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Vision Research Nov 2020Recent work has transformed our ideas about the neural mechanisms, behavioral consequences and effective therapies for amblyopia. Since the 1700's, the clinical... (Review)
Review
Recent work has transformed our ideas about the neural mechanisms, behavioral consequences and effective therapies for amblyopia. Since the 1700's, the clinical treatment for amblyopia has consisted of patching or penalizing the strong eye, to force the "lazy" amblyopic eye, to work. This treatment has generally been limited to infants and young children during a sensitive period of development. Over the last 20 years we have learned much about the nature and neural mechanisms underlying the loss of spatial and binocular vision in amblyopia, and that a degree of neural plasticity persists well beyond the sensitive period. Importantly, the last decade has seen a resurgence of research into new approaches to the treatment of amblyopia both in children and adults, which emphasize that monocular therapies may not be the most effective for the fundamentally binocular disorder that is amblyopia. These approaches include perceptual learning, video game play and binocular methods aimed at reducing inhibition of the amblyopic eye by the strong fellow eye, and enhancing binocular fusion and stereopsis. This review focuses on the what we've learned over the past 20 years or so, and will highlight both the successes of these new treatment approaches in labs around the world, and their failures in clinical trials. Reconciling these results raises important new questions that may help to focus future directions.
Topics: Adult; Amblyopia; Child; Child, Preschool; Depth Perception; Humans; Infant; Video Games; Vision, Binocular; Visual Acuity
PubMed: 32866759
DOI: 10.1016/j.visres.2020.07.014 -
American Family Physician Dec 2019Amblyopia is the leading cause of monocular vision loss in children. Early recognition and treatment are important to prevent vision loss. The U.S. Preventive Services...
Amblyopia is the leading cause of monocular vision loss in children. Early recognition and treatment are important to prevent vision loss. The U.S. Preventive Services Task Force recommends vision screening for all children at least once between three and five years of age to detect the presence of amblyopia or its risk factors. The American Association for Pediatric Ophthalmology and Strabismus and the American Academy of Pediatrics recommend routine, age-appropriate red reflex testing, examination for signs of strabismus, and vision chart testing. Photoscreening may be a useful adjunct to traditional vision screening, but there is limited evidence that it improves visual outcomes. Treatments for amblyopia include patching, atropine eye drops, and optical penalization of the nonamblyopic eye. In children with moderate amblyopia, patching for two hours per day is as effective as six hours, and daily atropine is as effective as daily patching. Children younger than seven years receive the most benefit from treatment, but older children may still benefit. Amblyopia recurs in 25% of children, so continued surveillance is important.
Topics: Amblyopia; Child; Child, Preschool; Humans; Vision Screening
PubMed: 31845774
DOI: No ID Found -
Indian Journal of Ophthalmology Jul 2023The optimal method of treatment for a child depends on the patient's age at the time of diagnosis, the onset and type of amblyopia, and the degree of compliance... (Review)
Review
The optimal method of treatment for a child depends on the patient's age at the time of diagnosis, the onset and type of amblyopia, and the degree of compliance attainable. In deprivation amblyopia, the cause of visual impairment (e.g., cataract, ptosis) needs to be treated first, and then the disorder can be treated such as other types of amblyopia. Anisometropic amblyopia needs glasses first. In strabismic amblyopia, conventionally amblyopia should be treated first, and then strabismus corrected. Correction of strabismus will have little if any effect on the amblyopia, although the timing of surgery is controversial. Best outcomes are achieved if amblyopia is treated before the age of 7 years. The earlier the treatment, the more efficacious it is. In selected cases of bilateral amblyopia, the more defective eye must be given a competitive advantage over the comparatively good eye. Glasses alone can work when a refractive component is present, but occlusion might make the glasses work faster. The gold standard therapy for amblyopia remains occlusion of the better eye although penalization is also evidenced to achieve equal results. Pharmacotherapy has been shown to achieve suboptimal outcomes. Newer monocular and binocular therapies based on neural tasks and games are adjuncts to patching and can also be used in adults.
