A Randomized Pilot Study of Near Activities Versus Non-Near Activities During Patching Therapy for Amblyopia

Abstract

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. 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. 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. 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.