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Hastings GD, Tiruveedhula P, Roorda A. Wide-field optical eye models for emmetropic and myopic eyes. J Vis 2024; 24:9. [PMID: 38995108 PMCID: PMC11246097 DOI: 10.1167/jov.24.7.9] [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: 01/28/2024] [Accepted: 06/03/2024] [Indexed: 07/13/2024] Open
Abstract
Ocular wavefront aberrations are used to describe retinal image formation in the study and modeling of foveal and peripheral visual functions and visual development. However, classical eye models generate aberration structures that generally do not resemble those of actual eyes, and simplifications such as rotationally symmetric and coaxial surfaces limit the usefulness of many modern eye models. Drawing on wide-field ocular wavefront aberrations measured previously by five laboratories, 28 emmetropic (-0.50 to +0.50 D) and 20 myopic (-1.50 to -4.50 D) individual optical eye models were reverse-engineered by optical design ray-tracing software. This involved an error function that manipulated 27 anatomical parameters, such as curvatures, asphericities, thicknesses, tilts, and translations-constrained within anatomical limits-to drive the output aberrations of each model to agree with the input (measured) aberrations. From those resultant anatomical parameters, three representative eye models were also defined: an ideal emmetropic eye with minimal aberrations (0.00 D), as well as a typical emmetropic eye (-0.02 D) and myopic eye (-2.75 D). The cohorts and individual models are presented and evaluated in terms of output aberrations and established population expectations, such as Seidel aberration theory and ocular chromatic aberrations. Presented applications of the models include the effect of dual focus contact lenses on peripheral optical quality, the comparison of ophthalmic correction modalities, and the projection of object space across the retina during accommodation.
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Affiliation(s)
- Gareth D Hastings
- Herbert Wertheim School of Optometry and Vision Science, University of California Berkeley, Berkeley, CA, USA
| | - Pavan Tiruveedhula
- Herbert Wertheim School of Optometry and Vision Science, University of California Berkeley, Berkeley, CA, USA
| | - Austin Roorda
- Herbert Wertheim School of Optometry and Vision Science, University of California Berkeley, Berkeley, CA, USA
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2
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Moon B, Poletti M, Roorda A, Tiruveedhula P, Liu SH, Linebach G, Rucci M, Rolland JP. Alignment, calibration, and validation of an adaptive optics scanning laser ophthalmoscope for high-resolution human foveal imaging. APPLIED OPTICS 2024; 63:730-742. [PMID: 38294386 PMCID: PMC11062499 DOI: 10.1364/ao.504283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 12/26/2023] [Indexed: 02/01/2024]
Abstract
In prior art, advances in adaptive optics scanning laser ophthalmoscope (AOSLO) technology have enabled cones in the human fovea to be resolved in healthy eyes with normal vision and low to moderate refractive errors, providing new insight into human foveal anatomy, visual perception, and retinal degenerative diseases. These high-resolution ophthalmoscopes require careful alignment of each optical subsystem to ensure diffraction-limited imaging performance, which is necessary for resolving the smallest foveal cones. This paper presents a systematic and rigorous methodology for building, aligning, calibrating, and testing an AOSLO designed for imaging the cone mosaic of the central fovea in humans with cellular resolution. This methodology uses a two-stage alignment procedure and thorough system testing to achieve diffraction-limited performance. Results from retinal imaging of healthy human subjects under 30 years of age with refractive errors of less than 3.5 diopters using either 680 nm or 840 nm light show that the system can resolve cones at the very center of the fovea, the region where the cones are smallest and most densely packed.
