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Cheng CY, Sheu MM, Chen PS, Chuang YT, Cheng HM, Hsieh HP. Assessing low vision care and the utilisation of optical low vision aids among patients with visual impairment in Taiwan. Ophthalmic Physiol Opt 2023; 43:1356-1363. [PMID: 37476932 DOI: 10.1111/opo.13205] [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: 12/09/2022] [Revised: 07/06/2023] [Accepted: 07/07/2023] [Indexed: 07/22/2023]
Abstract
PURPOSE The aim of this study was to examine the quality of assessment and the utilisation of optical low vision aids (OLVAs) among people with visual impairment (VI) in Taiwan. METHODS The study included 577 participants between 4 and 100 years of age (314 males and 263 females). All participants had been certified by the Ministry of the Interior of Taiwan, indicating that they had undergone a thorough and comprehensive low vision assessment, including evaluation of visual acuity (VA), contrast sensitivity, colour vision, visual fields and glare disability. Furthermore, all participants who consented to refraction had received prescriptions for OLVAs. RESULT All participants were prescribed one or more OLVAs such as eyeglasses, tinted lenses, magnifiers, closed-circuit television magnifiers, telescopes, or screen magnifiers. Among the 577 individuals, 515 received correction for refractive errors, providing the best-corrected VA (BCVA). The improvement in VA was significant at both distance and near, improving from 1.29 ± 0.55 to 1.01 ± 0.52 logMAR (p < 0.001) and from 1.29 ± 0.56 to 1.01 ± 0.52 logMAR (p < 0.001), respectively. Eyeglasses were the primary OLVAs chosen by 333 participants (64.7%), while 53.3%-80.3% of participants combined eyeglasses with other OLVAs to enhance their visual performance. CONCLUSIONS The most commonly used and effective OLVA was eyeglasses. Skilfully utilising appropriate refractive and VA measurements is crucial for determining the most suitable and beneficial OLVA for individuals with VI.
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Affiliation(s)
- Ching-Ying Cheng
- Department of Optometry, Chung Shan Medical University, Taichung, Taiwan
- Department of Ophthalmology, Chung Shan Medical University Hospital, Taichung, Taiwan
| | - Min-Muh Sheu
- Department of Ophthalmology, Mennonite Christian Hospital, Hualien, Taiwan
- Eye Health Promotion Centre of Eastern Taiwan, Hualien, Taiwan
| | - Po-Sen Chen
- Department of Ophthalmology, Mennonite Christian Hospital, Hualien, Taiwan
- Eye Health Promotion Centre of Eastern Taiwan, Hualien, Taiwan
| | - Yi-Ting Chuang
- Department of Ophthalmology, Mennonite Christian Hospital, Hualien, Taiwan
- Eye Health Promotion Centre of Eastern Taiwan, Hualien, Taiwan
| | | | - Hsi-Pao Hsieh
- Department of Ophthalmology, Mennonite Christian Hospital, Hualien, Taiwan
- Eye Health Promotion Centre of Eastern Taiwan, Hualien, Taiwan
- Department of Special Education, National Taiwan Normal University, Taipei, Taiwan
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Habitual visual acuity and visual acuity threshold demands in Nigerian school classrooms. Sci Rep 2022; 12:17816. [PMID: 36280771 PMCID: PMC9592605 DOI: 10.1038/s41598-022-21048-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 09/22/2022] [Indexed: 01/19/2023] Open
Abstract
This study was designed to estimate the burden of blindness and vision impairment in school children, and to determine the proportion of students meeting the visual acuity (VA) demand for their classrooms. From 148 primary and secondary school classrooms in Edo State, Nigeria, the habitual distance and near VA of over 2000 students were measured. Values obtained were compared with the calculated distance VA demand and actual near VA demand for their classrooms. Measures used to calculate the VA demand were working distance and smallest text size on learning materials, at both distance and near. We also determined the relationship between age and calculated VA demand and the effect of factors such as school ownership and school type on the VA demand. Habitual distance vision impairment was found in 0.8% of pupils, including 2 (0.10%) who met the WHO criteria for blindness. The average VA demand at the furthest and nearest sitting position to the board was 0.21 ± 0.23 and 0.65 ± 0.33LogMAR, respectively. Near working distance of students ranged from 15.00 to 37.20 cm, and the near VA demand as well as actual near VA demand (using a 2.5 times acuity reserve) was 0.60 ± 0.17 and 0.20 ± 1.7LogMAR, respectively. LogMAR VA demand increased (size of print decreases) with increasing age, at both distance (r = - 0.549, p = 0.070) and near (r = - 0.921, p < 0.0001). The VA demand at maximum distance and the actual near VA demand differed significantly by school ownership and between primary and secondary schools. Most students had VA better, but up to 11% of students per class had VA poorer than their classroom demands. Although the majority of students had better VA than their classroom demands, for students with reduced vision, learning could be negatively impacted. It is important to continually screen students for vision impairment and ensure prompt referral and treatment. These findings have implications for managing vision problems in children, as well as enabling appropriate classroom arrangements for those with vision impairment.
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Xiong YZ, Atilgan N, Fletcher DC, Legge GE. Digital Reading with Low Vision: Principles for Selecting Display Size. Optom Vis Sci 2022; 99:655-661. [PMID: 35731508 PMCID: PMC9357187 DOI: 10.1097/opx.0000000000001919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
SIGNIFICANCE Digital reading devices have become increasingly popular among people with low vision. Because displays come in many sizes ranging from smart watches to large desktop computer displays, it is important to have principles to guide people with low vision in selecting suitable displays for reading. PURPOSE The selection of effective digital displays for reading by people with low vision focuses attention on the interacting effects of print size, display size, font, visual acuity, and reading distance. This technical report aims to provide principles for identifying the minimum size of digital displays required for fluent reading by people with low vision. METHODS We emphasize two critical factors in selecting an appropriate reading display: angular print size, which should exceed the individual's critical print size, and display size, which should allow at least 13 characters to be presented on each line. Our approach considers a low-vision individual's acuity and preferences for viewing distance and fonts. RESULTS Through an illustrative example, we demonstrate how our approach can be used to determine display size for a low-vision individual with 20/200 acuity and central field loss who wants to read at 30-cm viewing distance with the Times Roman font. We have developed a web application based on our recommended approach to provide easy access to our algorithm. CONCLUSIONS We provide a procedure to guide the selection of appropriate displays for a wide range of acuities. Our approach can help clinicians in making recommendations for their patients, digital product designers in developing more accessible devices, and low-vision individuals in selecting digital displays for reading.
