Effect of Postvitrectomy Proactive Use of Conbercept on Postoperative Complications in PDR Patients

Inclusion Criteria: * PDR patients undergoing vitrectomy Exclusion Criteria: * patients who had received intravitreal injection or systemic use of all types of anti-VEGF agents in the recent three months before vitrectomy * patients who had received intravitreal injection or systemic use of all types of steroid in the recent one month before vitrectomy * patients who had received complete PRP before vitrectomy * patients who are pregnant