | - Farzaneh Navaeipour
- Department of Physics, Engineering Physics and Astronomy, Queen’s University, Kingston, Ontario K7L 3N6, Canada
| | - Stephy Vijaya Kumar Jayasree
- Department of Physics, School of Physics, Mathematics and Computing, The University of Western Australia, Perth WA 6009, Australia
| | - Robert J. Zawadzki
- Department of Ophthalmology and Vision Science, University of California Davis, Sacramento, CA 95817, USA
| | - Dilusha Silva
- Microelectronics Research Group, Department of Electrical, Electronic and Computer Engineering, The University of Western Australia, Perth WA 6009, Australia
| | - Chulmin Joo
- Department of Mechanical Engineering, Yonsei University, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Barry Cense
- Optical+Biomedical Engineering Laboratory, Department of Electrical, Electronic and Computer Engineering, The University of Western Australia, Perth WA 6009, Australia
- Department of Mechanical Engineering, Yonsei University, Seodaemun-gu, Seoul 03722, Republic of Korea
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De Lestrange-Anginieur E, Leung TW, Kee CS. Joint effect of defocus blur and spatial attention. Vision Res 2021; 185:88-97. [PMID: 33964585 DOI: 10.1016/j.visres.2021.04.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 04/04/2021] [Accepted: 04/05/2021] [Indexed: 10/21/2022]
Abstract
Defocus blur and spatial attention both act on our ability to see clearly over time. However, it is currently unknown how these two factors interact because studies on spatial resolution only focused on the separate effects of attention and defocus blurs. In this study, eleven participants performed a resolution acuity task along the diagonal 135˚/315˚ with horizontal, at 8˚ eccentricity for clear and blurred Landolt C images under various manipulations of covert endogenous attention. All the conditions were interleaved and viewed binocularly on a visual display. We observed that attention not just improves the resolution of clear stimuli, but also modulates the resolution of defocused stimuli for compensating the loss of resolution caused by retinal blur. Our results show, however, that as the degree of attention decreases, the differences between clear and blurred images largely diminish, thus limiting the benefit of an image quality enhancement. It also appeared that attention tends to enhance the resolution of clear targets more than blurred targets, suggesting potential variations in the gain of vision correction with the level of attention. This demonstrates that the interaction between spatial attention and defocus blur can play a role in the way we see things. In view of these findings, the development of adaptive interventions, which adjust the eye's defocus to attention, may hold promise.
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Affiliation(s)
| | - T W Leung
- School of Optometry, Hong Kong Polytechnic University, Hong Kong, China
| | - C S Kee
- School of Optometry, Hong Kong Polytechnic University, Hong Kong, China; Interdisciplinary Division of Biomedical Engineering, Hong Kong Polytechnic University, Hong Kong SAR, China
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33
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Cochrane Corner: wavefront-guided laser vision correction. Eye (Lond) 2021; 35:2454-2455. [PMID: 33911210 DOI: 10.1038/s41433-021-01534-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 03/29/2021] [Accepted: 03/31/2021] [Indexed: 11/08/2022] Open
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34
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Vincent SJ, Collins MJ, Read SA, Carney LG. Myopic anisometropia: ocular characteristics and aetiological considerations. Clin Exp Optom 2021; 97:291-307. [DOI: 10.1111/cxo.12171] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 02/14/2014] [Indexed: 12/20/2022] Open
Affiliation(s)
- Stephen J Vincent
- Contact Lens and Visual Optics Laboratory, School of Optometry and Vision Science, Queensland University of Technology, Brisbane, Queensland, Australia,
| | - Michael J Collins
- Contact Lens and Visual Optics Laboratory, School of Optometry and Vision Science, Queensland University of Technology, Brisbane, Queensland, Australia,
| | - Scott A Read
- Contact Lens and Visual Optics Laboratory, School of Optometry and Vision Science, Queensland University of Technology, Brisbane, Queensland, Australia,
| | - Leo G Carney
- Contact Lens and Visual Optics Laboratory, School of Optometry and Vision Science, Queensland University of Technology, Brisbane, Queensland, Australia,
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35
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Dobos MJ, Twa MD, Bullimore MA. An evaluation of the Bausch & Lomb Zywave aberrometer. Clin Exp Optom 2021; 92:238-45. [PMID: 19469012 DOI: 10.1111/j.1444-0938.2009.00360.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Affiliation(s)
- Michael J Dobos
