Trial Comparing Patching With Active Vision Therapy to Patching With Control Vision Therapy as Treatment for Amblyopia

Study Overview
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Brief Summary
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This study is comparing the effectiveness of patching combined with active vision therapy plus near activities versus patching combined with control vision therapy plus near activities for moderate amblyopia (20/40-20/100) in 7 to <13 year olds. The primary outcome measure is the proportion of patients with visual acuity of 20/25 or better in the amblyopic eye at the 17-week masked exam. These patients will be considered treatment responders. The primary analysis will consist of a comparison between the 2 treatment groups of the proportion of treatment responders with adjustment for baseline visual acuity. Secondary outcomes are stereoacuity at the 17-week masked exam, mean improvement in visual acuity at the 17-week masked exam, and rate of improvement of visual acuity.

Detailed Description
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Patching and atropine have been traditionally used for the improvement of visual acuity in children with amblyopia. Previous studies have shown that these methods of treatment are effective in young children with functional amblyopia. More recently ATS3, a randomized clinical trial of 507 children ages 7-<18, found that part-time patching combined with atropine and near activities improved visual acuity by two or more lines in 53% of the 7 to 12 year olds compared to 25% for optical correction alone. For the 13 to 17 year olds, part-time patching and near activities improved visual acuity by 2 or more lines in 25%, compared to 23% for optical correction alone. While it appears that patching and/or atropine, combined with near activities, can improve visual acuity in some patients ages 7-<18, most patients in the study were left with residual visual acuity deficits. To further improve visual acuity and binocularity in children with amblyopia some eye care providers augment these traditional therapies with vision therapy. Vision therapy is prescribed initially if there is moderate amblyopia with stereopsis. Vision therapy can be added to the treatment regimen once the patient has reached moderate levels of vision loss with stereopsis and if the patient is still not responding to the current treatment and still has moderate amblyopia. It is thought that the best candidates for this type of therapy are those children with a minimum level of stereopsis (at least 800) and without constant strabismus. Those children with no stereopsis would not be able to perform the activities in the later stages of therapy utilizing binocular vision. Vision therapy is a sequence of prescribed activities typically performed on a daily basis at home and weekly in-office, and is directed toward an individual patient's deficient skills. Visual skills are practiced under conditions that provide the patient with feedback. The feedback, along with a gradual increase in the demand of the activities as improvement occurs, enables the patient to improve visual functions such as visual acuity, fixation, accommodation, and vergence skills. There have been case reports and small sample studies that have shown that vision therapy in combination with spectacles and occlusion is effective in improving the visual acuity of patients with amblyopia. Wick et al looked at nineteen patients who were diagnosed with anisometropic amblyopia between the ages of 6 to 49. Seventeen of the patients had moderate amblyopia and two had severe amblyopia, based on the definition of amblyopia used in the Amblyopia Treatment Studies. The patients were treated with a sequence that included spectacle correction, occlusion therapy and both monocular and binocular vision therapy. Thirteen of the seventeen patients with moderate amblyopia had a final visual acuity of 20/25 or better and all of the patients with moderate amblyopia had 20/30 or better final visual acuity. More recent reports on perceptual learning, an active form of therapy in which amblyopic subjects practice a position-discrimination task, have shown a mean acuity improvement of approximately 30% (two lines) in amblyopic children and adults who had completed occlusion therapy. These studies provide support for the notion that the practice of particular visual skills under conditions that provide the patient with feedback (e.g., vision therapy) may be beneficial in improving the visual performance of amblyopic eyes. The second reason to prescribe active therapy is to enhance or facilitate the effects of occlusion by directly treating the aforementioned deficits found to be associated with amblyopia. Most therapy procedures are designed to remediate specific deficiencies in four main areas: fixation, spatial perception, accommodative efficiency, binocular function and oculomotor control. Lastly, some investigators have suggested that the use of vision therapy may reduce the likelihood of recurrence of the amblyopia. This may be particularly true with anisometropic amblyopia in which vision therapy can be used to improve binocular function.

Official Title
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A Randomized Trial Comparing Patching With Active Vision Therapy to Patching With Control Vision Therapy as Treatment for Amblyopia in Children 7 to <13 Years Old

Conditions
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Amblyopia

Intervention / Treatment
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* Device: Patching
* Procedure: Near activities
* Procedure: Active vision therapy
* Procedure: Control vision therapy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age 7 to <13 years Amblyopia associated with anisometropia, strabismus (comitant or incomitant), or both at the time of the eligibility examination Visual acuity in the amblyopic eye between 49 and 71 letters inclusive (20/40 to 20/100 inclusive) on the eETDRS Visual acuity in the sound eye of 79 or more letters on the eETDRS (20/25 or better) Inter-eye acuity difference of 15 or more letters (3 or more logMAR lines) At least 800 seconds of arc on the Randot Preschool Stereoacuity Test Previous or current amblyopia treatment with spectacles or contact lenses, patching or atropine is permitted. No myopia more than -6.00 D spherical equivalent in the amblyopic eye Single vision spectacles, if needed, worn for at least 16 weeks or until visual acuity documented to be stable The child has access to a computer on a daily basis (to use the home vision therapy software) Exclusion Criteria: Previous vision therapy or orthoptics Known skin reactions to patch or bandage adhesives Prior intraocular or refractive surgery Bifocals Constant strabismus at near at the eligibility examination A family member is (or has been) enrolled in this study

