Diabetic retinopathy (DR) is the main cause of blindness among working-age adults in the world. Proliferative diabetic retinopathy (PDR) is the severe stage of DR, which is characterized by neovascularization of the retina. Vitreous hemorrhage and traction retinal detachment caused by PDR often require vitrectomy. The purpose of vitrectomy is to remove vitreous hemorrhage, peel off the preretinal proliferative membrane and help restore the retina. With the deepening of people's understanding of diabetes and the development and application of various hypoglycemic drugs, the life expectancy of patients with diabetes continues to prolong. Therefore, the goal of vitrectomy in patients with DR is not only to prevent blindness, but also to maintain good vision for a long time. The purpose of this study is to analyze the risk factors related to the occurrence of long-term low vision postoperatively and establish a risk prediction model, which can help patients adjust their psychological expectations reasonably and promote communication between doctors and patients.