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Affiliation(s)
| | - Nilsu Atilgan
- Department of Psychology, University of Minnesota, Minneapolis, Minnesota
| | | | - Gordon E Legge
- Department of Psychology, University of Minnesota, Minneapolis, Minnesota
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Latham K, Subhi H. Can listening provide a useful clinical estimate of low vision reading parameters? Ophthalmic Physiol Opt 2022; 42:504-513. [PMID: 35243674 DOI: 10.1111/opo.12966] [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: 11/23/2021] [Revised: 02/08/2022] [Accepted: 02/08/2022] [Indexed: 11/28/2022]
Abstract
PURPOSE The purpose of this study was to determine whether a clinician can assess critical print size (CPS) and/or reading fluency by listening to a visually impaired patient reading aloud across a range of print sizes on an MNREAD chart, rather than needing to plot and analyse reading speed data as a function of print size. METHODS Fifty-six low vision participants were audio-recorded reading an MNREAD chart under standard conditions. Two experienced raters listened to the recordings and made judgments of the CPS (logMAR), and of the level of reading fluency achieved at large print sizes on a 4-point rating scale. Reading times were plotted as a function of print size to determine the CPS as the smallest print size that supported the participant's maximum reading speed (MRS) by inspection, and the MRS as the mean reading speed across print sizes including, and larger than, the CPS. RESULTS Listened CPS judgments made for each rater were slightly larger than the CPS values obtained by inspection (mean differences 0.04logMAR (p = 0.06), 0.08logMAR (p < 0.01); limits of agreement (LoA) ±0.28logMAR, ±0.39logMAR, respectively). CPS judgments were consistent both between raters (mean difference 0.04logMAR [p = 0.18]; LoA ±0.42logMAR) and between two judgments made by each rater (mean differences 0.00logMAR (p = 1.0), 0.03logMAR (p < 0.05); LoA ±0.23logMAR, ±0.17logMAR). Reading fluency could be categorised as 'functional' (MRS > 80 wpm) or 'non-functional' (MRS < 80 wpm) with a sensitivity of 88%-90% and a specificity of 100%. CONCLUSIONS Experienced raters listening to a patient reading an MNREAD chart can determine a clinically useful estimate of critical print size and can discriminate maximum reading speeds that are above and below that likely to provide sustained reading ability. Listening to a patient reading an MNREAD chart is an option for the low vision clinician's armoury of assessments.
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Affiliation(s)
- Keziah Latham
- Vision and Hearing Sciences Research Centre, Anglia Ruskin University, Cambridge, UK
| | - Hikmat Subhi
- Vision and Hearing Sciences Research Centre, Anglia Ruskin University, Cambridge, UK
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Latham K, Macnaughton J. Is patient identification of ‘comfortable’ print size a useful clinical parameter for low vision reading assessment? Ophthalmic Physiol Opt 2022; 42:482-490. [DOI: 10.1111/opo.12946] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 10/15/2021] [Accepted: 10/18/2021] [Indexed: 11/30/2022]
Affiliation(s)
- Keziah Latham
- Vision and Hearing Sciences Research Centre Anglia Ruskin University Cambridge UK
| | - Jane Macnaughton
- Vision and Hearing Sciences Research Centre Anglia Ruskin University Cambridge UK
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Prediction of postoperative visual acuity after vitrectomy for macular hole using deep learning-based artificial intelligence. Graefes Arch Clin Exp Ophthalmol 2021; 260:1113-1123. [PMID: 34636995 DOI: 10.1007/s00417-021-05427-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 08/20/2021] [Accepted: 09/19/2021] [Indexed: 10/20/2022] Open
Abstract
PURPOSE To create a model for prediction of postoperative visual acuity (VA) after vitrectomy for macular hole (MH) treatment using preoperative optical coherence tomography (OCT) images, using deep learning (DL)-based artificial intelligence. METHODS This was a retrospective single-center study. We evaluated 259 eyes that underwent vitrectomy for MHs. We divided the eyes into four groups, based on their 6-month postoperative Snellen VA values: (A) ≥ 20/20; (B) 20/25-20/32; (C) 20/32-20/63; and (D) ≤ 20/100. Training data were randomly selected, comprising 20 eyes in each group. Test data were also randomly selected, comprising 52 total eyes in the same proportions as those of each group in the total database. Preoperative OCT images with corresponding postoperative VA values were used to train the original DL network. The final prediction of postoperative VA was subjected to regression analysis based on inferences made with DL network output. We created a model for predicting postoperative VA from preoperative VA, MH size, and age using multivariate linear regression. Precision values were determined, and correlation coefficients between predicted and actual postoperative VA values were calculated in two models. RESULTS The DL and multivariate models had precision values of 46% and 40%, respectively. The predicted postoperative VA values on the basis of DL and on preoperative VA and MH size were correlated with actual postoperative VA at 6 months postoperatively (P < .0001 and P < .0001, r = .62 and r = .55, respectively). CONCLUSION Postoperative VA after MH treatment could be predicted via DL using preoperative OCT images with greater accuracy than multivariate linear regression using preoperative VA, MH size, and age.
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Morrice E, Murphy C, Soldano V, Addona C, Wittich W, Johnson AP. Assessing optimal colour and illumination to facilitate reading: an analysis of print size. Ophthalmic Physiol Opt 2021; 41:1209-1221. [PMID: 34549808 DOI: 10.1111/opo.12885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 08/02/2021] [Accepted: 08/03/2021] [Indexed: 11/30/2022]
Abstract
PURPOSE This study examined how optimal colour/illumination conditions and the efficacy of the iPad, LuxIQ and Smart Bulb varied as a function of print size in younger, older and visually impaired adults. METHODS Participants with visual impairments and simulated low vision (SLV) read the MNRead using the iPad, LuxIQ and Smart Bulb. RESULTS In the impairment condition at 1.20 logMAR, the iPad (M = 9.49, 95% CI [3.18, 19.42]) and LuxIQ (M = 15.95, 95% CI [9.54, 24.86]) improved the reading speeds. At 0.80 logMAR (SLV), all devices improved reading speeds of older adults (iPad (M = 28.70, 95% CI [14.65, 42.51]); LuxIQ (M = 49.63, 95% CI [30.04, 69.68]); Smart Bulb (M = 23.11, 95% CI [3.33, 42.11])), but in younger adults only the LuxIQ (M = 13.04, 95% CI [3.21, 21.27]) did so. In the impairment condition, the iPad (M = 5.54, 95% CI [0.31, 12.13]) and LuxIQ (M = 13.90, 95% CI [7.88, 23.49]) improved reading speeds. In the SLV condition, age was a significant predictor of reading speed at 1.20 logMAR (F3,164 = 10.74, p < 0.001, Adj. R2 = 0.16). At 0.80 logMAR, age and luminance, but not colour, were significant predictors (F3,164 = 52.52, p < 0.001, Adj. R2 = 0.49). In the impairment condition, both age and lux were significant predictors of reading speed at 1.20 (F3,85 = 7.14, p < 0.001, Adj. R2 = 0.20) and 0.80 logMAR (F3,85 = 7.97, p < 0.001, Adj. R2 = 0.22), but colour was not. CONCLUSIONS Light source effectiveness and optimal colour/illumination vary as a function of print size. It appears that print size is the most important factor for improving reading speed. As print size decreases, luminance becomes crucial, and only at the smallest print sizes does the effect of colour become useful.
