Diabetes mellitus damages the retinal microvasculature, resulting in retinal capillary endothelial cell damage and leakage, manifested as retinal edema, punctate hemorrhage, exudation, macular cystoid edema; retinal circulation impairment, limited retinal hypoxia causing capillary occlusion, resulting in microangioma and neovascularization, with the aggravation of the disease, vitreous blood accumulation, proliferation pull retinal detachment. In terms of treatment, the first step is to actively control blood sugar, blood pressure and blood lipids; if retinal ischemia reaches a certain level, retinal photocoagulation therapy is required, as judged by retinal angiography; if diabetic retinopathy enters the proliferative phase (severe vitreous hemosiderosis, vitreoretinal proliferation), surgical treatment is required.