1
|
Korn S, Al-Nosairy KO, Gopiswaminathan AV, João C, Scanferla L, Bach M, Hoffmann MB. Scotopic and Photopic Conventional Visual Acuity and Hyperacuity - Binocular Summation. Transl Vis Sci Technol 2024; 13:25. [PMID: 38639931 PMCID: PMC11037493 DOI: 10.1167/tvst.13.4.25] [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: 01/08/2024] [Accepted: 03/11/2024] [Indexed: 04/20/2024] Open
Abstract
Purpose The purpose of this study was to determine and compare binocular summation (BiS) of conventional visual acuity (cVA) versus hyperacuity (hVA) for photopic and scotopic luminance conditions as a potential biomarker to assess the outcome of interventions on binocular function. Methods Sixteen young adults (age range [years] = 21-31; 8 women; cVA logMAR < 0.0) participated in this study. The Freiburg Visual Acuity Test (FrACT) was used for VA testing and retested on another day. Both cVA and hVA were determined for dark grey optotypes on light grey background. Participants underwent 40 minutes of dark adaptation prior to scotopic VA testing. Binocular and monocular VA testing was performed. The eye with better VA over the 2 days of testing was selected, the BiS was quantified (binocular VA - better monocular VA) and repeated measures ANOVAs were performed. Results Binocular VA exceeded monocular VA for all luminance conditions, VA-types, and sessions. We report BiS estimates for photopic and scotopic cVA and hVA, (logMAR BiS ± SEM [decimal BiS]): photopic = -0.01 ± 0.01 [1.03] and -0.06 ± 0.03 [1.15]; and scotopic = -0.05 ± 0.01 [1.12] and -0.11 ± 0.04 [1.28], respectively). Improvement for binocular vision estimates ranged from 0.01 to 0.11 logMAR. A repeated-measures ANOVA (RM ANOVA) did not reveal significant effects of LUMINANCE or VA TYPE on BiS, albeit a trend for strongest BiS for scotopic hVA (15% vs. 28%, photopic versus scotopic, respectively) and weakest for photopic cVA (3% vs. 12%, photopic versus scotopic conditions, respectively). Conclusions Our results indicate that BiS of VA is relevant to scotopic and photopic hVA and cVA. It appears therefore a plausible candidate biomarker to assess the outcome of retinal therapies restoring rod or cone function on binocular vision. Translational Relevance Binocular summation of visual acuity might serve as a clinical biomarker to monitor therapy outcome on binocular rod and cone-mediated vision.
Collapse
Affiliation(s)
- Sophie Korn
- Department of Ophthalmology, Otto-von-Guericke-University, Magdeburg, Germany
| | | | | | - Catarina João
- Department of Ophthalmology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- Graduate School of Medical Sciences (Research School of Behavioural and Cognitive Neurosciences), University of Groningen, Groningen, The Netherlands
| | - Lorenzo Scanferla
- Department of Ophthalmology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- Graduate School of Medical Sciences (Research School of Behavioural and Cognitive Neurosciences), University of Groningen, Groningen, The Netherlands
| | - Michael Bach
- Eye Center, Medical Center – University of Freiburg, Faculty of Medicine, University of Freiburg, Germany
| | - Michael B. Hoffmann
- Department of Ophthalmology, Otto-von-Guericke-University, Magdeburg, Germany
- Center for Behavioural Brain Sciences, Magdeburg, Germany
| |
Collapse
|
2
|
Liu L, Xu L, Yu B, Zhao L, Wu H. The influence of simulated visual impairment on distance stereopsis. J Vis 2024; 24:1. [PMID: 38300556 PMCID: PMC10846341 DOI: 10.1167/jov.24.2.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Accepted: 11/22/2023] [Indexed: 02/02/2024] Open
Abstract
The intricate interrelationships between visual acuity (VA) and stereopsis depend on an array of factors, incorporating the nature of vision impairment, its manifestation (monocular versus binocular), and the classification of stereopsis test symbols used. The objectives of this study were to methodically dissect these multifaceted interactions by simulating a diverse range of vision loss conditions. Thirty medical students with normal vision were subjected to simulated vision loss through opacification and blurring methodologies. Stereopsis was assessed at a distance using both contour-based and random-dot-based symbols under equal binocular and varied monocular VA conditions. In this study, opacification consistently affected stereopsis more than blurring at equivalent VA reductions. However, this difference was absent in contour-based symbols under binocular vision impairment conditions. Significant differences in stereopsis emerged between monocular and binocular vision within the opacification contour-based groups. These differences were less evident in the opacification and blurring groups using random-dot-based patterns. In terms of symbols, the contour-based test demonstrated superior results to the random-dot-based test, particularly under decreased VA. In sum, the method of VA reduction and the choice of stereogram significantly impact distance stereopsis outcomes. This understanding can guide clinical assessments of stereopsis in individuals with varying visual impairments.