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Affiliation(s)
- Benjamin Moon
- The Institute of Optics, University of Rochester, Rochester, NY 14627, USA
- Center for Visual Science, University of Rochester, Rochester, NY 14627, USA
| | - Martina Poletti
- Center for Visual Science, University of Rochester, Rochester, NY 14627, USA
- Department of Brain and Cognitive Sciences, University of Rochester, Rochester, NY 14627, USA
- Department of Neuroscience, University of Rochester, Rochester, NY 14627, USA
| | - Austin Roorda
- Herbert Wertheim School of Optometry and Vision Science, University of California Berkeley, Berkeley, CA 94720, USA
| | - Pavan Tiruveedhula
- Herbert Wertheim School of Optometry and Vision Science, University of California Berkeley, Berkeley, CA 94720, USA
| | - Soh Hang Liu
- The Institute of Optics, University of Rochester, Rochester, NY 14627, USA
- Center for Visual Science, University of Rochester, Rochester, NY 14627, USA
| | - Glory Linebach
- The Institute of Optics, University of Rochester, Rochester, NY 14627, USA
- Center for Visual Science, University of Rochester, Rochester, NY 14627, USA
| | - Michele Rucci
- Center for Visual Science, University of Rochester, Rochester, NY 14627, USA
- Department of Brain and Cognitive Sciences, University of Rochester, Rochester, NY 14627, USA
| | - Jannick P. Rolland
- The Institute of Optics, University of Rochester, Rochester, NY 14627, USA
- Center for Visual Science, University of Rochester, Rochester, NY 14627, USA
- Department of Biomedical Engineering, University of Rochester, Rochester, NY 14627, USA
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3
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Fischer J, van der Merwe J, Vandenheever D. The influence of eye model parameter variations on simulated eye-tracking outcomes. J Eye Mov Res 2023; 11:10.16910/jemr.16.3.1. [PMID: 38116296 PMCID: PMC10730094 DOI: 10.16910/jemr.16.3.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2023] Open
Abstract
The simulated data used in eye-tracking-related research has been largely generated using normative eye models with little consideration of how the variations in eye biometry found in the population may influence eye-tracking outcomes. This study investigated the influence that variations in eye model parameters have on the ability of simulated data to predict real-world eye-tracking outcomes. The real-world experiments performed by two pertinent comparative studies were replicated in a simulated environment using a highcomplexity stochastic eye model that includes anatomically accurate distributions of eye biometry parameters. The outcomes showed that variations in anterior corneal asphericity significantly influence simulated eye-tracking outcomes of both interpolation and model-based gaze estimation algorithms. Other, more commonly varied parameters such as the corneal radius of curvature and foveal offset angle had little influence on simulated outcomes.
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Hastings GD, Banks MS, Roorda A. Radial and Tangential Retinal Magnifications as Functions of Visual Field Angle Across Spherical, Oblate, and Prolate Retinal Profiles. Transl Vis Sci Technol 2022; 11:10. [PMID: 36121677 PMCID: PMC9503314 DOI: 10.1167/tvst.11.9.10] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To provide a tool for calculating radial and tangential retinal magnifications as functions of field angle and retinal shape and to articulate patterns of magnification across the retina for monocular and binocular combinations of prolate-, oblate-, and spherical-shaped retinas. Methods Formulae were derived to calculate radial and tangential retinal magnifications (mm/deg) from field angle (degrees), retinal asphericity (unitless conic constant), retinal vertex radius of curvature (mm), and nodal point position (mm). Monocular retinal magnifications were determined for eyes with prolate, spherical, and oblate retinas as functions of field angle. Bilateral differences in magnifications were examined for combinations of those eyes. Results Retinal shape substantially affects magnification profiles even for eyes with the same axial length. Greatest magnification changes across a retina and between eyes, as well as greatest increase in radial-tangential differences (distortion), occur with prolate retinas. Binocular magnification differences were smallest for oblate retinas. Nodal points anterior to the vertex center of curvature and oblate asphericity both cause field-dependent reductions in magnification relative to the fovea (barrel distortion), whereas nodal points posterior to vertex center of curvature and prolate asphericity cause the opposite (pincushion distortion). Retinal magnification differences due to eye shape are much greater than aniseikonia thresholds and chromatic differences in magnification. A spreadsheet tool implements the magnification calculations. Conclusions Local retinal magnifications as functions of field angle have substantial effects on objective applications (imaging retinal anatomy) and subjective experiences (aniseikonia) and quantify an ocular property that differs across eye shapes and refractive errors. Translational Relevance Methods are provided to customize the calculation of radial and tangential magnifications across the retina for individual eyes, which will bolster the multifactorial study of the effects of foveal and peripheral optics across eye shapes and refractive errors.
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Affiliation(s)
- Gareth D. Hastings
- Herbert Wertheim School of Optometry and Vision Science, University of California Berkeley, Berkeley, CA, USA
| | - Martin S. Banks
- Herbert Wertheim School of Optometry and Vision Science, University of California Berkeley, Berkeley, CA, USA
| | - Austin Roorda
- Herbert Wertheim School of Optometry and Vision Science, University of California Berkeley, Berkeley, CA, USA
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Jindal S, Kaur H, Manduchi R. Tracker/Camera Calibration for Accurate Automatic Gaze Annotation of Images and Videos. PROCEEDINGS. EYE TRACKING RESEARCH & APPLICATIONS SYMPOSIUM 2022; 2022:15. [PMID: 35673555 PMCID: PMC9169673 DOI: 10.1145/3517031.3529643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Modern appearance-based gaze tracking algorithms require vast amounts of training data, with images of a viewer annotated with "ground truth" gaze direction. The standard approach to obtain gaze annotations is to ask subjects to fixate at specific known locations, then use a head model to determine the location of "origin of gaze". We propose using an IR gaze tracker to generate gaze annotations in natural settings that do not require the fixation of target points. This requires prior geometric calibration of the IR gaze tracker with the camera, such that the data produced by the IR tracker can be expressed in the camera's reference frame. This contribution introduces a simple tracker/camera calibration procedure based on the PnP algorithm and demonstrates its use to obtain a full characterization of gaze direction that can be used for ground truth annotation.
