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Hou C. A new approach to measure interocular suppression in amblyopia and strabismus. MethodsX 2024; 12:102527. [PMID: 38204980 PMCID: PMC10777102 DOI: 10.1016/j.mex.2023.102527] [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: 09/22/2023] [Accepted: 12/17/2023] [Indexed: 01/12/2024] Open
Abstract
Interocular suppression is commonly estimated by the contrast "balance point" between the eyes in individuals with amblyopia, in which the depth of suppression is defined as the increased contrast in the amblyopic eye that is perceptually matched to the fellow eye. However, this method may not be suitable for individuals with strabismus who have normal or even better contrast sensitivity in the non-fixating eye. In this study, I introduced a new approach that can be used for measuring interocular suppression for both amblyopia and strabismus without balancing contrasts between the eyes. The method consists of the following components: •The stimuli have equal contrasts in both eyes.•The percepts of objects seen monocularly and binocularly are compared.•Interocular suppression is defined as the percept of object in the amblyopic eye is suppressed when an object is presented in the fellow eye.
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Affiliation(s)
- Chuan Hou
- The Smith-Kettlewell Eye Research Institute, United States
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2
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Birch EE, Duffy KR. Leveraging neural plasticity for the treatment of amblyopia. Surv Ophthalmol 2024:S0039-6257(24)00046-8. [PMID: 38763223 DOI: 10.1016/j.survophthal.2024.04.006] [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: 11/25/2023] [Revised: 04/27/2024] [Accepted: 04/29/2024] [Indexed: 05/21/2024]
Abstract
Amblyopia is a form of visual cortical impairment that arises from abnormal visual experience early in life. Most often, amblyopia is a unilateral visual impairment that can develop as a result of strabismus, anisometropia, or a combination of these conditions that result in discordant binocular experience. Characterized by reduced visual acuity and impaired binocular function, amblyopia places a substantial burden on the developing child. Although frontline treatment with glasses and patching can improve visual acuity, residual amblyopia remains for most children. Newer binocular-based therapies can elicit rapid recovery of visual acuity and may also improve stereoacuity in some children. Nevertheless, for both treatment modalities full recovery is elusive, recurrence of amblyopia is common, and improvements are negligible when treatment is administered at older ages. Insights derived from animal models about the factors that govern neural plasticity have been leveraged to develop innovative treatments for amblyopia. These novel therapies exhibit efficacy to promote recovery, and some are effective even at ages when conventional treatments fail to yield benefit. Approaches for enhancing visual system plasticity and promoting recovery from amblyopia include altering the balance between excitatory and inhibitory mechanisms, reversing the accumulation of proteins that inhibit plasticity, and harnessing the principles of metaplasticity. Although these therapies have exhibited promising results in animal models, their safety and ability to remediate amblyopia need to be evaluated in humans.
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Affiliation(s)
- Eileen E Birch
- Crystal Charity Ball Pediatric Vision Laboratory, Retina Foundation, Dallas, TX, USA; University of Texas Southwestern Medical Center, Dallas, TX, USA.
| | - Kevin R Duffy
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS, Canada
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Wiecek E, Kosovicheva A, Ahmed Z, Nabasaliza A, Kazlas M, Chan K, Hunter DG, Bex PJ. Peripheral Binocular Imbalance in Anisometropic and Strabismic Amblyopia. Invest Ophthalmol Vis Sci 2024; 65:36. [PMID: 38652649 PMCID: PMC11044833 DOI: 10.1167/iovs.65.4.36] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 03/27/2024] [Indexed: 04/25/2024] Open
Abstract
Purpose Individuals with amblyopia experience central vision deficits, including loss of visual acuity, binocular vision, and stereopsis. In this study, we examine the differences in peripheral binocular imbalance in children with anisometropic amblyopia, strabismic amblyopia, and typical binocular vision to determine if there are systematic patterns of deficits across the visual field. Methods This prospective cohort study recruited 12 participants with anisometropic amblyopia, 10 with strabismic amblyopia, and 10 typically sighted controls (age range, 5-18 years). Binocular imbalance was tested at 0°, 4°, and 8° eccentricities (4 angular locations each) using band-pass filtered Auckland optotypes (5 cycles per optotype) dichoptically presented with differing contrast to each eye. The interocular contrast ratio was adjusted until the participant reported each optotype with equal frequency. Results Participants with anisometropic and strabismic amblyopia had a more balanced contrast ratio, or decreased binocular imbalance, at 4° and 8° eccentricities as compared with central vision. Participants with strabismic amblyopia had significantly more binocular imbalance in the periphery as compared with individuals with anisometropic amblyopia or controls. A linear mixed effects model showed a main effect for strabismic amblyopia and eccentricity on binocular imbalance across the visual field. Conclusions There is evidence of decreased binocularity deficits, or interocular suppression, in the periphery in anisometropic and strabismic amblyopia as compared with controls. Notably, those with strabismic amblyopia exhibited more significant peripheral binocular imbalance. These variations in binocularity across the visual field among different amblyopia subtypes may necessitate tailored approaches for dichoptic treatment.
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Affiliation(s)
- Emily Wiecek
- Department of Ophthalmology, Boston Children's Hospital, Boston, Massachusetts, United States
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States
| | - Anna Kosovicheva
- Department of Psychology, University of Toronto, Toronto, Ontario, Canada
| | - Zain Ahmed
- Department of Ophthalmology, Boston Children's Hospital, Boston, Massachusetts, United States
| | - Amanda Nabasaliza
- Department of Ophthalmology, Boston Children's Hospital, Boston, Massachusetts, United States
| | - Melanie Kazlas
- Department of Ophthalmology, Boston Children's Hospital, Boston, Massachusetts, United States
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States
| | - Kimberley Chan
- Department of Ophthalmology, Boston Children's Hospital, Boston, Massachusetts, United States
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States
| | - David G. Hunter
- Department of Ophthalmology, Boston Children's Hospital, Boston, Massachusetts, United States
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States
| | - Peter J. Bex
- Department of Psychology, Northeastern University, Boston, Massachusetts, United States
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Giaschi DE, Asare AK, Jost RM, Kelly KR, Birch EE. Motion-Defined Form Perception in Deprivation Amblyopia. Invest Ophthalmol Vis Sci 2024; 65:13. [PMID: 38573617 PMCID: PMC10996940 DOI: 10.1167/iovs.65.4.13] [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: 10/11/2023] [Accepted: 03/20/2024] [Indexed: 04/05/2024] Open
Abstract
Purpose The purpose of this study was to assess motion-defined form perception, including the association with clinical and sensory factors that may drive performance, in each eye of children with deprivation amblyopia due to unilateral cataract. Methods Coherence thresholds for orientation discrimination of motion-defined form were measured using a staircase procedure in 30 children with deprivation amblyopia and 59 age-matched controls. Visual acuity, stereoacuity, fusion, and interocular suppression were also measured. Fixation stability and fellow-eye global motion thresholds were measured in a subset of children. Results Motion-defined form coherence thresholds were elevated in 90% of children with deprivation amblyopia when viewing with the amblyopic eye and in 40% when viewing with the fellow eye. The deficit was similar in children with a cataract that had been visually significant at birth (congenital) and in children for whom the cataract appeared later in infancy or childhood (developmental). Poorer motion-defined form perception in amblyopic eyes was associated with poorer visual acuity, poorer binocular function, greater interocular suppression, and the presence of nystagmus. Fellow-eye deficits were not associated with any of these factors, but a temporo-nasal asymmetry for global motion perception in favor of nasalward motion suggested a general disruption in motion perception. Conclusions Deficits in motion-defined form perception are common in children with deprivation amblyopia and may reflect a problem in motion processing that relies on binocular mechanisms.
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Affiliation(s)
- Deborah E Giaschi
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Akosua K Asare
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Reed M Jost
- Pediatric Vision Laboratory, Retina Foundation of the Southwest, Dallas, Texas, United States
| | - Krista R Kelly
- School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
| | - Eileen E Birch
- Pediatric Vision Laboratory, Retina Foundation of the Southwest, Dallas, Texas, United States
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Plaumann MD, Roberts KL, Wei W, Han C, Ooi TL. Refining Clinical Quantification of Depth of Suppression in Amblyopia through Synoptophore Measurement. Life (Basel) 2023; 13:1900. [PMID: 37763304 PMCID: PMC10532546 DOI: 10.3390/life13091900] [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: 08/01/2023] [Revised: 09/06/2023] [Accepted: 09/07/2023] [Indexed: 09/29/2023] Open
Abstract
BACKGROUND Amblyopia is associated with unbalanced suppression between the two eyes. Existing clinical measures of suppression, such as the Worth 4 Dot test, provide qualitative information about suppression but cannot precisely quantify it. The Synoptophore, a well-established instrument in binocular vision clinics, has historically been used to gauge suppression qualitatively as well but has the capability to quantify suppression. We extended the capability of the Synoptophore through the development of a systematic protocol of illumination manipulation to quantify suppression in amblyopia. METHODS Twenty-six previously treated adult amblyopes underwent our protocol on the Synoptophore to measure the illumination balance needed to obtain fusion responses. Separately, these same amblyopes were tested with Worth 4 Dot as it is classically performed in the United States, utilizing different test distances and room illuminations to qualify the suppression response. RESULTS Smaller, more central targets revealed larger magnitudes of suppression for both the Synoptophore and Worth 4 Dot tests (Synoptophore: χ25,26 = 25.538, p < 0.001; Worth 4 Dot: χ23,26 = 39.020, p < 0.001). There was a significant correlation between the two tests for depth of suppression measurements (rΤ > 0.345, p < 0.036), with more sensitivity measured by the Synoptophore, as suppression could be graded on a quantitative scale. Strabismic amblyopes demonstrated more suppression than non-strabismic amblyopes (z > 2.410, p < 0.016). Additionally, depth of suppression was correlated with interocular difference in both visual acuity (rΤ = 0.604, p < 0.001) and stereoacuity (rΤ = 0.488, p = 0.001). CONCLUSIONS We extended the utility of the Synoptophore by measuring its illuminance outputs and developing a suppression testing protocol that compared favorably with Worth 4 Dot (clinic standard) while improving upon the latter through more sensitive quantification of suppression.
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Affiliation(s)
| | | | | | | | - Teng Leng Ooi
- College of Optometry, The Ohio State University, Columbus, OH 43210, USA; (M.D.P.)
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Hozumi K, Yagasaki T, Yokoyama Y, Yagasaki A, Haga Y, Eboshita R. Relationship Between Suppression Scotomas and Stereoacuity in Anisometropic Amblyopia With Successfully Treated Visual Acuity. Invest Ophthalmol Vis Sci 2023; 64:16. [PMID: 37561448 PMCID: PMC10424799 DOI: 10.1167/iovs.64.11.16] [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: 12/02/2022] [Accepted: 07/23/2023] [Indexed: 08/11/2023] Open
Abstract
Purpose The purpose of this study was to investigate the relationship among suppression scotoma size, stereoacuity, and four-prism base-out test (4ΔBOT) results in anisometropic amblyopia with successfully treated visual acuity. Methods We included 103 cases of anisometropic amblyopia successfully treated for visual acuity without strabismus. Stereoacuity was measured using a Randot Stereotest. The size of the suppression scotomas was measured using a new device, the polarized four dot (P4D) test. This is a modification of the Worth 4 dot test (W4D) device. The patients were divided into three groups based on the 4ΔBOT results: normal (group A = 29 cases), subnormal (group B = 48 cases), and abnormal (group C = 26 cases) response groups. The horizontal diameter of the suppression scotomas and stereoacuity in logarithmic values with a base of 20 seconds of arc (″) were compared among the 3 groups. Results The mean age at P4D testing was 8.4 ± 2.1 years. The average horizontal diameters of the suppression scotomas were 0.35 ± 0.79Δ, 2.01 ± 0.82Δ, and 5.50 ± 2.72Δ in groups A, B, and C, respectively, showing significant differences (A versus B: P < 0.0001, A versus C: P < 0.0001, and B versus C: P < 0.0001; 1-way ANOVA). The average logarithmic stereoacuity were 1.07 (24.95″), 1.22 (38.84″), and 1.47 (82.79″) in groups A, B, and C, respectively, thereby showing significant differences between the groups (A versus B: P < 0.0001, A versus C: P < 0.0001, and B versus C: P < 0.0001; 1-way ANOVA). Stereoacuity and horizontal diameter of the suppression scotoma were strongly correlated (r = 0.732, P < 0.0001). Conclusions The suppression scotoma size measured using P4D correlated significantly with stereoacuity and the 4ΔBOT results.
