To evaluate the efficacy and safety of vitreoretinal surgery combined with anti-VEGF therapy in the replacement of intraoperative PRP in PDR therapy.

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.