AIM: To explore the effects of anti-vascular endothelial growth factor(VEGF)agents(Conbercept)before pars plana vitrectomy(PPV)on inflammatory cytokine levels of patients with proliferative diabetic retinopathy(PDR).

METHODS: A total of 49 patients(49 eyes)who diagnosed with PDR at the First Affiliated Hospital with Nanjing Medical University from June 2017 to January 2018 were recruited and randomly divided into two groups. A total of 25 cases(25 eyes)who did not receive intravitreal injection before PPV were included in no-intravitreal injection of Conbercept(IVC)group, and 24 cases(24 eyes)who received IVC 5～7d before PPV were included in IVC group. The vitreous samples were collected from all the patients at the start of PPV. Levels of VEGF-A, monocyte chemotactic protein-1(MCP-1)and inflammatory cytokines in the vitreous humor were measured using Luminex technology.

RESULTS: Compared with the no-IVC group, the level of VEGF-A decreased significantly(P<0.001), the concentration of IL-6(P=0.004), IL-8(P=0.002), IL-18(P=0.04)and TNF-α(P=0.03)increased remarkably in the IVC group. The other inflammatory cytokines in the vitreous humor showed no significant difference between the IVC and no-IVC groups.

CONCLUSION: IVC before PPV can effectively decrease the concentration of VEGF-A, but had limited influence on the level of inflammatory cytokines in the vitreous humor of patients with PDR.