A Clinical Trial to Evaluate the Time Point of Anti-VEGF Pretreatment of PDR Based on Intraoperative FFA
The goal of this prospective randomized controlled study is to compare the therapeutic effect of injecting anti-VEGF drugs before surgery for patients with proliferative diabetic retinopathy at different time points. At present, studies have confirmed that anti-VEGF drugs are effective in inhibiting fundus neovascularization in proliferative diabetic retinopathy. The main question it aims to answer is which time point is better to injecting anti-VEGF drugs before surgery for patients with proliferative diabetic retinopathy.

Participants will be randomly divided into three groups. And time points of injecting anti-VEGF drugs before surgery for each group will be 3 days, 7 days, 14 days. And we have a new technology that can have fluorescein fundus angiography during operation, so it can reflect the condition of fundus neovascularization immediately and precisely. In that case, we can compare the Inhibitory effect of anti-VEGF drugs on fundus neovascularization at different time points.
- EligibilityCriteria: Inclusion Criteria:  PDR is diagnosed in people 18 years of age or older with type 1 or type 2 diabetes， Hemoglobin A1c (HbA1c) ≤10% Persistent vitreous hemorrhage for more than one month or recurrent vitreous hemorrhage (within six months) Did not undergo retintis photocoagulation (PRP) Vitreous hemorrhage disease course within six months  Exclusion Criteria:  Patients who have had previous vitreoretinal surgery Intravitreal drug injection within 3 months Eye diseases other than PDR that may hinder vision improvement, such as optic atrophy or macular hole Thromboembolic events (including cerebrovascular or myocardial infarction) or clotting system disorders or receiving anticoagulation or antiplatelet therapy B-ultrasound or indirect fundus microscopy showing retina detachment (pull or hole origin) Vitrectomy, FFA contraindicated patients, patients with severe abnormality of cardiopulmonary, liver and kidney function - HealthyVolunteers: No - Gender: All - MinimumAge: 18 Years - StdAgeList: Adult, Older Adult