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Vision Research Sep 2015Amblyopia is a neuro-developmental disorder of the visual cortex that arises from abnormal visual experience early in life. Amblyopia is clinically important because it... (Review)
Review
Amblyopia is a neuro-developmental disorder of the visual cortex that arises from abnormal visual experience early in life. Amblyopia is clinically important because it is a major cause of vision loss in infants and young children. Amblyopia is also of basic interest because it reflects the neural impairment that occurs when normal visual development is disrupted. Amblyopia provides an ideal model for understanding when and how brain plasticity may be harnessed for recovery of function. Over the past two decades there has been a rekindling of interest in developing more effective methods for treating amblyopia, and for extending the treatment beyond the critical period, as exemplified by new clinical trials and new basic research studies. The focus of this review is on stereopsis and its potential for recovery. Impaired stereoscopic depth perception is the most common deficit associated with amblyopia under ordinary (binocular) viewing conditions (Webber & Wood, 2005). Our review of the extant literature suggests that this impairment may have a substantial impact on visuomotor tasks, difficulties in playing sports in children and locomoting safely in older adults. Furthermore, impaired stereopsis may also limit career options for amblyopes. Finally, stereopsis is more impacted in strabismic than in anisometropic amblyopia. Our review of the various approaches to treating amblyopia (patching, perceptual learning, videogames) suggests that there are several promising new approaches to recovering stereopsis in both anisometropic and strabismic amblyopes. However, recovery of stereoacuity may require more active treatment in strabismic than in anisometropic amblyopia. Individuals with strabismic amblyopia have a very low probability of improvement with monocular training; however they fare better with dichoptic training than with monocular training, and even better with direct stereo training.
Topics: Adult; Age Factors; Amblyopia; Anisometropia; Child; Depth Perception; Humans; Strabismus; Vision, Binocular; Visual Acuity
PubMed: 25637854
DOI: 10.1016/j.visres.2015.01.002 -
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 -
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 -
Ophthalmic & Physiological Optics : the... Nov 2016
Topics: Amblyopia; History, 20th Century; History, 21st Century; Orthoptics
PubMed: 27790768
DOI: 10.1111/opo.12337 -
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 AAPOS : the Official... Feb 2018Pediatric ophthalmologists are increasingly expected to promote, preserve, and restore binocular vision. (Review)
Review
BACKGROUND
Pediatric ophthalmologists are increasingly expected to promote, preserve, and restore binocular vision.
METHODS
Clinical studies on restoring alignment and stereopsis in the management of amblyopia, esotropia, exotropia, and complex strabismus are reviewed from the perspective of the author's published work and personal experiences.
RESULTS
Treatment of amblyopia by means of optical rehabilitation, occlusion, or penalization has been reinforced by medical treatment and perceptual training with monocular or binocular video games. Studies indicate that early management of esotropia and alignment within 8 is required for regaining stereopsis. In the surgical management of intermittent exotropia, distance stereopsis by Frisby Davis Distance stereotest can predict better stereopsis, with patients having preoperative distance stereopsis of <70 arcsec less likely to improve after surgery. The surgeon's armamentarium for correcting alignment and restoring binocular vision include procedures such as adjustable, partial vertical rectus muscle transposition in cases of exotropic Duane syndrome and lateral rectus palsy, periosteal fixation of the globe or of the lateral rectus muscle, and medial transposition of the split lateral rectus muscle.
CONCLUSIONS
The goal for present-day strabismologists is not merely to correct strabismus but also to achieve alignment of eyes in time to ensure normal development of stereopsis in children and to restore alignment and stereopsis in adults.
Topics: Amblyopia; Child; Clinical Studies as Topic; Depth Perception; Humans; Ophthalmologic Surgical Procedures; Strabismus; Vision, Binocular
PubMed: 29292047
DOI: 10.1016/j.jaapos.2017.10.009 -
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 -
JAMA Jan 2021
Topics: Amblyopia; Child; Humans; Infant; Strabismus; Vision Screening
PubMed: 33496776
DOI: 10.1001/jama.2020.5741