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Ruggeri M, Belloni G, Chang YC, Durkee H, Masetti E, Cabot F, Yoo SH, Ho A, Parel JM, Manns F. Combined anterior segment OCT and wavefront-based autorefractor using a shared beam. BIOMEDICAL OPTICS EXPRESS 2021; 12:6746-6761. [PMID: 34858678 PMCID: PMC8606132 DOI: 10.1364/boe.435127] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 09/29/2021] [Accepted: 09/29/2021] [Indexed: 05/30/2023]
Abstract
We have combined an anterior segment (AS) optical coherence tomography (OCT) system and a wavefront-based aberrometer with an approach that senses ocular wavefront aberrations using the OCT beam. Temporal interlacing of the OCT and aberrometer channels allows for OCT images and refractive error measurements to be acquired continuously and in real-time. The system measures refractive error with accuracy and precision comparable to that of clinical autorefractors. The proposed approach provides a compact modular design that is suitable for integrating OCT and wavefront-based autorefraction within the optical head of the ophthalmic surgical microscope for guiding cataract surgery or table-top devices for simultaneous autorefraction and ocular biometry.
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Affiliation(s)
- Marco Ruggeri
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA
- Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, FL 33146, USA
| | - Giulia Belloni
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA
- Department of Engineering “Enzo Ferrari”, University of Modena and Reggio Emilia, Modena, MO 41125, Italy
| | - Yu-Cherng Chang
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA
- Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, FL 33146, USA
| | - Heather Durkee
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA
- Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, FL 33146, USA
| | - Ettore Masetti
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA
- Department of Engineering “Enzo Ferrari”, University of Modena and Reggio Emilia, Modena, MO 41125, Italy
| | - Florence Cabot
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA
- Anne Bates Leach Eye Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Sonia H. Yoo
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA
- Anne Bates Leach Eye Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Arthur Ho
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA
- Brien Holden Vision Institute, Sydney, NSW 2052, Australia
- School of Optometry and Vision Science, University of New South Wales, Sydney, NSW 2033, Australia
| | - Jean-Marie Parel
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA
- Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, FL 33146, USA
- Anne Bates Leach Eye Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA
- Brien Holden Vision Institute, Sydney, NSW 2052, Australia
| | - Fabrice Manns
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA
- Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, FL 33146, USA
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7
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Kilpeläinen M, Putnam NM, Ratnam K, Roorda A. The retinal and perceived locus of fixation in the human visual system. J Vis 2021; 21:9. [PMID: 34643658 PMCID: PMC8525830 DOI: 10.1167/jov.21.11.9] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 09/03/2021] [Indexed: 01/04/2023] Open
Abstract
Due to the dramatic difference in spatial resolution between the central fovea and the surrounding retinal regions, accurate fixation on important objects is critical for humans. It is known that the preferred retinal location (PRL) for fixation of healthy human observers rarely coincides with the retinal location with the highest cone density. It is not currently known, however, whether the PRL is consistent within an observer or is subject to fluctuations and, moreover, whether observers' subjective fixation location coincides with the PRL. We studied whether the PRL changes between days. We used an adaptive optics scanning laser ophthalmoscope to project a Maltese cross fixation target on an observer's retina and continuously imaged the exact retinal location of the target. We found that observers consistently use the same PRL across days, regardless of how much the PRL is displaced from the cone density peak location. We then showed observers small stimuli near the visual field location on which they fixated, and the observers judged whether or not the stimuli appeared in fixation. Observers' precision in this task approached that of fixation itself. Observers based their judgment on both the visual scene coordinates and the retinal location of the stimuli. We conclude that the PRL in a normally functioning visual system is fixed, and observers use it as a reference point in judging stimulus locations.
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Affiliation(s)
- Markku Kilpeläinen
- Department of Psychology and Logopedics, University of Helsinki, Helsinki, Finland
| | - Nicole M Putnam
- Arizona College of Optometry, Midwestern University, Glendale, AZ, USA
| | | | - Austin Roorda
- Herbert Wertheim School of Optometry and Vision Science, University of California, Berkeley, Berkeley, CA, USA
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8
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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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9
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De Lestrange-Anginieur E, Kee C. Testing impacts of global blur profiles using a multiscale vision simulator. Heliyon 2020; 6:e04153. [PMID: 32743083 PMCID: PMC7387829 DOI: 10.1016/j.heliyon.2020.e04153] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 01/17/2020] [Accepted: 06/03/2020] [Indexed: 10/25/2022] Open
Abstract
Although it is possible to specify the impact of blur at a specific retinal location, a lack of understanding exists regarding how the inhomogeneous blur distribution across the retina (i.e., global blur) affects the quality of an optical correction at a specific retinal location. To elucidate this issue, a multiscale visual simulator combining the projection of a controllable high-resolution stimulus and an ocular monitoring system was constructed to simultaneously simulate foveal and extrafoveal blurs. To define the range and capability of a wide-angle stimulation, an optimal working pupil was evaluated by optical ray-tracing via a Monte Carlo simulation, including optical variations corresponding to fixational eye movements. To investigate the impacts of global blur on the perception of discrete regions of the visual field, the bothersome blur threshold from five subjects was measured through this novel system using a collection of zonal blurs (annuli image projected sequentially at discrete retinal regions), and these impacts were compared with those using a spatially-varying blur (continuum of simultaneously projected zonal blurs of varying strengths, simulating retinal blur variations). Our results show that the zonal blur threshold does not entirely predict the global blur threshold, having a tendency to overestimate blur the threshold. It was concluded that, in addition to the amount of defocus present at a defined retinal location, the perception of individual defocused retinal regions can be affected by global blur. Given that blur tolerance can affect the perception of optically induced blurs, the findings provide useful implications for designing new optical correction.
