Effectiveness of Monocular Orientation-Specific Perceptual Training in Restoring Visual Function of Residual Meridional Amblyopia

Abstract

Purpose : This investigation aims to evaluate the effectiveness of monocular orientation-specific perceptual training, a strategy developed for visual deficits related to meridional deprivation, in restoring spatial visual capabilities in individuals with residual meridional amblyopia.

Methods : The study enrolled twenty-one individuals with persistent meridional amblyopia, with an average age of 8.14 ± 0.91 years. These individuals were subjected to a 14-day regimen of monocular orientation-specific perceptual training, which was fixationally centered around a grating orientation discrimination exercise (±5°) aligned with the vertical or horizontal meridian based on each individual's threshold spatial frequencies. Evaluations of both the best-corrected and uncorrected visual acuity (VA) were carried out daily. Assessments before and after the training regimen encompassed measurements of both the best-corrected and uncorrected contrast sensitivity function (CSF) and stereoacuity. Additionally, retrospective data from 19 patients who underwent traditional monocular perceptual learning were also reviewed for comparative analysis regarding the effectiveness.

Results : Significant improvements were observed in uncorrected VA (increased by 1.3 lines, P < 0.001) and best-corrected VA (increased by 0.3 lines, P = 0.002). Post-training assessments showed enhancements in all measured CSF metrics, both with and without correction (all P < 0.05), and in both distance and near stereopsis (all P < 0.05). Compared to traditional training, the orientation-specific approach more effectively addressed residual deficits in uncorrected vision. Early changes in uncorrected VA correlated significantly with final VA outcomes. A 6-month follow-up confirmed the retention of these gains.

Conclusions : The use of monocular orientation-specific perceptual training has shown to be more effective in improving both uncorrected and best-corrected spatial and binocular functions in residual meridional amblyopia. These findings indicate a promising avenue for tailored visual rehabilitation approaches in the management of meridional amblyopia.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.