Collapse
Affiliation(s)
- Lu Liu
- Department of Optometry, The Second Hospital of Jilin University, Changchun, China
| | - Lingxian Xu
- Department of Optometry, The Second Hospital of Jilin University, Changchun, China
| | - Bo Yu
- Department of Optometry, The Second Hospital of Jilin University, Changchun, China
| | - Lingzhi Zhao
- Department of Optometry, The Second Hospital of Jilin University, Changchun, China
| | - Huang Wu
- Department of Optometry, The Second Hospital of Jilin University, Changchun, China
| |
Collapse
|
3
|
Liu S, Kersten DJ, Legge GE. Effect of expansive optic flow and lateral motion parallax on depth estimation with normal and artificially reduced acuity. J Vis 2023; 23:3. [PMID: 37801321 PMCID: PMC10561791 DOI: 10.1167/jov.23.12.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 09/07/2023] [Indexed: 10/07/2023] Open
Abstract
When an observer moves in space, the retinal projection of a stationary object either expands if the motion is toward the object or shifts horizontally if the motion contains a lateral component. This study examined the impact of expansive optic flow and lateral motion parallax on the accuracy of depth perception for observers with normal or artificially reduced acuity and asked whether any benefit is due to the continuous motion or to the discrete object image displacement. Stationary participants viewed a virtual room on a computer screen. They used an on-screen slider to estimate the depth of a target object relative to a reference object after seeing 2-second videos simulating five conditions: static viewing, expansive optic flow, and lateral motion parallax in either continuous motion or image displacement. Ten participants viewed the stimuli with normal acuity in Experiment 1 and 11 with three levels of artificially reduced acuity in Experiment 2. Linear regression models represented the relationship between the depth estimates of participants and the ground truth. Lateral motion parallax produced more accurate depth estimates than expansive optic flow and static viewing. Depth perception with continuous motion was more accurate than that with displacement under mild and moderate, but not severe, acuity reduction. For observers with both normal and artificially reduced acuity, lateral motion parallax was more helpful for object depth estimation than expansive optic flow, and continuous motion parallax was more helpful than object image displacement.
Collapse
Affiliation(s)
- Siyun Liu
- Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- Department of Psychology, University of Minnesota, Minneapolis, MN, USA
| | - Daniel J Kersten
- Department of Psychology, University of Minnesota, Minneapolis, MN, USA
| | - Gordon E Legge
- Department of Psychology, University of Minnesota, Minneapolis, MN, USA
| |
Collapse
|
4
|
Yu D, Watson E. Binocular summation in high and low contrast letter acuities. Front Neurosci 2023; 17:1174900. [PMID: 37397468 PMCID: PMC10309007 DOI: 10.3389/fnins.2023.1174900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 05/30/2023] [Indexed: 07/04/2023] Open
Abstract
Binocular summation, a well-known phenomenon in letter acuity measurement, refers to the improvement in visual performance when viewing with both eyes compared to one eye alone. The present study aims to assess the relationship in binocular summation between high and low contrast letter acuities, and examine whether baseline measure (binocular summation at either high or low contrast) is predictive of the change in binocular summation between contrast conditions. Corrected high and low contrast letter acuities were assessed monocularly and binocularly in 358 normal vision observers aged 18-37 years using Bailey-Lovie charts. All observers had high contrast acuities (both monocular and binocular) of 0.1 LogMAR or better and no known eye disease. Binocular summation was calculated as the difference in LogMAR between the better eye acuity and binocular acuity. We found that binocular summation was present at both contrast levels (0.044 ± 0.002 LogMAR for high and 0.069 ± 0.002 LogMAR for low contrast) with higher magnitude of summation at low contrast, and declined with increasing interocular difference. There was a correlation in binocular summation between high and low contrast. The difference in binocular summation between the two contrast levels was found to be correlated with the baseline measurement. Using common commercially available letter acuity charts, we replicated the findings on binocular acuity summation in normally sighted young adults for both high and low contrast letters. Our study revealed a positive relationship in binocular acuity summation between high and low contrast, and an association between a baseline measure and the change in binocular summation between contrast levels. These findings may serve as a reference in clinical practice and research when high and low contrast binocular summations are measured in assessing binocular functional vision.