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Affiliation(s)
- Kenta Hozumi
- Department of Ophthalmology, Japan Community Health Care Organization Chukyo Hospital, Minamiku, Nagoya, Aichi, Japan
| | - Teiji Yagasaki
- Department of Ophthalmology, Japan Community Health Care Organization Chukyo Hospital, Minamiku, Nagoya, Aichi, Japan
- Yagasaki Eye Clinic, Ichinomiya, Aichi, Japan
| | - Yoshimi Yokoyama
- Department of Ophthalmology, Japan Community Health Care Organization Chukyo Hospital, Minamiku, Nagoya, Aichi, Japan
| | - Ayaka Yagasaki
- Yagasaki Eye Clinic, Ichinomiya, Aichi, Japan
- Department of Ophthalmology, Gifu Prefectural General Medical Center, Gifu, Japan
| | - Yayoi Haga
- Yagasaki Eye Clinic, Ichinomiya, Aichi, Japan
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Meier K, Tarczy-Hornoch K, Boynton GM, Fine I. Characterizing amblyopic perception under non-rivalrous viewing conditions. Sci Rep 2023; 13:7993. [PMID: 37198211 PMCID: PMC10189719 DOI: 10.1038/s41598-023-31301-8] [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: 10/18/2022] [Accepted: 03/09/2023] [Indexed: 05/19/2023] Open
Abstract
Current assessments of interocular interactions in amblyopia often use rivalrous stimuli, with conflicting stimuli in each eye, which does not reflect vision under typical circumstances. Here we measure interocular interactions in observers with amblyopia, strabismus with equal vision, and controls using a non-rivalrous stimulus. Observers used a joystick to continuously report the perceived binocular contrast of dichoptic grating stimuli, identical except that the stimulus was contrast-modulated independently in each eye over time. Consistent with previous studies, a model predicting the time-course of perceived contrast found increased amblyopic eye attenuation, and reduced contrast normalization of the fellow eye by the amblyopic eye, in amblyopic participants compared to controls. However, these suppressive interocular effects were weaker than those found in previous studies, suggesting that rivalrous stimuli may overestimate the effects of amblyopia on interocular interactions during naturalistic viewing conditions.
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Affiliation(s)
- Kimberly Meier
- Department of Psychology, University of Washington, Seattle, WA, USA.
| | | | | | - Ione Fine
- Department of Psychology, University of Washington, Seattle, WA, USA
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Kelly KR, Jost RM, Hudgins LA, Stager DR, Hunter JS, Beauchamp CL, Dao LM, Birch EE. Slow Binocular Reading in Amblyopic Children Is a Fellow Eye Deficit. Optom Vis Sci 2023; 100:194-200. [PMID: 36715973 PMCID: PMC10245300 DOI: 10.1097/opx.0000000000001995] [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: 01/31/2023] Open
Abstract
SIGNIFICANCE Amblyopic children read 25% slower than their peers during binocular silent reading. PURPOSE We compared binocular reading to fellow eye reading to determine whether slow reading in amblyopic children is due to binocular inhibition; that is, the amblyopic eye is interfering during binocular reading. METHODS In a cross-sectional study, 38 children with amblyopia and 36 age-similar control children who completed grades 1 to 6 were enrolled. Children silently read grade-appropriate paragraphs during binocular reading and fellow eye reading while wearing ReadAlyzer eye-tracking goggles (Compevo AB, Stockholm, Sweden). Reading rate, number of forward saccades, number of regressive saccades, and fixation duration were analyzed between groups and between viewing conditions. We also examined whether sensory factors (amblyopia severity, stereoacuity, suppression) were related to slow reading. RESULTS For amblyopic children, binocular reading versus fellow eye reading did not differ for reading rate (176 ± 60 vs. 173 ± 53 words per minute, P = .69), number of forward saccades (104 ± 35 vs. 97 ± 33 saccades/100 words, P = .18), number of regressive saccades (21 ± 15 vs. 22 ± 13 saccades/100 words, P = .75), or fixation duration (0.31 ± 0.06 vs. 0.32 ± 0.07 seconds, P = .44). As expected, amblyopic children had a slower reading rate and more forward saccades than control children during binocular reading and fellow eye reading. Slow reading was not related to any sensory factors. CONCLUSIONS Binocular reading did not differ from fellow eye reading in amblyopic children. Thus, binocular inhibition is unlikely to play a role in slow binocular reading and is instead a fellow eye deficit that emerges from a disruption in binocular visual experience during development.
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Affiliation(s)
| | - Reed M Jost
- Retina Foundation of the Southwest, Dallas, Texas
| | | | - David R Stager
- Pediatric Ophthalmology and Adult Strabismus, PA, Plano, Texas
| | | | | | - Lori M Dao
- ABC Eyes Pediatric Ophthalmology, PA, Dallas, Texas
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Birch EE, Kelly KR. Amblyopia and the whole child. Prog Retin Eye Res 2023; 93:101168. [PMID: 36736071 PMCID: PMC9998377 DOI: 10.1016/j.preteyeres.2023.101168] [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: 09/20/2022] [Revised: 01/04/2023] [Accepted: 01/05/2023] [Indexed: 02/04/2023]
Abstract
Amblyopia is a disorder of neurodevelopment that occurs when there is discordant binocular visual experience during the first years of life. While treatments are effective in improving visual acuity, there are significant individual differences in response to treatment that cannot be attributed solely to difference in adherence. In this considerable variability in response to treatment, we argue that treatment outcomes might be optimized by utilizing deep phenotyping of amblyopic deficits to guide alternative treatment choices. In addition, an understanding of the broader knock-on effects of amblyopia on developing visually-guided skills, self-perception, and quality of life will facilitate a whole person healthcare approach to amblyopia.
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Affiliation(s)
- Eileen E Birch
- Pediatric Vision Laboratory, Retina Foundation of the Southwest, 9600 North Central Expressway #200, Dallas, TX, 75225, USA; Department of Ophthalmology, University of Texas Southwestern Medical Center, 5303 Harry Hines Boulevard, Dallas, TX, 75390, USA.
| | - Krista R Kelly
- Department of Ophthalmology, University of Texas Southwestern Medical Center, 5303 Harry Hines Boulevard, Dallas, TX, 75390, USA; Vision and Neurodevelopment Laboratory, Retina Foundation of the Southwest, 9600 North Central Expressway #200, Dallas, TX, 75225, USA.
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Birch EE, Morale SE, Jost RM, Cheng-Patel CS, Kelly KR. Binocular amblyopia treatment improves manual dexterity. J AAPOS 2023; 27:18.e1-18.e6. [PMID: 36567045 PMCID: PMC9974856 DOI: 10.1016/j.jaapos.2022.10.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 10/04/2022] [Accepted: 10/06/2022] [Indexed: 12/24/2022]
Abstract
PURPOSE To determine whether deficits in manual dexterity in children with amblyopia improve after binocular amblyopia treatment and whether improvements are related to age at treatment, baseline sensory status, or amount of improvement in sensory status with treatment. METHODS Manual dexterity (Movement Assessment Battery for Children-2), visual acuity, fusion, suppression, and stereoacuity were measured at baseline and after 4-8 weeks of binocular amblyopia in 134 children with amblyopia, including 75 children in the "younger group" (aged 3 to <7 years) and 59 in the "older group" (aged 7-10 years), and in 40 age-similar control children. RESULTS Baseline manual dexterity standard scores of amblyopic children were significantly below those of controls in both the younger (8.81 ± 0.33 vs 11.80 ± 0.60 [P < 0.0001]) and older groups (7.19 ± 0.34 vs 9.75 ± 0.57 [P = 0.00013]). After 4-8 weeks of binocular amblyopia treatment, the younger group standard score improved to 9.85 ± 0.35 and the older group improved to 8.08 ± 0.39, but both groups remained significantly lower than controls (P = 0.03 and P = 0.01, resp.). Improvement in manual dexterity standard score was not associated with any baseline factors but was weakly correlated with the amount of visual acuity improvement (rs = 0.26; 95% CI, 0.09-0.41) CONCLUSIONS: Manual dexterity impairments are common among children with amblyopia. In our study cohort, binocular amblyopia treatment improved visual acuity and manual dexterity.
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Affiliation(s)
- Eileen E Birch
- Retina Foundation of the Southwest, Dallas, Texas; Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas.
| | | | - Reed M Jost
- Retina Foundation of the Southwest, Dallas, Texas
| | | | - Krista R Kelly
- Retina Foundation of the Southwest, Dallas, Texas; Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas
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Kelly KR, Norouzi DM, Nouredanesh M, Jost RM, Cheng-Patel CS, Beauchamp CL, Dao LM, Luu BA, Stager DR, Tung JY, Niechwiej-Szwedo E. Temporal Eye–Hand Coordination During Visually Guided Reaching in 7- to 12-Year-Old Children With Strabismus. Invest Ophthalmol Vis Sci 2022; 63:10. [DOI: 10.1167/iovs.63.12.10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Affiliation(s)
- Krista R. Kelly
- Retina Foundation of the Southwest, Dallas, TX, United States
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, TX, United States
| | | | - Mina Nouredanesh
- School of Rehabilitation Science, McMaster University, Hamilton, Ontario, Canada
| | - Reed M. Jost
- Retina Foundation of the Southwest, Dallas, TX, United States
| | | | | | - Lori M. Dao
- ABC Eyes Pediatric Ophthalmology, PA, Dallas, TX, United States
| | - Becky A. Luu
- Pediatric Ophthalmology & Adult Strabismus, PA, Plano, TX, United States
| | - David R. Stager
- Pediatric Ophthalmology & Adult Strabismus, PA, Plano, TX, United States
| | - James Y. Tung
- Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, Ontario, Canada
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Birch EE, Jost RM, Hudgins LA, Morale SE, Donohoe M, Kelly KR. Dichoptic and Monocular Visual Acuity in Amblyopia. Am J Ophthalmol 2022; 242:209-214. [PMID: 35738394 PMCID: PMC9847578 DOI: 10.1016/j.ajo.2022.06.002] [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] [Received: 04/04/2022] [Revised: 05/27/2022] [Accepted: 06/06/2022] [Indexed: 01/21/2023]
Abstract
PURPOSE Standard-of-care assessment for children with amblyopia includes measuring amblyopic eye best-corrected visual acuity (AE BCVA) with the fellow eye occluded. By definition, this abolishes the interocular suppression fundamental to amblyopia. Thus, measured AE BCVA may not accurately represent that eye's contribution to natural binocular viewing. We compared dichoptic and monocular AE BCVA and examined whether any differences were associated with eye-hand coordination or reading speed. DESIGN Cross-sectional study. METHODS Dichoptic and monocular AE BCVA of children aged 6-12 years (42 with amblyopia, 24 with recovered normal AE BCVA, 30 control) were measured. Stereoacuity, suppression, eye-hand coordination, and reading speed were also assessed. RESULTS Overall, 81% of amblyopic children had worse dichoptic than monocular AE BCVA (mean difference=0.15±0.11 logMAR; P < .0001), and 71% of children with recovered normal AE BCVA had worse dichoptic than monocular AE BCVA (mean difference = 0.20±0.17 logMAR, P < .0001). Controls had no significant difference. The difference between dichoptic and monocular AE BCVA was correlated with performance in standardized aiming/catching (r = -0.48, 95% CI -0.72, -0.14) and manual dexterity tasks (r = -0.37, 95% CI -0.62, -0.06), and with reading speed (r = -0.38, 95% CI -0.65, -0.03). CONCLUSIONS Dichoptic AE BCVA deficits were worse than monocular AE BCVA deficits and were associated with reduced stereoacuity and suppression, consistent with the hypothesis that binocular dysfunction plays a role. Further, impaired eye-hand coordination and slow reading were associated with dichoptic, but not monocular, AE BCVA. Some children with amblyopia may benefit from extra time for school tasks requiring eye-hand coordination or reading.
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Affiliation(s)
- Eileen E Birch
- From the Retina Foundation of the Southwest, Dallas, TX (E.E.B., R.M.J., L.A.H., S.E.M., M.D., K.R.K.), Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas, USA (E.E.B., K.R.K.).
| | - Reed M Jost
- From the Retina Foundation of the Southwest, Dallas, TX (E.E.B., R.M.J., L.A.H., S.E.M., M.D., K.R.K.), Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas, USA (E.E.B., K.R.K.)
| | - Lindsey A Hudgins
- From the Retina Foundation of the Southwest, Dallas, TX (E.E.B., R.M.J., L.A.H., S.E.M., M.D., K.R.K.), Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas, USA (E.E.B., K.R.K.)
| | - Sarah E Morale
- From the Retina Foundation of the Southwest, Dallas, TX (E.E.B., R.M.J., L.A.H., S.E.M., M.D., K.R.K.), Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas, USA (E.E.B., K.R.K.)
| | - Matthew Donohoe
- From the Retina Foundation of the Southwest, Dallas, TX (E.E.B., R.M.J., L.A.H., S.E.M., M.D., K.R.K.), Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas, USA (E.E.B., K.R.K.)
| | - Krista R Kelly
- From the Retina Foundation of the Southwest, Dallas, TX (E.E.B., R.M.J., L.A.H., S.E.M., M.D., K.R.K.), Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas, USA (E.E.B., K.R.K.)