Ages Eligible for Study
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Minimum Age: 7 Years
Maximum Age: 12 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Active<br>2 hours of daily patching combined with 1 hour daily of near activities (that includes 30 minutes of at-home active vision therapy) and weekly in-office active vision therapy | Device: Patching<br>* 2 hours daily patching<br>* Other names: Coverlet, 3M Opticlude, Ortopad®;Procedure: Near activities<br>* 30 minutes daily near activities at home<br>Procedure: Active vision therapy<br>* 30 minutes of daily at-home active vision therapy and a weekly 45 minute in-office active vision therapy session<br>|
| Sham Comparator: Control<br>2 hours of daily patching combined with 1 hour of daily near activities (that includes 30 minutes of at-home control vision therapy) and weekly in-office control vision therapy | Device: Patching<br>* 2 hours daily patching<br>* Other names: Coverlet, 3M Opticlude, Ortopad®;Procedure: Near activities<br>* 30 minutes daily near activities at home<br>Procedure: Control vision therapy<br>* 30 minutes of daily at-home control vision therapy and a weekly 45 minute in-office control vision therapy session<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Distribution of Distance Visual Acuity in Amblyopic Eye at 17-week Outcome | Visual acuity was measured with the electronic early treatment diabetic retinopathy (E-ETDRS) method and resulted in a letter score that could range from 0 to 97 letters, with 0 being the worst and 97 being the best. | 17 weeks | 
| Mean (SD): Distance Visual Acuity in Amblyopic Eye at 17-week Outcome | Visual acuity was measured with the electronic early treatment diabetic retinopathy (E-ETDRS) method and resulted in a letter score that could range from 0 to 97 letters, with 0 being the worst and 97 being the best. | 17 weeks | 
| Distribution of Change in Amblyopic Eye Visual Acuity From Baseline to 17 Weeks | Visual acuity was measured with the electronic early treatment diabetic retinopathy (E-ETDRS) method and resulted in a letter score that could range from 0 to 97 letters, with 0 being the worst and 97 being the best. A difference was calculated as the difference in letters between baseline and outcome with positive difference indicating improvement in acuity. | Baseline to 17 weeks | 
| Mean (SD) of Change in Amblyopic Eye Visual Acuity From Baseline to 17 Weeks | Visual acuity was measured with the electronic early treatment diabetic retinopathy (E-ETDRS) method and resulted in a letter score that could range from 0 to 97 letters, with 0 being the worst and 97 being the best. A difference was calculated as the difference in letters between baseline and outcome with positive difference indicating improvement in acuity. | Baseline to 17 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Distribution of Fellow Eye Visual Acuity at 17 Weeks | Visual acuity was measured with the electronic early treatment diabetic retinopathy (E-ETDRS) method and resulted in a letter score that could range from 0 to 97 letters, with 0 being the worst and 97 being the best. | 17 weeks | 
| Mean (SD) of Fellow Eye Visual Acuity at 17 Weeks | Visual acuity was measured with the electronic early treatment diabetic retinopathy (E-ETDRS) method and resulted in a letter score that could range from 0 to 97 letters, with 0 being the worst and 97 being the best. | 17 weeks | 
| Distribution of Change in Fellow Eye Visual Acuity From Baseline to 17 Weeks | Visual acuity was measured with the electronic early treatment diabetic retinopathy (E-ETDRS) method and resulted in a letter score that could range from 0 to 97 letters, with 0 being the worst and 97 being the best. A difference was calculated as the difference in letters between baseline and outcome with positive difference indicating improvement in acuity. | Baseline to 17 weeks | 
| Mean (SD) of Change in Fellow Eye Visual Acuity From Baseline to 17 Weeks | Visual acuity was measured with the electronic early treatment diabetic retinopathy (E-ETDRS) method and resulted in a letter score that could range from 0 to 97 letters, with 0 being the worst and 97 being the best. A difference was calculated as the difference in letters between baseline and outcome with positive difference indicating improvement in acuity. | Baseline to 17 weeks | 
| Mean (SD) of Intereye Visual Acuity at 17 Weeks | Visual acuity was measured with the electronic early treatment diabetic retinopathy (E-ETDRS) method and resulted in a letter score that could range from 0 to 97 letters, with 0 being the worst and 97 being the best. | 17 weeks | 
| Mean (SD) of Change in Intereye Visual Acuity From Baseline to 17 Weeks | Visual acuity was measured with the electronic early treatment diabetic retinopathy (E-ETDRS) method and resulted in a letter score that could range from 0 to 97 letters, with 0 being the worst and 97 being the best. A difference was calculated as the difference in letters between baseline and outcome with positive difference indicating improvement in acuity. | Baseline to 17 weeks | 
| Distribution of Randot Preschool Stereoacuity at 17 Weeks | The Randot Preschool Stereotest measures stereopsis from 800 to 40 seconds of arc. This Stereotest is designed as a matching game in which the patient matches pictures in a test booklet wearing special glasses. A subject can fail the pretest (not see any pictures) or can score >800 (the worst), 800, 400, 200, 100, 60, or 40 (the best) seconds of arc. If two shapes are identified correctly the patient progresses to the next lower stereoacuity level. A failed test occurs when the patient cannot identify any shapes. | 17 weeks | 
| Distribution of Change in Randot Preschool Steroacuity From Baseline to 17 Weeks | The Randot Preschool Stereotest measures stereopsis from 800 to 40 seconds of arc on patients as young as 2 years of age. This Stereotest is designed as a matching game in which the patient matches pictures in a test booklet wearing special glasses. A subject can fail the pretest (not see any pictures) or can score >800 (the worst), 800, 400, 200, 100, 60, or 40 (the best) seconds of arc. If two shapes are identified correctly the patient progresses to the next lower stereoacuity level. A failed test occurs when the patient cannot identify any shapes. | Baseline to 17 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Amblyopia, Vision Therapy, Patching