Abstract
PURPOSE: To investigate retinal microvascular functional differences among amblyopic eyes, fellow eyes of patients with anisometropic amblyopia, and healthy controls using three-dimensional optical coherence tomography angiography (3D-OCTA). METHODS: This study included 52 participants (78 eyes): 26 amblyopic eyes, 26 fellow eyes in anisometropic amblyopia patients, and 26 age-matched healthy controls. Using 3D-OCTA, retinal microvascular parameters in the parafoveal region were evaluated, including vessel tortuosity index (VTI), vessel volume density (VVD), vessel skeleton density (VSD), and vessel diameter index (VDI) in the superficial vascular plexus, intermediate capillary plexus, and deep capillary plexus. Intergroup differences were analyzed using generalized estimating equations with Bonferroni-adjusted pairwise comparisons. RESULTS: Both amblyopic and fellow eyes in anisometropic amblyopia patients showed reduced VVD and VSD across multiple sectors compared to healthy controls, with further reductions in amblyopic eyes in select regions. The VDI was elevated in both amblyopic and fellow eyes relative to healthy controls (P < 0.05), with no difference between the two (P = 1.00). The VTI was significantly higher in amblyopic eyes than in healthy controls (1.42 ± 0.005 vs. 1.41 ± 0.019; P = 0.01), but differences involving fellow eyes were not significant (P > 0.3). CONCLUSIONS: Amblyopic eyes showed decreased retinal perfusion, with increased vessel diameter and tortuosity, and fellow eyes in anisometropic amblyopia patients also demonstrated deviations in vascular parameters compared to healthy controls. TRANSLATIONAL RELEVANCE: Retinal vascular changes detected by 3D-OCTA may provide non-invasive biomarkers for early detection, progression monitoring, and treatment evaluation of anisometropic amblyopia.