Inhibition of corneal neovascularization by subconjunctival bevacizumab in an animal model.

PURPOSE: To evaluate the effect of subconjunctival injection of bevacizumab on experimentally induced corneal neovascularization.

DESIGN

Experimental animal study.

METHODS

Twelve New Zealand white rabbits were involved, divided equally into four groups. Only one eye per rabbit was used. Topical instillation of 10 microl 5% NaOH solution was used, under general anesthesia, to induce corneal neovascularization secondary to corneal alkali burn in groups 2, 3, and 4. A single dose of 3.75 mg (25 mg/ml) bevacizumab was injected subconjunctivally. Group 1 (control group 1) was neither cauterized nor treated. Group 2 (control group 2) received a sham injection of balanced salt solution on day 14. Group 3 was treated on day 14 (after corneal neovascularization had been established). Group 4 was treated on day 1. Digital photographs were obtained and analyzed during the entire 28-day procedure. The area of neovascularization and scarring were measured in terms of the percentage of corneal surface affected.

RESULTS

On day 28, the difference of neovascularization between groups 2, 3, and 4 was found to be statistically significant at the .05 level (one-way analysis of variance [ANOVA]): group 4 (4.7%+/-3.1%)<group 3 (13.3%+/-2.3%)<group 2 (41.0%+/-3.6%; P<.05, Mann-Whitney U test). In group 3, the area of neovascularization decreased 14 days after treatment by 42%. Neovascularization was almost completely absent in group 4. The development of scarring was unaffected by bevacizumab (P>.1, one-way ANOVA). No side effects were noted.

CONCLUSIONS

Subconjunctival administration of bevacizumab inhibits corneal neovascularization effectively in the rabbit experimental model, especially if administered early.