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Affiliation(s)
| | - C.S. Kee
- School of Optometry, Hong Kong Polytechnic University, Hong Kong
- Interdisciplinary Division of Biomedical Engineering, Hong Kong Polytechnic University, Hong Kong SAR, China
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10
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Abstract
In this review, I develop an empirically based model of optical image formation by the human eye, followed by neural sampling by retinal ganglion cells, to demonstrate the perceptual effects of blur, aliasing, and distortion of visual space in the brain. The optical model takes account of ocular aberrations and their variation across the visual field, in addition to variations of defocus due to variation of target vergence in three-dimensional scenes. Neural sampling by retinal ganglion cells with receptive field size and spacing that increases with eccentricity is used to visualize the neural image carried by the optic nerve to the brain. Anatomical parameters are derived from psychophysical studies of sampling-limited visual resolution of sinusoidal interference fringes. Retinotopic projection of the neural image onto brainstem nuclei reveals features of the neural image in a perceptually uniform brain space where location and size of visual objects may be measured by counting neurons.
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Affiliation(s)
- Larry N Thibos
- School of Optometry, Indiana University, Bloomington, Indiana 47405, USA;
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11
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Bartuzel MM, Wróbel K, Tamborski S, Meina M, Nowakowski M, Dalasiński K, Szkulmowska A, Szkulmowski M. High-resolution, ultrafast, wide-field retinal eye-tracking for enhanced quantification of fixational and saccadic motion. BIOMEDICAL OPTICS EXPRESS 2020; 11:3164-3180. [PMID: 32637248 PMCID: PMC7316009 DOI: 10.1364/boe.392849] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 04/30/2020] [Accepted: 05/07/2020] [Indexed: 05/23/2023]
Abstract
We introduce a novel, noninvasive retinal eye-tracking system capable of detecting eye displacements with an angular resolution of 0.039 arcmin and a maximum velocity of 300°/s across an 8° span. Our system is designed based on a confocal retinal imaging module similar to a scanning laser ophthalmoscope. It utilizes a 2D MEMS scanner ensuring high image frame acquisition frequencies up to 1.24 kHz. In contrast with leading eye-tracking technology, we measure the eye displacements via the collection of the observed spatial excursions for all the times corresponding a full acquisition cycle, thus obviating the need for both a baseline reference frame and absolute spatial calibration. Using this approach, we demonstrate the precise measurement of eye movements with magnitudes exceeding the spatial extent of a single frame, which is not possible using existing image-based retinal trackers. We describe our retinal tracker, tracking algorithms and assess the performance of our system by using programmed artificial eye movements. We also demonstrate the clinical capabilities of our system with in vivo subjects by detecting microsaccades with angular extents as small as 0.028°. The rich kinematic ocular data provided by our system with its exquisite degree of accuracy and extended dynamic range opens new and exciting avenues in retinal imaging and clinical neuroscience. Several subtle features of ocular motion such as saccadic dysfunction, fixation instability and abnormal smooth pursuit can be readily extracted and inferred from the measured retinal trajectories thus offering a promising tool for identifying biomarkers of neurodegenerative diseases associated with these ocular symptoms.