- The Ohio State University College of Optometry, Columbus, Ohio, USA
| | - Michael D Twa
- University of Houston, College of Optometry, Houston, Texas, USA
E‐mail:
| | - Mark A Bullimore
- The Ohio State University College of Optometry, Columbus, Ohio, USA
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36
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Zhu M, Collins MJ, Yeo AC. Stability of corneal topography and wavefront aberrations in young Singaporeans. Clin Exp Optom 2021; 96:486-93. [DOI: 10.1111/cxo.12040] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Revised: 09/17/2012] [Accepted: 10/30/2012] [Indexed: 11/29/2022] Open
Affiliation(s)
- Mingxia Zhu
- Optometry Centre, School of Chemical and Life Sciences, Singapore Polytechnic, Singapore,
| | - Michael J Collins
- Contact Lens and Visual Optics Laboratory, School of Optometry and Vision Science, Queensland University of Technology, Kelvin Grove, Queensland, Australia,
| | - Anna Ch Yeo
- Optometry Centre, School of Chemical and Life Sciences, Singapore Polytechnic, Singapore,
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37
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Rae SM, Price HC. The effect of soft contact lens wear and time from blink on wavefront aberration measurement variation. Clin Exp Optom 2021; 92:274-82. [DOI: 10.1111/j.1444-0938.2009.00377.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
- Sheila M Rae
- Vision and Eye Research Unit, Anglia Ruskin University, Cambridge, United Kingdom
E‐mail:
| | - Holly C Price
- Vision and Eye Research Unit, Anglia Ruskin University, Cambridge, United Kingdom
E‐mail:
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38
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Atchison DA. Recent advances in representation of monochromatic aberrations of human eyes. Clin Exp Optom 2021; 87:138-48. [PMID: 15186204 DOI: 10.1111/j.1444-0938.2004.tb03166.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2004] [Revised: 04/29/2004] [Accepted: 05/01/2004] [Indexed: 11/30/2022] Open
Abstract
The field of aberrations of the human eye is moving rapidly, being driven by the desire to monitor and optimise vision following refractive surgery. In this paper, I discuss the different ways of representing aberrations of the human eye, the terminology used, how wave aberrations are used to determine refractions, the influence of pupil size on aberrations, how to compare right and left eye aberrations, how aberrations can be manipulated into different forms, how to make corrections for changes in wavelength, the appropriate ocular axis, and corneal and lenticular components of the aberrations.
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Affiliation(s)
- David A Atchison
- School of Optometry, Queensland University of Technology, Victoria Park Road, Kelvin Grove, QLD, 4059, Australia
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39
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Repeatability of corneal and ocular aberration measurements and changes in aberrations over one week. Clin Exp Optom 2021; 92:253-66. [DOI: 10.1111/j.1444-0938.2009.00364.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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40
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Lombardo M, Lombardo G. New methods and techniques for sensing the wave aberrations of human eyes. Clin Exp Optom 2021; 92:176-86. [DOI: 10.1111/j.1444-0938.2009.00356.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Affiliation(s)
- Marco Lombardo
- Vision Engineering, Reggio Calabria, Italy and CNR‐INFM LiCryL Laboratory, Department of Physics, University of Calabria, Rende (CS), Italy
E‐mail:
| | - Giuseppe Lombardo
- Vision Engineering, Reggio Calabria, Italy and CNR‐INFM LiCryL Laboratory, Department of Physics, University of Calabria, Rende (CS), Italy
E‐mail:
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41
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Atchison DA. Recent advances in measurement of monochromatic aberrations of human eyes. Clin Exp Optom 2021; 88:5-27. [PMID: 15658922 DOI: 10.1111/j.1444-0938.2005.tb06659.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2004] [Revised: 11/18/2004] [Accepted: 11/27/2004] [Indexed: 11/29/2022] Open
Abstract
The field of aberrations of the human eye is moving rapidly, being driven by the desire to monitor and optimise vision following refractive surgery. It is important for ophthalmologists and optometrists to have an understanding of the magnitude of various aberrations and how these are likely to be affected by refractive surgery and other corrections. In this paper, I consider methods used to measure aberrations, the magnitude of aberrations in general populations and how these are affected by various factors (for example, age, refractive error, accommodation and refractive surgery) and how aberrations and their correction affect spatial visual performance.
