AIM: To explore the effect and safety of pars plana vitrectomy(PPV)assisted by intravitreal injection of conbercept in the treatment of proliferative diabetic retinopathy(PDR)combined with vitreous hemorrhage(VH).

METHODS: In the prospective randomized controlled study, patients with PDR and VH who were admitted to ophthalmology department of the hospital from February 2017 to September 2019 were enrolled as the research objects. They were randomly divided into observation group(39 cases, 39 eyes)and control group(38 cases, 38 eyes). Both groups underwent standard 27G PPV. The observation group underwent intravitreal injection of conbercept within 6-7d before surgery. The perioperative indexes were collected. The best corrected visual acuity(BCVA), intraocular pressure and central macular thickness(CMT)were followed up. The occurrence of surgical related complications was statistically analyzed.

RESULTS: Operation time(74.18±15.26 vs 96.17±14.27min), number of bleeding eyes(8% vs 37%), ratio of silicone oil filling(18% vs 53%)and incidence of iatrogenic retinal breaks(15% vs 47%)were lower in observation than control group(P<0.05). BCVA at 1mo after surgery(0.33±0.10 vs 0.60±0.21), 3mo after surgery(0.29±0.08 vs 0.59±0.30)and 6mo after surgery(0.28±0.10 vs 0.66±0.25)were significantly better in observation than control group(P<0.05). CMT at 3mo after surgery(252.15±56.96 vs 278.41±57.48μm)and 6mo after surgery(239.65±41.52 vs 268.59±33.71μm)were significantly better in observation than control group(P<0.05). During follow up, the incidence rates of VH in observation group and control group were 5% and 21%, respectively(P<0.05). In control group, there were 3 eyes(8%)with tractional retinal detachment after surgery, while there was no tractional retinal detachment in observation group(P>0.05).

CONCLUSION: For patients with PDR and VH, intravitreal injection of conbercept before PPV can shorten operation time, reduce intraoperative blood loss and alleviate macular edema to obtain better visual acuity, with better curative effect and safety.