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Zhu B, Liao M, Liu L. Measuring the impact of suppression on visual acuity in children with amblyopia using a dichoptic visual acuity chart. Front Neurosci 2022; 16:860620. [PMID: 35911993 PMCID: PMC9334724 DOI: 10.3389/fnins.2022.860620] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Accepted: 06/29/2022] [Indexed: 11/13/2022] Open
Abstract
PurposeTo develop a novel dichoptic visual acuity chart that measures the impact of interocular suppression on the visual acuity of each eye when two eyes are open.MethodsFifty-four subjects (19 anisometropic amblyopia, 20 treated amblyopia, and 15 normal children) participated in this study. The visual acuity that was tested under dichoptic-optotypes condition (i.e., presented optotypes to the untested eye) was compared with that under monocular condition (i.e., cover the untested eye with opaque patch). Visual acuity differences between these two conditions were compared among the three groups. The correlations between visual acuity differences and the depth of interocular suppression were then computed. Some participants performed the visual acuity test under dichoptic-luminance condition (i.e., presented mean luminance to the untested eye), and the test-retest reliability was established.ResultsA reduced visual acuity of the non-dominant eye was found in the dichoptic-optotypes condition for the amblyopia group (P < 0.001) and the treated group (P = 0.001); the difference in the treated group was less than that in the amblyopia group (P < 0.001) but more than that in the normal group (P = 0.026). A significant correlation was found between the visual acuity differences and the depth of suppression, which was tested with a binocular phase combination task (P = 0.005). No change was found in the dichoptic-luminance condition.ConclusionThe amblyopic eye and the previous amblyopic eye seem to suffer from a reduced visual acuity when two eyes are open due to suppression. This was successfully captured by our novel and reliable dichoptic-optotypes visual acuity chart.
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Affiliation(s)
- Bixia Zhu
- Department of Optometry and Visual Science, West China Hospital, Sichuan University, Chengdu, China
| | - Meng Liao
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China
| | - Longqian Liu
- Department of Optometry and Visual Science, West China Hospital, Sichuan University, Chengdu, China
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China
- *Correspondence: Longqian Liu,
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Gong L, Wei L, Yu X, Reynaud A, Hess RF, Zhou J. The Orientation Selectivity of Dichoptic Masking Suppression is Contrast Dependent in Amblyopia. Invest Ophthalmol Vis Sci 2022; 63:9. [PMID: 35675061 PMCID: PMC9187942 DOI: 10.1167/iovs.63.6.9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Purpose We aimed to study the effect of stimulus contrast on the orientation selectivity of interocular interaction in amblyopia using a dichoptic masking paradigm. Methods Eight adults with anisometropic or mixed amblyopia and 10 control adults participated in our study. The contrast threshold in discriminating a target Gabor in the tested eye was measured with mean luminance in the untested eye, as well as with a bandpass oriented filtered noise in the other eye at low spatial frequency (0.25 c/d). Threshold elevation, which represents interocular suppression, was assessed using a the dichoptic masking paradigm (i.e. the contrast threshold difference between the target only and masked conditions), for each eye. Orientation selectivity of the interocular suppression as reflected by dichoptic masking was quantified by the difference between the parallel and orthogonal masking configurations. Two levels of mask's contrast (3 times or 10 times that of an individual's contrast threshold) were tested in this study. Results The strength of dichoptic masking suppression was stronger at high, rather than low mask contrast in both amblyopic and control subjects. Normal controls showed orientation-dependent dichoptic masking suppression both under high and low contrast levels. However, amblyopes showed orientation-tuned dichoptic masking suppression only under the high contrast level, but untuned under the low contrast level. Conclusions We demonstrate that interocular suppression assessed by dichoptic masking is contrast-dependent in amblyopia, being orientation-tuned only at high suprathreshold contrast levels of the mask.
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Affiliation(s)
- Ling Gong
- School of Ophthalmology and Optometry, Eye Hospital, State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Lili Wei
- School of Ophthalmology and Optometry, Eye Hospital, State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xi Yu
- School of Ophthalmology and Optometry, Eye Hospital, State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Alexandre Reynaud
- McGill Vision Research, Department of Ophthalmology and Visual Sciences, McGill University, Montreal, Canada
| | - Robert F Hess
- McGill Vision Research, Department of Ophthalmology and Visual Sciences, McGill University, Montreal, Canada
| | - Jiawei Zhou
- School of Ophthalmology and Optometry, Eye Hospital, State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, Zhejiang, China
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Randomized clinical trial of streaming dichoptic movies versus patching for treatment of amblyopia in children aged 3 to 7 years. Sci Rep 2022; 12:4157. [PMID: 35264692 PMCID: PMC8905014 DOI: 10.1038/s41598-022-08010-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 03/01/2022] [Indexed: 11/14/2022] Open
Abstract
Contrast-rebalanced dichoptic movies have been shown to be an effective binocular treatment for amblyopia in the laboratory. Yet, at-home therapy is a more practical approach. In a randomized clinical trial, we compared dichoptic movies, streamed at-home on a handheld 3D-enabled game console, versus patching as amblyopia treatment. Sixty-five amblyopic children (3–7 years; 20/32–125) were randomly assigned to one of two parallel arms, binocular treatment (3 movies/week) or patching (14 h/week). The primary outcome, change in best corrected visual acuity (BCVA) at the 2-week visit was completed by 28 and 30, respectively. After the primary outcome, both groups of children had the option to complete up to 6 weeks of binocular treatment. At the 2-week primary outcome visit, BCVA had improved in the movie (0.07 ± 0.02 logMAR; p < .001) and patching (0.06 ± 0.01 logMAR; p < 0.001) groups. There was no significant difference between groups (CI95%: − 0.02 to 0.04; p = .48). Visual acuity improved in both groups with binocular treatment up to 6 weeks (0.15 and 0.18 logMAR improvement, respectively). This novel, at-home, binocular movie treatment improved amblyopic eye BCVA after 2 weeks (similar to patching), with additional improvement up to 6 weeks. Repeated binocular visual experience with contrast-rebalanced binocular movies provides an additional treatment option for amblyopia. Clincaltrials.gov identifier: NCT03825107 (31/01/2019).
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16
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Arnold R, Angi M. Multifaceted Amblyopia Screening with blinq, 2WIN, and PDI Check. Clin Ophthalmol 2022; 16:411-421. [PMID: 35210746 PMCID: PMC8858021 DOI: 10.2147/opth.s349638] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 01/11/2022] [Indexed: 12/25/2022] Open
Abstract
Background Novel devices target different facets of amblyopia risk factors (ARFs). Through birefringence, the Rebion blinq assesses binocular foveation. The Adaptica 2WIN is a multiradial infrared photorefractor that also estimates ocular alignment. PDI Check is a forced-choice, dynamic near-vision game for the autostereoscopic Nintendo 3DS. Methods New and returning patients to a pediatric ophthalmology clinic had concomitant confirmatory exams after all three vision screens had been validated with ROC curves, Bland–Altman plots, and Alaska Blind Child Discovery ellipsoid grades. Exam outcomes were classified by ARF visual acuity, strabismus, binocularity, and refractive errors following the 2021 AAPOS guidelines and Bosque–Hunter rubric for the blinq. Results A total of 202 ethnically diverse students aged 10±4 (4–19) years, 33% treatment-naïve, had a high (58%) prevalence of ARFs. Linear logMAR visual acuity, intereye differences, stereo and three-cone color correlated well between PDI Check and exams. Mean score on the 2WIN matched sphero-cylinder exam with ellipsoid scoring was 2.1±1.5. For AAPOS 2021 refractive plus strabismus, sensitivity/specificity for PDI Check was 68%/59%, 2WIN 72%/95%, and blinq 87%/32%. For the amblyopia or strabismus rubric, PDI Check was 79%/68%, 2WIN 56%/65%, and blinq 94%/37%. Conclusion Each device had advantages and disadvantages in screening this cohort of older, high-prevalence students, many of whom had already been treated. Validation methods should cover more than just refraction, as the new 2021 AAPOS guidelines do. ![]()
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Affiliation(s)
- Robert Arnold
- Alaska Blind Child Discovery, Alaska Children’s Eye and Strabismus, Anchorage, Alaska, 99508, USA
- Correspondence: Robert Arnold, Alaska Blind Child Discovery, Alaska Children’s Eye and Strabismus, Office 280, 3500 Latouche Street, Anchorage, Alaska99508, Tel +1-907 561-1917, Fax +1907 563-5373, Email
| | - Mario Angi
- Senior Scientist, Department of Ophthalmology, University of Padua, Padua, Padua Province, Italy
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Birch EE, Kelly KR, Wang J. Recent Advances in Screening and Treatment for Amblyopia. Ophthalmol Ther 2021; 10:815-830. [PMID: 34499336 PMCID: PMC8589941 DOI: 10.1007/s40123-021-00394-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 08/26/2021] [Indexed: 11/30/2022] Open
Abstract
Amblyopia is the most common cause of monocular visual impairment in children, with a prevalence of 2-3%. Not only is visual acuity reduced in one eye but binocular vision is affected, fellow eye deficits may be present, eye-hand coordination and reading can be affected, and self-perception may be diminished. New technologies for preschool vision screening hold promise for accessible, early, and accurate detection of amblyopia. Together with recent advances in our theoretical understanding of amblyopia and technological advances in amblyopia treatment, we anticipate improved visual outcomes for children affected by this very common eye condition. This article is based on previously conducted studies and does not contain any new studies with human participants or animals performed by any of the authors.
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Affiliation(s)
- Eileen E Birch
- Retina Foundation of the Southwest, 9600 N. Central Expressway, Suite 200, Dallas, TX, 75231, USA.
- Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
| | - Krista R Kelly
- Retina Foundation of the Southwest, 9600 N. Central Expressway, Suite 200, Dallas, TX, 75231, USA
- Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jingyun Wang
- SUNY College of Optometry, State University of New York, New York, NY, USA
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Webber AL, Schmid KL, Baldwin AS, Hess RF. Suppression Rather Than Visual Acuity Loss Limits Stereoacuity in Amblyopia. Invest Ophthalmol Vis Sci 2021; 61:50. [PMID: 32579677 PMCID: PMC7419721 DOI: 10.1167/iovs.61.6.50] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To investigate the influence of interocular suppression and visual acuity loss on stereoacuity in observers with and without abnormal vision development from strabismus or amblyopia. To determine whether stereoacuity improves in amblyopic observers when suppression is neutralized. Methods Experiment 1: Visual acuity (VA), depth of suppression (contrast ratio [CR]), and stereoacuity (digital random-dot) were tested in adult amblyopic observers (n = 21; age 27 ± 11 years). Experiment 2: VA, stereoacuity, and CR were measured at baseline and through a series of monocular contrast attenuation and Bangerter filter conditions that degrade visual input in participants with normal binocular vision (n = 19; age 31 ± 13 years). Multiple regression models were used to determine relative contribution of VA and CR to stereoacuity in both groups. Experiment 3: stereoacuity was retested in a subsample of amblyopic observers (n = 7) after contrast reduction of the stimulus presented to dominant eye to neutralize suppression. Results In amblyopic observers, stereoacuity significantly correlated with CR (P < 0.001), but not with interocular VA difference (P = 0.863). In participants with normal vision development, stereoacuity, VA, and CR declined with introduction of monocular Bangerter filter (P < 0.001), and stereoacuity reduced with monocular attenuation of stimulus contrast (P < 0.001). Reduction in stereoacuity correlated with both VA decrement and degraded CR. Stereoacuity significantly improved in amblyopic observers when the contrast to the dominant eye was adjusted based on the contrast ratio. Conclusions Suppression rather than visual acuity loss limits stereoacuity in observers with abnormal vision development. Stereopsis can be improved when interocular sensory dominance is neutralized.
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Kelly KR, Morale SE, Beauchamp CL, Dao LM, Luu BA, Birch EE. Factors Associated with Impaired Motor Skills in Strabismic and Anisometropic Children. Invest Ophthalmol Vis Sci 2021; 61:43. [PMID: 32845292 PMCID: PMC7452850 DOI: 10.1167/iovs.61.10.43] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose We evaluated motor skills in children diagnosed with strabismus and anisometropia, with or without amblyopia, and explored factors associated with impairments. Methods A total of 143 strabismic and anisometropic children 3 to 13 years of age (96 amblyopic, 47 nonamblyopic) and a group of age-similar 35 control children completed Manual Dexterity, Aiming and Catching, and Balance tasks from the Movement Assessment Battery for Children, Second Edition. Raw scores were converted to standardized scores, and amblyopic and nonamblyopic children were compared to controls. Clinical and sensory factors associated with motor performance were also evaluated. Results Overall, amblyopic and nonamblyopic children were three to six times more likely than controls to be at risk for or to have a total motor impairment (≤15th percentile). Although amblyopic children scored lower than controls for the Manual Dexterity, Aiming and Catching, and Balance tasks, nonamblyopic children scored lower on Manual Dexterity only. Factors related to manual dexterity deficits include the presence of amblyopia and binocularity deficits typical of these eye conditions. Aiming, catching, and balance deficits were most pronounced in children with an infantile onset of the eye condition, a history of strabismus, and reduced binocularity. Conclusions Amblyopia and strabismus disrupt the development of motor ability in children. These findings highlight the widespread effects of discordant binocular input early in life and the visual acuity and binocularity deficits typical of these eye conditions.
