Evaluation of retinal microcirculation alterations using OCTA in hyperopic ametropic amblyopia patients before and after treatment

PURPOSE: We aimed to compare retinal microcirculation in hyperopic ametropic amblyopia patients before and after treatment and in healthy children using optical coherence tomography angiography (OCTA), and to explore the pathogenesis of hyperopic ametropic amblyopia. METHODS: Eighteen patients with hyperopic ametropic amblyopia aged 4–8 years were selected as the patient group, and 18 age-matched healthy children were randomly selected as controls. The foveal avascular zone (FAZ) area, perimeter and circularity, vessel density (VD) and perfusion density (PD) of macular superficial retinal capillary plexus, macular thickness, peripapillary retinal nerve fiber layer thickness, and ganglion cell-inner plexiform layer thickness were compared between both groups. After 6 months of amblyopia treatment, the same parameters were measured again. RESULTS: The VD and PD in the central, inner, inner nasal, and inner inferior regions in hyperopic ametropic amblyopia were lower than in the control group after adjustment for axial length. After 6 months of treatment, the VD increased significantly, except in the outer nasal and outer inferior regions. The PD in the central (p < 0.001), inner superior (p = 0.001), inner inferior (p = 0.011) and inner temporal (p = 0.026) regions increased. The FAZ perimeter and circularity significantly differed between the groups. After 6 months of treatment, the FAZ area and perimeter decreased, but circularity increased. CONCLUSION: Hyperopic ametropic amblyopia eyes showed a significant decrease in vessel and perfusion densities. After amblyopia treatment, the vessel and perfusion densities of patients with hyperopic ametropic amblyopia increased, suggesting that abnormalities in the microvascular system are a pathogenic factor of amblyopia.