[Pharmacologic vitreolysis in diabetic rats].

ABSTRACT

OBJECTIVE: To evaluate the efficacy and safety of plasmin or hyaluronidase in the inducing of posterior vitreous detachment in diabetic rats. METHODS: Forty SD rats were induced diabetes by Streptozotocin (STZ). Four weeks later, these rats were randomized into 4 groups rats in group A received 5 U hyaluronidase intravitreal injection in right eyes; rats in group B received 0.5 U plasmin intravitreal injection in right eyes; rats in group C received 0.5 U plasmin +5 U hyaluronidase intravitreal injection in right eyes; rats in group D received BSS (balance salt solution) 2 microl intravitreal injection in right eyes. Clinical examination were performed at 1, 3, 7 days after injection. After 1 week, scanning electron microscope (SEM) was performed to judge whether the PVD was induced. ERG and histology were examined to evaluate the toxicity after the intravitreal injection of these two drugs. RESULTS: No PVD was found in SEM disclosed group A and group D. Forty percent eyes were induced complete PVD in groups B, and one hundred percent eyes were induced complete PVD in group C. ERG and histology showed no toxicity changes in any group. CONCLUSION: Intravitreal injection of 0.5 U plasmin + 5 U hyaluronidase can induce complete PVD without obvious toxicity in diabetic rats. Solo usage of plasmin or hyaluronidase can not induce complete PVD.