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Affiliation(s)
- Maciej M. Bartuzel
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Grudziądzka 5, Toruń 87-100, Poland
- Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wyb. Wyspiańskiego 27, Wrocław 50-370, Poland
| | - Krystian Wróbel
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Grudziądzka 5, Toruń 87-100, Poland
| | - Szymon Tamborski
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Grudziądzka 5, Toruń 87-100, Poland
| | - Michał Meina
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Grudziądzka 5, Toruń 87-100, Poland
- AM2M Ltd. L.P., Mickiewicza 7/17, Toruń 87-100, Poland
| | | | | | | | - Maciej Szkulmowski
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Grudziądzka 5, Toruń 87-100, Poland
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12
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Liu Q, Yang X, Lin L, Liu M, Lin H, Liu F, Xie Y, Lam DS. Review on Centration, Astigmatic Axis Alignment, Pupil Size and Optical Zone in SMILE. Asia Pac J Ophthalmol (Phila) 2019; 8:385-390. [PMID: 31567265 PMCID: PMC6784779 DOI: 10.1097/01.apo.0000580144.22353.46] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 08/06/2019] [Indexed: 11/25/2022] Open
Abstract
The advent of "flapless" small-incision lenticule extraction (SMILE), employing all-in-one technology, has resulted in a revolutionary breakthrough in refractive surgeries. SMILE has been gaining popularity due to fewer potential complications, such as postoperative dry eyes and greater biomechanical stability, etc. However, attention must be given to 1) the centration on the corneal vertex, 2) the proper alignment of the astigmatic axis, and 3) the relationship between pupil size and treatment diameter, to achieve good SMILE results. There is no pupil-tracking system to ascertain the accuracy of centration during the SMILE surgery. To improve the centration accuracy, our center uses two corneal topographers (Pentacam and Sirius) to measure and determine corneal vertex. Proper predicted optical zone diameter is not clearly defined yet in SMILE. Some scholars insist that mesopic pupil size should be taken into consideration when setting the predicted optical zone. Meanwhile, the issue of "functional optical zone" still has many unresolved issues and warrants further studies.
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Affiliation(s)
- Quan Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xiaonan Yang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Limian Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Manli Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Haiqin Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Fang Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Yi Xie
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Dennis S.C. Lam
- International Eye Research Institute of the Chinese University of Hong Kong (Shenzhen), Shenzhen, China
- C-MER (Shenzhen) Dennis Lam Eye Hospital, Futian, Shenzhen, China
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13
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Effect of high-order aberrations on pattern-reversal visual evoked potentials. Vision Res 2019; 161:52-59. [DOI: 10.1016/j.visres.2019.05.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 04/18/2019] [Accepted: 05/17/2019] [Indexed: 11/23/2022]
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14
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Steven S, Sulai YN, Cheong SK, Bentley J, Dubra A. Long eye relief fundus camera and fixation target with partial correction of ocular longitudinal chromatic aberration. BIOMEDICAL OPTICS EXPRESS 2018; 9:6017-6037. [PMID: 31065410 PMCID: PMC6491002 DOI: 10.1364/boe.9.006017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 10/19/2018] [Accepted: 10/19/2018] [Indexed: 05/14/2023]
Abstract
A combined 32° full field of view refractive fundus camera and fixation target with a -20 to +10 diopter sphere correction range is described and demonstrated. The optical setup partially corrects the average longitudinal chromatic aberration and spherical aberration of the human eye, while providing a long eye relief to allow integration with reflective adaptive optics ophthalmoscopes, as a viewfinder. The fundus camera operates with 940 nm light, using a maximum 2.9 mm diameter imaging pupil at the eye. The fixation target uses a light projector capable of delivering red, green and/or blue spatially and temporally modulated stimuli to the retina. The design and performance of each sub-system are discussed, and retinal imaging at various wavelengths is demonstrated.
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Affiliation(s)
- Samuel Steven
- Institute of Optics, University of Rochester, Rochester, NY 14620, USA
- Department of Ophthalmology, Stanford University, Palo Alto, CA 94303, USA
| | - Yusufu N. Sulai
- Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Currently at Facebook Reality Labs Redmond, WA 98052, USA
| | - Soon K. Cheong
- Department of Ophthalmology, Stanford University, Palo Alto, CA 94303, USA
| | - Julie Bentley
- Institute of Optics, University of Rochester, Rochester, NY 14620, USA
| | - Alfredo Dubra
- Department of Ophthalmology, Stanford University, Palo Alto, CA 94303, USA
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15
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Coughlan MF, Goncharov AV. Nonpupil adaptive optics for visual simulation of a customized contact lens. APPLIED OPTICS 2018; 57:E57-E63. [PMID: 30117922 DOI: 10.1364/ao.57.000e57] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 05/21/2018] [Indexed: 06/08/2023]
Abstract
We present a method for determining the deformable mirror profile to simulate the optical effect of a customized contact lens in the central visual field. Using nonpupil-conjugated adaptive optics allows a wider field simulation compared to traditional pupil-conjugated adaptive optics. For a given contact lens, the mirror shape can be derived analytically using Fermat's principle of the stationary optical path or numerically using optimization in ray-tracing programs. An example of an aspheric contact lens simulation is given to illustrate the method, and the effect of eye misalignment with respect to the deformable mirror position is investigated. The optimal deformable mirror conjugation position is found to be near the posterior corneal surface. Chromatic aberration analysis is also presented, and our findings indicate that the polychromatic simulation quality is similar to that of the monochromatic case, even though the mirror is a reflective component. The limitations of a single continuous surface deformable mirror to mimic a contact lens are outlined, with some recommendations for improving the quality of simulation.
