A pilot study of anisometropic amblyopia improved in adults and children by perceptual learning: an alternative treatment to patching

Abstract

Background: To compare the effects of perceptual learning or patching on improving visual acuity and contrast sensitivity in patients with anisometropic amblyopia.

Methods: Patients with anisometropic amblyopia received either patching or perceptual learning treatment. Corrected amblyopic logMAR visual acuity and contrast sensitivity function were measured at four-weekly intervals until visual acuity stabilized or amblyopia resolved. Improvements in visual acuity, contrast sensitivity and resolution of amblyopia were compared between the two groups.

Results: The mean visual acuities of the amblyopic eyes improved by 0.34 logMAR (95% CI: 0.22-0.47 logMAR) with patching and 0.25 logMAR (95% CI: 0.16-0.35 logMAR) with perceptual learning (p=0.125). Resolution of amblyopia was achieved in 10 of 26 patients (38%) in the perceptual learning group and 17 of 27 patients (63%) in the patching group (p=0.809). Amblyopia improved by two or more lines in 20 of 26 (76%) patients in the perceptual learning group and 26 of 27 (96%) patients in the patching group (p=0.0001). The mean time for patching was 37.3 weeks (522.2 h) and the average number of training sessions in the perceptual learning group was 48 (29.5 h) (p=0.0001).

Conclusions: Visual acuity can be improved with perceptual learning and patching in older children and adult patients with anisometropic amblyopia. The improvements in visual acuity achieved with patching were one line better than those achieved with perceptual learning. Perceptual learning might provide an alternative treatment in patients with anisometropic amblyopia.