Purpose: Although numerous studies have shown that perceptual learning can improve deficient visual functions in adults with amblyopia, the efficacy of perceptual learning in treating children with amblyopia has rarely been investigated. Here, we designed a child-friendly, individualized adaptive vision training (iAVT) based on a visual training procedure originally developed to train adults with amblyopia (Zhou et al., 2006) to evaluate e?ects of perceptual learning in children with amblyopia.
Methods: Nineteen amblyopic children (7.78±2.73 yrs) were trained with the iAVT in a filtered letter E orientation identification task near their individual cutoff frequency for 8 sessions, with 300 trials or 30 minutes per session. Contrast sensitivity function (CSF) and visual acuity in both the amblyopic and fellow eyes, and stereo acuity were assessed before and after training. CSF was measured using the qCSF procedure (Lesmes, Lu, Baek, & Albright, 2010). Each qCSF assessment took less than ?ve minutes.
Results: Training signi?cantly improved visual acuity (2 lines) and contrast sensitivity (53.9%, from 13.01 to 20.02, p< 0.0001) in the amblyopic eye, stereo acuity (80.8%, from 606 to 116.2, p< 0.0001), and contrast sensitivity (24.7%, from 28.4 to 35.4, p< 0.01) in the fellow eye. The magnitudes of improvements were correlated with pre-training visual deficits: The worse the pre-training measure was, the greater the improvements. Interestingly, we found no significant correlation among the magnitudes of improvements in visual acuity, contrast sensitivity, and stereo acuity (all p > 0.39).
Conclusions: These results demonstrate the merit of perceptual learning in treating children with amblyopia. Consistent with results in adults with amblyopia (Xi, Jia, Feng, Lu, & Huang, 2014), the lack of correlation among improvements in visual acuity, contrast sensitivity, and stereo acuity suggests that structured monocular and binocular treatments are necessary to fully restore de?cient visual functions in amblyopia.