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Laslandes M, Salas M, Hitzenberger CK, Pircher M. Increasing the field of view of adaptive optics scanning laser ophthalmoscopy. BIOMEDICAL OPTICS EXPRESS 2017; 8:4811-4826. [PMID: 29188083 PMCID: PMC5695933 DOI: 10.1364/boe.8.004811] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 09/27/2017] [Accepted: 09/27/2017] [Indexed: 05/03/2023]
Abstract
An adaptive optics scanning laser ophthalmoscope (AO-SLO) set-up with two deformable mirrors (DM) is presented. It allows high resolution imaging of the retina on a 4°×4° field of view (FoV), considering a 7 mm pupil diameter at the entrance of the eye. Imaging on such a FoV, which is larger compared to classical AO-SLO instruments, is allowed by the use of the two DMs. The first DM is located in a plane that is conjugated to the pupil of the eye and corrects for aberrations that are constant in the FoV. The second DM is conjugated to a plane that is located ∼0.7 mm anterior to the retina. This DM corrects for anisoplanatism effects within the FoV. The control of the DMs is performed by combining the classical AO technique, using a Shack-Hartmann wave-front sensor, and sensorless AO, which uses a criterion characterizing the image quality. The retinas of four healthy volunteers were imaged in-vivo with the developed instrument. In order to assess the performance of the set-up and to demonstrate the benefits of the 2 DM configuration, the acquired images were compared with images taken in conventional conditions, on a smaller FoV and with only one DM. Moreover, an image of a larger patch of the retina was obtained by stitching of 9 images acquired with a 4°×4° FoV, resulting in a total FoV of 10°×10°. Finally, different retinal layers were imaged by shifting the focal plane.
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17
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Polans J, Keller B, Carrasco-Zevallos OM, LaRocca F, Cole E, Whitson HE, Lad EM, Farsiu S, Izatt JA. Wide-field retinal optical coherence tomography with wavefront sensorless adaptive optics for enhanced imaging of targeted regions. BIOMEDICAL OPTICS EXPRESS 2017; 8:16-37. [PMID: 28101398 PMCID: PMC5231289 DOI: 10.1364/boe.8.000016] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Revised: 10/28/2016] [Accepted: 11/19/2016] [Indexed: 05/03/2023]
Abstract
The peripheral retina of the human eye offers a unique opportunity for assessment and monitoring of ocular diseases. We have developed a novel wide-field (>70°) optical coherence tomography system (WF-OCT) equipped with wavefront sensorless adaptive optics (WSAO) for enhancing the visualization of smaller (<25°) targeted regions in the peripheral retina. We iterated the WSAO algorithm at the speed of individual OCT B-scans (~20 ms) by using raw spectral interferograms to calculate the optimization metric. Our WSAO approach with a 3 mm beam diameter permitted primarily low- but also high- order peripheral wavefront correction in less than 10 seconds. In preliminary imaging studies in five normal human subjects, we quantified statistically significant changes with WSAO correction, corresponding to a 10.4% improvement in average pixel brightness (signal) and 7.0% improvement in high frequency content (resolution) when visualizing 1 mm (~3.5°) B-scans of the peripheral (>23°) retina. We demonstrated the ability of our WF-OCT system to acquire non wavefront-corrected wide-field images rapidly, which could then be used to locate regions of interest, zoom into targeted features, and visualize the same region at different time points. A pilot clinical study was conducted on seven healthy volunteers and two subjects with prodromal Alzheimer's disease which illustrated the capability to image Drusen-like pathologies as far as 32.5° from the fovea in un-averaged volume scans. This work suggests that the proposed combination of WF-OCT and WSAO may find applications in the diagnosis and treatment of ocular, and potentially neurodegenerative, diseases of the peripheral retina, including diabetes and Alzheimer's disease.