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Affiliation(s)
- David A Atchison
- School of Optometry, Queensland University of Technology, Kelvin Grove, QLD 4059, Australia
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42
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Radhakrishnan H, Jinabhai A, O'donnell C. Dynamics of ocular aberrations in keratoconus. Clin Exp Optom 2021; 93:164-74. [DOI: 10.1111/j.1444-0938.2010.00471.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Affiliation(s)
- Hema Radhakrishnan
- Faculty of Life Sciences, Moffat Building, University of Manchester, Manchester, United Kingdom
E‐mail:
| | - Amit Jinabhai
- Faculty of Life Sciences, Moffat Building, University of Manchester, Manchester, United Kingdom
E‐mail:
| | - Clare O'donnell
- Faculty of Life Sciences, Moffat Building, University of Manchester, Manchester, United Kingdom
E‐mail:
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43
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Nam J, Thibos LN, Iskander DR. Describing ocular aberrations with wavefront vergence maps. Clin Exp Optom 2021; 92:194-205. [DOI: 10.1111/j.1444-0938.2009.00358.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Affiliation(s)
- Jayoung Nam
- Indiana University, Bloomington, Indiana, USA
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44
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Łabuz G, Varadi D, Khoramnia R, Auffarth GU. Progressive-toric IOL design reduces residual astigmatism with increasing pupil size: a ray-tracing simulation based on corneal topography data. BIOMEDICAL OPTICS EXPRESS 2021; 12:1568-1576. [PMID: 33796373 PMCID: PMC7984777 DOI: 10.1364/boe.417894] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 02/04/2021] [Accepted: 02/12/2021] [Indexed: 06/12/2023]
Abstract
Population studies indicate that astigmatism decreases from the corneal center toward the periphery. A standard toric intraocular lens (IOL) with a constant cylinder power cannot correct uniformly across this gradient. We built an astigmatic eye model based on corneal topography data. A progressive-toric lens with gradually decreasing cylinder power was compared with an identically designed lens but featuring conventional astigmatism correction. Residual astigmatism did not differ significantly (P=0.06) at 3 mm, and the Strehl ratio was identical for both lenses (0.51 ±0.15, P=0.88). At 5 mm, the progressive IOL yielded significantly lower residual astigmatism by 0.10 D (P<0.001). The Strehl ratio was 0.30 ±0.08 with the progressive and 0.29 ±0.08 with the standard lens (P<0.001). At 3 mm, the optical performance was comparable for both IOLs. However, at 5 mm, the progressive-toric was more effective in correcting astigmatism, and it yielded reduced residual astigmatism compared to a standard toric lens.