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Affiliation(s)
- Elliott Morrice
- Department of Psychology, Concordia University, Montreal, Quebec, Canada.,Lethbridge-Layton-Mackay Rehabilitation Centre, Integrated Health and Social Services University Network for West-Central Montreal, Montreal, Quebec, Canada
| | - Caitlin Murphy
- Department of Psychology, Concordia University, Montreal, Quebec, Canada.,Lethbridge-Layton-Mackay Rehabilitation Centre, Integrated Health and Social Services University Network for West-Central Montreal, Montreal, Quebec, Canada.,School of Optometry, University of Montreal, Montreal, Quebec, Canada
| | - Vanessa Soldano
- Department of Psychology, Concordia University, Montreal, Quebec, Canada
| | - Cynthia Addona
- Department of Psychology, Concordia University, Montreal, Quebec, Canada
| | - Walter Wittich
- Department of Psychology, Concordia University, Montreal, Quebec, Canada.,Lethbridge-Layton-Mackay Rehabilitation Centre, Integrated Health and Social Services University Network for West-Central Montreal, Montreal, Quebec, Canada.,School of Optometry, University of Montreal, Montreal, Quebec, Canada.,Centre for Interdisciplinary Research in Rehabilitation of Greater Montreal/The Nazareth and Louis Braille Institute, Integrated Health and Social Services Centre Montérégie-Centre, Longueuil, Quebec, Canada
| | - Aaron P Johnson
- Department of Psychology, Concordia University, Montreal, Quebec, Canada.,Lethbridge-Layton-Mackay Rehabilitation Centre, Integrated Health and Social Services University Network for West-Central Montreal, Montreal, Quebec, Canada
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Lovie-Kitchin J, Feigl B. Assessment of age‐related maculopathy using subjective vision tests. Clin Exp Optom 2021; 88:292-303. [PMID: 16255688 DOI: 10.1111/j.1444-0938.2005.tb06713.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2005] [Revised: 08/29/2005] [Accepted: 09/06/2005] [Indexed: 11/30/2022] Open
Abstract
This paper reviews non-standard, clinical vision tests that may be used to detect the earliest visual loss in age-related maculopathy (ARM), before fundus changes are detected. We recommend a clinical test battery for all patients aged 60 years and older, comprising low luminance/low contrast (SKILL) VA or low contrast VA, desaturated D-15 colour vision assessment, flicker perimetry, glare recovery and dark adaptation if possible, together with conventional assessments of case history, ophthalmoscopy and high contrast visual acuity (VA) for the detection and diagnosis of ARM. Reading rate is also discussed as a potential indicator of early visual loss. For monitoring the progressive visual loss in age-related macular degeneration (AMD) and determining the requirements for optometric vision rehabilitation, we recommend more conventional clinical vision tests of distance and near visual acuity, reading rate, the effects of varying illumination and a functional central visual field assessment.
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Affiliation(s)
- Jan Lovie-Kitchin
- Queensland University of Technology, Faculty of Health, Victoria Park Road, Kelvin Grove, QLD, 4059, Australia.
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Lovie–kitchin J. Reading with low vision: the impact of research on clinical management*. Clin Exp Optom 2021; 94:121-32. [DOI: 10.1111/j.1444-0938.2010.00565.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Affiliation(s)
- Jan Lovie–kitchin
- School of Optometry, Queensland University of Technology, Brisbane, Queensland, Australia E‐mail:
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10
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Jamous KF, Jalbert I, Kalloniatis M, Boon MY. Australian general medical practitioner referral pathways for people with different ocular conditions. Clin Exp Optom 2021; 97:152-9. [DOI: 10.1111/cxo.12102] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Revised: 04/09/2013] [Accepted: 06/11/2013] [Indexed: 11/30/2022] Open
Affiliation(s)
- Khalid F Jamous
- School of Optometry and Vision Science, University of New South Wales, Kensington, New South Wales, Australia,
- Department of Ophthalmology, Faculty of Medicine, King Saud University, Riyadh, Saudi Arabia,
| | - Isabelle Jalbert
- School of Optometry and Vision Science, University of New South Wales, Kensington, New South Wales, Australia,
| | - Michael Kalloniatis
- School of Optometry and Vision Science, University of New South Wales, Kensington, New South Wales, Australia,
- Centre for Eye Health, University of New South Wales, Kensington, New South Wales, Australia,
| | - Mei Ying Boon
- School of Optometry and Vision Science, University of New South Wales, Kensington, New South Wales, Australia,
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Morrice E, Murphy C, Soldano V, Addona C, Wittich W, Johnson AP. Assessing optimal colour and illumination to facilitate reading. Ophthalmic Physiol Opt 2021; 41:281-294. [PMID: 33533095 DOI: 10.1111/opo.12785] [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: 08/14/2020] [Accepted: 12/04/2020] [Indexed: 11/28/2022]
Abstract
PURPOSE This study examined the effectiveness of the LuxIQ, the Apple iPad and a smart bulb in assessing optimal colour and illumination to facilitate reading in younger, older and visually impaired adults. METHODS Participants read standardised texts at baseline (normal lighting/no device), then using the Apple iPad, LuxIQ and smart bulb, with their normal vision (20/20 condition) and using a simulated reduction in visual acuity/contrast sensitivity (20/80 condition). Visually impaired participants followed the same procedure used in the 20/80 condition. RESULTS There was a significant interaction between condition and device in younger, F(1.5, 43.51) = 30.41, p < 0.001, ω2 = 0.34 and older, F(1.5, 4.51) = 4.51, p = 0.03, ω2 = 0.05 adults with normal vision, and there was a significant effect of device, F(2, 58) = 5.95, p = 0.004, ω2 = 0.12 in visually impaired adults. In the 20/20 condition, age and colour predicted reading speed, F(3, 176) = 36.25, p < 0.001, Adj. R2 = 0.37, whereas age, lighting and colour predicted reading speed, F(3, 176) = 36.25, p < 0.001, Adj. R2 = 0.37 in the 20/80 condition. In the visual impairment condition, lighting, colour and impairment severity predicted reading speed, F(3, 85) = 10.10, p < 0.001, Adj. R2 = 0.24. CONCLUSIONS The clinical implications of this study are that reading speeds improve in individuals with low vision under improved lighting conditions, specifically, with higher levels of luminance and colour temperature. The effectiveness of the devices varied across groups; however, the LuxIQ was the only device to improve reading speeds from baseline in older adults with visual impairments.
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Affiliation(s)
- Elliott Morrice
- Department of Psychology, Concordia University, Montréal, Canada.,CRIR/Centre de réadaptation Lethbridge-Layton-Mackay Réhabilitation Centre du Centre Intégré Universitaire de Santé et Services Sociaux (CIUSSS) Centre ouest de l'ile de Montréal, Montréal, Canada
| | - Caitlin Murphy
- Department of Psychology, Concordia University, Montréal, Canada.,CRIR/Centre de réadaptation Lethbridge-Layton-Mackay Réhabilitation Centre du Centre Intégré Universitaire de Santé et Services Sociaux (CIUSSS) Centre ouest de l'ile de Montréal, Montréal, Canada.,École d'optométrie, Université de Montréal, Montréal, Canada
| | - Vanessa Soldano
- Department of Psychology, Concordia University, Montréal, Canada
| | - Cynthia Addona
- Department of Psychology, Concordia University, Montréal, Canada
| | - Walter Wittich
- Department of Psychology, Concordia University, Montréal, Canada.,CRIR/Centre de réadaptation Lethbridge-Layton-Mackay Réhabilitation Centre du Centre Intégré Universitaire de Santé et Services Sociaux (CIUSSS) Centre ouest de l'ile de Montréal, Montréal, Canada.,École d'optométrie, Université de Montréal, Montréal, Canada.,CRIR/Institut Nazareth et Louis-Braille du CISSS de la Montérégie-Centre, Longueuil, Canada
| | - Aaron P Johnson
- Department of Psychology, Concordia University, Montréal, Canada.,CRIR/Centre de réadaptation Lethbridge-Layton-Mackay Réhabilitation Centre du Centre Intégré Universitaire de Santé et Services Sociaux (CIUSSS) Centre ouest de l'ile de Montréal, Montréal, Canada
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12
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Technical Report: A New Method for Determining Image Distance for Stand Magnifiers. Optom Vis Sci 2020; 97:1048-1052. [PMID: 33259379 DOI: 10.1097/opx.0000000000001613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
SIGNIFICANCE Low vision rehabilitation clinicians must sometimes evaluate stand magnifiers to determine their true optical properties. A novel method is described for measuring the image distance of stand magnifiers. PURPOSE We describe a new method for determining the image distance of stand magnifiers, which has some advantages over previously described methods. METHODS Diverging light emerging from a stand magnifier is brought to a focus on the ceiling or other flat surface using convex lenses placed on the top of the stand magnifier lens. Knowing the power of this convex lens and the distance from the magnifier lens to the imaging surface, one can calculate the degree to which the emerging light is diverging and, from that, the image distance. Each author evaluated three stand magnifiers using this method and compared our results with each other and with the values for image distance published by the manufacturer. RESULTS Our method produced measurements that were consistent between three clinicians, with emerging divergence values differing by no more than 0.37 D and image distance differing by 0.6 to 3.1 cm for the three magnifiers evaluated. Our measured values also corresponded favorably with the published image distances listed in the manufacturer's catalog, deviating by a maximum of 3.7 cm and a mean of 1.3 cm. When the manufacturer's image distances were converted to dioptric divergence, our measurements varied by a maximum of 0.48 D and a mean of 0.17 D. CONCLUSIONS Our method provides an expedient and clinically accurate way to evaluate the divergence and image distance of a stand magnifier. Knowing the image distance is valuable by itself, but the divergence of the emerging light is also critical in determining the stand magnifier's enlargement ratio.
