Evaluation and comparison of the inhibitory effect of subconjunctival bevacizumab application doses in an experimental model of corneal neovascularization

ABSTRACT Evaluation and Comparison of the Inhibitory Effect of Subconjunctival Bevacizumab Application Doses in an Experimental Model of Corneal Neovascularization This study was carried out to evaluate and compare the inhibitory effects of subconjunctival high dose and low dose bevacizumab on corneal neovascularization in a rat model. In this study, thirty adult Sprague- Dawley rats were used. The central corneas of the rats were cauterized chemically. The rats were randomly enrolled into three groups. In group 1 (control group) (n=10), on the first day 0.05 ml 0.9% NaCl solution was injected subconjunctivally. In group 2 (n=10), 0.05 ml bevacizumab (1.25mg) was injected on the first day subconjunctivally. In group 3 (n=10), four doses of 0.05 ml bevacizumab (1.25mg) were injected subconjunctivally on the first, third, fifth and seventh day. Biomicroscopic examination of all rats were performed at the third and ninth day. Digital images of the corneas were taken and analyzed using an image analysis software to calculate corneal neovascularization area. All rats were sacrificed on the tenth day. The number of blood vessels, state of inflammation and collagen formation were evaluated histopathologically in corneal sections. In group 3, corneal edema and opacity scores were significantly lower than group 2 and 1. The mean percentage of neovascularized corneal area in group 1 was significantly higher than group 2 and group 3. The mean percentage of neovascularized corneal area in group 3 was significantly lower than group 2. In histopathological examination, group 2 and group 3 showed significantly less number of blood vessels than group 1. In addition, group 3 showed significantly less number of blood vessels than group 2. In the histopathological evaluation, inflammation and edema scores were observed significantly lower in group 3 than group 1. Subconjunctival bevacizumab injection treatment has been shown to be effective in inhibition of corneal neovascularization. The multiple dose bevacizumab treatment was more effective compared to single dose bevacizumab treatment. Keywords: Corneal neovascularization, Bevacizumab, Inflammation.