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Affiliation(s)
- Grzegorz Łabuz
- The David J. Apple Center for Vision Research, Department of Ophthalmology, Heidelberg University Hospital, INF 400, 69120 Heidelberg, Germany
| | - Dorottya Varadi
- The David J. Apple Center for Vision Research, Department of Ophthalmology, Heidelberg University Hospital, INF 400, 69120 Heidelberg, Germany
| | - Ramin Khoramnia
- The David J. Apple Center for Vision Research, Department of Ophthalmology, Heidelberg University Hospital, INF 400, 69120 Heidelberg, Germany
| | - Gerd U. Auffarth
- The David J. Apple Center for Vision Research, Department of Ophthalmology, Heidelberg University Hospital, INF 400, 69120 Heidelberg, Germany
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De Lestrange-Anginieur E, Kee CS. Optical performance of progressive addition lenses (PALs) with astigmatic prescription. Sci Rep 2021; 11:2984. [PMID: 33542417 PMCID: PMC7862262 DOI: 10.1038/s41598-021-82697-0] [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] [Received: 06/08/2020] [Accepted: 01/18/2021] [Indexed: 11/09/2022] Open
Abstract
The progressive addition lens (PAL) is a spectacle lens design with progressive refractive power changes across the lens surface to provide sharp vision at different viewing distances for patients with reduced accommodative strength. It has gained in popularity not just for presbyopic patients, but also patients with occupational (office, driving, or digital device) and therapeutic (e.g., myopia control) needs. However, despite the increasing prevalence of astigmatism in adults > 40 years old who rely on PAL correction, no metric is available to reflect the optical variation in PALs with astigmatic prescriptions. Based on recent studies, four novel optical metrics sensitive to variation of refractive power across the lens surface of PALs have been developed. These metrics were used to compare the optical performance of PALs of various prescriptions, designs, and manufacturers. For each lens, the refractive power profile was first measured with a Moire-deflectometry-based instrument.The data was then exported and analyzed using a two-dimensional error map for each of the four metrics. The results revealed significant impacts of astigmatic prescription, providing evidence for the usefulness of these metrics in quantifying the optical performance of PALs for patients with astigmatic prescriptions.
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Affiliation(s)
| | - C S Kee
- School of Optometry, Hong Kong Polytechnic University, Hong Kong, China.,Interdisciplinary Division of Biomedical Engineering, Hong Kong Polytechnic University, Hong Kong, SAR, China
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Marella BL, Conway ML, Suttle C, Bharadwaj SR. Contrast Rivalry Paradigm Reveals Suppression of Monocular Input in Keratoconus. Invest Ophthalmol Vis Sci 2021; 62:15. [PMID: 33570601 PMCID: PMC7884294 DOI: 10.1167/iovs.62.2.12] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Keratoconus results in image quality loss in one or both eyes due to increased corneal distortion. This study quantified the depth of monocular suppression in keratoconus due to this image quality loss using a binocular contrast rivalry paradigm. Methods Contrast rivalry was induced in 50 keratoconic cases (11–31 years) and 12 age-matched controls by dichoptically viewing orthogonal Gabor patches of 5 cycles per degree (cpd) and 1.5 cpd spatial frequency for 120 seconds with their best-corrected spectacles and rigid gas permeable (RGP) contact lenses. The dwell time on each eye's percept was determined at baseline (100% contrast bilaterally) and at varying contrast levels (80–2.5%) in the stronger eye of keratoconus or dominant eye of controls. The contrast reduction needed in the stronger eye to balance dwell times on both eyes was considered a measure of suppression depth. Results At baseline with 5 cpd stimuli and spectacle correction, the rivalry switches were less frequent and biased toward the stronger eye of cases, all relative to controls (P < 0.001). The contrast balance point of cases (20.51% [10.7–61%]) was lower than the controls (99.80% [98.6–100%]; P < 0.001) and strongly associated with the overall and interocular difference in disease severity (r = 0.83, P < 0.001). The suppression depth reduced for 1.5 cpd (70.8% [21.7–94%]), relative to 5 cpd stimulus (P < 0.001) and with contact lenses (80.1% [49.5–91.7%]), relative to spectacles (P < 0.001). Conclusions The eye with lesser disease severity dominates binocular viewing in keratoconus. The suppression depth of the poorer eye depends on the extent of bilateral disease severity, optical correction modality, and the target spatial frequency.
