Expression and significance of Ang-2/Ang-1 in the vitreous of patients with proliferative diabetic retinopathy

Abstract Purpose To explore the significance of the Ang-2/Ang-1 ratio and VEGF expression in the vitreous of PDR patients. Methods A total of 50 PDR patients were enrolled in this study, including 25 who received intravitreal conbercept injection and 25 who did not. The control group consisted of 10 patients with macular holes. Vitreous samples were collected after vitrectomy for determination of Ang-1, Ang-2 and VEGF expression levels by enzyme-linked immunosorbent assay. Results The vitreous expression of Ang-1, Ang-2, and VEGF and the Ang-2/Ang-1 expression ratio were significantly greater in the PDR group than in the control group (P < 0.05). The expression of Ang-2 and the Ang-2/Ang-1 expression ratio in the vitreous of the active PDR group were significantly greater than those of the inactive PDR group administered injection and the PDR group without injection. There was a significant positive correlation between the Ang-2/Ang-1 expression ratio and the vitreous expression of VEGF in the PDR group without injection (correlation coefficient: 0.843, P < 0.001). Conclusions The increased Ang-2/Ang-1 expression in the vitreous of PDR patients suggest that Ang-2/Ang-1 and VEGF expression are associated with angiogenic activity in PDR.