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Affiliation(s)
- Krista R Kelly
- Retina Foundation of the Southwest, Dallas, Texas, United States.,Department of Ophthalmology, UT Southwestern Medical Center, Dallas, Texas, United States
| | - Sarah E Morale
- Retina Foundation of the Southwest, Dallas, Texas, United States
| | | | - Lori M Dao
- ABC Eyes Pediatric Ophthalmology, PA, Dallas, Texas, United States
| | - Becky A Luu
- Pediatric Ophthalmology & Adult Strabismus, PA, Plano, Texas, United States
| | - Eileen E Birch
- Retina Foundation of the Southwest, Dallas, Texas, United States.,Department of Ophthalmology, UT Southwestern Medical Center, Dallas, Texas, United States
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Jin J, Apple A, Friess A, Lehman S, Salvin J, Hendricks D, Reid J, Wang J. Using OCT Fixation Shift to Assess Eccentric Fixation in Children With Residual Amblyopia. Transl Vis Sci Technol 2020; 9:30. [PMID: 33262904 PMCID: PMC7691785 DOI: 10.1167/tvst.9.12.30] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 10/06/2020] [Indexed: 11/24/2022] Open
Abstract
Purpose Eccentric fixation in amblyopia is often estimated grossly without precision. Although the usefulness of optical coherence tomography (OCT) fixation shift in the quantification of eccentric fixation in a small cohort of amblyopic children was recently reported, there is a lack of understanding of characteristics of OCT fixation shift. In a retrospective cohort study, we evaluated eccentric fixation with OCT in a large cohort of children with residual amblyopia. Methods Children, age 4 to 17 years, with residual amblyopia (amblyopic, n = 56) and without amblyopia (control, n = 75) were enrolled. Amblyopia was associated with anisometropia alone (anisometropia subtype, n = 28) and strabismus without or with anisometropia (strabismic subtype, n = 28). Spectral domain OCT was used to estimate fixation. The OCT fixation shift, defined as the distance between the fovea and the fixation point, was measured and adjusted with calculated axial length and converted into visual degrees. Fixation shift in amblyopic eyes, fellow nonamblyopic eyes, and right eyes of the control group were compared. Fixation shift between the anisometropic and strabismic amblyopia subtypes was also compared. Its correlation with visual acuity was estimated. Results The mean fixation shift was significantly different: 0.17° ± 0.29° for control right eyes, 0.94° ± 1.24° for amblyopic eyes, and 0.34° ± 0.57° for fellow eyes (χ2 = 23.3; P < 0.001). There was no significant difference between fellow eyes and control eyes (P = 0.11). Fixation shift in amblyopic eyes was significantly correlated with visual acuity (R = 0.44; P < 0.001), and it was significantly smaller in the anisometropic subtype than in the strabismic subtypes (0.34° ± 0.46° vs. 1.54° ± 1.48°, W = 338, P < 0.001). Conclusions OCT fixation shift can be used both in detection and quantification of eccentric fixation in children with residual amblyopia, especially in those with strabismus. Translational Relevance OCT fixation shift offers a convenient clinical approach in quantitative evaluation of eccentric fixation in children with strabismic amblyopia.
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Affiliation(s)
- Jing Jin
- Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, USA
| | - Annie Apple
- Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Amanda Friess
- Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, USA
| | - Sharon Lehman
- Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, USA
| | - Jonathan Salvin
- Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, USA
| | | | - Julia Reid
- Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, USA
| | - Jingyun Wang
- State University of New York, College of Optometry, New York, NY, USA
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Sehgal S, Satgunam P. Quantifying Suppression in Anisometropic Amblyopia With VTS4 (Vision Therapy System 4). Transl Vis Sci Technol 2020; 9:24. [PMID: 33244444 PMCID: PMC7683859 DOI: 10.1167/tvst.9.12.24] [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: 06/11/2020] [Accepted: 10/12/2020] [Indexed: 11/24/2022] Open
Abstract
Purpose Visual acuity (VA) of the amblyopic eye is usually considered for monitoring improvement with therapy. However, participation of the amblyopic eye under binocular viewing conditions is also important. This study investigated the use of a clinically available tool VTS4 (Vision Therapy System 4) to quantify the participation or suppression of the amblyopic eye under binocular viewing conditions. Methods A cross-sectional study on patients with anisometropic amblyopia was undertaken. Monocular VA was thresholded. Stereo acuity was measured with Randot stereo test. Simultaneous macular perception (SMP) targets in VTS4 were dichoptically presented. SMP target size was reduced till the amblyopic eye's target disappeared (suppression scotoma size). An average of three measurements was taken for the suppression scotoma size. Results Twenty-eight patients participated (aged 6 to 21 years). The mean interocular VA difference was 0.50 ± 0.27 logMAR. The mean scotoma size was 8.2° ± 5.4°. Mean stereo acuity was 2.06 ± 0.34 log arc seconds from 21 patients on whom stereopsis could be measured. Suppression scotoma size showed a significant (P < 0.001) positive correlation with both interocular VA difference (r = 0.59) and stereoacuity (r = 0.72). Conclusions Participation of the amblyopic eye under binocular viewing condition can be assessed by measuring the suppression scotoma size in VTS4, even when stereoacuity is poor or not measurable. Smaller the suppression scotoma, better is the amblyopic eye's participation. Translational Relevance VTS4 can be used in monitoring amblyopia therapy by quantifying suppression of the amblyopic eye.
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Affiliation(s)
- Shivalika Sehgal
- Brien Holden Institute of Optometry and Vision Sciences, Hyderabad Eye Research Foundation, L V Prasad Eye Institute, Hyderabad, India
| | - PremNandhini Satgunam
- Brien Holden Institute of Optometry and Vision Sciences, Hyderabad Eye Research Foundation, L V Prasad Eye Institute, Hyderabad, India
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22
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Panachakel JT, Ramakrishnan AG, Manjunath KP. VR Glasses based Measurement of Responses to Dichoptic Stimuli: A Potential Tool for Quantifying Amblyopia? ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020; 2020:5106-5110. [PMID: 33019135 DOI: 10.1109/embc44109.2020.9176510] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Amblyopia is a medical condition in which the visual inputs from one of the eyes is suppressed by the brain. This leads to reduced visual acuity and poor or complete loss of stereopsis. Conventional clinical tests such as Worth 4-dot test and Bagolini striated lens test can only detect the presence of suppression but cannot quantify the extent of suppression, which is important for identifying the effectiveness of treatments for amblyopia. A novel approach for quantifying the level of suppression in amblyopia is proposed in this paper. We hypothesize that the level of suppression in amblyopia can be measured by measuring the symmetry/asymmetry in the suppression experienced during a dichoptic image recognition task. Preliminary studies done on fifty one normal subjects prove that the differences between the accuracies of the left and right eyes can be used as a measure of asymmetry. Equivalence test performed using 'two-one-sided t-tests' procedure shows that the equivalence of the accuracies of left and right eyes for normal subjects is statistically significant (p = .03, symmetric equivalence margin of 5 percentage points). To validate this method, six amblyopic children underwent this test and the results obtained are promising. To the knowledge of the authors, this is the first work to make use of VR glasses and dichoptic image recognition task for quantifying the level of ocular suppression in amblyopic patients.
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23
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Jost RM, Kelly KR, Hunter JS, Stager DR, Luu B, Leffler JN, Dao L, Beauchamp CL, Birch EE. A randomized clinical trial of contrast increment protocols for binocular amblyopia treatment. J AAPOS 2020; 24:282.e1-282.e7. [PMID: 33045374 PMCID: PMC8328197 DOI: 10.1016/j.jaapos.2020.06.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 06/16/2020] [Accepted: 06/17/2020] [Indexed: 10/23/2022]
Abstract
BACKGROUND Most clinical trials of contrast-rebalanced binocular amblyopia treatment used a contrast increment protocol of 10% daily with successful play. Paired with a definition of success requiring only 15-30 min/day of gameplay, this increment protocol could allow children to reach 100% fellow eye contrast in 3-9 hours; however, this may not provide adequate therapeutic time with reduced fellow eye contrast. The purpose of this study was to compare the original protocol against three alternative contrast increment protocols designed to increase the number of treatment hours. METHODS In this prospective study, 63 amblyopic children (4-10 years; amblyopic eye visual acuity, 20/40-125) were randomly assigned one of four daily contrast increment protocols for 4 weeks, all starting with 20% fellow eye contrast: 10%, 5%, 0%, or 10% for first 4 weeks then reset to 20% and repeat 10% increment for the final 4 weeks. Children played contrast-rebalanced games for 1 hour/day, 5 days/week. Best-corrected visual acuity, stereoacuity, and suppression were assessed at baseline and every 2 weeks until the 8-week outcome visit. RESULTS At baseline, mean amblyopic eye best-corrected visual acuity was 0.47 ± 0.14 logMAR (20/60), improving overall 0.14 ± 0.08 logMAR (1.4 lines; P < 0.0001) at 8 weeks. All four protocols resulted in similar improvement in visual acuity (0.13-0.16 logMAR; all Ps < 0.0002). Stereoacuity and suppression also improved (all Ps < 0.05). CONCLUSIONS None of the new protocols resulted in less improvement than the original 10% contrast increment protocol. Contrast-rebalanced binocular games yielded significant improvements in visual acuity, stereoacuity, and suppression with or without daily contrast increments.
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Affiliation(s)
- Reed M Jost
- Retina Foundation of the Southwest, Dallas, Texas.
| | | | | | - David R Stager
- Pediatric Ophthalmology & Adult Strabismus, Plano, Texas
| | - Becky Luu
- Pediatric Ophthalmology & Adult Strabismus, Plano, Texas
| | | | - Lori Dao
- ABC Eyes Pediatric Ophthalmology, Dallas, Texas
| | | | - Eileen E Birch
- Retina Foundation of the Southwest, Dallas, Texas; University of Texas Southwestern Medical Center, Dallas, Texas
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Birch EE, Castañeda YS, Cheng-Patel CS, Morale SE, Kelly KR, Jost RM, Hudgins LA, Leske DA, Holmes JM. Associations of Eye-Related Quality of Life With Vision, Visuomotor Function, and Self-Perception in Children With Strabismus and Anisometropia. Invest Ophthalmol Vis Sci 2020; 61:22. [PMID: 32926105 PMCID: PMC7490229 DOI: 10.1167/iovs.61.11.22] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 08/08/2020] [Indexed: 11/24/2022] Open
Abstract
Purpose To evaluate associations between eye-related quality of life (ER-QOL) assessed by the Child Pediatric Eye Questionnaire (Child PedEyeQ) and functional measures (vision, visuomotor function, self-perception) in children with strabismus, anisometropia, or both. Our hypothesis was that children with functional deficits would have lower ER-QOL, and if so, these associations would support the convergent construct validity of the Child PedEyeQ. Methods We evaluated 114 children (ages 5-11 years) with strabismus, anisometropia, or both. Each child completed the Child PedEyeQ to assess four Rasch-scored domains of ER-QOL: Functional Vision, Bothered by Eyes/Vision, Social, and Frustration/Worry. In addition, children completed one or more functional tests: visual acuity (n = 114), Randot Preschool Stereoacuity (n = 92), contrast balance index (suppression; n = 91), Readalyzer reading (n = 44), vergence instability (n = 50), Movement Assessment Battery for Children-2 manual dexterity (n = 57), and Pictorial Scale of Perceived Competence and Social Acceptance for Young Children (n = 44). Results Child PedEyeQ Functional Vision domain scores were correlated with self-perception of physical competence (rs = 0.65; 95% confidence interval [CI], 0.35-0.96) and reading speed (rs = 0.47; 95% CI, 0.16-0.77). Bothered by Eyes/Vision domain scores were correlated with self-perception of physical competence (rs = 0.52; 95% CI, 0.21-0.83). Moderate correlations were observed between Social domain scores and vergence instability (rs = -0.46; 95% CI, -0.76 to -0.15) and self-perception of physical competence (rs = 0.43; 95% CI, 0.12-0.73) and peer acceptance (rs = 0.49; 95% CI, 0.18-0.80). Frustration/Worry domain scores were moderately correlated with self-perception of physical competence (rs = 0.41; 95% CI, 0.10-0.71) and peer acceptance (rs = 0.47; 95% CI, 0.16-0.77). Conclusions Strong and moderate correlations were observed between functional measures and Child PedEyeQ domain scores. These associations provide supporting evidence that the Child PedEyeQ has convergent construct validity.