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Affiliation(s)
- Bhagya Lakshmi Marella
- Brien Holden Institute of Optometry and Vision Sciences, L V Prasad Eye Institute, Banjara Hills, Hyderabad, Telangana, India.,Prof. Brien Holden Eye Research Centre, Hyderabad Eye Research Foundation, L V Prasad Eye Institute, Banjara Hills, Hyderabad, Telangana, India.,School of Health Sciences, Division of Optometry and Visual Sciences, City, University of London, Northampton Square, London, United Kingdom
| | - Miriam L Conway
- School of Health Sciences, Division of Optometry and Visual Sciences, City, University of London, Northampton Square, London, United Kingdom
| | - Catherine Suttle
- School of Health Sciences, Division of Optometry and Visual Sciences, City, University of London, Northampton Square, London, United Kingdom
| | - Shrikant R Bharadwaj
- Brien Holden Institute of Optometry and Vision Sciences, L V Prasad Eye Institute, Banjara Hills, Hyderabad, Telangana, India.,Prof. Brien Holden Eye Research Centre, Hyderabad Eye Research Foundation, L V Prasad Eye Institute, Banjara Hills, Hyderabad, Telangana, India
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Abstract
Adaptive optics (AO) is a technique that corrects for optical aberrations. It was originally proposed to correct for the blurring effect of atmospheric turbulence on images in ground-based telescopes and was instrumental in the work that resulted in the Nobel prize-winning discovery of a supermassive compact object at the centre of our galaxy. When AO is used to correct for the eye's imperfect optics, retinal changes at the cellular level can be detected, allowing us to study the operation of the visual system and to assess ocular health in the microscopic domain. By correcting for sample-induced blur in microscopy, AO has pushed the boundaries of imaging in thick tissue specimens, such as when observing neuronal processes in the brain. In this primer, we focus on the application of AO for high-resolution imaging in astronomy, vision science and microscopy. We begin with an overview of the general principles of AO and its main components, which include methods to measure the aberrations, devices for aberration correction, and how these components are linked in operation. We present results and applications from each field along with reproducibility considerations and limitations. Finally, we discuss future directions.
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Coco G, Cremonesi P, Menassa N, Pagano L, Gadhvi KA, Semeraro F, Kaye SB, Romano V. Changes in pupillometry associated with dissipated energy during phacoemulsification. Eur J Ophthalmol 2020; 31:2962-2968. [PMID: 33372549 DOI: 10.1177/1120672120984377] [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] [Indexed: 11/16/2022]
Abstract
PURPOSE To investigate the effect of ultrasound level during phacoemulsification on pupil dynamics. METHODS Comparative retrospective study on patients who underwent routine cataract surgery at the Royal Liverpool University Hospital. Clinical parameters, anterior chamber measurements, axial length, surgeon grade, time of surgery, level of ultrasound used (cumulative dissipated energy, CDE), intra- and post-operative complications were collected. Pupil diameters were collected before and 4 ± 1 weeks after surgery in static scotopic, mesopic, photopic pupil conditions. Also, pupil dynamic measurements after luminous stimulus were recorded. Changes in static pupil diameters, relative dilation at 3.5 s after luminous stimulus, and time to reach 75% and 95% of maximum dilation were measured. RESULTS Forty-eight eyes of 24 patients (13 males) were included with a mean age of 73.1 ± 14.6 years. Mean CDE value was 18.11 ± 10.56. Mean scotopic pupil diameters decreased by 0.24 ± 0.48 mm (p = 0.021) in the operated eye. Significant correlation was found between reduction in scotopic pupil diameter and CDE (p = 0.05). A generalized linear model confirmed that the level of CDE was significantly associated with reduction in scotopic pupil diameter (p = 0.026). Patients who underwent surgeries with lower CDE (0 < CDE ⩽ 10 and 10 < CDE ⩽ 20) did not experience significant changes in scotopic pupil diameter after surgery (p = 0.28 and p = 0.79, respectively) as opposed to those with higher CDE (CDE > 20; p = 0.03). CONCLUSION Phacoemulsification cataract surgery and the cumulative dissipated energy may be associated with changes in pupil behaviour.
