The course of moderate amblyopia treated with patching in children: experience of the amblyopia treatment study.
OBJECTIVE
To assess the course of the response to patching treatment of moderate amblyopia and to assess factors predictive of the response in children 3 years old to younger than 7 years old.


METHODS
Multicenter, randomized clinical trial comparing patching and atropine (one of the amblyopia treatment studies).


METHODS
A total of 209 children 3 years old to younger than 7 years of age with amblyopia in the range of 20/40 to 20/100 from the patching treatment arm of this trial were treated with patching of the sound eye from 6 hours per day up to all waking hours. Follow-up examinations were performed at 5 weeks, 16 weeks, and 6 months. The primary outcome measure was visual acuity in the amblyopic eye at 6 months.


RESULTS
After 5 weeks of treatment, mean amblyopic eye acuity improved from baseline by 2.2 lines. For patients with baseline acuity of 20/80 or 20/100, a greater number of hours of prescribed patching was associated with greater improvement in the first 5 weeks (P =.05). However, this relationship was not present when baseline acuity was 20/40 to 20/60 (P =.57). At 6 months, visual acuity was improved from baseline by a mean of 3.1 lines, with the amount of improvement no longer related to the number of hours patching prescribed at baseline (P =.93). Among the 157 patients improving at least 3 lines from baseline, 15% achieved their maximum improvement by 5 weeks and 52% by 16 weeks. None of the demographic or clinical factors assessed was predictive of the response to treatment.


CONCLUSIONS
In the treatment of moderate amblyopia, a beneficial effect of patching is present throughout the age range of 3 years old to younger than 7 years old and the acuity range of 20/40 to 20/100. At 6 months, the amount of improvement appears to be similar when 6 hours of daily patching are initially prescribed vs a greater number of hours. However, when the baseline acuity is 20/80 to 20/100, a greater number of hours of prescribed patching may improve acuity faster.
D000550:Amblyopia / Q000503:physiopathology / Q000628:therapy*; D001285:Atropine / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009184:Mydriatics / Q000627:therapeutic use; D012683:Sensory Deprivation; D013997:Time Factors; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology*
D009184:Mydriatics; D001285:Atropine