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Tsai LH, Hsieh HP, Chen PS, Jou CL, Tseng KY, Cheng CY. Relationship between refractive correction, visual symptoms, and optical device selection for low-vision patients in Taiwan. JOURNAL OF OPTOMETRY 2020; 13:249-256. [PMID: 31787520 PMCID: PMC7520520 DOI: 10.1016/j.optom.2019.09.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 08/31/2019] [Accepted: 09/10/2019] [Indexed: 06/10/2023]
Abstract
UNLABELLED According to Taiwan optometry act, low-vision services, such as refractive correction and low vision assessment, are now included in Optometric profession. This study was designed to investigate the efficiency of refractive correction and the relationship between refractive correction, eye diseases, visual symptoms, and optical device selection for patients with low vision. METHODS This study involved a total of 220 participants aged from 7 to 99, with 119 males and 101 females. All of them were referred from three institutes of Taiwan Resource Portal of Assistive Technology under the supervision of the Ministry of Health and Welfare during Feb 2016 to Jan 2018. Accordingly, 42, 76, and 102 of the participants were identified as having mild, moderate, and severe visual impairments, respectively, by five experienced and licensed optometrists for this comprehensive low vision examination. RESULTS The most common eye diseases in this study were retinal disease, cataract, glaucoma, and optic nerve hypoplasia; some of the participants had multiple eye diseases while participating in the study. Except visual acuity decrease, eye diseases were highly correlated with participants' visual symptoms. Refractive correction is the first step in low-vision examination, therefore, it might be much helpful to some types of eye diseases, visual symptoms, and to the decisions of optical devices for low-vision patients. The results herein suggest that color vision and contrast sensitivity should be taken into consideration when calculating the second optical magnifying power after refractive correction. CONCLUSIONS Refractive correction is necessary for the treatment of patients' visual symptoms and also for the prescription of low-vision aids.
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Affiliation(s)
- Lung-Hui Tsai
- Department of Optometry, Chung Shan Medical University, Taichung, Taiwan; Department of Optometry, Chung Hwa University of Medical Technology, Tainan, Taiwan
| | - Hsi-Pao Hsieh
- Department of Ophthalmology, Mennonite Christian Hospital, Hualien, Taiwan; Department of Special Education, National Taiwan Normal University, Taipei, Taiwan
| | - Po-Sen Chen
- Department of Ophthalmology, Mennonite Christian Hospital, Hualien, Taiwan; Department of Special Education, National Dong Hwa University, Hualien, Taiwan
| | - Chia-Lin Jou
- Department of Optometry, Chung Shan Medical University, Taichung, Taiwan
| | - Kai-Yuan Tseng
- Department of Optometry, Chung Shan Medical University, Taichung, Taiwan; Institute of medicine, Chung Shan Medical University, Taichung, Taiwan
| | - Ching-Ying Cheng
- Department of Optometry, Chung Shan Medical University, Taichung, Taiwan; Department of Ophthalmology, Chung Shan Medical University Hospital, Taichung, Taiwan.
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14
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Nirghin U. Design of a paediatric rate of reading test chart. AFRICAN VISION AND EYE HEALTH 2020. [DOI: 10.4102/aveh.v79i1.536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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15
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Lukman AL, Bridge C, Dain SJ, Boon MY. Luminance Contrast of Accessible Tactile Indicators for People With Visual Impairment. ERGONOMICS IN DESIGN 2020. [DOI: 10.1177/1064804619841841] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Australia is one of only two known countries with a safety standard specifying levels of contrast required to provide accessible environments for people with visual impairment. However, these requirements were not developed based on empirical research involving people with vision loss. We investigated whether the level of luminance contrast in Australian accessibility standards, 30%, is adequate for people with visual impairments to detect and identify discrete tactile ground surface indicators over a range of contrasts with the background flooring before contact. We found that the 30% luminance contrast is adequate for people with low vision, although they preferred higher contrast.
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Hernández-Moreno L, Senra H, Lewis P, Moreno N, Linhares J, Santana R, Ramos PL, Marques AP, Macedo AF. Cost-effectiveness of basic vision rehabilitation (The basic VRS-effect study): study protocol for a randomised controlled trial. Ophthalmic Physiol Opt 2020; 40:350-364. [PMID: 31989690 DOI: 10.1111/opo.12665] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Revised: 12/13/2019] [Accepted: 12/20/2019] [Indexed: 11/29/2022]
Abstract
PURPOSE To investigate the cost-effectiveness of a basic vision rehabilitation service (basic-VRS) in Portugal. We designed a parallel group, randomised controlled trial whose aim is to compare the effects and costs of 'usual low vision care' with a 'basic-VRS intervention' on self-reported visual ability and other psychosocial and health-related quality-of-life outcomes. METHODS The trial will recruit participants that meet the following inclusion criteria: (1) visual acuity between 0.4-1.0 logMAR in the better-seeing eye, (2) cause of vision loss is diabetic retinopathy or age-related macular degeneration, (3) 18 years or older and iv) live in the community (not in nursing homes or other type of institution). Participants will be randomised to one of the study arms consisting of immediate intervention and delayed intervention. The delayed intervention group will receive 'usual care' or no intervention in the first 12 weeks. Visual acuity, contrast sensitivity and retinal structure will be assessed during the study. RESULTS The primary outcome measure is visual ability, which will be evaluated with the Massof Activity Inventory, we expect that the intervention will raise the overall person measure or visual ability. Reading, health-related quality-of-life, anxiety and depression and social support will be also assessed. The analysis will be undertaken on an intention-to-treat basis. A cost-effectiveness analysis will be performed to provide information about the cost per unit of utility. To evaluate the cost-effectiveness of the intervention we will adopt the perspective of the healthcare system. CONCLUSION This study will provide additional evidence about the effects of basic-VRS on self-reported visual ability. Findings from this study should also contribute to better planning of low vision provision and, consequently, may contribute to reduce barriers to basic-VRS.
