Perceptual learning based on lateral masking paradigm in anisometropic amblyopia with and without patching history

Abstract

Purpose : Perceptual learning (PL) has shown promising performance in visual function restoring in adolescent amblyopes. The potential impact of patching histories on PL remains to be verified. Here, we retrospectively compared the effect of a well-accepted PL paradigm based on lateral masking on anisometropic amblyopia with and without a patching history (PT group vs NPT group).

Methods : Eighteen PT and 13 NPT (mean age=11.97±3.14 years) with anisometropic amblyopia underwent monocular PL for three continuous months (40 sessions/days). All training was performed at home, except for the first week was performed under supervision at the hospital. During training, patients practiced a Gabor detection task following lateral masking paradigm by applying a temporal-2AFC procedure with the amblyopic eye (AE), while the fellow eye was patched. The interactive training data is connected to a central database server and optimized for the next training module. Monocular contrast sensitivity function (qCSF paradigm), monocular ETDRS visual acuity, interocular difference (IOD) of visual acuity, IOD of AULCSF, IOD of cut-off, and stereoacuity were compared before and after training.

Results : Training improved the visual acuity of AEs on average by 0.5 lines in the PT group and 1.5-line in the NPT group. A significant reduction in the IOD of visual acuity was also observed in the NPT group (P<0.01) but not in the PT group (P=0.05). For CSF metrics, area under the log CSF(AULCSF), cut-off, low spatial frequency-AULCSF and mid spatial frequency-AULCSF in the AEs of the NPT groups increased significantly after PL (P<0.05), except for the high spatial frequency-AULCSF. In addition, the IOD of AULCSF (P<0.01), the IOD of mid spatial frequency-AULCSF (P<0.01) and the IOD of cut-off (P<0.05) in the NPT group were also significantly reduced. However, in the PT group, all the CSF metrics including all the IOD of CSF metrics were unchanged after training (all P>0.05). 27/31 patients in both two groups had no measurable stereopsis pre-training, and recovery after training was not significant.

Conclusions : Monocular perceptual learning based on the lateral masking training paradigm improved visual function in anisometropic amblyopia beyond the critical period. Moreover, patients without patching therapy obtained more significant benefits of spatial vision and more balance vision function after training.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.