Bevacizumab (Avastin) inhibits corneal neovascularization in rabbits / 第二军医大学学报

ABSTRACT

Objective: To evaluate the effect of subconjunctival injection of Bevacizumab (Avastin) on corneal neovascularization(CNV) in rabbits. Methods: Forty-eight New Zealand rabbits were randomly divided into three groups normal control group (group A, 3 rabbits), neovascularization group (group B, 9 rabbits) and Bevacizumab treatment group (group C, 36 rabbits). Group C was further divided into group C1 (1 day small dose group), C2 (1 day high dose group), C3 (14 days small dose group) and C4 (14 days high dose group), with 9 rabbits each group. CNV model was made by suture in group B and C. Animals in group C were injected subconjunctivally with 0.1 ml or 0.2 ml Bevacizumab (25 mg/ml) in the left eyes. The growth of CNV was observed every day after operation and the neovascularization areas calculated. Expression of VEGF in the cornea was detected by immunohistochemistry on day 7, 14 and 28 after suture. VEGF content in the aqueous humor was determined by ELISA assay. Results: CNV growth in group C1 and C2 was inhibited significantly compared with that in group B on day 7, 14 and 28 (P<0.01). On day 28 the growth in group C3 and C4 was significantly inhibited compared with that in group B (P<0.01), that in group C1 was significantly inhibited than that in group C3, and that in group C2 was significantly inhibited compared with that in group C4 (P<0.01). VEGF levels in the cornea and aqueous humor in group B increased as time passed by, and they were positively associated with CNV area (P<0.01). On day 7, 14, and 28, the VEGF levels in the cornea and aqueous humor in C1 and C2 groups were significantly lower than that in group B (P<0.01). On day 28, those in group C3 and C4 were significantly lower than those in group B (P<0.01); those in group C1 were significantly lower than those in group C3 (P<0.01); and those in group C2 were significantly lower than those in group C4 (P<0.01). The CNV area and VEGF levels in the cornea and aqueou humor were similar between C1 and C2 groups and between C3 and C4 groups. Conclusion: Subconjunctival administration of Bevacizumab can effectively inhibit corneal neovascularization in experimental CNV model, and early administration has a better outcome than late administration. Bevacizumab may exert its effect by down-regulating VEGF in cornea and aqueous humor.