Background: To plan a future randomized clinical trial, we conducted a pilot study to determine whether children randomized to near or non-near activities would perform prescribed activities. A secondary aim was to obtain a preliminary estimate of the effect of near versus non-near activities on amblyopic eye visual acuity, when combined with 2 hours of daily patching.
Methods: Sixty-four children, 3 to less than 7 years of age, with anisometropic, strabismic, or combined amblyopia (20/40 to 20/400) were randomly assigned to receive either 2 hours of daily patching with near activities or 2 hours of daily patching without near activities. Parents completed daily calendars for 4 weeks recording the activities performed while patched and received a weekly telephone call in which they were asked to describe the activities performed during the previous 2 hours of patching. Visual acuity was assessed at 4 weeks.
Results: The children assigned to near visual activities performed more near activities than those assigned to non-near activities (by calendars, mean 1.6 +/- 0.5 hours versus 0.2 +/- 0.2 hours daily, P < 0.001; by telephone interviews, 1.6 +/- 0.4 hours versus 0.4 +/- 0.5 hours daily, P < 0.001). After 4 weeks of treatment, there was a suggestion of greater improvement in amblyopic eye visual acuity in those assigned to near visual activities (mean 2.6 lines versus 1.6 lines, P = 0.07). The treatment group difference in visual acuity was present for patients with severe amblyopia but not moderate amblyopia.
Conclusions: Children patched and instructed to perform near activities for amblyopia spent more time performing those near activities than children who were instructed to perform non-near activities. Our results suggest that performing near activities while patched may be beneficial in treating amblyopia. Based on our data, a formal randomized amblyopia treatment trial of patching with and without near activities is both feasible and desirable.