AIM: To investigate the efficacy of pars plana vitrectomy(PPV)combined with preoperative intravitreal injection of conbercept in the treatment of proliferative diabetic retinopathy(PDR)and its effect on aqueous humor inflammatory factors.

METHODS: A non-randomized controlled clinical trial was designed. The clinical data of 100 patients(100 eyes)with PDR who were admitted to the hospital from March 2019 to January 2022 were collected(the heavier eye was selected when both eyes had PDR, while the right eye was selected when the PDR degree was the same)and divided into control group and combined group according to their treatment wishes. The 48 eyes in the control group received PPV alone, and 52 eyes in the combined group received intravitreal injection of conbercept combined with PPV. Follow-up period was 12mo. The operative time, pre-and post-operative best corrected visual acuity(BCVA LogMAR), central retinal thickness(CRT)and postoperative complications in the two groups were statistically analyzed. And the levels of inflammatory factors(IL-6, IL-10, IFN-γ and TNF-α)in aqueous humor were compared between the two groups.

RESULTS: Compared with the control group, the levels of inflammatory factors IL-6, IL-10, IFN-γ and TNF-α in aqueous humor in combination group were significantly decreased. The operation time of the combined group was significantly shorter than that of the control group, and the number of electrocoagulation, iatrogenic retinal hole and silicone oil filling were less in the combined group than those in the control group(all P<0.05). There was no significant difference in preoperative BCVA and CRT between the two groups(all P>0.05). The BCVA and CRT improved at 1, 6 and 12mo after surgery in both groups, but the improvement was more significant in the combined group(all P<0.05). The postoperative incidence of complications in the combined group were lower than that in the control group(11.5% vs. 35.4%, P<0.05). There was no significant difference in the recurrence rate of PDR between the two groups(P>0.05).

CONCLUSIONS: Intravitreal injection of conbercept combined with PPV in the treatment of PDR has a significant effect, which can shorten the operation time, inhibit the inflammatory effect, reduce postoperative complications, and contribute to the improvement of patients' vision.