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Affiliation(s)
- James Polans
- Department of Biomedical Engineering, Duke University, 136 Hudson Hall, Box 90281, Durham, North Carolina 27708, USA
| | - Brenton Keller
- Department of Biomedical Engineering, Duke University, 136 Hudson Hall, Box 90281, Durham, North Carolina 27708, USA
| | - Oscar M. Carrasco-Zevallos
- Department of Biomedical Engineering, Duke University, 136 Hudson Hall, Box 90281, Durham, North Carolina 27708, USA
| | - Francesco LaRocca
- Department of Biomedical Engineering, Duke University, 136 Hudson Hall, Box 90281, Durham, North Carolina 27708, USA
| | - Elijah Cole
- Department of Biomedical Engineering, Duke University, 136 Hudson Hall, Box 90281, Durham, North Carolina 27708, USA
| | - Heather E. Whitson
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina 27710, USA
- Department of Medicine (Geriatrics)/Duke Aging Center, Duke University Medical Center, Durham, North Carolina 27710, USA
- Geriatrics Research Education & Clinical Center, Durham VA Medical Center, Durham, North Carolina 27705, USA
| | - Eleonora M. Lad
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Sina Farsiu
- Department of Biomedical Engineering, Duke University, 136 Hudson Hall, Box 90281, Durham, North Carolina 27708, USA
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Joseph A. Izatt
- Department of Biomedical Engineering, Duke University, 136 Hudson Hall, Box 90281, Durham, North Carolina 27708, USA
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina 27710, USA
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18
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Zhang P, Goswami M, Zam A, Pugh EN, Zawadzki RJ. Effect of scanning beam size on the lateral resolution of mouse retinal imaging with SLO. OPTICS LETTERS 2015; 40:5830-3. [PMID: 26670523 PMCID: PMC4915368 DOI: 10.1364/ol.40.005830] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Scanning laser ophthalmoscopy (SLO) employs the eye's optics as a microscope objective for retinal imaging in vivo. The mouse retina has become an increasingly important object for investigation of ocular disease and physiology with optogenetic probes. SLO imaging of the mouse eye, in principle, can achieve submicron lateral resolution thanks to a numerical aperture (NA) of ∼0.5, about 2.5 times larger than that of the human eye. In the absence of adaptive optics, however, natural ocular aberrations limit the available optical resolution. The use of a contact lens, in principle, can correct many aberrations, permitting the use of a wider scanning beam and, thus, achieving greater resolution then would otherwise be possible. In this Letter, using an SLO equipped with a rigid contact lens, we report the effect of scanning beam size on the lateral resolution of mouse retinal imaging. Theory predicts that the maximum beam size full width at half-maximum (FWHM) that can be used without any deteriorating effects of aberrations is ∼0.6 mm. However, increasing the beam size up to the diameter of the dilated pupil is predicted to improve lateral resolution, though not to the diffraction limit. To test these predictions, the dendrites of a retinal ganglion cell expressing YFP were imaged, and transverse scans were analyzed to quantify the SLO system resolution. The results confirmed that lateral resolution increases with the beam size as predicted. With a 1.3 mm scanning beam and no high-order aberration correction, the lateral resolution is ∼1.15 μm, superior to that achievable by most human AO-SLO systems. Advantages of this approach include stabilization of the mouse eye and simplified optical design.
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Affiliation(s)
- Pengfei Zhang
- UC Davis RISE Eye-Pod Small Animal Imaging Laboratory, Department of Cell Biology and Human Anatomy, University of California Davis, 4320 Tupper Hall, Davis, California 95616, USA
| | - Mayank Goswami
- UC Davis RISE Eye-Pod Small Animal Imaging Laboratory, Department of Cell Biology and Human Anatomy, University of California Davis, 4320 Tupper Hall, Davis, California 95616, USA
| | - Azhar Zam
- UC Davis RISE Eye-Pod Small Animal Imaging Laboratory, Department of Cell Biology and Human Anatomy, University of California Davis, 4320 Tupper Hall, Davis, California 95616, USA
| | - Edward N. Pugh
- UC Davis RISE Eye-Pod Small Animal Imaging Laboratory, Department of Cell Biology and Human Anatomy, University of California Davis, 4320 Tupper Hall, Davis, California 95616, USA
| | - Robert J. Zawadzki
- UC Davis RISE Eye-Pod Small Animal Imaging Laboratory, Department of Cell Biology and Human Anatomy, University of California Davis, 4320 Tupper Hall, Davis, California 95616, USA
- UC Davis Eye Center, Department of Ophthalmology & Vision Science, University of California Davis, 4860 Y Street, Suite 2400, Sacramento, California 95817, USA
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Huang G, Gast TJ, Burns SA. In vivo adaptive optics imaging of the temporal raphe and its relationship to the optic disc and fovea in the human retina. Invest Ophthalmol Vis Sci 2014; 55:5952-61. [PMID: 25146991 DOI: 10.1167/iovs.14-14893] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
PURPOSE To investigate the anatomy of the temporal raphe and its angular relationship to the optic disc and fovea in the human retina in vivo. METHODS Adaptive optics scanning laser ophthalmoscope (AOSLO) was used to image the temporal raphe in 11 young subjects. The raphe's angle relative to a horizontal line and the raphe-fovea-disc angle (angle between the raphe and the line connecting the disc and fovea center) were determined. In addition, to investigate the impact of aging on the raphe, we imaged the raphe at 9° eccentricity in 10 additional older healthy subjects and compared the raphe's anatomy between the two age groups. RESULTS The raphe's in vivo appearance was generally in agreement with major findings of ex vivo studies. The raphe angle was -1.67° ± 4.8°, with the ranges from -9° to 6°. It was related to the angle of the foveal depression relative to the disc. The raphe-fovea-disc angle was 170.3° ± 3.6°. The raphe gap, defined as the averaged distance between superior and inferior bundles, was significantly larger in the older subjects than in younger subjects (230.83 ± 113.22 μm vs. 1.93 ± 68.73 μm, P < 0.0001). CONCLUSIONS The angle of the raphe in the study was not consistent with classic raphe models. While the angle showed relatively large individual variability, there seems to be a systematic relation between the disc, fovea, and raphe. It may be useful for individualizing retinal measurement strategies with regard to perimetry.
