Microvascular changes in amblyopic eyes detected by optical coherence tomography angiography

Abstract

To investigate retinal microvascular findings detected by optical coherence tomography angiography (OCT-A) in amblyopic eyes compared with normal eyes. A total of 23 amblyopic (strabismic, ametropic, anisometropic, and meridional amblyopia) and 22 normal eyes were included in this prospective observational, comparative study. All patients underwent complete ophthalmological examination and OCT-A imaging. Vessel density (VD) percentage in the superficial and deep retinal vessel plexus, foveal avascular zone (FAZ) area, flow area in the outer retina and choriocapillaris, and retinal thickness in μm in a 6.00×6.00mm scan size were measured and compared between groups. There were no statistically significant differences between groups in terms of age (P=0.584) and sex (P=0.661). Mean FAZ area was smaller in the amblyopic group; however, the difference was not statistically significant (P=0.145). The outer retina flow area was significantly wider in the amblyopic group (P=0.03). The fovea was thicker in the amblyopic group (P=0.02). In addition, VD in both the superficial and deep retinal plexus was significantly lower in amblyopic eyes in all quadrants except the fovea. In amblyopic subgroups, VD of anisometropic amblyopic eyes was significantly higher than other subgroups in both superficial and deep retinal plexuses at all regions except the fovea. Other measures were similar in between groups. Microvascular retinal structural anomalies detectable on OCT-A could shed further light on the causes of amblyopia.