AIM: To observe retinal vessel leakage of streptozotocin(STZ)induced diabetic rat, and the effect of traditional Chinese medicine on it.

METHODS: We induced diabetic rat model by peritoneal injection of STZ, after the blood glucose raised, we used Evans blue to trace the leakage of blood-retina barrier(BRB)every month. After blood glucose rose three months later, we treated the Chinese medicine group diabetic rat with Qidengmingmu capsule. There were three groups of different dose, low dose group of 125mg/kg, middle dose group of 250mg/kg, high dose group of 500mg/kg. The control group was treated with calcium dobesilate(200mg/kg). After three months treated by medicine, the leakage of rat blood-retina barrier was evaluated.

RESULTS: The damage of BRB and visual function occurred at two week after the blood glucose rose, and the damage aggravated with the continuing of high diabetic. But after the Chinese medicine treated three months, the rat's retina vessel leakage was reduced.

CONCLUSION: BRB break down and visual acuity damage appears in early phase of STZ diabetic rat and get worse as the hyperglycemia keep on. The Chinese medicine Qidengmingmu capsule can prevent the vessel leakage by damage of BRB.