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Amblyopia Outcomes Through Clinical Trials and Practice Measurement: Room for Improvement: The LXXVII Edward Jackson Memorial Lecture. Am J Ophthalmol 2020; 219:A1-A26. [PMID: 32777377 DOI: 10.1016/j.ajo.2020.07.053] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 07/27/2020] [Indexed: 11/21/2022]
Abstract
PURPOSE To describe amblyopia prevalence and outcomes using results from randomized studies and a clinical registry. DESIGN Review of published studies, analysis of data in Intelligent Research in Sight (IRIS) Registry from 2013 to 2019, personal perspective. METHODS Literature review, analysis of IRIS Registry data and IRIS-50, a visual acuity quality measure. RESULTS Clinical trials have reduced the treatment burden of amblyopia by reducing hours of patching and frequency of atropine eye drops with clinical success of about 83%. There is no appreciable age effect if treatment is started before 5 years of age, outcomes are stable to at least 15 years of age, and treatment can be somewhat effective until 12 years of age. The IRIS Registry identified 1,760,066 individuals with amblyopia for a prevalence of 2.47%. Refractive error alone accounted for 68.9% of childhood cases. Mean amblyopic eye visual acuity improved 1.8 lines for children 3-6 years of age and 0.8 lines for 7-12 years, but mean residual amblyopia was more than 2 lines. Among 18,841 children aged 3-7 years eligible for IRIS-50, 77.3% were successful. The odds ratios for success were significantly lower for African-American (0.67; 95% confidence interval [CI] = 0.58 to 0.78) and Hispanic or Latino (0.84; 95% CI = 0.75 to 0.94) children compared with white children. CONCLUSIONS Clinical trials provided evidence of a beneficial effect from several treatments, with substantially reduced doses than previously recommended. Registry data from clinical practice found residual visual acuity impairment among all ages and races, especially among minorities.
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Rosa HA, Adrián AC, Beatriz IS, María-José LC, Miguel-Ángel S. Psychomotor, Psychosocial and Reading Skills in Children with Amblyopia and the Effect of Different Treatments. J Mot Behav 2020; 53:176-184. [PMID: 32281918 DOI: 10.1080/00222895.2020.1747384] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Amblyopia influences psychomotor and psychosocial skills, although not all studies are unanimous. Different treatments coexist, but the effect on those variables is not clear. This study aims to probe whether children with amblyopia have impairments in these areas and if different optometric treatments reduce them effectively. 50 children, diagnosed with amblyopia, and 33 without amblyopia participated in this study. Eye-hand coordination, psychosocial skills and reading abilities, were measured before and after three months of different treatments (patch, patch and near vision activities and perceptual learning). Results revealed lower scores in eye-hand coordination and some reading issues in children with amblyopia, without differences in psychosocial skills in regard to the control group. Moreover, optometric treatments improved eye-hand coordination.
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Affiliation(s)
- Hernández-Andrés Rosa
- Dpto. de Óptica y Optometría y Ciencias de la Visión, Facultad de Físicas. Universitat de València
| | | | | | - Luque-Cobija María-José
- Dpto. de Óptica y Optometría y Ciencias de la Visión, Facultad de Físicas. Universitat de València.,Dpto. de Psicobiología, Facultad de Psicología. Universitat de València
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Suprathreshold Motion Perception in Anisometropic Amblyopia: Interocular Speed Matching and the Pulfrich Effect. Optom Vis Sci 2020; 96:434-442. [PMID: 31107841 PMCID: PMC6581295 DOI: 10.1097/opx.0000000000001381] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
SIGNIFICANCE Our results indicate that the difference in perceived luminance between the amblyopic and fellow eyes that is present under dichoptic viewing conditions does not affect the perceived speed of suprathreshold motion stimuli. This finding provides a new insight into suprathreshold perception in amblyopia. PURPOSE Interocular matching experiments indicate that dichoptically presented stimuli have a lower perceived luminance in amblyopic eyes relative to fellow eyes. This may be a consequence of interocular suppression. We investigated whether this effect extends to suprathreshold motion perception. METHODS Participants with amblyopia and control observers matched the perceived speed of dichoptically presented random-dot kinematograms and the perceived luminance of gray patches. Control participants also performed the speed matching task with a neutral density filter over one eye to simulate a perceived luminance reduction. RESULTS The amblyopia group exhibited lower perceived luminance in the amblyopic than in the fellow eye, as has previously been reported. However, interocular speed matching was veridical. For control observers, perceived speed was reduced in the eye with a neutral density filter relative to the nonfiltered eye. To assess whether the perceived luminance reduction in the amblyopic eye affected binocular function, we also measured the Pulfrich effect in the amblyopia group with equal luminance presented to each eye. No patients reported a spontaneous Pulfrich effect. CONCLUSIONS The results suggest that suprathreshold speed perception is intact in the amblyopic eye when both eyes are open.