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Affiliation(s)
- Giulia Coco
- St Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool, UK.,Department of Clinical Science and Translational Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Pierluca Cremonesi
- St Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool, UK.,Department of Medical and Surgical Specialties, Radiological Specialties and Public Health, University of Brescia, Brescia, Italy
| | - Nardine Menassa
- St Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool, UK
| | - Luca Pagano
- St Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool, UK
| | - Kunal A Gadhvi
- St Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool, UK
| | - Francesco Semeraro
- Department of Medical and Surgical Specialties, Radiological Specialties and Public Health, University of Brescia, Brescia, Italy
| | - Stephen B Kaye
- St Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool, UK.,Department of Eye and Vision Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
| | - Vito Romano
- St Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool, UK.,Department of Eye and Vision Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
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Leung TW, Chan CT, Lam CH, Tong YK, Kee CS. Changes in corneal astigmatism and near heterophoria after smartphone use while walking and sitting. PLoS One 2020; 15:e0243072. [PMID: 33270709 PMCID: PMC7714198 DOI: 10.1371/journal.pone.0243072] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 11/14/2020] [Indexed: 11/23/2022] Open
Abstract
Background/Aims Smartphone use has become an indispensable part of our daily life. The handy design and powerful processor allow smartphone users to perform diversified tasks even when walking. This study aimed to investigate and compare the optical aftereffect and vergence adaptation of using a smartphone while walking and sitting. Methods Twenty-nine young healthy adults (aged 19 to 24 years old) with normal binocular and accommodative functions were recruited. Participants were asked to watch a movie for 30 minutes using a smartphone while either walking on a treadmill or sitting on a chair. Corneal aberrations and near heterophoria were measured before and after smartphone use by a corneal topographer and modified Thorington heterophoria test, respectively. Results Using the smartphone while walking induced a change in corneal H/V astigmatism, becoming 0.11±0.03 μm less negative (two-way ANOVA repeated measures, Bonferroni post-hoc test, p = 0.001). This optical aftereffect was significantly higher than after smartphone use while sitting by 0.10±0.03 μm (paired t-test, p = 0.003). Although smartphone use did not result in a significant change in near heterophoria (Bonferroni post-hoc test, p > 0.15), the vergence adaptation showed relatively more eso- or less exo-deviation by 0.79±0.36Δ in the walking than the sitting condition (paired t-test, p = 0.037). Conclusions Eyecare practitioners should be cautious of the potential optical after effect and vergence adaptation after prolonged smartphone usage.
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Affiliation(s)
- Tsz Wing Leung
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China
- The Centre for Myopia Research, School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China
- * E-mail:
| | - Chui-Ting Chan
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Chi-Hin Lam
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Yuk-Kwan Tong
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Chea-Su Kee
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China
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Beeck A, Muckenhirn S, Herkommer A. Particle swarm optimization for wavefront correction in ophthalmic applications. JPHYS PHOTONICS 2020. [DOI: 10.1088/2515-7647/aba420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Many optical systems require the correction of the cumulative wavefront error of the system for performance optimization. In ophthalmology the wavefront error of the eye corresponds to the visual defect and can be measured up to high-order aberrations today. Lower orders of the wavefront error are usually corrected with spectacles, contact lenses or refractive surgery. In this paper we apply an optimization method called particle swarm optimization to calculate the optimal correction for visual defects based on measured high-order wavefront results. It is shown that an optimized conventional correction and in particular an extended wavefront correction including higher orders yields a better result for the visual Strehl ratio, as compared to a simple conjugate correction scheme.
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