Anti-vascular endothelial growth factor(VEGF)agents are revolutionary in the treatment of retinal diseases, such as exudative age-related macular degeneration,diabetic retinopathy(DR), and retinal vein occlusion. Intravitreal injection of anti-VEGF agents can reduce macular edema significantly, but whether anti-VEGF therapy impairs retinal microcirculation and facilitates retinal vascular occlusion. This article reviews on the effect of anti-VEGF therapy on retinal capillary in diabetic macular edema, from three aspects of foveal avascular zones, areas of nonperfusion and retinal capillary density, using optical coherence tomography angiography(OCTA)and ultra-wide field fluorescein angiography(UWFA).