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Affiliation(s)
- Eileen E. Birch
- Retina Foundation of the Southwest, Dallas, Texas, United States
- Ophthalmology, UT Southwestern Medical Center, Dallas, Texas, United States
| | | | | | - Sarah E. Morale
- Retina Foundation of the Southwest, Dallas, Texas, United States
| | - Krista R. Kelly
- Retina Foundation of the Southwest, Dallas, Texas, United States
- Ophthalmology, UT Southwestern Medical Center, Dallas, Texas, United States
| | - Reed M. Jost
- Retina Foundation of the Southwest, Dallas, Texas, United States
| | | | - David A. Leske
- Ophthalmology, Mayo Clinic, Rochester, Minnesota, United States
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Barboni MTS, Maneschg OA, Németh J, Nagy ZZ, Vidnyánszky Z, Bankó ÉM. Dichoptic Spatial Contrast Sensitivity Reflects Binocular Balance in Normal and Stereoanomalous Subjects. Invest Ophthalmol Vis Sci 2020; 61:23. [PMID: 32931571 PMCID: PMC7500129 DOI: 10.1167/iovs.61.11.23] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 08/17/2020] [Indexed: 01/27/2023] Open
Abstract
Purpose To study binocular balance by comparing dichoptic and standard monocular contrast sensitivity function (CSF) in stereonormal and stereoanomalous/stereoblind amblyopic subjects. Methods Sixteen amblyopes and 17 controls participated. Using the capability of the passive three-dimensional display, we measured their CSF both monocularly and dichoptically at spatial frequencies 0.5, 1, 2, 4, and 8 cpds using achromatic Gabor patches on a luminance noise background. During monocular stimulation, the untested eye was covered, while for the dichoptic stimulation the untested eye viewed background noise. Dichoptic CSF of both eyes was acquired within one block. Results In patients with central fixation, dichoptic viewing had a large negative impact on the CSF of the amblyopic eye, although it hardly affected that of the dominant eye. In contrast, dichoptic viewing had a small but significant effect on both eyes for controls. In addition, all participants lay along a continuum in terms of how much their two eyes were affected by dichoptic stimulation: by using two predefined contrast sensitivity ratios, namely, amblyopic sensitivity decrement and dichoptic sensitivity decrement, not only did we find a significant correlation between these variables among all participants, but also the two groups were identified with minimum error using a cluster analysis. Conclusions Dichoptic CSF may be considered to measure visual performance in patients with altered binocular vision, because it better reflects the visual capacity of the amblyopic eye than the standard monocular examinations. It may also be a more reliable parameter to assess the efficacy of modern approaches to treat amblyopia.
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Affiliation(s)
| | - Otto Alexander Maneschg
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
- Bionic Innovation Center, Budapest, Hungary
| | - János Németh
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
- Bionic Innovation Center, Budapest, Hungary
| | - Zoltán Zsolt Nagy
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Zoltán Vidnyánszky
- Brain Imaging Centre, Research Centre for Natural Sciences, Budapest, Hungary
| | - Éva M. Bankó
- Brain Imaging Centre, Research Centre for Natural Sciences, Budapest, Hungary
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Martín S, Portela JA, Ding J, Ibarrondo O, Levi DM. Evaluation of a Virtual Reality implementation of a binocular imbalance test. PLoS One 2020; 15:e0238047. [PMID: 32822405 PMCID: PMC7446887 DOI: 10.1371/journal.pone.0238047] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 08/07/2020] [Indexed: 01/12/2023] Open
Abstract
The purpose of this study was (1) to implement a test for binocular imbalance in a Virtual Reality headset, (2) to assess its testability, reliability and outcomes in a population of clinical patients and (3) to evaluate the relationships of interocular acuity difference, stereoacuity and binocular imbalance to amblyogenic risk factors. 100 volunteers (6 to 70 years old, mean 21.2 ± 16.2), 21 with no amblyogenic risk factors and 79 with amblyopia or a history of amblyopia participated. Participants were classified by amblyogenic risk factor (24 anisometropic, 25 strabismic and 30 mixed) and, for those with strabismus, also by refractive response (16 accommodative and 39 non-accommodative). We characterized our sample using three variables, called the ‘triplet’ henceforth: interocular acuity difference, stereoacuity and imbalance factor. Binocular imbalance showed high test-retest reliability (no significant difference between test and retest in a subgroup, n = 20, p = 0.831); was correlated with Worth 4 dots test (r = 0.538, p<0.0001); and correlated with both interocular acuity difference (r = 0.575, p<0.0001) and stereoacuity (r = 0.675, p<0.0001). The mean values of each variable of the triplet differed depending on group classification. Mixed and non-accommodative groups showed the worst mean values compared with the other groups. Among participants with strabismus, strabismic vs mixed subgroups did not show significant differences in any variable of the triplet, whereas the accommodative vs non-accommodative subgroups showed significant differences in all of them. According to a univariate logistic model, any variable of the triplet provides a good metric for differentiating patients from controls, except for binocular imbalance for anisometropic subgroup. The proposed binocular imbalance test is feasible and reliable. We recommend monitoring amblyopia clinically not only considering visual acuity, but also stereoacuity and interocular imbalance. Stereoacuity on its own fails because of the high percentage of patients with no measurable stereoacuity. Binocular imbalance may help to fill that gap.
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Affiliation(s)
| | | | - Jian Ding
- School of Optometry, University of California, Berkeley, CA, United States of America
| | | | - Dennis M. Levi
- School of Optometry, University of California, Berkeley, CA, United States of America
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Webber AL, Mandall TR, Molloy DT, Lister LJ, Birch EE. Worth 4 Dot App for Determining Size and Depth of Suppression. Transl Vis Sci Technol 2020; 9:9. [PMID: 32818097 PMCID: PMC7396169 DOI: 10.1167/tvst.9.4.9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 12/13/2019] [Indexed: 11/24/2022] Open
Abstract
Purpose To describe and evaluate an iOS application suppression test, Worth 4 Dot App (W4DApp), which was designed and developed to assess size and depth of suppression. Methods Characteristics of sensory fusion were evaluated in 25 participants (age 12–69 years) with normal (n = 6) and abnormal (n = 19) binocular vision. Suppression zone size and classification of fusion were determined by W4DApp and by flashlight Worth 4 Dot (W4D) responses from 33 cm to 6 m. Measures of suppression depth were compared between the W4DApp, the flashlight W4D with neutral density filter bar and the dichoptic letters contrast balance index test. Results There was high agreement in classification of fusion between the W4DApp method and that derived from flashlight W4D responses from 33 cm to 6 m (α = 0.817). There were no significant differences in success rates or in reliability between the W4DApp or the flashlight W4D methods for determining suppression zone size. W4DApp suppression zone size strongly correlated to that determined with the flashlight W4D (rho = 0.964, P < 0.001). W4DApp depth of suppression measures showed significantly higher success rates (χ2 = 5.128, P = 0.043) and reliability (intraclass correlation analysis = 0.901) but no significant correlation to the depth of suppression calculated by flashlight W4D and neutral density bar (rho = 0.301, P = 0.399) or contrast balance index (rho = −0.018, P = 0.958). Conclusions The W4DApp has potential clinical benefit in measuring suppression zone size; however, further modifications are required to improve validity of suppression depth measures. Translational Relevance W4DApp iOS application will be a convenient tool for clinical determination of suppression characteristics.
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Affiliation(s)
- Ann L Webber
- School of Optometry and Vision Science, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia
| | - Thomas R Mandall
- School of Optometry and Vision Science, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia
| | - Darcy T Molloy
- School of Optometry and Vision Science, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia
| | - Lucas J Lister
- School of Optometry and Vision Science, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia
| | - Eileen E Birch
- Retina Foundation of the Southwest, Dallas, TX, USA.,UT Southwestern Medical Center, Dallas, TX, USA
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Chen Y, He Z, Mao Y, Chen H, Zhou J, Hess RF. Patching and Suppression in Amblyopia: One Mechanism or Two? Front Neurosci 2020; 13:1364. [PMID: 32009874 PMCID: PMC6974542 DOI: 10.3389/fnins.2019.01364] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 12/03/2019] [Indexed: 01/26/2023] Open
Abstract
Purpose To determine if benefits from occlusion therapy are due to decreased suppression from the fellow eye in children with amblyopia. Methods Ten newly diagnosed amblyopes (7.2 ± 1.4 years old), two with strabismus and eight with anisometropia, participated. Patients were first given a 2-month period of refractive adaptation, followed by occlusion therapy (i.e., patching their fellow eye with an opaque patch for 4 h/day). Visual acuity of the amblyopic eye and interocular suppression were measured before and after 0.5, 1, 2, 4, and 6 months of occlusion therapy. We quantified interocular suppression with a binocular phase combination task. Results Visual acuity (in logMAR) improved from 0.50 ± 0.22 (mean ± SD) to 0.33 ± 0.20 for patients who finished a short-term (2 months) occlusion (A1–A10), from 0.53 ± 0.20 to 0.32 ± 0.22 for patients who finished a medium-term (4 months) occlusion (A1–A9), and from 0.48 ± 0.19 to 0.22 ± 0.10 for patients who finished a long-term (6 months) occlusion (A1–A8). Although their visual acuity significantly improved, their degree of suppression, which was abnormal in all cases, did not change consistently. This was true in all durations of occlusion therapy. Conclusion Reduced suppression from the fixing eye might not be result from occlusion therapy.
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Affiliation(s)
- Yiya Chen
- School of Ophthalmology and Optometry and Eye Hospital, State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
| | - Zhifen He
- School of Ophthalmology and Optometry and Eye Hospital, State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
| | - Yu Mao
- School of Ophthalmology and Optometry and Eye Hospital, State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
| | - Hao Chen
- School of Ophthalmology and Optometry and Eye Hospital, State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
| | - Jiawei Zhou
- School of Ophthalmology and Optometry and Eye Hospital, State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
| | - Robert F Hess
- McGill Vision Research, Department of Ophthalmology and Visual Sciences, McGill University, Montreal, QC, Canada
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Impaired fine motor skills in children following extraction of a dense congenital or infantile unilateral cataract. J AAPOS 2019; 23:330.e1-330.e6. [PMID: 31669206 PMCID: PMC6925330 DOI: 10.1016/j.jaapos.2019.08.278] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 08/02/2019] [Accepted: 08/24/2019] [Indexed: 11/21/2022]
Abstract
PURPOSE To evaluate fine motor ability in children treated for unilateral congenital or infantile cataract. METHODS Twenty-three children 3-13 years of age who were treated for unilateral congenital or infantile cataract and 38 age-similar control children were enrolled. Children completed five fine motor skills tasks (unimanual dexterity, bimanual dexterity, drawing trail, aiming, catching) from the Movement Assessment Battery for Children-2. Raw scores were converted into standardized scores, with higher scores indicating better performance. RESULTS Compared with controls, children treated for unilateral cataract scored lower on drawing trail (P = 0.009), aiming (P = 0.009), and catching (P < 0.001) but not on unimanual (P = 0.77) or bimanual dexterity (P = 0.31). Poorer affected eye visual acuity was moderately related to poorer performance for unimanual dexterity (r = -0.47; P = 0.025), bimanual dexterity (r = -0.50; P = 0.014), and catching (r = -0.41; P = 0.051). Those with a poor visual outcome (>0.6 logMAR) had worse performance than those with a good visual outcome (≤0.6 logMAR) for all tasks (all P values, 0.008-0.09) except aiming. Cataract type (congenital, 9; infantile, 14) and sensory fusion by Worth 4-Dot testing at 33 cm (pass, 10; fail, 13) had no effect on fine motor performance (all P values, 0.12-0.98). CONCLUSIONS In our study cohort, fine motor deficits were found in children treated for congenital or infantile unilateral cataract.
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Kosovicheva A, Ferreira A, Vera-Diaz FA, Bex PJ. Effects of temporal frequency on binocular deficits in amblyopia. Vision Res 2019; 163:52-62. [PMID: 31404553 PMCID: PMC6726518 DOI: 10.1016/j.visres.2019.08.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 07/30/2019] [Accepted: 08/05/2019] [Indexed: 12/11/2022]
Abstract
Amblyopia is associated with a range of well-known visual spatial deficits, which include reduced contrast sensitivity, spatial distortions, interocular suppression, and impaired stereopsis. Previous work has also pointed to deficits in processing dynamic visual information, but it is unknown whether these deficits influence performance under binocular conditions. We examined the effects of temporal modulation on contrast sensitivity and binocular interactions in a preliminary study of 8 adults with amblyopia and 14 normally-sighted control subjects. For each observer, we measured interocular balance and stereopsis thresholds with binocular flicker across a range of four temporal (0, 4, 7.5, and 12 Hz) and spatial (1, 2, 4, and 8 cpd) frequencies. Interocular balance was estimated by varying the relative contrast of dichoptic letter pairs to produce perceptual reports of each letter with equal frequency, and stereopsis thresholds were measured by determining the minimum disparity at which subjects identified a front-depth target with 75% accuracy. Consistent with previous findings, we observed greater interocular imbalance and impaired stereoacuity at high spatial frequencies in amblyopes. In contrast, the effects of temporal frequency on performance were smaller: across both groups, interocular imbalance was largest at mid-to-low temporal frequencies, and stereopsis thresholds were unaffected by temporal frequency. Our results suggest that there may be a previously unreported effect of temporal frequency on interocular balance, as well as a possible dissociation between the effects of flicker on interocular balance and stereopsis.
