A comparison of atropine and patching treatments for moderate amblyopia by patient age, cause of amblyopia, depth of amblyopia, and other factors

Abstract

Objective: To assess whether the relative treatment effect of patching compared with atropine for moderate amblyopia varies according to patient age, cause of amblyopia or depth of amblyopia, and initial number of patching hours prescribed.

Design: Multicenter, randomized clinical trial.

Participants: Four hundred nineteen children younger than 7 years of age with amblyopia in the range of 20/40 to 20/100.

Methods: Patients were assigned randomly to receive treatment with either patching or atropine and followed up for 6 months.

Primary outcome measure: Single-surrounded HOTV optotype visual acuity in the amblyopic eye after 6 months.

Results: Improvement in the amblyopic eye visual acuity was slightly greater in the patching group compared with the atropine group in all subgroups based on patient characteristics. The relative treatment effect did not vary with age (P = 0.84), cause of amblyopia (P = 0.68), or baseline amblyopic eye acuity (P = 0.59). Patients with acuity of 20/80 to 20/100 who were prescribed 10 or more hours a day of patching showed a more rapid improvement in acuity than did patients prescribed a lesser amount of patching (P = 0.01) or than did patients in the atropine group (P < 0.001), but by 6 months, the differences were not significant (P = 0.47 and 0.15, respectively).

Conclusions: A beneficial effect of both patching and atropine is present throughout the age range of 3 to younger than 7 years old and the acuity range of 20/40 to 20/100. Patients with acuity of 20/80 to 20/100 improve faster when a greater number of hours of patching is prescribed, but by 6 months, the amount of improvement is not related to the number of hours of patching initially prescribed.