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Affiliation(s)
- Laura Hernández-Moreno
- Department and Center of Physics-Optometry and Vision Science, University of Minho, Braga, Portugal
| | - Hugo Senra
- School of Health and Social Care, University of Essex, Colchester, UK.,Centre for Research in Neuropsychology and Cognitive Behavioural Intervention (CINEICC), Faculty of Psychology and Educational Sciences, University of Coimbra, Coimbra, Portugal
| | - Peter Lewis
- Department of Medicine and Optometry, Linnaeus University, Kalmar, Sweden
| | | | - João Linhares
- Department and Center of Physics-Optometry and Vision Science, University of Minho, Braga, Portugal
| | - Rui Santana
- Public Health Research Centre, National School of Public Health, University NOVA, Lisbon, Portugal
| | - Pedro Lima Ramos
- Department and Center of Physics-Optometry and Vision Science, University of Minho, Braga, Portugal.,Department of Medicine and Optometry, Linnaeus University, Kalmar, Sweden
| | - Ana Patrícia Marques
- Public Health Research Centre, National School of Public Health, University NOVA, Lisbon, Portugal
| | - Antonio Filipe Macedo
- Department and Center of Physics-Optometry and Vision Science, University of Minho, Braga, Portugal.,Department of Medicine and Optometry, Linnaeus University, Kalmar, Sweden
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Carkeet A. Stand magnifiers for low vision: description, prescription, assessment. Clin Exp Optom 2019; 103:11-20. [PMID: 31429123 DOI: 10.1111/cxo.12948] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 07/03/2019] [Accepted: 07/03/2019] [Indexed: 11/27/2022] Open
Abstract
Stand magnifiers are still one of the most commonly prescribed classes of low vision devices. Their performance can be difficult to understand because stand magnifiers usually do not give an image at infinity. This review summarises the methods of describing image enlargement for stand magnifiers, emphasising their relationship to equivalent viewing distance (EVD). This is done in terms of the underlying optical equations, and measurement methods, and methods of prescribing. In the past, methods of determining EVD have been somewhat indirect, requiring accurate measurement of lens power, and image position. The use of digital photography provides an alternative, more direct, simpler method of determining EVD, which can be accomplished in-office. This method is described and it is demonstrated how it gives comparable results to older methods with small, clinically non-meaningful differences, that may be due to differences in image distance reference planes. Describing the performance of stand magnifiers in terms of their dioptric power, or in terms of 'nominal magnification' or 'trade magnification', is imprecise and misleading. It is better to use indices such as equivalent viewing power and EVD, which take into account the magnifier dioptric power, the image position of the magnifier and the distance a patient is from the magnifier. While EVD is a useful index for prescribing stand magnifiers, manufacturers do not always provide sufficient technical details to determine EVD for their stand magnifiers, and available tables of EVDs are more than a decade old and are likely to need updating. Photographic comparison provides a method for determining EVD, and this method can also be applied to other low vision devices.
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Affiliation(s)
- Andrew Carkeet
- School of Optometry and Vision Science, and Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
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Xiong YZ, Calabrèse A, Cheong AMY, Legge GE. Reading Acuity as a Predictor of Low-Vision Reading Performance. Invest Ophthalmol Vis Sci 2019; 59:4798-4803. [PMID: 30347073 PMCID: PMC6181187 DOI: 10.1167/iovs.18-24716] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Most people with low vision experience difficulty with reading. Reading assessment can provide guidance for prescription of reading aids and strategies for reading rehabilitation. Here we investigate the effectiveness of letter acuity (LA) and reading acuity (RA) as predictors of low-vision reading performance. Methods Low-vision subjects (n = 58), young control subjects (n = 52), and older control subjects (n = 14) participated in this study. The low-vision subjects were separated into a Macular group (n = 30) and a Nonmacular group (n = 28) based on whether the diagnoses primarily affected the macular area. LA was measured with the Lighthouse Distance Visual Acuity Chart and RA with the MNREAD Acuity Chart. Reading speeds were obtained across a range of print sizes from the MNREAD test. The MNREAD data were used to estimate required print sizes for three functionally important types of reading for each subject: spot reading (40 words/min [wpm]), fluent reading (80 wpm), and critical print size (required to achieve maximum reading speed). Results For equal values of LA, the Macular group had significantly worse RA than the Nonmacular group. The differences between vision groups, as well as individual variations within groups, were largely explained by the differences in RA. RA is a better predictor than LA for spot reading size, fluent reading size, and critical print size. Conclusions RA may provide more accurate assessment of reading performance than LA for purposes of low-vision reading rehabilitation.
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Affiliation(s)
- Ying-Zi Xiong
- Department of Psychology, University of Minnesota, Minneapolis, Minnesota, United States
| | - Aurélie Calabrèse
- Department of Psychology, University of Minnesota, Minneapolis, Minnesota, United States.,Laboratoire de Psychologie Cognitive, Aix-Marseille University, Marseille, France
| | - Allen M Y Cheong
- Department of Psychology, University of Minnesota, Minneapolis, Minnesota, United States.,School of Optometry, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, China
| | - Gordon E Legge
- Department of Psychology, University of Minnesota, Minneapolis, Minnesota, United States
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19
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Small Text on Product Labels Poses a Special Challenge for Emerging Presbyopes. Optom Vis Sci 2019; 96:291-300. [DOI: 10.1097/opx.0000000000001362] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Jhetam S, Mashige KP. Ocular findings and vision status of learners with oculocutaneous albinism. AFRICAN VISION AND EYE HEALTH 2019. [DOI: 10.4102/aveh.v78i1.466] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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21
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Eccentric Viewing Training in the Home Environment: Can it Improve the Performance of Activities of Daily Living? JOURNAL OF VISUAL IMPAIRMENT & BLINDNESS 2019. [DOI: 10.1177/0145482x0910300506] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Macular degeneration has a severe impact on a person's ability to perform activities of daily living. This study investigated the impact of in-home training in eccentric viewing on near acuity and performance of activities of daily living. The results suggest that eccentric viewing can ameliorate the impact of the loss of vision that is due to macular degeneration.
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Rodrigues TM, Cortez L, Murta JN, Paiva C. Low-vision aids improve the visual performance of children with bilateral chorioretinal coloboma. J AAPOS 2018; 22:202-206. [PMID: 29730056 DOI: 10.1016/j.jaapos.2017.12.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 12/28/2017] [Accepted: 12/31/2017] [Indexed: 11/25/2022]
Abstract
PURPOSE To quantify the improvements in visual performance for both distance and near tasks attained by children with bilateral chorioretinal coloboma (CRC) with use of low-vision aids (LVAs). METHODS This was a hospital-based, cross-sectional, interventional case series of children with bilateral CRC. Demographic data were collected through a structured questionnaire and review of medical records. Distance and near best-corrected visual acuity, contrast sensitivity, and reading speed were evaluated with refractive correction alone and with the use of LVAs (Keplerian telescopes for distance; handheld magnifiers and a tinted lens [400 nm filter] for near). Effects are presented as medians of differences with 95% binomial-exact confidence intervals. RESULTS Six children were included (median age, 11.5 years; range, 7-17 years), of whom 5 were already using LVAs on a daily basis. The use of a Keplerian telescope achieved a significant median improvement in distance best-corrected visual acuity of 0.75 logMAR (95% CI, 0.20-1.20). Contrast sensitivity was also improved across all tested spatial frequencies. Use of near LVAs resulted in a significant median improvement in near reading acuity of 0.47 logRAD (95% CI, 0.28-0.90). Critical print size and reading speed at N10 were also improved. CONCLUSIONS LVAs enable meaningful improvements in the visual performance of children with bilateral CRC, allowing noteworthy increases in distance and near visual acuities as well as good reading speeds at small print sizes.
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Affiliation(s)
- Tiago M Rodrigues
- Department of Ophthalmology, Centro Hospitalar e Universitário de Coimbra - CHUC, Coimbra, Portugal; Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Liliana Cortez
- Department of Ophthalmology, Centro Hospitalar e Universitário de Coimbra - CHUC, Coimbra, Portugal
| | - Joaquim N Murta
- Department of Ophthalmology, Centro Hospitalar e Universitário de Coimbra - CHUC, Coimbra, Portugal; Faculty of Medicine, University of Coimbra (FMUC), Coimbra, Portugal
| | - Catarina Paiva
- Department of Ophthalmology, Centro Hospitalar e Universitário de Coimbra - CHUC, Coimbra, Portugal.
