METHODS: Prospective randomized controlled clinical trial. 28 cases(30 eyes)of NVG in stage Ⅲ secondary to PDR with VH were enrolled in the study. All patients received 25G PPV combined with trabeculectomy. They were randomly divided into two groups: group 1(14 eyes)received intravitreal injection of 0.5mg/0.05mL of conbercept(IVC)3d before operation and group 2(16 eyes)received IVC after operation; the operation time, intraoperative bleeding and postoperative complications were compared between the two groups. The differences of pain relief, the regression of iris neovascularization(INV), the best corrected visual acuity(BCVA)and intraocular pressure(IOP)control rate were observed.

RESULTS: The two groups all completed the operation and were followed up 12.40±2.21mo and 12.23±2.11mo respectively(P>0.05). The incidence of intraoperative and early postoperative hyphema of group 1(29%, 14%)was lower than group 2(75%, 56%, P<0.05). There was no significant difference in operation time, shallow anterior chamber, choroidal detachment and vitreous rebleeding between the two groups(P>0.05). The pain was relieved in all patients 3d after operation. In group 1, 93% of INV completely disappeared 3d after IVC and 94% of INV completely disappeared 7d after PPV in group 2. At the last follow-up, one eye in each group remained a little atrophic INV. At 1wk, 1mo, 3mo, 6mo postoperation, the IOP control rate of group 1 was 93%, 79%, 64% and 57% respectively, and that of group 2 was 94%, 75%, 50%, 44% respectively(each time period, P>0.05). IOP of the two groups at different time points after operation was significantly lower than that before operation(P<0.05). At the last follow-up, the IOP of the two groups were 20.45±10.55 and 22.63±7.24mmHg respectively, which were significantly lower than those of 42.21± 9.11 and 44.88±11.83mmHg before operation(P<0.05). BCVA in two groups at different follow-up time after operation has no significant difference compared with that of preoperation(P>0.05).

CONCLUSION: Compared with IVC after operation, IVC before operation combined with 25G PPV and trabeculectomy for NVG secondary to PDR with VH could reduce the incidence of intraoperative hemorrhage and early postoperative hyphema. The IOP control rate of the two methods is equal and gradually decreases with time, but after timely treatment can finally get better results.