AIM: To analyze the effects of two kinds of anti-vascular endothelial growth factor(VEGF)drugs, conbercept and ranibizumab, on proliferative diabetic retinopathy(PDR)patients as pre-treatment for pars plana vitrectomy(PPV).

METHODS: From June 2016 to December 2016, 62 patients(64 eyes)aged 41-59 years old diagnosed with PDR with nonclearing vitreous hemorrhage(VH)and/or tractional retinal detachment(TRD)requiring PPV were enrolled in our study. Patients were treated with intravitreal injection of anti-VEGF drugs 0.50mg(0.05mL)3d before PPV. Then the standard 23G minimally invasive sclera three-channel vitrectomy was performed where there were no significant complications after the injection of anti-VEGF drugs. The operation time, intraoperative bleeding, iatrogenic retinal breaks, the use of endodiathermy and silicone oil, and postoperative complications were recorded and analyzed. We compared and analyzed the visual acuity and macular thickness before and 1mo after the surgery with the preoperative data.

RESULTS: Both conbercept and ranibizumab could improve the postoperative visual acuity and reduce the postoperative macular thickness of PPV. There was no significant difference between the impacts of two kinds of anti-VEGF drug pre-treatment on operation time, intraoperative bleeding, iatrogenic retinal breaks, the use of endodiathermy, silicone oil filling and postoperative vitreous secondary hemorrhage.

CONCLUSION: The effects of conbercept and ranibizumab pre-treatment were similar. PPV combined with anti-VEGF pre-treatment could improve postoperative visual acuity and macular edema. The choice of conbercept or ranibizumab should be made flexibly according to the actual situation of patients.