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Coco-Martín MB, López-Miguel A, Cuadrado R, Mayo-Iscar A, Herrero AJ, Pastor JC, Maldonado MJ. Reading Performance Improvements in Patients with Central Vision Loss without Age-Related Macular Degeneration after Undergoing Personalized Rehabilitation Training. Curr Eye Res 2017. [PMID: 28632405 DOI: 10.1080/02713683.2017.1315140] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
PURPOSE To evaluate the efficacy of a reading rehabilitation program (RRP) in patients with central visual loss (CVL) and assess the impact of the RRP on the quality of life (QoL). METHODS The RRP included four in-office and 39 in-home training sessions over 6 weeks. Reading speed, duration, and font size were evaluated during each in-office session. The subjective perception of the QoL was assessed before and after the RRP using the short version of a questionnaire (World Health Organization Quality of Life). A control group who received advice about ocular conditions and low-vision aids also was included. RESULTS Seventeen patients with Stargardt's disease (STGD), 11 with adult-onset foveomacular vitelliform dystrophy (AFVD), and eight with myopic macular degeneration (MMD) were included. The control group included five patients each with STGD, AFVD, and MMD. The respective mean corrected distance visual acuities (VAs) in patients with STGD, AFVD, MMD, and the control group were 0.57 ± 0.38, 0.51 ± 0.38, 0.49 ± 0.24, and 0.55 ± 0.25 logarithm of the minimum angle of resolution; the mean corrected near VAs were 0.89 ± 0.20, 1.08 ± 0.17, 0.99 ± 0.34, and 1.18 ± 0.37 (M notation) using low-vision aids. The reading speed, duration, and font size improved in all groups. The RRP groups obtained (p ≤ 0.01) greater improvements than the control group in each reading performance variable assessed. Patients with STGD obtained greater improvements in the subjective evaluation; the control group did not obtain noteworthy improvement in any domain. CONCLUSIONS The RRP improved reading performance in patients with CVL and positively impacted the subjective perception of the QoL.
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Affiliation(s)
- María B Coco-Martín
- a Instituto de Oftalmobiología Aplicada (IOBA), Universidad de Valladolid , Valladolid , Spain.,b Faculty of Health Sciences , European University Miguel de Cervantes , Valladolid , Spain
| | - Alberto López-Miguel
- a Instituto de Oftalmobiología Aplicada (IOBA), Universidad de Valladolid , Valladolid , Spain
| | - Rubén Cuadrado
- a Instituto de Oftalmobiología Aplicada (IOBA), Universidad de Valladolid , Valladolid , Spain
| | - Agustín Mayo-Iscar
- c Department of Statistics and Operative Research, Science Faculty , University of Valladolid , Valladolid , Spain
| | - Azael J Herrero
- b Faculty of Health Sciences , European University Miguel de Cervantes , Valladolid , Spain
| | - José C Pastor
- a Instituto de Oftalmobiología Aplicada (IOBA), Universidad de Valladolid , Valladolid , Spain
| | - Miguel J Maldonado
- a Instituto de Oftalmobiología Aplicada (IOBA), Universidad de Valladolid , Valladolid , Spain
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Sasso P, Scupola A, Silvestri V, Amore FM, Abed E, Calandriello L, Grimaldi G, Caporossi A. Morpho-functional analysis of Stargardt Disease for reading. CANADIAN JOURNAL OF OPHTHALMOLOGY 2017; 52:287-294. [DOI: 10.1016/j.jcjo.2016.10.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 10/19/2016] [Accepted: 10/24/2016] [Indexed: 10/20/2022]
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Aguilar C, Castet E. Evaluation of a gaze-controlled vision enhancement system for reading in visually impaired people. PLoS One 2017; 12:e0174910. [PMID: 28380004 PMCID: PMC5381883 DOI: 10.1371/journal.pone.0174910] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 03/17/2017] [Indexed: 11/23/2022] Open
Abstract
People with low vision, especially those with Central Field Loss (CFL), need magnification to read. The flexibility of Electronic Vision Enhancement Systems (EVES) offers several ways of magnifying text. Due to the restricted field of view of EVES, the need for magnification is conflicting with the need to navigate through text (panning). We have developed and implemented a real-time gaze-controlled system whose goal is to optimize the possibility of magnifying a portion of text while maintaining global viewing of the other portions of the text (condition 1). Two other conditions were implemented that mimicked commercially available advanced systems known as CCTV (closed-circuit television systems)—conditions 2 and 3. In these two conditions, magnification was uniformly applied to the whole text without any possibility to specifically select a region of interest. The three conditions were implemented on the same computer to remove differences that might have been induced by dissimilar equipment. A gaze-contingent artificial 10° scotoma (a mask continuously displayed in real time on the screen at the gaze location) was used in the three conditions in order to simulate macular degeneration. Ten healthy subjects with a gaze-contingent scotoma read aloud sentences from a French newspaper in nine experimental one-hour sessions. Reading speed was measured and constituted the main dependent variable to compare the three conditions. All subjects were able to use condition 1 and they found it slightly more comfortable to use than condition 2 (and similar to condition 3). Importantly, reading speed results did not show any significant difference between the three systems. In addition, learning curves were similar in the three conditions. This proof of concept study suggests that the principles underlying the gaze-controlled enhanced system might be further developed and fruitfully incorporated in different kinds of EVES for low vision reading.
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Affiliation(s)
| | - Eric Castet
- LPC, Aix Marseille Univ, CNRS, Marseille, France
- * E-mail:
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26
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Early detection of age related macular degeneration: current status. Int J Retina Vitreous 2015; 1:20. [PMID: 27847613 PMCID: PMC5088451 DOI: 10.1186/s40942-015-0022-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 10/13/2015] [Indexed: 12/04/2022] Open
Abstract
Early diagnosis and treatment of choroidal neovascularization (CNV), a main cause of severe vision loss in age related macular degeneration (AMD), is crucial in order to preserve vision and the quality of life of patients. This review summarizes current literature on the subject of early detection of CNV, both in the clinic setting and mainly in the patient’s home. New technologies are evolving to allow for earlier detection and thus vision preservation in AMD patients.
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Abstract
PURPOSE This study compared three different methods of determining a reading addition and the possible improvement on reading performance in children and young adults with low vision. METHODS Twenty-eight participants with low vision, aged 8 to 32 years, took part in the study. Reading additions were determined with (a) a modified Nott dynamic retinoscopy, (b) a subjective method, and (c) an age-based formula. Reading performance was assessed with MNREAD-style reading charts at 12.5 cm, with and without each reading addition in random order. Outcome measures were reading speed, critical print size, MNREAD threshold, and the area under the reading speed curve. RESULTS For the whole group, there was no significant improvement in reading performance with any of the additions. When participants with normal accommodation at 12.5 cm were excluded, the area under the reading speed curve was significantly greater with all reading additions compared with no addition (p = 0.031, 0.028, and 0.028, respectively). Also, the reading acuity threshold was significantly better with all reading additions compared with no addition (p = 0.014, 0.030, and 0.036, respectively). Distance and near visual acuity, age, and contrast sensitivity did not predict improvement with a reading addition. All, but one, of the participants who showed a significant improvement in reading with an addition had reduced accommodation. CONCLUSIONS A reading addition may improve reading performance for young people with low vision and should be considered as part of a low vision assessment, particularly when accommodation is reduced.
