A randomized trial to evaluate 2 hours of daily patching for strabismic and anisometropic amblyopia in children

Abstract

Objective: To compare 2 hours of daily patching (combined with 1 hour of concurrent near visual activities) with a control group of spectacle wear alone (if needed) for treatment of moderate to severe amblyopia in children 3 to 7 years old.

Design: Prospective randomized multicenter clinical trial (46 sites).

Participants: One hundred eighty children 3 to 7 years old with best-corrected amblyopic-eye visual acuity (VA) of 20/40 to 20/400 associated with strabismus, anisometropia, or both who had worn optimal refractive correction (if needed) for at least 16 weeks or for 2 consecutive visits without improvement.

Intervention: Randomization either to 2 hours of daily patching with 1 hour of near visual activities or to spectacles alone (if needed). Patients were continued on the randomized treatment (or no treatment) until no further improvement was noted.

Main outcome measure: Best-corrected VA in the amblyopic eye after 5 weeks.

Results: Improvement in VA of the amblyopic eye from baseline to 5 weeks averaged 1.1 lines in the patching group and 0.5 lines in the control group (P = 0.006), and improvement from baseline to best measured VA at any visit averaged 2.2 lines in the patching group and 1.3 lines in the control group (P<0.001).

Conclusion: After a period of treatment with spectacles, 2 hours of daily patching combined with 1 hour of near visual activities modestly improves moderate to severe amblyopia in children 3 to 7 years old.

Figures

Figure 1

Flowchart showing study completion for patching and control groups – primary cohort. Both patching and control groups wore spectacles if required, and the patching group was prescribed 2 hours of patching per day plus one hour of near activities. Patients continued with these treatments until there was no improvement or the IOD6 to 10 weeks). In the control group, 79 patients completed the outcome examination within the time window (4 - 6 weeks), 2 were early (3 to 6 to 10 weeks). IOD – Interocular acuity difference

Figure 2

Cumulative distribution of best measured amblyopic eye visual acuity scores obtained at any study visit according to group assignment at randomization – primary cohort. A. Patients with moderate amblyopia at baseline (20/40-20/100). B. Patients with severe amblyopia at baseline (20/125-20/400).

Figure 2

Cumulative distribution of best measured amblyopic eye visual acuity scores obtained at any study visit according to group assignment at randomization – primary cohort. A. Patients with moderate amblyopia at baseline (20/40-20/100). B. Patients with severe amblyopia at baseline (20/125-20/400).