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.