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Coco-Martín MB, Cuadrado-Asensio R, López-Miguel A, Mayo-Iscar A, Maldonado MJ, Pastor JC. Design and Evaluation of a Customized Reading Rehabilitation Program for Patients with Age-related Macular Degeneration. Ophthalmology 2013; 120:151-9. [DOI: 10.1016/j.ophtha.2012.07.035] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Revised: 07/13/2012] [Accepted: 07/13/2012] [Indexed: 11/27/2022] Open
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Arditi A, Cho J. Letter case and text legibility in normal and low vision. Vision Res 2007; 47:2499-505. [PMID: 17675131 PMCID: PMC2016788 DOI: 10.1016/j.visres.2007.06.010] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2006] [Revised: 06/14/2007] [Accepted: 06/17/2007] [Indexed: 11/22/2022]
Abstract
It is thought by cognitive scientists and typographers alike, that lower-case text is more legible than upper-case. Yet lower-case letters are, on average, smaller in height and width than upper-case characters, which suggests an upper-case advantage. Using a single unaltered font and all upper-, all lower-, and mixed-case text, we assessed size thresholds for words and random strings, and reading speeds for text with normal and visually impaired participants. Lower-case thresholds were roughly 0.1 log unit higher than upper. Reading speeds were higher for upper- than for mixed-case text at sizes twice acuity size; at larger sizes, the upper-case advantage disappeared. Results suggest that upper-case is more legible than the other case styles, especially for visually-impaired readers, because smaller letter sizes can be used than with the other case styles, with no diminution of legibility.
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Affiliation(s)
- Aries Arditi
- Arlene R. Gordon Research Institute, Lighthouse International, 111 East 59th Street, New York, NY 10022, USA.
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Markowitz SN. Principles of modern low vision rehabilitation. CANADIAN JOURNAL OF OPHTHALMOLOGY 2006; 41:289-312. [PMID: 16767184 DOI: 10.1139/i06-027] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Low vision rehabilitation is a new emerging subspecialty drawing from the traditional fields of ophthalmology, optometry, occupational therapy, and sociology, with an ever-increasing impact on our customary concepts of research, education, and services for the visually impaired patient. A multidisciplinary approach and coordinated effort are necessary to take advantage of new scientific advances and achieve optimal results for the patient. Accordingly, the intent of this paper is to outline the principles and details of a modern low vision rehabilitation service. All rehabilitation attempts must start with a first hand interview (the intake) for assessing functionality and priority tasks for rehabilitation, as well as assessing the patient's all-important cognitive skills. The assessment of residual visual functions follows the intake and offers a unique opportunity to measure, evaluate, and document accurately the extent of functional loss sustained by the patient from disease. An accurate assessment of residual visual functions includes assessment of visual acuity, contrast sensitivity, binocularity, refractive errors, perimetry, oculomotor functions, cortical visual integration, and light characteristics affecting visual functions. Functional vision assessment in low vision rehabilitation measures how well one uses residual visual functions to perform routine tasks, using different items under various conditions, throughout the day. Of the many functional vision skills known, reading skills is an obligatory item for all low vision rehabilitation assessments. Results of assessment guide rehabilitation professionals in developing rehabilitation plans for the individual and recommending appropriate low vision devices. The outcome from assessing residual visual functions is detection of visual functions that can be improved with the use of optical devices. Methods for prescribing devices such as image relocation with prisms to a preferred retinal locus, field displacement to primary gaze position, field expansion, and manipulation of light are practiced today in addition to, or instead of, magnification. Correction of refractive errors, occlusion therapy, enhancement of oculomotor skills, and field restitution are additional methods now available for prescribing devices leading to rehabilitation of visual functions. The outcome from assessing residual functional vision is detection of functional vision that can be improved with the use of vision therapy training. After restoration of optimal residual visual functions is achieved with optical devices, one can follow with training programs for restoration of lost vision-related skills. If an optical dispensary is available where prescribing of low vision devices routinely take place, this will help ensure familiarity and specialization of the dispensary and staff with low vision devices and their special dispensing requirements. The dispensing of low vision devices is an opportunity to introduce the device to the patient, train the patient in the correct use of the device for the task selected, and create a direct and continuous connection with the patient until the next encounter. Following assessment, prescribing, and dispensing of devices, a low vision practitioner, ophthalmologist or optometrist, is responsible for recommending and prescribing vision therapy training to improve residual functional vision. An attempt to present a template for a comprehensive modern low vision rehabilitation practice is made here by summarizing scientific developments in the field and stressing the multidisciplinary involvement required for this kind of practice. It is hoped that this paper and other initiatives from colleagues, the public, and government will promote and raise awareness of modern low vision rehabilitation for the benefit of all.
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Affiliation(s)
- Samuel N Markowitz
- Low Vision Service, University Health Network, Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON, Canada.
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Herse P. Retinitis pigmentosa: visual function and multidisciplinary management. Clin Exp Optom 2006; 88:335-50. [PMID: 16255692 DOI: 10.1111/j.1444-0938.2005.tb06717.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2005] [Revised: 06/25/2005] [Accepted: 07/31/2005] [Indexed: 12/01/2022] Open
Abstract
Retinitis pigmentosa (RP) is a leading cause of blindness and visual disability in younger people. Optometrists have a major role in detecting RP and in reducing the visual disability associated with RP. This review summarises the literature relating to visual function in people with RP, with particular attention given to night-blindness, visual acuity decrease and visual field contraction. The range of low vision aids available for people with RP is reviewed and suggestions given on aids that have been found to be most successful. Most importantly, this review overviews the range of services available to people with RP and emphasises how optometrists need to work with a network of professionals to ensure the best possible visual outcomes for people with RP. Particular mention is made of current findings relating to orientation and mobility training, driving, sensory substitution and adaptive technology. The modern optometrist needs to be aware of the multiple needs of people with RP and have the ability to link them with the professionals best able to help them.
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Affiliation(s)
- Peter Herse
- School of Optometry and Vision Science, University of New South Wales, Sydney, NSW, 2052, Australia.
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Rubin GS. Visual Acuity and Contrast Sensitivity. Retina 2006. [DOI: 10.1016/b978-0-323-02598-0.50017-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Cheong AMY, Lovie-Kitchin JE, Bowers AR, Brown B. Short-Term In-Office Practice Improves Reading Performance with Stand Magnifiers for People with AMD. Optom Vis Sci 2005; 82:114-27. [PMID: 15711458 DOI: 10.1097/01.opx.0000153244.93582.ff] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
PURPOSE People with low vision often use optical low vision aids to assist reading. There have been numerous training programs recommended to train people using magnifiers for reading. However, most of the programs are time consuming and labor intensive. In this study, we investigated the effects of home-based large print reading practice on reading performance when stand magnifiers (STM's) are first prescribed. METHODS Thirty-two subjects with age-related macular degeneration (AMD) and with minimal experience in using magnifiers for reading were recruited. They were divided into three groups: control, practice 1 (P1), and practice 2 (P2). Before the prescription of STM's, all the subjects were given the same amount of in-office practice with the STM (weeks 0 to 2). In addition, in these 2 weeks, P1 and P2 subjects were given large print books to read daily at home. P2 subjects were required to read the large print books through a reduced field of view. The control group subjects received no additional reading practice. Reading rates with and without STM's on passages of text were assessed for all the subjects regularly for 20 weeks. RESULTS There were no significant differences between the control, P1, and P2 groups in the increase in reading rate with STM (p = 0.29). At week 0, reading rate for small print with STM was significantly slower than reading rate on the equivalent-sized large print (p = 0.004); however, as time went on, reading rate with STM's increased significantly (p = 0.02). After 2 weeks of in-office magnifier practice and repeated measures of reading rate with STM, reading rate with STM had improved such that it was not significantly different from reading rate on large print (p = 0.11). CONCLUSION Supervised, short-term, in-office practice with the magnifier was effective in improving magnifier reading performance to achieve maximum reading rate. Additional large print reading practice did not result in any greater improvement in reading rate than in-office magnifier practice alone.