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Affiliation(s)
- Anna Kosovicheva
- Department of Psychology, Northeastern University, 125 Nightingale Hall, 360 Huntington Avenue, Boston, MA 02115, USA.
| | - Adriana Ferreira
- New England College of Optometry, 424 Beacon Street, Boston, MA 02115, USA
| | | | - Peter J Bex
- Department of Psychology, Northeastern University, 125 Nightingale Hall, 360 Huntington Avenue, Boston, MA 02115, USA
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Al-Haddad C, Hoyeck S, Torbey J, Houry R, Boustany RMN. Eye Tracking Abnormalities in School-Aged Children With Strabismus and With and Without Amblyopia. J Pediatr Ophthalmol Strabismus 2019; 56:297-304. [PMID: 31545863 DOI: 10.3928/01913913-20190726-01] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 07/22/2019] [Indexed: 11/20/2022]
Abstract
PURPOSE To detect eye tracking abnormalities in children with strabismus in the absence or presence of amblyopia. METHODS A total of 100 patients aged 7 to 17 years were enrolled prospectively for 2 years from the pediatric ophthalmology clinic of the American University of Beirut Medical Center: 50 children with strabismus (including 24 with amblyopia) and 50 age- and gender-matched controls. Eye tracking with different paradigms was performed. RESULTS Mean age was 10.66 ± 2.90 years in the strabismus group and 10.02 ± 2.75 years in the control group. Demographic characteristics were similar with respect to vision, gender, and refraction. Four paradigms were tested using the eye tracker: (1) distance/near paradigm: patients with strabismus showed a lower fixation count and longer fixation at both distances and a tendency for decreased latency and percentage of fixation in distant elements; (2) reading paradigm: the strabismus group had a higher fixation count and duration, especially those without amblyopia; (3) location identification paradigm: strabismus group without amblyopia fixated less and with shorter duration on the most flagrant element; and (4) video paradigm: no differences in eye movements were noted. CONCLUSIONS Significant eye movement deficits were demonstrated in patients with strabismus compared to controls while reading text and identifying prominent elements in a crowded photograph. This was significant in the non-amblyopic subgroup. [J Pediatr Ophthalmol Strabismus. 2019;56(5):297-304.].
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Contribution of Short-Time Occlusion of the Amblyopic Eye to a Passive Dichoptic Video Treatment for Amblyopia beyond the Critical Period. Neural Plast 2019; 2019:6208414. [PMID: 31558900 PMCID: PMC6735187 DOI: 10.1155/2019/6208414] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 04/29/2019] [Accepted: 06/17/2019] [Indexed: 01/25/2023] Open
Abstract
Dichoptic movie viewing has been shown to significantly improve visual acuity in amblyopia in children. Moreover, short-term occlusion of the amblyopic eye can transiently increase its contribution to binocular fusion in adults. In this study, we first asked whether dichoptic movie viewing could improve the visual function of amblyopic subjects beyond the critical period. Secondly, we tested if this effect could be enhanced by short-term monocular occlusion of the amblyopic eye. 17 subjects presenting stable functional amblyopia participated in this study. 10 subjects followed 6 sessions of 1.5 hour of dichoptic movie viewing (nonpatched group), and 7 subjects, prior to each of these sessions, had to wear an occluding patch over the amblyopic eye for two hours (patched group). Best-corrected visual acuity, monocular contrast sensitivity, interocular balance, and stereoacuity were measured before and after the training. For the nonpatched group, mean amblyopic eye visual acuity significantly improved from 0.54 to 0.46 logMAR (p < 0.05). For the patched group, mean amblyopic eye visual acuity significantly improved from 0.62 to 0.43 logMAR (p < 0.05). Stereoacuity improved significantly when the data of both groups were combined. No significant improvement was observed for the other visual functions tested. Our training procedure combines modern video technologies and recent fundamental findings in human plasticity: (i) long-term plasticity induced by dichoptic movie viewing and (ii) short-term adaptation induced by temporary monocular occlusion. This passive dichoptic movie training approach is shown to significantly improve visual acuity of subjects beyond the critical period. The addition of a short-term monocular occlusion to the dichoptic training shows promising trends but was not significant for the sample size used here. The passive movie approach combined with interocular contrast balancing even over such a short period as 2 weeks has potential as a clinical therapy to treat amblyopia in older children and adults.
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Birch EE, Jost RM, Wang YZ, Kelly KR, Giaschi DE. Impaired Fellow Eye Motion Perception and Abnormal Binocular Function. Invest Ophthalmol Vis Sci 2019; 60:3374-3380. [PMID: 31387113 PMCID: PMC6685447 DOI: 10.1167/iovs.19-26885] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 07/02/2019] [Indexed: 11/24/2022] Open
Abstract
Purpose Binocular discordance due to strabismus, anisometropia, or both may result in not only monocular visual acuity deficits, but also in motion perception deficits. We determined the prevalence of fellow-eye deficits in motion-defined form (MDF) perception, the ability to identify a two-dimensional (2D) shape defined by motion rather than luminance contrast. We also examined the following: the causative role of reduced visual acuity and binocularity, associations with clinical and sensory factors, and effectiveness of binocular amblyopia treatment in alleviating deficits. Methods Participants included 91 children with residual amblyopia (strabismic, anisometropic, or both; age, 9.0 ± 1.7 years), 79 nonamblyopic children with treated strabismus or anisometropia (age, 8.5 ± 2.1 years), and 20 controls (age, 8.6 ± 1.5 years). MDF coherence thresholds, visual acuity, stereoacuity, and interocular suppression were measured. Results MDF deficits, relative to controls, were present in the fellow eye of 23% of children with residual amblyopia and 20% of nonamblyopic children. Stereoacuity and age first patched were correlated with MDF threshold (r = 0.29, 95% CI: 0.09-0.47; r = -0.33, 95% CI: -0.13 to -0.50, respectively). MDF deficits were more common in children treated with patching alone than in those receiving contrast-rebalanced binocular treatment with games or movies (t89 = 3.46; P = 0.0008). The latter was associated with a reduction in mean fellow eye MDF threshold (t26 = 6.32, P < 0.0001). Conclusions Fellow eye MDF deficits are common and likely reflect abnormalities in binocular cortical mechanisms that result from early discordant visual experience. Binocular amblyopia treatment, which is effective in improving amblyopic eye visual acuity, appears to provide a benefit for the fellow eye.
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Affiliation(s)
- Eileen E. Birch
- Crystal Charity Ball Pediatric Vision Laboratory, Retina Foundation of the Southwest, Dallas, Texas, United States
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, Texas, United States
| | - Reed M. Jost
- Crystal Charity Ball Pediatric Vision Laboratory, Retina Foundation of the Southwest, Dallas, Texas, United States
| | - Yi-Zhong Wang
- Crystal Charity Ball Pediatric Vision Laboratory, Retina Foundation of the Southwest, Dallas, Texas, United States
| | - Krista R. Kelly
- Crystal Charity Ball Pediatric Vision Laboratory, Retina Foundation of the Southwest, Dallas, Texas, United States
| | - Deborah E. Giaschi
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada
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Chen H, He Z, Xu J, Mao Y, Liang Y, Lin D, Xu M, Dai Z, Chen X, Zhou J, Yu X. A Convenient and Robust Test to Quantify Interocular Suppression for Children With Amblyopia. Iperception 2019; 10:2041669519864971. [PMID: 31384415 PMCID: PMC6657131 DOI: 10.1177/2041669519864971] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 06/28/2019] [Indexed: 11/16/2022] Open
Abstract
Interocular suppression was quantified by the interocular luminance difference that was needed when the two eyes were balanced in discriminating a black-white stripe formed butterfly stimulus, which was dichoptically presented through polarized glasses. Stronger interocular suppression was found in amblyopes than that in controls at both the near (33 cm, 0.95 ± 1.00 vs. 0.14 ± 0.18, p < .001) and far (5 m, 2.18 ± 0.97 vs. 0.24 ± 0.16, p < .001) viewing distances. The interocular suppression in amblyopes was significantly correlated with the interocular visual acuity difference, the visual acuity of amblyopic eye, the Worth-4-Dot test, and the stereo acuity at both the near and far distances (for all cases, p < .001). Our new test enables convenient and robust measurements of interocular suppression in children with amblyopia. The measured interocular suppression is in agreement with other clinical measures.
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Affiliation(s)
- Hui Chen
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Zhifen He
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Jinling Xu
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Yu Mao
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Yunjie Liang
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Danli Lin
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Meiping Xu
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Zhiyue Dai
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Xiaoxin Chen
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Jiawei Zhou
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Xinping Yu
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
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Birch EE, Jost RM, De La Cruz A, Kelly KR, Beauchamp CL, Dao L, Stager D, Leffler JN. Binocular amblyopia treatment with contrast-rebalanced movies. J AAPOS 2019; 23:160.e1-160.e5. [PMID: 31103562 PMCID: PMC6698207 DOI: 10.1016/j.jaapos.2019.02.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 01/31/2019] [Accepted: 02/01/2019] [Indexed: 11/17/2022]
Abstract
BACKGROUND Binocular amblyopia treatments promote visual acuity recovery and binocularity by rebalancing the signal strength of dichoptic images. Most require active participation by the amblyopic child to play a game or perform a repetitive visual task. The purpose of this study was to investigate a passive form of binocular treatment with contrast-rebalanced dichoptic movies. METHODS A total of 27 amblyopic children, 4-10 years of age, wore polarized glasses to watch 6 contrast-rebalanced dichoptic movies on a passive 3D display during a 2-week period. Amblyopic eye contrast was 100%; fellow eye contrast was initially set to a lower level (20%-60%), which allowed the child to overcome suppression and use binocular vision. Fellow eye contrast was incremented by 10% for each subsequent movie. Best-corrected visual acuity, random dot stereoacuity, and interocular suppression were measured at baseline and at 2 weeks. RESULTS Amblyopic eye best-corrected visual acuity improved from 0.57 ± 0.22 at baseline to 0.42 ± 0.23 logMAR (t26 = 8.09; P < 0.0001; 95% CI for improvement, 0.11-0.19 logMAR). Children aged 3-6 years had more improvement (0.21 ± 0.11 logMAR) than children aged 7-10 years (0.11 ± 0.06 logMAR; t25 = 3.05; P = 0.005). Children with severe amblyopia (≥0.7 logMAR) at baseline experienced greater improvement (0.24 ± 0.12 logMAR) than children with moderate amblyopia at baseline (0.12 ± 0.06 logMAR; t25 = 3.49; P = 0.002). CONCLUSIONS In this cohort, passive viewing of contrast-rebalanced dichoptic movies effectively improved visual acuity in amblyopic subjects. The degree of improvement observed was similar to that previously reported for 2 weeks of binocular games treatment and with 3-4 months of occlusion therapy.
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Affiliation(s)
- Eileen E Birch
- Retina Foundation of the Southwest, Dallas, Texas; UT Southwestern Medical Center, Dallas, Texas.
| | - Reed M Jost
- Retina Foundation of the Southwest, Dallas, Texas
| | | | | | | | | | - David Stager
- Pediatric Ophthalmology & Adult Strabismus, Plano, Texas
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Webber AL, Wood JM, Thompson B, Birch EE. From suppression to stereoacuity: a composite binocular function score for clinical research. Ophthalmic Physiol Opt 2019; 39:53-62. [PMID: 30628744 DOI: 10.1111/opo.12599] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2018] [Accepted: 11/19/2018] [Indexed: 02/04/2023]
Abstract
PURPOSE This study aimed to validate a binocular function score that is based on common clinical measures of visual function, providing a more complete analysis of binocular outcomes, against laboratory-based dichoptic tests of threshold stereoacuity and depth of suppression. METHODS Scores on a composite binocular function (BF) score derived from clinical stereoacuity measures (Randot Preschool Stereoacuity Test and Randot Butterfly) and the Worth 4 Dot test were determined in adults (n = 20; age 24.8 ± 7.2 years) and children (N = 77; age 8.3 ± 1.7 years) with abnormal binocular vision from strabismus or amblyopia. Adults had threshold stereoacuity measured with a novel, computerised dichoptic psychophysical test of stereopsis. Depth of suppression (dichoptic eye chart inter-ocular contrast balance test) was determined in both adults and children. RESULTS Clinical Randot stereoacuity was measurable in 50% of adult and 61% of child participants. Threshold stereoacuity was measurable in 65% of the adult participants. The presence of suppression or simultaneous perception (flat fusion or diplopia) was measurable in all participants, enabling assignment of a BF score to all participants in both groups. In adults, the BF score was highly correlated with the psychophysical threshold stereoacuity measure (ρ = 0.71; p < 0.001). In both adults and children, there was also a high correlation between the BF score and inter-ocular contrast balance (adult ρ = 0.90; child ρ = 0.86; p < 0.001). CONCLUSIONS The composite BF score is a convenient and valid scale of binocularity that can be used to extend the stereoacuity measure in cohorts where nil stereoacuity is common and thus could be considered as an outcome measure in clinical trials.
