Macular edema (ME) secondary to central retinal vein occlusion（CRVO) often cause severe visual impairment. Intravitreal anti-vascular endothelial growth factor agents and steroids can effectively eliminate ME and improve visual function, but the visual outcome is affected by multiple factors. Retinal blood flow, especially the macular microcirculation, has significant correlation with visual outcome. Ischemic CRVO, especially patients with severe damage in the deep and superficial vascular layer of the macular zone, usually have poor visual outcome. In addition, the integrity of the multi-layer retinal structure closely correlates with the visual outcome. Patients with intact ellipsoid zone, external limit membrane beneath the fovea have good visual recovery. Additionally, good baseline visual acuity, positive response to treatment in early phase, young age and timely treatment usually brings about better visual outcome.