Abstract: Objective: To explore the role of VEGF and IL-6 in the aqueous humor in the pathogenesis of diabetic retinopathy (DR) . Methods: Aqueous humor samples were collected from diabetic patients with cataracts or without retinopathy,and aqueous humor samples from non-diabetic patients with cataracts were chosen as controls. The content of VEGF in the aqueous humor was determined by using the ELISA technique. Results: The level of VEGF in the aqueous humor samples of diabetic patients without retinopathy(NDR), background diabetic retinopathy (BDR) and proliferative diabetic retinopathy (PDR) were（220.27±25.69）pg/ml, （284.31±58.92）pg/ml and （459.07±90.90）pg/ml. The level of IL-6 in the aqueous humor from NDR, BDR and PDR were（154.09±32.76）pg/ml,（ 221.81±60.52 ）pg/ml and （387.95±90.22）pg/ml． The levels of VEGF and IL-6 in the aqueous humour from the control group were（135.50±25.69）pg/ml,（ 78.71±20.37）pg/ml. Compared with the control, the level of VEGF and IL6 in the aqueous humor of diabetic patients increased significantly (P＜0.01). The level of VEGF and IL-6 in the aqueous of the NDR, BDR and PDR also increased significantly (P＜0.01). The level of VEGF significantly correlated with the level of IL-6 in the aqueous humor（r=0.995, P＜0.01）. The level of VEGF and IL-6 in the aqueous humor also significantly correlated with the severity and prolongation of DR（r=0.869,　P＜0.01; r=0.865,　P＜0.01）. Conclusion: VEGF and IL-6 play active roles in the generation and development of DR, and the level of VEGF in the aqueous humor closely correlates with the level of IL-6 in the aqueous humour of diabetic patients.

Key words: Vascular endothelial growth factor, Interleukin-6, Diabetic retinopathy, Ⅱ diabetes mellitus