Abstract: Objective To investigate the effect of preoperative prophylactic injection of conbercept into the vitreous cavity on proliferative diabetic retinopathy(PDR)and to analyze the factors influencing prognosis. Methods A retrospective analysis was performed on 40 patients(54 eyes)with PDR who underwent vitrectomy from January 2015 to June 2017. Of these, 20 patients(26 eyes, the observation group)received preoperative prophylactic intravitreal injection of conbercept and 20(28 eyes)without treatment were in the control group. The surgical outcomes and prognosis were compared between the 2 groups. Prognosis was evaluated according to the effect on visual improvement, and prognostic factors were analyzed using single and multiple factor analysis. Results The duration of surgery in the observation group was much shorter than in the control group. The incidence of iatrogenic perforation or intraoperative bleeding and the need for intraoperative electrocoagulation or silicone oil filling were much less in the observation group than in the control group, and the differences were statistically significant. There was no significant difference in macular thickness between the 2 groups before surgery. After surgery, the macular thickness in the observation group was much less than that in the control group, with a statistically significant difference. There was no significant difference between the 2 groups in the rate of retinal repositioning, postoperative vitreous reaccumulation, and recovery of visual acuity. Higher preoperative glycated hemoglobin levels and higher preoperative macular thickness were independent risk factors for prognosis. Conclusion Preoperative prophylactic intravitreal injection of conbercept can improve the effect of vitrectomy for PDR patients, and can help reduce complications. However, this measure had no obvious effect on recovery of visual acuity.

Key words: Diabetic retinopathy, Vitrectomy, Conbercept, Neovascularization