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Progress in Retinal and Eye Research Mar 2013Amblyopia is the most common cause of monocular visual loss in children, affecting 1.3%-3.6% of children. Current treatments are effective in reducing the visual acuity... (Review)
Review
Amblyopia is the most common cause of monocular visual loss in children, affecting 1.3%-3.6% of children. Current treatments are effective in reducing the visual acuity deficit but many amblyopic individuals are left with residual visual acuity deficits, ocular motor abnormalities, deficient fine motor skills, and risk for recurrent amblyopia. Using a combination of psychophysical, electrophysiological, imaging, risk factor analysis, and fine motor skill assessment, the primary role of binocular dysfunction in the genesis of amblyopia and the constellation of visual and motor deficits that accompany the visual acuity deficit has been identified. These findings motivated us to evaluate a new, binocular approach to amblyopia treatment with the goals of reducing or eliminating residual and recurrent amblyopia and of improving the deficient ocular motor function and fine motor skills that accompany amblyopia.
Topics: Amblyopia; Child; Child, Preschool; Humans; Infant; Strabismus; Vision, Binocular
PubMed: 23201436
DOI: 10.1016/j.preteyeres.2012.11.001 -
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 -
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 -
Clinical & Experimental Optometry Nov 2019Aniseikonia is a difference in the perceived size or shape of images between eyes, and can arise from a variety of physiological, neurological, retinal, and optical... (Review)
Review
Aniseikonia is a difference in the perceived size or shape of images between eyes, and can arise from a variety of physiological, neurological, retinal, and optical causes. Aniseikonia is associated with anisometropia, as both anisometropia itself and the optical correction for anisometropia can cause aniseikonia. Image size differences above one to three per cent can be clinically symptomatic. Common symptoms include asthenopia, headache and diplopia in vertical gaze. Size differences of three and more impair binocular visual functions such as binocular summation and stereopsis. Above five per cent of aniseikonia, binocular inhibition or suppression tend to occur to prevent diplopia and confusion. Aniseikonia can be measured using a range of techniques and can be corrected or reduced by prescribing contact lenses or specially designed spectacle lenses. Subjective testing of aniseikonia is the only way to accurately measure the overall perceived amount of aniseikonia. However, currently it is not routinely assessed in most clinical settings. At least two-thirds of patients with amblyopia have anisometropia, thus we may expect aniseikonia to be common in patients with anisometropic amblyopia. However, aniseikonia may not be experienced by the patient under normal binocular viewing conditions if the image from the amblyopic eye is of poor quality or is too strongly suppressed for image size differences to be recognised. This lack of binocular simultaneous perception in amblyopia may also prevent the measurement of aniseikonia, as most common techniques require direct comparisons of images seen by each eye. Current guidelines for the treatment of amblyopia advocate full correction of anisometropia to equalise image clarity, but do not address aniseikonia. Significant image size differences between eyes may lead to suppression and abnormal binocular adaptations. It is possible that correcting anisometropia and aniseikonia simultaneously, particularly at the initial diagnosis of anisometropia, would reduce the need to develop suppression and improve treatment outcomes for anisometropic amblyopia.
Topics: Amblyopia; Aniseikonia; Anisometropia; Humans
PubMed: 30791133
DOI: 10.1111/cxo.12881 -
Vision Research May 2017We investigated the potential causal relationships between anisometropia, amblyopia and strabismus, specifically to determine whether either amblyopia or strabismus... (Review)
Review
We investigated the potential causal relationships between anisometropia, amblyopia and strabismus, specifically to determine whether either amblyopia or strabismus interfered with emmetropization. We analyzed data from non-human primates that were relevant to the co-existence of anisometropia, amblyopia and strabismus in children. We relied on interocular comparisons of spatial vision and refractive development in animals reared with 1) monocular form deprivation; 2) anisometropia optically imposed by either contact lenses or spectacle lenses; 3) organic amblyopia produced by laser ablation of the fovea; and 4) strabismus that was either optically imposed with prisms or produced by either surgical or pharmacological manipulation of the extraocular muscles. Hyperopic anisometropia imposed early in life produced amblyopia in a dose-dependent manner. However, when potential methodological confounds were taken into account, there was no support for the hypothesis that the presence of amblyopia interferes with emmetropization or promotes hyperopia or that the degree of image degradation determines the direction of eye growth. To the contrary, there was strong evidence that amblyopic eyes were able to detect the presence of a refractive error and alter ocular growth to eliminate the ametropia. On the other hand, early onset strabismus, both optically and surgically imposed, disrupted the emmetropization process producing anisometropia. In surgical strabismus, the deviating eyes were typically more hyperopic than their fellow fixating eyes. The results show that early hyperopic anisometropia is a significant risk factor for amblyopia. Early esotropia can trigger the onset of both anisometropia and amblyopia. However, amblyopia, in isolation, does not pose a significant risk for the development of hyperopia or anisometropia.