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Piano MEF, Simmers AJ. 'It's too late'. Is it really? Considerations for amblyopia treatment in older children. Ther Adv Ophthalmol 2019; 11:2515841419857379. [PMID: 31259304 PMCID: PMC6585235 DOI: 10.1177/2515841419857379] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 05/17/2019] [Indexed: 01/20/2023] Open
Abstract
In recent years, media coverage has demonstrated instances in which families of children aged 7 and older, newly diagnosed with strabismic and/or anisometropic amblyopia through community eyecare services, were told it was 'too late' for their child to effectively respond to conventional amblyopia treatment (occlusion or atropine penalisation). Formal guidance pertaining to binocular vision anomalies from eyecare professional bodies does not specifically make reference to a child's age, beyond stating the importance of early diagnosis and treatment of strabismus/amblyopia. However, there have been many changes in the way we view the recovery period for amblyopia, and it is well demonstrated both within literature and clinical practice that conventional treatment can improve amblyopic eye visual acuity in children beyond the age of 7 years. The occurrence of these media described cases within the community eyecare sphere would suggest it is worthwhile revisiting the literature on the subject of amblyopia treatment in older children (aged 7+ years), to address misconceptions and place in the spotlight current considerations facing clinicians when treating newly diagnosed amblyopia within this age group. This perspective review provides an evidence-based update covering the various considerations associated with treatment of amblyopia in older children, along with recent amblyopia treatment advances that could have an impact on treatment prospects for this patient group. Considerations include the risks, benefits and efficacy of treating newly diagnosed amblyopia in older children, monitoring density of suppression to mitigate intractable diplopia risk, and recent findings regarding binocular treatments for amblyopia.
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Affiliation(s)
| | - Anita J Simmers
- Department of Vision Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, UK
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Gao Y, Reynaud A, Tang Y, Feng L, Zhou Y, Hess RF. The amblyopic deficit for 2nd order processing: Generality and laterality. Vision Res 2015; 114:111-21. [DOI: 10.1016/j.visres.2014.10.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Revised: 09/30/2014] [Accepted: 10/03/2014] [Indexed: 10/24/2022]
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Zihl J, Heywood CA. The contribution of LM to the neuroscience of movement vision. Front Integr Neurosci 2015; 9:6. [PMID: 25741251 PMCID: PMC4330684 DOI: 10.3389/fnint.2015.00006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 01/21/2015] [Indexed: 11/29/2022] Open
Abstract
The significance of early and sporadic reports in the 19th century of impairments of motion vision following brain damage was largely unrecognized. In the absence of satisfactory post-mortem evidence, impairments were interpreted as the consequence of a more general disturbance resulting from brain damage, the location and extent of which was unknown. Moreover, evidence that movement constituted a special visual perception and may be selectively spared was similarly dismissed. Such skepticism derived from a reluctance to acknowledge that the neural substrates of visual perception may not be confined to primary visual cortex. This view did not persist. First, it was realized that visual movement perception does not depend simply on the analysis of spatial displacements and temporal intervals, but represents a specific visual movement sensation. Second persuasive evidence for functional specialization in extrastriate cortex, and notably the discovery of cortical area V5/MT, suggested a separate region specialized for motion processing. Shortly thereafter the remarkable case of patient LM was published, providing compelling evidence for a selective and specific loss of movement vision. The case is reviewed here, along with an assessment of its contribution to visual neuroscience.