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Affiliation(s)
- Ann L Webber
- School of Optometry & Vision Science and Institute of Health & Biomedical Innovation, Queensland University of Technology, Brisbane, Australia
| | - Joanne M Wood
- School of Optometry & Vision Science and Institute of Health & Biomedical Innovation, Queensland University of Technology, Brisbane, Australia
| | - Benjamin Thompson
- School of Optometry and Vision Science, University of Waterloo, Waterloo, Canada
| | - Eileen E Birch
- Retina Foundation of the Southwest, Dallas, USA.,Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, USA
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Kugathasan L, Partanen M, Chu V, Lyons C, Giaschi D. Reading ability of children treated for amblyopia. Vision Res 2019; 156:28-38. [PMID: 30633876 DOI: 10.1016/j.visres.2019.01.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 01/01/2019] [Accepted: 01/03/2019] [Indexed: 10/27/2022]
Abstract
Previous studies have reported compromised reading ability in children with amblyopia. Standardized psychoeducational test norms have not been used; therefore, the practical consequences of poor reading ability, such as eligibility for reading supports at school, have not been assessed. Furthermore, several studies have used atypical reading conditions such as monocular or distant viewing. It is also not clear how amblyopia treatment impacts reading ability. Thus, the goal of this study was to use standardized tests to compare binocular reading performance in children treated for amblyopia to that of a large normative sample, as well as to the types of control groups used in previous studies. Children treated for strabismic or anisometropic amblyopia (N = 14) were compared to children treated for strabismus without amblyopia (N = 12) and to children with healthy vision (N = 39). Visual acuity, stereoacuity, interocular suppression, intellectual functioning, oral single-word reading (TOWRE-2), and oral paragraph reading (GORT-5) were assessed. The control group showed significantly higher single-word reading accuracy than the amblyopia and strabismus groups. However, mean performance for all groups was within the average range of the normative sample. While mean scores were in the average range, six children (four amblyopia, two strabismus) performed below average on the single-word reading task; four of these children also showed below average paragraph reading. Reading scores were not correlated with visual acuity in the patient groups. The results raise the possibility that both strabismus and amblyopia can disrupt reading ability, even following successful treatment, to an extent that might benefit from reading supports at school.
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Affiliation(s)
- Laveniya Kugathasan
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Marita Partanen
- Department of Educational and Counselling Psychology, and Special Education, University of British Columbia, Vancouver, British Columbia, Canada
| | - Violet Chu
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Christopher Lyons
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Deborah Giaschi
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada.
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38
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Vera-Diaz FA, Bex PJ, Ferreira A, Kosovicheva A. Binocular temporal visual processing in myopia. J Vis 2018; 18:17. [PMID: 30372727 PMCID: PMC6205559 DOI: 10.1167/18.11.17] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 07/16/2018] [Indexed: 02/07/2023] Open
Abstract
Our ability to utilize binocular visual information depends on the visibility of the retinal images in each eye, which varies with both their spatial and temporal frequency content. Although the effects of spatial information on binocular function have been established, the effects of temporal frequency on binocularity are less well understood. These factors may also vary with refractive error if spatiotemporal sensitivity is affected by structural changes during the emmetropization process that may differentially affect distinct ganglion cells. In a cross-sectional study, we evaluated the potential effects of temporal and spatial frequency on binocularity in young individuals with emmetropia or myopia. Stereopsis and binocular balance were measured as a function of temporal (0-12 Hz) and spatial (1-8 c/deg) frequency. Stereopsis thresholds were measured by determining the minimum disparity at which subjects accurately identified the depth of bandpass-filtered rings. Binocular balance was measured by determining the relative contrast at which subjects reported dichoptic bandpass-filtered letters with equal frequency. Stereopsis thresholds were temporal but not spatial frequency dependent whereas binocular balance was spatial and temporal frequency dependent. There were no differences in monocular spatiotemporal contrast sensitivity between refractive groups in our sample. However, individuals with myopia showed reduced stereopsis with flickering stimuli and greater binocular imbalance at higher spatial and lower temporal frequencies compared to emmetropes. Differences in binocular vision between emmetropia and corrected myopia depend on temporal as well as spatial frequency and may be the cause or consequence of abnormal emmetropization during visual development.
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39
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Chow A, Giaschi D, Thompson B. Dichoptic Attentive Motion Tracking is Biased Toward the Nonamblyopic Eye in Strabismic Amblyopia. ACTA ACUST UNITED AC 2018; 59:4572-4580. [DOI: 10.1167/iovs.18-25236] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Amy Chow
- Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
| | - Deborah Giaschi
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Benjamin Thompson
- Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
- Optometry and Vision Science, University of Auckland, Auckland, New Zealand
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40
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Kelly KR, Jost RM, Wang YZ, Dao L, Beauchamp CL, Leffler JN, Birch EE. Improved Binocular Outcomes Following Binocular Treatment for Childhood Amblyopia. Invest Ophthalmol Vis Sci 2018; 59:1221-1228. [PMID: 29625442 PMCID: PMC5839256 DOI: 10.1167/iovs.17-23235] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Purpose Childhood amblyopia can be treated with binocular games or movies that rebalance contrast between the eyes, which is thought to reduce depth of interocular suppression so the child can experience binocular vision. While visual acuity gains have been reported following binocular treatment, studies rarely report gains in binocular outcomes (i.e., stereoacuity, suppression) in amblyopic children. Here, we evaluated binocular outcomes in children who had received binocular treatment for childhood amblyopia. Methods Data for amblyopic children enrolled in two ongoing studies were pooled. The sample included 41 amblyopic children (6 strabismic, 21 anisometropic, 14 combined; age 4–10 years; ≤4 prism diopters [PD]) who received binocular treatment (20 game, 21 movies; prescribed 9–10 hours treatment). Amblyopic eye visual acuity and binocular outcomes (Randot Preschool Stereoacuity, extent of suppression, and depth of suppression) were assessed at baseline and at 2 weeks. Results Mean amblyopic eye visual acuity (P < 0.001) and mean stereoacuity improved (P = 0.045), and mean extent (P = 0.005) and depth of suppression (P = 0.003) were reduced from baseline at the 2-week visit (87% game adherence, 100% movie adherence). Depth of suppression was reduced more in children aged <8 years than in those aged ≥8 years (P = 0.004). Worse baseline depth of suppression was correlated with a larger depth of suppression reduction at 2 weeks (P = 0.001). Conclusions After 2 weeks, binocular treatment in amblyopic children improved visual acuity and binocular outcomes, reducing the extent and depth of suppression and improving stereoacuity. Binocular treatments that rebalance contrast to overcome suppression are a promising additional option for treating amblyopia.
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Affiliation(s)
- Krista R Kelly
- Retina Foundation of the Southwest, Dallas, Texas, United States
| | - Reed M Jost
- Retina Foundation of the Southwest, Dallas, Texas, United States
| | - Yi-Zhong Wang
- Retina Foundation of the Southwest, Dallas, Texas, United States.,Department of Ophthalmology, UT Southwestern Medical Center, Dallas, Texas, United States
| | - Lori Dao
- ABC Eyes Pediatric Ophthalmology, PA, Dallas, Texas, United States
| | | | - Joel N Leffler
- Children's Eye Care of North Texas, PA, Plano, Texas, United States
| | - Eileen E Birch
- Retina Foundation of the Southwest, Dallas, Texas, United States.,Department of Ophthalmology, UT Southwestern Medical Center, Dallas, Texas, United States
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Fixation instability during binocular viewing in anisometropic and strabismic children. Exp Eye Res 2018; 183:29-37. [PMID: 30006273 DOI: 10.1016/j.exer.2018.07.013] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 06/16/2018] [Accepted: 07/09/2018] [Indexed: 11/22/2022]
Abstract
PURPOSE Strabismus or anisometropia disrupts binocularity and results in fixation instability, which is increased with amblyopia. Fixation instability has typically been assessed for each eye individually. Recently, vergence instability was reported in exotropic adults and monkeys during binocular viewing. We evaluated fixation instability during binocular viewing in children treated for anisometropia and/or strabismus. METHODS 160 children age 4-12 years with treated esotropia and/or anisometropia (98 amblyopic, 62 nonamblyopic) were compared to 46 age-similar controls. Fixation instability was recorded during binocular fixation of a 0.3 deg diameter dot for 20 s using a 500 Hz remote video binocular eye tracker (EyeLink 1000; SR Research). The bivariate contour ellipse area (BCEA; log deg2) for fixation instability was calculated for each eye (nonpreferred, preferred) and for vergence instability (left eye position - right eye position). Best-corrected visual acuity, Randot Preschool stereoacuity, and extent of suppression scotoma (Worth 4-Dot) were also obtained. RESULTS When binocularly viewing, both amblyopic and nonamblyopic children treated for anisometropia and/or strabismus had larger fixation instability and vergence instability than controls. Amblyopia primarily added to the instability of the nonpreferred eye. Anisometropic children had less nonpreferred eye instability and vergence instability than those with strabismus or combined mechanism. Nonpreferred eye instability and vergence instability were related to poorer stereoacuity and a larger suppression scotoma. Preferred eye instability was not related to any visual outcome measure. No relationships were found with visual acuity. CONCLUSIONS Fixation instability and vergence instability during binocular viewing suggests that discordant binocular visual experience during childhood, especially strabismus, interferes with ocular motor development. Amblyopia adds to instability of the nonpreferred eye. Vergence instability may limit potential for recovery of binocular vision in these children.
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Mendola JD, Lam J, Rosenstein M, Lewis LB, Shmuel A. Partial correlation analysis reveals abnormal retinotopically organized functional connectivity of visual areas in amblyopia. NEUROIMAGE-CLINICAL 2018; 18:192-201. [PMID: 29868445 PMCID: PMC5984596 DOI: 10.1016/j.nicl.2018.01.022] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 12/10/2017] [Accepted: 01/18/2018] [Indexed: 11/30/2022]
Abstract
Amblyopia is a prevalent developmental visual disorder of childhood that typically persists in adults. Due to altered visual experience during critical periods of youth, the structure and function of adult visual cortex is abnormal. In addition to substantial deficits shown with task-based fMRI, previous studies have used resting state measures to demonstrate altered long-range connectivity in amblyopia. This is the first study in amblyopia to analyze connectivity between regions of interest that are smaller than a single cortical area and to apply partial correlation analysis to reduce network effects. We specifically assess short-range connectivity between retinotopically defined regions of interest within the occipital lobe of 8 subjects with amblyopia and 7 subjects with normal vision (aged 19–45). The representations of visual areas V1, V2, and V3 within each of the four quadrants of visual space were further subdivided into three regions based on maps of visual field eccentricity. Connectivity between pairs of all nine regions of interest in each quadrant was tested via correlation and partial correlation for both groups. Only the tests of partial correlation, i.e., correlation between time courses of two regions following the regression of time courses from all other regions, yielded significant differences between resting state functional connectivity in amblyopic and normal subjects. Subjects with amblyopia showed significantly higher partial correlation between para-foveal and more eccentric representations within V1, and this effect associated with poor acuity of the worse eye. In addition, we observed reduced correlation in amblyopic subjects between isoeccentricity regions in V1 and V2, and separately, between such regions in V2 and V3. We conclude that partial correlation-based connectivity is altered in an eccentricity-dependent pattern in visual field maps of amblyopic patients. Moreover, results are consistent with known clinical and psychophysical vision loss. More broadly, this provides evidence that abnormal cortical adaptations to disease may be better isolated with tests of partial correlation connectivity than with the regular correlation techniques that are currently widely used. Cortical functional connectivity abnormalities exist in amblyopia at a scale finer than previously reported. Connectivity changes within primary visual cortex are consistent with known loss of function. Connectivity changes between visual areas are consistent with concept of deafferentation. Partial correlation differentiates patients from controls, whereas correlation does not.
