AIM: To observe the effects of Shuangdanmingmu capsule on VEGF expression and retinal vascular morphology in rats with diabetic retinopathy(DR).

METHODS: DR rats were fed with Shuangdanmingmu capsule. By comparing with the normal group, the model control group, and positive control group, the effect of Shuangdanmingmu capsule on retinal tissue of DR rats was observed under electron microscopy. After HE staining, retinal structure was observed under the light microscope. Immunohitochemical staining was used to detect the VEGF expression in retina.

RESULTS:Two months after treatment, the layers tissue of retina presented mild edema, capillary pericytes performed edema, mitochondria showed mild swelling and less clear structure, some endothelial cells showed slight proliferation in Shuangdanmingmu group. Compared with the normal group, the expression level of VEGF in retina increased in the other groups, especially in model control group. A significant differential in expression of VEGF was found between Shuangdanmingmu group, positive control group and model control group(P<0.01).

CONCLUSION: Shuangdanmingmu capsule can effectively improve the retinal microvascular, reduce edema and necrosis of each layer of retina, improve the ultrastructure of retina's tissue and inhibit VEGF expression in DR rats.