Topics: Amblyopia; Animals; Anisometropia; Disease Models, Animal; Macaca; Strabismus; Visual Acuity
PubMed: 28404522
DOI: 10.1016/j.visres.2017.03.004 -
Vision Research Sep 2015In the past 20 years, there has been a great advancement in knowledge pertaining to compliance with amblyopia treatments. The occlusion dose monitor introduced... (Review)
Review
In the past 20 years, there has been a great advancement in knowledge pertaining to compliance with amblyopia treatments. The occlusion dose monitor introduced quantitative monitoring methods in patching, which sparked our initial understanding of the dose-response relationship for patching amblyopia treatment. This review focuses on current compliance knowledge and the impact it has on patching and atropine amblyopia treatment.
Topics: Amblyopia; Atropine; Child; Humans; Mydriatics; Patient Compliance; Sensory Deprivation; Visual Acuity
PubMed: 25743080
DOI: 10.1016/j.visres.2015.02.012 -
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 -
European Journal of Ophthalmology Jan 2022The most common cause of vision impairment in children is amblyopia. It is defined as impaired visual acuity in one or both eyes that is present with no demonstrable...
The most common cause of vision impairment in children is amblyopia. It is defined as impaired visual acuity in one or both eyes that is present with no demonstrable abnormality of the visual pathway and is not immediately resolved by wearing glasses. After the World Health Organization (WHO) recognized COVID-19 as a global pandemic on March 11, 2020, widespread changes and restrictions to social and sanitary practices have presented significant issues in access to eye care during the COVID-19 pandemic. A reduction of more than 80% in pediatric eye care volume up to its total cessation has been observed in different departments. In this scenario, reduced or absent eyesight, due to delay in timely treatment of amblyopic conditions, could create major, long-lasting effects on all aspects of life, including daily personal activities, interacting with the community, school and work opportunities and the ability to access public services. Processes coming out of lockdown should be gradually easing restrictions giving priority to ophthalmology and eye care facilities so that amblyopia does not remain unattended and irreversible as in adults due to lack of timely treatments. If not reversible, this process could lead to a dramatic increase in disability and unsustainable social costs for many governments.
Topics: Adult; Amblyopia; COVID-19; Child; Communicable Disease Control; Disease Outbreaks; Humans; Myopia; Pandemics; SARS-CoV-2
PubMed: 34751045
DOI: 10.1177/11206721211053175 -
British Medical Bulletin Sep 2016With a prevalence of 2-5%, amblyopia is the most common vision deficit in children in the UK and the second most common cause of functional low vision in children in... (Review)
Review
INTRODUCTION OR BACKGROUND
With a prevalence of 2-5%, amblyopia is the most common vision deficit in children in the UK and the second most common cause of functional low vision in children in low-income countries.
SOURCES OF DATA
Pubmed, Cochrane library and clinical trial registries (clinicaltrials.gov, ISRCTN, UKCRN portfolio database).
AREAS OF AGREEMENT
Screening and treatment at the age of 4-5 years are cost efficient and clinically effective. Optical treatment (glasses) alone can improve visual acuity, with residual amblyopia treated by part-time occlusion or pharmacological blurring of the better-seeing eye. Treatment after the end of the conventional 'critical period' can improve vision, but in strabismic amblyopia carries a low risk of double vision.
AREAS OF CONTROVERSY
It is not clear whether earlier vision screening would be cost efficient and associated with better outcomes. Optimization of treatment by individualized patching regimes or early start of occlusion, and novel binocular treatment approaches may enhance adherence to treatment, provide better outcomes and shorten treatment duration.
GROWING POINTS
Binocular treatments for amblyopia.
AREAS TIMELY FOR DEVELOPING RESEARCH
Impact of amblyopia on education and quality of life; optimal screening timing and tests; optimal administration of conventional treatments; development of child-friendly, effective and safe binocular treatments.
Topics: Amblyopia; Child; Cost-Benefit Analysis; Early Diagnosis; Eyeglasses; Humans; Mass Screening; Prevalence; Quality of Life; Treatment Outcome; United Kingdom
PubMed: 27543498
DOI: 10.1093/bmb/ldw030