Microvascular differences in amblyopic subgroups: An observational case-control study.

Abstract

To determine retinal microvascular differences among amblyopic subgroups and compare them with control eyes. This study was designed as an observational case-control study. Twenty-three strabismic, 23 anisometropic, 22 meridional, 22 ametropic amblyopic eyes, and 24 healthy control eyes were included. The mean vessel densities in the deep and superficial capillary plexus, the foveal avascular zone area, the choriocapillaris flow area, and the foveal thickness were compared. Vessel density was markedly lower in all sectors of the amblyopic subgroups in the deep capillary plexus than in control eyes. Density was significantly lower in the superficial capillary plexus only in ametropic and meridional amblyopic eyes. Among these groups, the meridional amblyopic eyes had the largest choriocapillaris flow area (p = 0.013) and the lowest vessel density in all sectors (p < 0.001). The foveal avascular zone area was similar in all groups (p = 0.561). The fovea was significantly thicker only in the anisometropic and meridional subgroups than control eyes (p = 0.011, p = 0.001, respectively). The foveal avascular zone area was inversely related to the foveal thickness in all groups. Retinal structural and microvascular differences were found among amblyopic subgroups. Optical coherence tomography angiography can noninvasively detect these variations, which may be related to the etiologic factors.