AIM: To clinical effect of 25G+ vitrectomy combined with intravitreal injection of Conbercept for severe proliferative diabetic retinopathy(PDR).

METHODS: A clinical case control study. A total of 35 patients(42 eyes)with severe PDR who underwent 25G+ vitrectomy in our hospital from October 2014 to August 2016 were randomly divided into two groups: A and B. Among them, 18 cases(22 eyes)was given conbercept intravitreal injection combined with vitrectomy as Group A; 17 cases(20 eyes)was only given vitrectomy without conbercept injection were Group B. Observation of operation duration, intraoperative complications, the incidence of vitreous hemorrhage(RVH), macular foveal thickness(CFT)at 3mo after operation were observed, best corrected visual acuity(logMAR BCVA), and macular foveal thickness(CFT)at 6mo after operation were observed too.

RESULTS: The operative time of Group A and B was 58.23±8.18min and 72.41±10.31min, the difference was statistically significant(t=2.9, P=0.002). During the operation, the main complications were iatrogenic hiatus and intraoperative bleeding, Group A of 2 eyes and 1 cases, Group B of 7 eyes and 6 eyes, the difference was statistically significant(P=0.041, 0.027). The incidence of vitreous hemorrhage(RVH): at 3mo after operation, that in Group A was 2 eyes, and in Group B was 8 eyes, the incidence of vitreous hemorrhage was statistically significant between the two Groups(P=0.030). The best corrected visual acuity was 0.92±0.35 in Group A and 1.04±0.43 in Group B at 6mo postoperatively, but there was no significant difference between the two groups(t=0.241, P=0.212), but compared with the preoperative visual acuity improved obviously, the difference was statistically significant(t=4.614, t=7.355; P<0.01). CFT: at 3mo after operation, that of Group A was 273.42±25.21μm, Group B was 284.58±27.44μm, there was no significant difference between the two groups(t=0.488, P=0.179), but there were significantly decrease, the difference was statistically significant(t=3.152, t=4.933; P<0.01); at 6mo after operation, CFT of Group A was 238.16±16.35μm, Group B was 247.04±17.43μm, there was no significant difference between the two groups(t=0.571, P=0.133), but there were significantly decrease, the difference was statistically significant(t=2.474, t=4.802; P<0.01).

CONCLUSION: The 25G+ vitrectomy combined with preoperative conbercept intravitreal injection in patients with severe proliferative diabetic retinopathy can effectively improve vision and reduce macular edema,compared with simple vitrectomy, the operation time can be shortened, the incidence of complications can be reduced, and the incidence of vitreous hemorrhage in 3mo after operation can be significantly reduced.