Occlusion Versus Pharmacologic Therapy for Moderate Amblyopia
Summary
- To determine whether the success rate with drug treatment (atropine) of amblyopia due to strabismus or anisometropia in patients less than 7 years old is equivalent to the success rate with occlusion (patching) therapy
- To develop more precise estimates of the success rates of amblyopia treatment
- To identify factors that may be associated with successful treatment of amblyopia
- To collect data on the course of treated amblyopia to provide more precise estimates of treatment effects than are now available
Extended Follow up of Study Patients
- Primary: To determine the long-term visual acuity outcome at age 10 years and at age 15 years in patients diagnosed with amblyopia before age 7 years.
- Secondary: To determine whether the long-term visual acuity outcome at age 10 years and at age 15 years differs between patients who received patching followed by best clinical care and patients who received atropine followed by best clinical care
Description
Amblyopia, or lazy eye, is the most common cause of visual impairment in children and often persists in adulthood. It is reported to be the leading cause of vision loss in one eye in the 20-70 year old age group, with a prevalence of 1-4 percent in various studies, indicating that both improved means of detection and treatment are needed.
Most of the available data on the natural history of amblyopia and success rates of its treatment with either patching or drug therapy are retrospective and uncontrolled. Despite the common occurrence of amblyopia, there is little quality data on treatment of this condition. Thus, there is much to be learned about the course of treated amblyopia, to provide more precise estimates of success rates and to identify factors that may be associated with successful and unsuccessful treatment.
Amblyopia, when diagnosed in children, is usually treated with occlusion (patching) of the sound eye. Occlusion therapy is subject to problems of compliance, due to the child's dislike of wearing a patch for visual, skin irritation, and social/psychological reasons. There is evidence that compliance may be one of, if not, the most important determinant of success of amblyopia therapy.
An alternative treatment, drug therapy with a cycloplegic drug (atropine) that dilates the pupils and blurs the image seen by the sound eye, has been known for almost a century. This method has been widely used for the management of occlusion treatment failures and for maintenance therapy. However, it has seen little use as a primary treatment for amblyopia. Clinical experience has found that it has a high acceptability to patients and parents, and hence high compliance. In addition to its acceptability, pharmacologic therapy has the known advantage over occlusion of providing a wider visual field with both eyes, which may have safety and other functional implications. There is also clinical and laboratory evidence suggesting that drug therapy may maintain and improve the ability to see with both eyes (binocularity).
Available data suggest that the success rate with drug therapy is as good as, if not better than, the success rate with occlusion therapy for mild to moderate degrees of amblyopia. If this is true, for many children with amblyopia, drug therapy may be the preferred initial therapy since it appears to be more readily accepted by the children and parents. Despite data to support the use of drug therapy as a primary therapy for amblyopia, it has gained only limited use among pediatric ophthalmologists. A definitive study comparing the outcomes from occlusion therapy and drug therapy is justified in order to determine if new practice guidelines for treatment of amblyopia are needed.
Regardless of whether the trial determines that one therapeutic approach is better than the other, the data that are collected will provide valuable information about the course of amblyopia treatment that is not presently available. The study also is expected to provide data that will help to determine whether factors such as age, refractive status, cause of amblyopia, or fixation pattern should be considered in determining which procedure is best for a given patient.
Extended Follow-up of Study Patients
The extended follow up study consists of annual visits prior to age 10, followed by a visit at age 10 years and a visit at age 15 years. There is no amblyopia treatment that is required during the extended follow up period.
Study Design
Allocation: Randomized, Control: Uncontrolled, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Treatment
Conditions
Amblyopia
Intervention
Atropine, Eye Patch
Location
Wilmer Eye Institute
Baltimore
Maryland
United States
21287-9028
Status
Active, not recruiting
Source
Jaeb Center for Health Research
Results (where available)
Links
- Source: http://clinicaltrials.gov/show/NCT00000170
- Information obtained from ClinicalTrials.gov on July 15, 2010
Published on BioPortfolio: 2014-08-27T04:00:15-0400
Clinical Trials
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Trial Comparing Patching Versus Atropine for Amblyopia in 7 to < 13 Year Olds
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Efficacy of Over-glasses Patch Treatment for Amblyopia in Children : OPTA Study
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Amblyopia (Lazy Eye) Treatment Study
The purpose of this study is to compare the results of two standard treatments for amblyopia in order to find out if one is more effective than the other. Amblyopia, which develops in chi...
Increasing Patching for Amblyopia in Children 3 to < 8 Years Old
This study is designed to evaluate the effectiveness of increasing prescribed patching treatment from 2 to 6 daily hours after visual acuity has stabilized with initial treatment and ambly...
PubMed Articles
Cerebral structural characteristics in children with unilateral amblyopia: a MRI study.
To study the mechanism of the development of amblyopia using the analysis of brain grey matter parameters. The areas primarily associated with visual cortex in children with amblyopia were analyzed.
Audiovisual perception in amblyopia: A review and synthesis.
Amblyopia is a common developmental sensory disorder that has been extensively and systematically investigated as a unisensory visual impairment. However, its effects are increasingly recognized to ex...
Specific quantification of atropine using molecularly imprinted polymer on graphene quantum dots.
Herein, development of a reliable and specific fluorometric assay was disclosed for the sensitive detection of atropine. The method was designed using the surface molecularly imprinted polymer on high...
Global and regional estimates of prevalence of amblyopia: A systematic review and meta-analysis.
Amblyopia is one of the most important causes of vision impairment in the world, especially in children. Although its prevalence varies in different parts of the world, no study has evaluated its prev...
Suppression in amblyopia may be an unequal form of normal interocular suppression or a distinct pathophysiology. To explore this issue, we examined the orientation tuning and contrast dependence of co...
Medical and Biotech [MESH] Definitions
Amblyopia
A nonspecific term referring to impaired vision. Major subcategories include stimulus deprivation-induced amblyopia and toxic amblyopia. Stimulus deprivation-induced amblyopia is a developmental disorder of the visual cortex. A discrepancy between visual information received by the visual cortex from each eye results in abnormal cortical development. STRABISMUS and REFRACTIVE ERRORS may cause this condition. Toxic amblyopia is a disorder of the OPTIC NERVE which is associated with ALCOHOLISM, tobacco SMOKING, and other toxins and as an adverse effect of the use of some medications.
Patch-clamp Techniques
An electrophysiologic technique for studying cells, cell membranes, and occasionally isolated organelles. All patch-clamp methods rely on a very high-resistance seal between a micropipette and a membrane; the seal is usually attained by gentle suction. The four most common variants include on-cell patch, inside-out patch, outside-out patch, and whole-cell clamp. Patch-clamp methods are commonly used to voltage clamp, that is control the voltage across the membrane and measure current flow, but current-clamp methods, in which the current is controlled and the voltage is measured, are also used.
Transdermal Patch
A medicated adhesive patch placed on the skin to deliver a specific dose of medication into the bloodstream.
Patch Tests
Skin tests in which the sensitizer is applied to a patch of cotton cloth or gauze held in place for approximately 48-72 hours. It is used for the elicitation of a contact hypersensitivity reaction.
Atropine Derivatives
Analogs and derivatives of atropine.