Topics: Child; Adult; Humans; Amblyopia; Visual Acuity; Sensory Deprivation; Strabismus; Refraction, Ocular; Treatment Outcome
PubMed: 37417105
DOI: 10.4103/IJO.IJO_338_23 -
Indian Journal of Ophthalmology May 2023Amblyopia is a monocular or binocular reduction in visual acuity that results from prolonged visual deprivation in the early years of life. It is second only to... (Review)
Review
Amblyopia is a monocular or binocular reduction in visual acuity that results from prolonged visual deprivation in the early years of life. It is second only to refractive error as a cause of poor vision in children. The gold standard treatment of amblyopia includes patching and, less commonly, atropine penalization and filters. These therapies are aimed at improvements in the visual acuity of the amblyopic eye alone. They have compliance and psychosocial issues and gains are accrued after prolonged periods. Experimental studies have demonstrated the presence of binocular cortical communication even in amblyopes and neural plasticity in late childhood as well as adulthood. On this basis, binocular vision therapy aimed at the stimulation of both eyes rather than forced use of the amblyopic eye was developed. Such therapies involve visual tasks designed in such a way that they can be completed only by binocular viewing. These tasks vary from simple game play using red-green glasses, to engaging 3D games and movie viewing. Preliminary data suggest that binocular vision therapy has led to lasting improvements in visual acuity and can be a useful adjunct, if not replacement, to the conventional treatment of amblyopia. In this article, we aim to describe the various binocular vision therapies and review the available literature on the same.
Topics: Child; Humans; Adult; Amblyopia; Vision, Binocular; Visual Acuity; Eye; Vision, Low
PubMed: 37203032
DOI: 10.4103/IJO.IJO_3098_22 -
Ophthalmology Jan 2022Digital therapeutics are a new class of interventions that are software driven and are intended to treat various conditions. We developed and evaluated a dichoptic... (Comparative Study)
Comparative Study Randomized Controlled Trial
PURPOSE
Digital therapeutics are a new class of interventions that are software driven and are intended to treat various conditions. We developed and evaluated a dichoptic digital therapeutic for amblyopia, a neurodevelopmental disorder for which current treatments may be limited by poor adherence and residual vision deficits.
DESIGN
Randomized controlled trial.
PARTICIPANTS
One hundred five children 4 to 7 years of age with amblyopia were enrolled at 21 academic and community sites in the United States. Participants were randomized 1:1 to the treatment or comparison group, stratified by site.
METHODS
We conducted a phase 3 randomized controlled trial to evaluate the safety and efficacy of a dichoptic digital therapeutic for amblyopia. Participants in the treatment group used the therapeutic at home for 1 hour per day, 6 days per week and wore glasses full-time. Participants in the comparison group continued wearing glasses full-time alone.
MAIN OUTCOME MEASURES
The primary efficacy outcome was change in amblyopic eye visual acuity (VA) from baseline at 12 weeks, and VA was measured by masked examiners. Safety was evaluated using the frequency and severity of study-related adverse events. Primary analyses were conducted using the intention-to-treat population.
RESULTS
Between January 16, 2019, and January 15, 2020, 105 participants were enrolled; 51 were randomized to the treatment group and 54 were randomized to the comparison group. At 12 weeks, amblyopic eye VA improved by 1.8 lines (95% confidence interval [CI], 1.4-2.3 lines; n = 45) in the treatment group and by 0.8 lines (95% CI, 0.4-1.3 lines; n = 45) in the comparison group. At the planned interim analysis (adjusted α = 0.0193), the difference between groups was significant (1.0 lines; P = 0.0011; 96.14% CI, 0.33-1.63 lines) and the study was stopped early for success, according to the protocol. No serious adverse events were reported.
CONCLUSIONS
Our findings support the value of the therapeutic in clinical practice as an effective treatment. Future studies should evaluate the therapeutic compared with other methods and in additional patient populations.
Topics: Amblyopia; Child; Child, Preschool; Digital Technology; Eyeglasses; Female; Humans; Male; Orthoptics; Treatment Outcome; Vision, Binocular; Visual Acuity
PubMed: 34534556
DOI: 10.1016/j.ophtha.2021.09.001 -
Handbook of Clinical Neurology 2021Amblyopia is a neurodevelopmental abnormality that results in physiological alterations in the visual pathways and impaired vision in one eye, less commonly in both. It...
Amblyopia is a neurodevelopmental abnormality that results in physiological alterations in the visual pathways and impaired vision in one eye, less commonly in both. It reflects a broad range of neural, perceptual, oculomotor, and clinical abnormalities that can occur when normal visual development is disrupted early in life. Aside from refractive error, amblyopia is the most common cause of vision loss in infants and young children. It causes a constellation of perceptual deficits in the vision of the amblyopic eye, including a loss of visual acuity, position acuity, and contrast sensitivity, particularly at high spatial frequencies, as well as increased internal noise and prolonged manual and saccadic reaction times. There are also perceptual deficits in the strong eye, such as certain types of motion perception, reflecting altered neural responses and functional connectivity in visual cortex (Ho et al., 2005). Treatment in young children consists of correction of any refractive error and patching of the strong eye. Compliance with patching is challenging and a substantial proportion of amblyopic children fail to achieve normal acuity or stereopsis even after extended periods of treatment. There are a number of promising experimental treatments that may improve compliance and outcomes, such as the playing of action video games with the strong eye patched. Although there may be a sensitive period for optimal effects of treatment, there is evidence that amblyopic adults may still show some benefit of treatment. However, there is as yet no consensus on the treatment of adults with amblyopia.
