Chen L, Yuan M, Sun L, et al. - Among 47 unilateral branch retinal vein occlusions (BRVO) patients and 47 normal controls, researchers assessed changes of microvascular network of macular and peripapillary regions and provided a quantitative measurement of foveal avascular zone (FAZ). According to findings, optical coherence tomography angiography provided quantitative information relating to BRVO vascular changes. FAZ in BRVO eyes displayed significant morphological changes and declines of vessel density (VD) in surrounding area. Decreases of VD in macular region not only occurred in SVC and DVC but also in radial peripapillary capillary in BRVO eyes. Unaffected eyes of unilateral BRVO displayed vascular abnormalities in superficial retinal layer, peri-FAZ area, and even peripapillary regions.