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Affiliation(s)
- J D Mendola
- Department of Ophthalmology, McGill University, Montreal, QC, Canada.
| | - J Lam
- Departments of Neurology, Neurosurgery, Physiology and Biomedical Engineering, McGill University, Montreal, QC, Canada; Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - M Rosenstein
- Department of Ophthalmology, McGill University, Montreal, QC, Canada
| | - L B Lewis
- Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - A Shmuel
- Departments of Neurology, Neurosurgery, Physiology and Biomedical Engineering, McGill University, Montreal, QC, Canada; Montreal Neurological Institute, McGill University, Montreal, QC, Canada
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43
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Gao TY, Anstice N, Babu RJ, Black JM, Bobier WR, Dai S, Guo CX, Hess RF, Jenkins M, Jiang Y, Kearns L, Kowal L, Lam CSY, Pang PCK, Parag V, South J, Staffieri SE, Wadham A, Walker N, Thompson B. Optical treatment of amblyopia in older children and adults is essential prior to enrolment in a clinical trial. Ophthalmic Physiol Opt 2018; 38:129-143. [PMID: 29356022 DOI: 10.1111/opo.12437] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 12/03/2017] [Indexed: 11/29/2022]
Abstract
PURPOSE Optical treatment alone can improve visual acuity (VA) in children with amblyopia, thus clinical trials investigating additional amblyopia therapies (such as patching or videogames) for children require a preceding optical treatment phase. Emerging therapies for adult patients are entering clinical trials. It is unknown whether optical treatment is effective for adults with amblyopia and whether an optical correction phase is required for trials involving adults. METHODS We examined participants who underwent optical treatment in the Binocular Treatment for Amblyopia using Videogames (BRAVO) clinical trial (ANZCTR ID: ACTRN12613001004752). Participants were recruited in three age groups (7 to 12, 13 to 17, or ≥18 years), and had unilateral amblyopia due to anisometropia and/or strabismus, with amblyopic eye VA of 0.30-1.00 logMAR (6/12 to 6/60, 20/40 to 20/200). Corrective lenses were prescribed based on cycloplegic refraction to fully correct any anisometropia. VA was assessed using the electronic visual acuity testing algorithm (e-ETDRS) test and near stereoacuity was assessed using the Randot Preschool Test. Participants were assessed every four weeks up to 16 weeks, until either VA was stable or until amblyopic eye VA improved to better than 0.30 logMAR, rendering the participant ineligible for the trial. RESULTS Eighty participants (mean age 24.6 years, range 7.6-55.5 years) completed four to 16 weeks of optical treatment. A small but statistically significant mean improvement in amblyopic eye VA of 0.05 logMAR was observed (S.D. 0.08 logMAR; paired t-test p < 0.0001). Twenty-five participants (31%) improved by ≥1 logMAR line and of these, seven (9%) improved by ≥2 logMAR lines. Stereoacuity improved in 15 participants (19%). Visual improvements were not associated with age, presence of strabismus, or prior occlusion treatment. Two adult participants withdrew due to intolerance to anisometropic correction. Sixteen out of 80 participants (20%) achieved better than 0.30 logMAR VA in the amblyopic eye after optical treatment. Nine of these participants attended additional follow-up and four (44%) showed further VA improvements. CONCLUSIONS Improvements from optical treatment resulted in one-fifth of participants becoming ineligible for the main clinical trial. Studies investigating additional amblyopia therapies must include an appropriate optical treatment only phase and/or parallel treatment group regardless of patient age. Optical treatment of amblyopia in adult patients warrants further investigation.
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Affiliation(s)
- Tina Y Gao
- School of Optometry and Vision Science, The University of Auckland, Auckland, New Zealand
| | - Nicola Anstice
- School of Optometry and Vision Science, The University of Auckland, Auckland, New Zealand
| | - Raiju J Babu
- School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
| | - Joanna M Black
- School of Optometry and Vision Science, The University of Auckland, Auckland, New Zealand
| | - William R Bobier
- School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
| | - Shuan Dai
- Department of Ophthalmology, Auckland City Hospital and Starship Children's Hospital, Auckland, New Zealand
| | - Cindy X Guo
- School of Optometry and Vision Science, The University of Auckland, Auckland, New Zealand
| | - Robert F Hess
- Department of Ophthalmology, McGill Vision Research, McGill University, Montreal, Quebec, Canada
| | - Michelle Jenkins
- National Institute for Health Innovation, School of Population Health, The University of Auckland, Auckland, New Zealand
| | - Yannan Jiang
- National Institute for Health Innovation, School of Population Health, The University of Auckland, Auckland, New Zealand
| | - Lisa Kearns
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia.,Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Victoria, Australia
| | - Lionel Kowal
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia.,Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Victoria, Australia
| | - Carly S Y Lam
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong, China
| | - Peter C K Pang
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong, China
| | - Varsha Parag
- National Institute for Health Innovation, School of Population Health, The University of Auckland, Auckland, New Zealand
| | - Jayshree South
- School of Optometry and Vision Science, The University of Auckland, Auckland, New Zealand
| | - Sandra Elfride Staffieri
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia.,Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Victoria, Australia
| | - Angela Wadham
- National Institute for Health Innovation, School of Population Health, The University of Auckland, Auckland, New Zealand
| | - Natalie Walker
- National Institute for Health Innovation, School of Population Health, The University of Auckland, Auckland, New Zealand
| | - Benjamin Thompson
- School of Optometry and Vision Science, The University of Auckland, Auckland, New Zealand.,School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
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Kelly KR, Jost RM, De La Cruz A, Dao L, Beauchamp CL, Stager D, Birch EE. Slow reading in children with anisometropic amblyopia is associated with fixation instability and increased saccades. J AAPOS 2017; 21:447-451.e1. [PMID: 29024763 PMCID: PMC5722702 DOI: 10.1016/j.jaapos.2017.10.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 10/03/2017] [Accepted: 10/03/2017] [Indexed: 11/24/2022]
Abstract
BACKGROUND Previous studies show slow reading in strabismic amblyopia. We recently identified amblyopia, not strabismus, as the key factor in slow reading in children. No studies have focused on reading in amblyopic children without strabismus. We examined reading in anisometropic children and evaluated whether slow reading was associated with ocular motor dysfunction in children with amblyopia. METHODS Anisometropic children (7-12 years) with or without amblyopia were compared to age-similar normal controls. Children silently read a grade-appropriate paragraph during binocular viewing. Reading rate (words/min), number of forward and regressive saccades (per 100 words) and fixation duration were recorded with the ReadAlyzer. Binocular fixation instability was also evaluated (EyeLink 1000). RESULTS Amblyopic anisometropic children read more slowly (n = 25; mean with standard deviation, 149 ± 42 words/min) than nonamblyopic anisometropic children (n = 15; 196 ± 80 words/min; P = 0.024) and controls (n = 25; 191 ± 65 words/min; P = 0.020). Nonamblyopic anisometropic children read at a comparable rate to controls (P = 0.81). Slow reading in amblyopic anisometropic children was correlated with increased forward saccades (r = -0.84, P < 0.001), increased regressive saccades (r = -0.85, P < 0.001), and fellow eye instability during binocular viewing (r = -0.52, P = 0.019). CONCLUSIONS Slow reading in school-age children with anisometropic amblyopia is related to increased frequency of saccades and fixation instability of the fellow eye. Further research should consider the effects of slower reading on academic performance.
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Affiliation(s)
| | - Reed M Jost
- Retina Foundation of the Southwest, Dallas, Texas
| | | | - Lori Dao
- ABC Eyes Pediatric Ophthalmology, PA, Dallas, Texas
| | | | - David Stager
- Pediatric Ophthalmology & Adult Strabismus, PA, Plano, Texas
| | - Eileen E Birch
- Retina Foundation of the Southwest, Dallas, Texas; Department of Ophthalmology, UT Southwestern Medical Center, Dallas, Texas
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Alterations in audiovisual simultaneity perception in amblyopia. PLoS One 2017; 12:e0179516. [PMID: 28598996 PMCID: PMC5466335 DOI: 10.1371/journal.pone.0179516] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 05/30/2017] [Indexed: 11/19/2022] Open
Abstract
Amblyopia is a developmental visual impairment that is increasingly recognized to affect higher-level perceptual and multisensory processes. To further investigate the audiovisual (AV) perceptual impairments associated with this condition, we characterized the temporal interval in which asynchronous auditory and visual stimuli are perceived as simultaneous 50% of the time (i.e., the AV simultaneity window). Adults with unilateral amblyopia (n = 17) and visually normal controls (n = 17) judged the simultaneity of a flash and a click presented with both eyes viewing. The signal onset asynchrony (SOA) varied from 0 ms to 450 ms for auditory-lead and visual-lead conditions. A subset of participants with amblyopia (n = 6) was tested monocularly. Compared to the control group, the auditory-lead side of the AV simultaneity window was widened by 48 ms (36%; p = 0.002), whereas that of the visual-lead side was widened by 86 ms (37%; p = 0.02). The overall mean window width was 500 ms, compared to 366 ms among controls (37% wider; p = 0.002). Among participants with amblyopia, the simultaneity window parameters were unchanged by viewing condition, but subgroup analysis revealed differential effects on the parameters by amblyopia severity, etiology, and foveal suppression status. Possible mechanisms to explain these findings include visual temporal uncertainty, interocular perceptual latency asymmetry, and disruption of normal developmental tuning of sensitivity to audiovisual asynchrony.
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46
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Kelly KR, Jost RM, Dao L, Beauchamp CL, Leffler JN, Birch EE. Binocular iPad Game vs Patching for Treatment of Amblyopia in Children: A Randomized Clinical Trial. JAMA Ophthalmol 2017; 134:1402-1408. [PMID: 27832248 DOI: 10.1001/jamaophthalmol.2016.4224] [Citation(s) in RCA: 116] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Importance Fellow eye patching has long been the standard treatment for amblyopia, but it does not always restore 20/20 vision or teach the eyes to work together. Amblyopia can be treated with binocular games that rebalance contrast between the eyes so that a child may overcome suppression. However, it is unclear whether binocular treatment is comparable to patching in treating amblyopia. Objectives To assess the effectiveness of a binocular iPad (Apple Inc) adventure game as amblyopia treatment and compare this binocular treatment with patching, the current standard of care. Design, Setting, and Participants This investigation was a randomized clinical trial with a crossover design at a nonprofit eye research institute. Between February 20, 2015, and January 4, 2016, a total of 28 patients were enrolled in the study, with 14 randomized to binocular game treatment and 14 to patching treatment. Interventions Binocular game and patching as amblyopia treatments. Main Outcomes and Measures The primary outcome was change in amblyopic eye best-corrected visual acuity (BCVA) at the 2-week visit. Secondary outcomes were change in stereoacuity and suppression at the 2-week visit and change in BCVA at the 4-week visit. Results Among 28 children, the mean (SD) age at baseline was 6.7 (1.4) years (age range, 4.6-9.5 years), and 7 (25%) were female. At baseline, the mean (SD) amblyopic eye BCVA was 0.48 (0.14) logMAR (approximately 20/63; range, 0.3-0.8 logMAR [20/40 to 20/125]), with 14 children randomized to the binocular game and 14 to patching for 2 weeks. At the 2-week visit, improvement in amblyopic eye BCVA was greater with the binocular game compared with patching, with a mean (SD) improvement of 0.15 (0.08) logMAR (mean [SD], 1.5 [0.8] lines) vs 0.07 (0.08) logMAR (mean [SD], 0.7 [0.8] line; P = .02) after 2 weeks of treatment. These improvements from baseline were significant for the binocular game (mean [SD] improvement, 1.5 [0.8] lines; P < .001) and for patching (mean [SD] improvement, 0.7 [0.8] line; P = .006). Depth of suppression improved from baseline at the 2-week visit for the binocular game (mean [SD], 4.82 [2.82] vs 3.24 [2.87]; P = .03) and for patching (mean [SD], 4.77 [3.10] vs 2.57 [1.67]; P = .004). Patching children crossed over to binocular game treatment, and all 28 children played the game for another 2 weeks. At the 4-week visit, no group difference was found in BCVA change, with children who crossed over to the binocular games catching up with children treated with binocular games, for a mean (SD) improvement of 0.17 (0.10) logMAR (mean [SD], 1.7 [1.0] lines) for the binocular game vs a mean (SD) improvement of 0.16 (0.12) logMAR (mean [SD], 1.6 [1.2] lines) for the patching crossover (P = .73). Conclusions and Relevance A binocular iPad game was effective in treating childhood amblyopia and was more efficacious than patching at the 2-week visit. Binocular games that rebalance contrast to overcome suppression are a promising additional option for treating amblyopia. Trial Registration clinicaltrials.gov Identifier: NCT02365090.
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Affiliation(s)
| | - Reed M Jost
- Retina Foundation of the Southwest, Dallas, Texas
| | - Lori Dao
- ABC Eyes Pediatric Ophthalmology, PA, Dallas, Texas
| | | | | | - Eileen E Birch
- Retina Foundation of the Southwest, Dallas, Texas4Department of Ophthalmology, The University of Texas Southwestern Medical Center, Dallas
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