Topics: Amblyopia; Child; Child, Preschool; Eye Movements; Humans; Infant; Motion Perception; Visual Acuity; Visual Pathways
PubMed: 33832673
DOI: 10.1016/B978-0-12-821377-3.00002-7 -
Progress in Retinal and Eye Research Mar 2023Amblyopia is a disorder of neurodevelopment that occurs when there is discordant binocular visual experience during the first years of life. While treatments are... (Review)
Review
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.
Topics: Child; Humans; Amblyopia; Quality of Life; Vision, Binocular; Visual Acuity
PubMed: 36736071
DOI: 10.1016/j.preteyeres.2023.101168 -
Survey of Ophthalmology 2022Amblyopia is visual impairment characterized by a structurally normal eye showing significantly lower visual acuity than the fellow eye. Traditional treatment of... (Meta-Analysis)
Meta-Analysis Review
Amblyopia is visual impairment characterized by a structurally normal eye showing significantly lower visual acuity than the fellow eye. Traditional treatment of amblyopia includes patching the good eye to force the amblyopic eye to work during normal daily activities; however, this approach is are limited by low compliance. Recently, researchers proposed a new treatment for amblyopia: video game playing. In the current review, we discuss whether video game playing can treat amblyopia, whether video game playing could better treat amblyopia than traditional treatments, and how the video game treats amblyopia and its possible mechanism. Based on results from our literature review and meta-analysis, we suggest there is strong evidence for the effectiveness of video game treatments. Moreover, multiple factors within and outside of video games could influence the treatment effect.
Topics: Amblyopia; Humans; Treatment Outcome; Video Games; Vision, Low; Visual Acuity
PubMed: 34606819
DOI: 10.1016/j.survophthal.2021.09.003 -
Current Opinion in Psychology Oct 2019Amblyopia is a neuro-developmental abnormality associated with deficits in a broad range of both low-level and high-level visual tasks. This is particularly true in... (Review)
Review
Amblyopia is a neuro-developmental abnormality associated with deficits in a broad range of both low-level and high-level visual tasks. This is particularly true in strabismic amblyopia where fixation is unstable and there is an increased frequency of microsaccades. In light of the close association between eye movements and attention, we propose a novel hypothesis: that the cost of unstable fixation in amblyopia is a deficit in selective attention. The increased latency for saccades and manual response time with amblyopic-eye viewing is consistent with attention being distracted by unwanted fixational eye movements. We review other attention deficits in amblyopia and discuss whether they are explained by fixation instability, or whether they involve a form of neglect or suppression of the visual input from the amblyopic eye.
Topics: Amblyopia; Attention; Humans; Reaction Time; Saccades
PubMed: 31030000
DOI: 10.1016/j.copsyc.2019.03.011 -
Journal of the Neurological Sciences Oct 2022Amblyopia is a neurodevelopmental disorder caused by abnormal visual experience in early life that affects 3-5% of the population. Amblyopia results in a host of... (Review)
Review
Amblyopia is a neurodevelopmental disorder caused by abnormal visual experience in early life that affects 3-5% of the population. Amblyopia results in a host of monocular and binocular visual afferent function deficits including reduced visual acuity, contrast sensitivity, depth perception, interocular suppression, and efferent function abnormalities such as unstable and inaccurate fixation. Conventional treatments such as patching therapy and newer dichoptic treatments are not always successful as 30-40% of patients experience recurrence/regression of amblyopia. There are numerous review articles focused on visual afferent function deficits and treatment modalities and outcomes in amblyopia. Recently, the advent of high spatial and temporal resolution eye trackers has spurred studies on fixation eye movements (FEMs) in healthy controls and neurologic and ophthalmic disorders. In this focused review, we will summarize studies evaluating FEM abnormalities in amblyopia. We will first describe the common devices and techniques used to quantify fixation abnormalities, and then highlight the importance of systematically evaluating the eye movements under different viewing conditions and describe the parameters crucial in assessing FEM abnormalities in amblyopia. We will summarize the evidence suggesting that FEM abnormalities are not limited to the amblyopic eye only but also affects the fellow eye and that FEM abnormalities can serve as biomarkers to predict the impact of amblyopia on visual functions. Beyond diagnosis, we will discuss the treatment and prognostic implications of the evaluation of FEM abnormalities in clinical practice.
Topics: Amblyopia; Biomarkers; Eye Movements; Humans; Vision, Binocular; Visual Acuity
PubMed: 36007287
DOI: 10.1016/j.jns.2022.120373