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Affiliation(s)
- Josef Zihl
- Department of Psychology, Max Planck Institute of Psychiatry, Ludwig Maximilian UniversityMunich, Germany
| | - Charles A. Heywood
- Department of Psychology, Science Laboratories, Durham UniversityDurham, UK
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Tang Y, Liu C, Liu Z, Hu X, Yu YQ, Zhou Y. Processing deficits of motion of contrast-modulated gratings in anisometropic amblyopia. PLoS One 2014; 9:e113400. [PMID: 25409477 PMCID: PMC4237427 DOI: 10.1371/journal.pone.0113400] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Accepted: 10/23/2014] [Indexed: 12/02/2022] Open
Abstract
Several studies have indicated substantial processing deficits for static second-order stimuli in amblyopia. However, less is known about the perception of second-order moving gratings. To investigate this issue, we measured the contrast sensitivity for second-order (contrast-modulated) moving gratings in seven anisometropic amblyopes and ten normal controls. The measurements were performed with non-equated carriers and a series of equated carriers. For comparison, the sensitivity for first-order motion and static second-order stimuli was also measured. Most of the amblyopic eyes (AEs) showed reduced sensitivity for second-order moving gratings relative to their non-amblyopic eyes (NAEs) and the dominant eyes (CEs) of normal control subjects, even when the detectability of the noise carriers was carefully controlled, suggesting substantial processing deficits of motion of contrast-modulated gratings in anisometropic amblyopia. In contrast, the non-amblyopic eyes of the anisometropic amblyopes were relatively spared. As a group, NAEs showed statistically comparable performance to CEs. We also found that contrast sensitivity for static second-order stimuli was strongly impaired in AEs and part of the NAEs of anisometropic amblyopes, consistent with previous studies. In addition, some amblyopes showed impaired performance in perception of static second-order stimuli but not in that of second-order moving gratings. These results may suggest a dissociation between the processing of static and moving second-order gratings in anisometropic amblyopia.
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Affiliation(s)
- Yong Tang
- CAS Key Laboratory of Brain Function and Diseases, and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, People's Republic of China
- Research and Treatment Center of Amblyopia and Strabismus, University of Science and Technology of China, Hefei, Anhui, People's Republic of China
| | - Caiyuan Liu
- Research and Treatment Center of Amblyopia and Strabismus, University of Science and Technology of China, Hefei, Anhui, People's Republic of China
| | - Zhongjian Liu
- Research and Treatment Center of Amblyopia and Strabismus, University of Science and Technology of China, Hefei, Anhui, People's Republic of China
| | - Xiaopeng Hu
- Department of Radiology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, People's Republic of China
| | - Yong-Qiang Yu
- Department of Radiology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, People's Republic of China
| | - Yifeng Zhou
- CAS Key Laboratory of Brain Function and Diseases, and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, People's Republic of China
- Research and Treatment Center of Amblyopia and Strabismus, University of Science and Technology of China, Hefei, Anhui, People's Republic of China
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Science, Beijing, People's Republic of China
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Hamm LM, Black J, Dai S, Thompson B. Global processing in amblyopia: a review. Front Psychol 2014; 5:583. [PMID: 24987383 PMCID: PMC4060804 DOI: 10.3389/fpsyg.2014.00583] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Accepted: 05/25/2014] [Indexed: 01/13/2023] Open
Abstract
Amblyopia is a neurodevelopmental disorder of the visual system that is associated with disrupted binocular vision during early childhood. There is evidence that the effects of amblyopia extend beyond the primary visual cortex to regions of the dorsal and ventral extra-striate visual cortex involved in visual integration. Here, we review the current literature on global processing deficits in observers with either strabismic, anisometropic, or deprivation amblyopia. A range of global processing tasks have been used to investigate the extent of the cortical deficit in amblyopia including: global motion perception, global form perception, face perception, and biological motion. These tasks appear to be differentially affected by amblyopia. In general, observers with unilateral amblyopia appear to show deficits for local spatial processing and global tasks that require the segregation of signal from noise. In bilateral cases, the global processing deficits are exaggerated, and appear to extend to specialized perceptual systems such as those involved in face processing.