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Affiliation(s)
- Allen M Y Cheong
- Centre for Health Research, School of Optometry, Queensland University of Technology, Australia.
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Cheong ACY, Lovie-Kitchin JE, Bowers AR. Determining magnification for reading with low vision. Clin Exp Optom 2002; 85:229-37. [PMID: 12135415 DOI: 10.1111/j.1444-0938.2002.tb03042.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2002] [Revised: 03/13/2002] [Accepted: 03/15/2002] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND In the past, practitioners have used distance and/or near visual acuity (VA) to calculate required magnification for low vision aids. Magnification was usually under-estimated when compared with the final magnification prescribed. Recent studies have emphasised the importance of acuity reserve in determining the required magnification for optimum reading rate. Two different approaches have been proposed for the appropriate acuity reserve to use in calculating magnification. These are a fixed acuity reserve of 0.3 log unit or an individual determination of optimum acuity reserve. The aim of this study was to investigate the magnification and reading rates with low vision aids selected by the two methods. METHODS Nineteen low vision subjects with age-related macular degeneration (AMD) who were experienced magnifier-users were recruited. Reading rates and near VA with low vision aids determined by the fixed and individual acuity reserve methods were compared with the same measures made with the subjects' own magnifiers. RESULTS There were no significant differences in reading rate and near VA measured with low vision aids selected by either the fixed or individual acuity reserve methods or the subjects' own magnifiers. Reading rate with low vision aids was not significantly different from reading rate for large print with conventional near additions. Thus, for experienced users, magnifiers do not cause reduced reading rate. CONCLUSIONS The fixed acuity reserve method is simple to apply as only near VA and print size of the target reading task are required. For the individual acuity reserve method, reading rates at different print sizes need to be measured. We recommend the use of a fixed acuity reserve (0.3 log unit) for the calculation of required magnification for low vision patients. If near VA or reading rate are not satisfactory with the magnification calculated by this method, individual assessment of required acuity reserve is necessary.
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Affiliation(s)
- Allen C Y Cheong
- Centre for Eye Research, School of Optometry, Queensland University of Technology, Kelvin Grove, QLD, 4059, Australia
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Bowers AR, Meek C, Stewart N. Illumination and reading performance in age-related macular degeneration. Clin Exp Optom 2001; 84:139-147. [PMID: 12366325 DOI: 10.1111/j.1444-0938.2001.tb04957.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/18/2001] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND: Previous studies have compared low vision reading performance at optimal task illuminance and consulting room illuminance (500 to 600 lux). However, it is uncertain the extent to which low vision reading performance can be improved when task illumination is increased from levels more representative of those found in the typical living room (50 lux) to levels likely to maximise performance. METHODS: Reading performance of 20 subjects with age-related macular degeneration (AMD) was assessed for a range of print sizes using sentence reading charts at six levels of task illuminance (50 to 5,000 lux). Subjects read without low vision devices. RESULTS: Sentence reading acuity and critical print size improved by a factor of two over the 50 to 5,000 lux range, while maximum reading rate improved by a factor of 1.4. For the majority of subjects (70 per cent), the optimal task illuminance (determined objectively) was higher (median 3,500 lux) than the subjectively preferred task illuminance (median 2,450 lux). Reading performance was significantly better at the optimal illuminance than at illuminances equivalent to those found in the domestic environment (50 lux) or consulting room (600 lux). CONCLUSIONS: The majority of AMD patients will require task illumination of at least 2,000 lux to maximise reading performance. Optimal illumination should be determined individually for each patient using both objective measures of performance, such as reading acuity, and subjective assessments of visual comfort.
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Affiliation(s)
- Alex R Bowers
- Department of Vision Sciences, Glasgow Caledonian University, Cowcaddens Rd, Glasgow, G4 0BA, Scotland, UK
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Lovie-Kitchin JE, Devereaux J, Wells S, Sculpher KA. Multi-disciplinary low vision care. Clin Exp Optom 2001; 84:165-170. [PMID: 12366329 DOI: 10.1111/j.1444-0938.2001.tb04961.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/25/2001] [Indexed: 11/30/2022] Open
Abstract
Case reports for three patients with low vision due to different ocular diseases are presented. In each case, a different rehabilitation professional was the main provider of the low vision care needed to meet the patient's goals. However, in all cases the patients benefited from the services of a range of professionals, agencies or groups for visually impaired people. The importance of defining patients' specific goals, referral to multi-disciplinary low vision services and regular reviews of vision and visual tasks is highlighted.
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Affiliation(s)
- Jan E Lovie-Kitchin
- School of Optometry, Queensland University of Technology, Victia Park Rd, Kelvin Grove, QLD, 4059, Australia
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Aquilante K, Yager D, Morris RA, Khmelnitsky F. Low-vision patients with age-related maculopathy read RSVP faster when word duration varies according to word length. Optom Vis Sci 2001; 78:290-6. [PMID: 11384006 DOI: 10.1097/00006324-200105000-00012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Normally sighted younger and elder subjects as well as subjects with central visual field loss (CFL) from age-related maculopathy read rapid serial visual presentation (RSVP) text with words presented at a constant rate and at three different rates where word presentation duration varied according to word length. The elder subjects reading sentences foveally read fastest when word duration was constant. The younger group reading random words peripherally read faster at a variable word duration rate. The subjects with CFL read sentences an average of 33% faster when the presentation rate varied with word length. There was a trend for slow readers with CFL to benefit more than fast readers with CFL. We conclude that varying word duration based on word length in rapid serial visual presentation reading would improve reading rates for low-vision patients with CFL.
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Affiliation(s)
- K Aquilante
- SUNY College of Optometry, New York, New York 10036, USA.
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Bowers AR, Lovie-Kitchin JE, Woods RL. Eye movements and reading with large print and optical magnifiers in macular disease. Optom Vis Sci 2001; 78:325-34. [PMID: 11384010 DOI: 10.1097/00006324-200105000-00016] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
PURPOSE Reading rate has been the main performance measure in studies that have compared reading with large print and optical magnifiers; eye movement characteristics have not been considered. We compared both eye movement characteristics and reading rates for subjects with macular disease reading without and with a range of low-vision devices. METHODS Silent reading rate and eye movement characteristics for text passages at critical print size of 21 subjects aged 14 to 88 years with macular disease were measured with and without their preferred low-vision device. Saccadic frequency was determined from a sequencing task comprising five letters each separated by 5 degrees. Eye movements were recorded using an infrared limbal reflection system. RESULTS There were no significant differences in reading rate, fixation durations, saccade numbers per word, or percent retrace time when using a low-vision device compared with reading without a low-vision device. The percentage of regressions was, however, lower with the low-vision device. Saccadic frequency in the sequencing task was predictive of reading performance with and without a low-vision device. CONCLUSIONS When reading at critical print size, in terms of reading rate or saccades per word, there was no advantage to using large print over an optical low-vision device.
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Affiliation(s)
- A R Bowers
- Department of Vision Sciences, Glasgow Caledonian University, Glasgow, Scotland, United Kingdom.
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