Collapse
Affiliation(s)
- Deyue Yu
- College of Optometry, The Ohio State University, Columbus, OH, United States
| | | |
Collapse
|
5
|
Lim J, Kim W, Kim I, Lee E. Effects of Visual Communication Design Accessibility (VCDA) Guidelines for Low Vision on Public and Open Government Health Data. Healthcare (Basel) 2023; 11:healthcare11071047. [PMID: 37046973 PMCID: PMC10094713 DOI: 10.3390/healthcare11071047] [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: 01/09/2023] [Revised: 03/28/2023] [Accepted: 04/01/2023] [Indexed: 04/14/2023] Open
Abstract
Since 2019, the Korean government's investments in making data more accessible to the public have grown by 337%. However, open government data, which should be accessible to everyone, are not entirely accessible to people with low vision, who represent an information-vulnerable class. Emergencies, such as the COVID-19 pandemic, decrease face-to-face encounters and inevitably increase untact encounters. Thus, the information gap experienced by low-vision people, who are underprivileged in terms of information, will be further widened, and they may consequently face various disadvantages. This study proposed visual communication design accessibility (VCDA) guidelines for people with low vision. Introduced screens enhanced by accessibility guidelines were presented to 16 people with low vision and 16 people with normal vision and the speed of visual information recognition was analyzed. No statistically significant difference (p > 0.05) was found due to the small sample size; however, this study's results approached significance with improved visual recognition speed for people with low vision after adopting VCDA. As a result of the intervention, the visual information recognition speed of both normal and low-vision people improved. Thus, our results can help improve information recognition speed among people with normal and low vision.
Collapse
Affiliation(s)
- Jongho Lim
- School of Computer Science & Engineering, College of IT Engineering, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Woojin Kim
- School of Computer Science & Engineering, College of IT Engineering, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Ilkon Kim
- School of Computer Science & Engineering, College of IT Engineering, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Eunjoo Lee
- School of Computer Science & Engineering, College of IT Engineering, Kyungpook National University, Daegu 41566, Republic of Korea
| |
Collapse
|
6
|
Sverdlichenko I, Mandelcorn MS, Issashar Leibovitzh G, Mandelcorn ED, Markowitz SN, Tarita-Nistor L. Binocular visual function and fixational control in patients with macular disease: A review. Ophthalmic Physiol Opt 2021; 42:258-271. [PMID: 34862635 PMCID: PMC9299778 DOI: 10.1111/opo.12925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 10/29/2021] [Accepted: 10/31/2021] [Indexed: 11/24/2022]
Abstract
For normally sighted observers, the centre of the macula—the fovea—provides the sharpest vision and serves as the reference point for the oculomotor system. Typically, healthy observers have precise oculomotor control and binocular visual performance that is superior to monocular performance. These functions are disturbed in patients with macular disease who lose foveal vision. An adaptation to central vision loss is the development of a preferred retinal locus (PRL) in the functional eccentric retina, which is determined with a fixation task during monocular viewing. Macular disease often affects the two eyes unequally, but its impact on binocular function and fixational control is poorly understood. Given that patients’ natural viewing condition is binocular, the aim of this article was to review current research on binocular visual function and fixational oculomotor control in macular disease. Our findings reveal that there is no overall binocular gain across a range of visual functions, although clear evidence exists for subgroups of patients who exhibit binocular summation or binocular inhibition, depending on the clinical characteristics of their two eyes. The monocular PRL of the better eye has different characteristics from that of the worse eye, but during binocular viewing the PRL of the better eye drives fixational control and may serve as the new reference position for the oculomotor system. We conclude that evaluating binocular function in patients with macular disease reveals important clinical aspects that otherwise cannot be determined solely from examining monocular functions, and can lead to better disease management and interventions.
Collapse
Affiliation(s)
| | - Mark S Mandelcorn
- Krembil Research Institute, Donald K Johnson Eye Institute, University Health Network, Toronto, Ontario, Canada.,Department of Ophthalmology and Vision Sciences, Toronto Western Hospital, Toronto, Ontario, Canada
| | - Galia Issashar Leibovitzh
- Krembil Research Institute, Donald K Johnson Eye Institute, University Health Network, Toronto, Ontario, Canada
| | - Efrem D Mandelcorn
- Krembil Research Institute, Donald K Johnson Eye Institute, University Health Network, Toronto, Ontario, Canada.,Department of Ophthalmology and Vision Sciences, Toronto Western Hospital, Toronto, Ontario, Canada
| | - Samuel N Markowitz
- Krembil Research Institute, Donald K Johnson Eye Institute, University Health Network, Toronto, Ontario, Canada.,Department of Ophthalmology and Vision Sciences, Toronto Western Hospital, Toronto, Ontario, Canada
| | - Luminita Tarita-Nistor
- Krembil Research Institute, Donald K Johnson Eye Institute, University Health Network, Toronto, Ontario, Canada
| |
Collapse
|