Anti-VEGF Instead of Intraoperative PRP in Proliferative Diabetic Retinopathy

Inclusion Criteria: 1. Age≥18 years old; 2. type 1 or type 2 diabetes. 3. proliferative diabetic retinopathy with vitreous hemorrhage, and conservative treatment of vitreous hemorrhage without obvious absorption for 1 month requires vitreoretinal surgery; 4. The postoperative refractive medium is clear and the pupil is large enough to obtain sufficient clear fundus Exclusion Criteria: 1. Previously received panretinal photocoagulation or unfinished panretinal photocoagulation; 2. Pulling retinal detachment involving the macula or the presence of extensive fiber proliferation requires silicone oil filling; 3. anterior chamber neovascularization or neovascular glaucoma; 4. other vascular diseases such as retinal vein occlusion, arterial occlusion, etc; 5. received intraocular anti-VEGF therapy or triamcinolone acetonide treatment which are still in the treatment period.