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Affiliation(s)
- Lisa M Hamm
- Department of Optometry and Vision Science, University of Auckland Auckland, New Zealand
| | - Joanna Black
- Department of Optometry and Vision Science, University of Auckland Auckland, New Zealand
| | - Shuan Dai
- Department of Ophthalmology, Starship Children's Hospital Auckland, New Zealand ; Department of Ophthalmology, University of Auckland Auckland, New Zealand
| | - Benjamin Thompson
- Department of Optometry and Vision Science, University of Auckland Auckland, New Zealand ; Department of Optometry and Vision Science, University of Waterloo Waterloo, Canada
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Hutchinson CV, Ledgeway T, Allen HA, Long MD, Arena A. Binocular summation of second-order global motion signals in human vision. Vision Res 2013; 84:16-25. [PMID: 23518134 DOI: 10.1016/j.visres.2013.03.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Revised: 02/07/2013] [Accepted: 03/08/2013] [Indexed: 10/27/2022]
Abstract
Although many studies have examined the principles governing first-order global motion perception, the mechanisms that mediate second-order global motion perception remain unresolved. This study investigated the existence, nature and extent of the binocular advantage for encoding second-order (contrast-defined) global motion. Motion coherence thresholds (79.4% correct) were assessed for determining the direction of radial, rotational and translational second-order motion trajectories as a function of local element modulation depth (contrast) under monocular and binocular viewing conditions. We found a binocular advantage for second-order global motion processing for all motion types. This advantage was mainly one of enhanced modulation sensitivity, rather than of motion-integration. However, compared to findings for first-order motion where the binocular advantage was in the region of a factor of around 1.7 (Hess et al., 2007), the binocular advantage for second-order global motion was marginal, being in the region of around 1.2. This weak enhancement in sensitivity with binocular viewing is considerably less than would be predicted by conventional models of either probability summation or neural summation.
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Affiliation(s)
- Claire V Hutchinson
- School of Psychology, College of Medicine, Biological Sciences and Psychology, University of Leicester, Lancaster Road, Leicester, UK.
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Lyon DW, Hopkins K, Chu RH, Tamkins SM, Cotter SA, Melia BM, Holmes JM, Repka MX, Wheeler DT, Sala NA, Dumas J, Silbert DI. Feasibility of a clinical trial of vision therapy for treatment of amblyopia. Optom Vis Sci 2013; 90:475-81. [PMID: 23563444 PMCID: PMC3662294 DOI: 10.1097/opx.0b013e31828def04] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
PURPOSE We conducted a pilot randomized clinical trial of office-based active vision therapy for the treatment of childhood amblyopia to determine the feasibility of conducting a full-scale randomized clinical trial. METHODS A training and certification program and manual of procedures were developed to certify therapists to administer a standardized vision therapy program in ophthalmology and optometry offices consisting of weekly visits for 16 weeks. Nineteen children, aged 7 to less than 13 years, with amblyopia (20/40-20/100) were randomly assigned to receive either 2 hours of daily patching with active vision therapy or 2 hours of daily patching with placebo vision therapy. RESULTS Therapists in diverse practice settings were successfully trained and certified to perform standardized vision therapy in strict adherence with protocol. Subjects completed 85% of required weekly in-office vision therapy visits. Eligibility criteria based on age, visual acuity, and stereoacuity, designed to identify children able to complete a standardized vision therapy program and judged likely to benefit from this treatment, led to a high proportion of screened subjects being judged ineligible, resulting in insufficient recruitment. There were difficulties in retrieving adherence data for the computerized home therapy procedures. CONCLUSIONS This study demonstrated that a 16-week treatment trial of vision therapy was feasible with respect to maintaining protocol adherence; however, recruitment under the proposed eligibility criteria, necessitated by the standardized approach to vision therapy, was not successful. A randomized clinical trial of in-office vision therapy for the treatment of amblyopia would require broadening of the eligibility criteria and improved methods to gather objective data regarding the home therapy. A more flexible approach that customizes vision therapy based on subject age, visual acuity, and stereopsis might be required to allow enrollment of a broader group of subjects.
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Affiliation(s)
- Don W Lyon
- Indiana University School of Optometry, Bloomington, Indiana, USA.
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Wong AM. New concepts concerning the neural mechanisms of amblyopia and their clinical implications. Can J Ophthalmol 2012; 47:399-409. [DOI: 10.1016/j.jcjo.2012.05.002] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2012] [Revised: 05/09/2012] [Accepted: 05/22/2012] [Indexed: 11/29/2022]
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