Comparison of Retinal and Choroidal Microvasculature Changes in Monocular Amblyopic and Non-amblyopic Eyes following Short-term Patch Occlusion Treatment

Abstract

Purpose: Our objective was to investigate whether there were differences in the short-term changes of retinal and choroidal microvasculature between amblyopic and non-amblyopic eyes after patch occlusion treatment in patients with monocular amblyopia. Additionally, we aimed to determine if these changes were associated with improvements in clinical parameters.

Methods: We conducted a retrospective, longitudinal paired-eye case-control study by analyzing the medical records of patients under the age of 12 who had monocular amblyopia and underwent patch occlusion treatment for a duration of 2 to 12 months. Using optical coherence tomography angiography images, we compared the foveal avascular zone width, retinal blood vessel density (VD), choroidal thickness (CT), and choroidal vascularity index (CVI) in amblyopic and non-amblyopic eyes before and after patch occlusion treatment. We analyzed the correlations between the aforementioned parameters and changes in best-corrected visual acuity (BCVA) and stereopsis.

Results: Overall, 114 eyes from 57 patients were enrolled. At baseline, parafoveal superficial plexus VD, foveal and parafoveal deep capillary plexus VD (DCPD) were lower by 0.994 ± 3.312% (p = .026), 2.403 ± 8.273% (p = .033), and 2.469 ± 4.095% (p < .001), respectively; CT was thicker by 30.6 ± 90.7 μm (p = .014); and CVI was higher by 1.920 ± 3.432% (p < 001) in the amblyopic eyes than in the non-amblyopic eyes. Following short-term patch occlusion treatment, foveal and parafoveal DCPD increased by 1.264 ± 3.829% (p = .017) and 1.028 ± 3.662% (p = .036), respectively, CT thinned by 15.5 ± 51.5 μm (p = .019), and CVI decreased by 1.296 ± 3.997% (p = .018) in the amblyopic eyes. Following patch occlusion treatment, as the foveal DCPD decreased and CVI increased, the BCVA improved (p = .017 and .035, respectively).

Conclusion: Following patch occlusion treatment, increased foveal DCPD and decreased CVI were associated with improved BCVA.