AIM: To evaluate aqueous humor level of vascular endothelial growth factor(VEGF)in proliferative diabetic retinopathy(PDR)patients before and after vitrectomy.

METHODS: Aqueous humor samples were collected from 30 PDR patients before and after vitrectomy. Thirty cases of cataract patients without diabetes mellitus were chosen as a normal control group. Aqueous humor concentrations of VEGF were determined by enzyme-linked immunosorbent assays(ELISA).

RESULTS: Aqueous humor concentrations of VEGF were significantly greater in PDR patients than in control(P<0.05). VEGF concentrations decreased significantly in postoperative samples than that in preoperative samples(P<0.05).

CONCLUSION: VEGF actively takes part in the occurrence and development of PDR, and has a close relationship with neovascularization in the late stage of PDR.