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Affiliation(s)
- Gang Huang
- School of Optometry, Indiana University, Bloomington, Indiana, United States
| | - Thomas J Gast
- School of Optometry, Indiana University, Bloomington, Indiana, United States
| | - Stephen A Burns
- School of Optometry, Indiana University, Bloomington, Indiana, United States
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Ramaswamy G, Devaney N. Pre-processing, registration and selection of adaptive optics corrected retinal images. Ophthalmic Physiol Opt 2013; 33:527-39. [PMID: 23627927 DOI: 10.1111/opo.12068] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Accepted: 03/12/2013] [Indexed: 11/29/2022]
Abstract
PURPOSE In this paper, the aim is to demonstrate enhanced processing of sequences of fundus images obtained using a commercial AO flood illumination system. The purpose of the work is to (1) correct for uneven illumination at the retina (2) automatically select the best quality images and (3) precisely register the best images. METHODS Adaptive optics corrected retinal images are pre-processed to correct uneven illumination using different methods; subtracting or dividing by the average filtered image, homomorphic filtering and a wavelet based approach. These images are evaluated to measure the image quality using various parameters, including sharpness, variance, power spectrum kurtosis and contrast. We have carried out the registration in two stages; a coarse stage using cross-correlation followed by fine registration using two approaches; parabolic interpolation on the peak of the cross-correlation and maximum-likelihood estimation. The angle of rotation of the images is measured using a combination of peak tracking and Procrustes transformation. RESULTS We have found that a wavelet approach (Daubechies 4 wavelet at 6th level decomposition) provides good illumination correction with clear improvement in image sharpness and contrast. The assessment of image quality using a 'Designer metric' works well when compared to visual evaluation, although it is highly correlated with other metrics. In image registration, sub-pixel translation measured using parabolic interpolation on the peak of the cross-correlation function and maximum-likelihood estimation are found to give very similar results (RMS difference 0.047 pixels). We have confirmed that correcting rotation of the images provides a significant improvement, especially at the edges of the image. We observed that selecting the better quality frames (e.g. best 75% images) for image registration gives improved resolution, at the expense of poorer signal-to-noise. The sharpness map of the registered and de-rotated images shows increased sharpness over most of the field of view. CONCLUSION Adaptive optics assisted images of the cone photoreceptors can be better pre-processed using a wavelet approach. These images can be assessed for image quality using a 'Designer Metric'. Two-stage image registration including correcting for rotation significantly improves the final image contrast and sharpness.
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Affiliation(s)
- Gomathy Ramaswamy
- Applied Optics Group, School of Physics, National University of Ireland, Galway, Galway, Ireland
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Felberer F, Kroisamer JS, Hitzenberger CK, Pircher M. Lens based adaptive optics scanning laser ophthalmoscope. OPTICS EXPRESS 2012; 20:17297-310. [PMID: 23038283 DOI: 10.1364/oe.20.017297] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
We present an alternative approach for an adaptive optics scanning laser ophthalmoscope (AO-SLO). In contrast to other commonly used AO-SLO instruments, the imaging optics consist of lenses. Images of the fovea region of 5 healthy volunteers are recorded. The system is capable to resolve human foveal cones in 3 out of 5 healthy volunteers. Additionally, we investigated the capability of the system to support larger scanning angles (up to 5°) on the retina. Finally, in order to demonstrate the performance of the instrument images of rod photoreceptors are presented.
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Affiliation(s)
- Franz Felberer
- Center for Medical Physics and Biomedical Engineering, Waehringerguertel 18-20, 1090 Vienna, Austria
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22
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Guo H, Fallah HR, Dainty C, Goncharov AV. Subjective evaluation of intraocular lenses by visual acuity measurement using adaptive optics. OPTICS LETTERS 2012; 37:2226-2228. [PMID: 22739863 DOI: 10.1364/ol.37.002226] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We present a new method for subjectively evaluating intraocular lenses (IOLs) without implantation surgery. To illustrate the method, three types of single-piece IOL (equispherical monofocal, rotational symmetric aspheric monofocal, and diffractive bifocal) were assembled into a model eye and evaluated using an ocular adaptive optics system by a single subject. To separate the spherical aberration of the crystalline lens, the subject's corneal topography and wavefront aberrations were measured and modeled. Three levels of Zernike spherical aberration were generated and superposed on the IOLs and the subject's eye. The corrected distance visual acuity was measured by psychophysical visual procedure.
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Affiliation(s)
- Huanqing Guo
- Applied Optics Group, School of Physics, National University of Ireland Galway, Ireland.
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