Effect of bevacizumab on corneal neovascularization in experimental rabbit model

Abstract

To investigate the effect of bevacizumab in an experimental rabbit model of corneal neovascularization. The right eyes of 24 white New Zealand rabbits were included in a corneal neovascularization model using alkaline burn. They were divided into four groups. Topical bevacizumab was installed three times daily in group 1, 5 mg bevacizumab subconjunctivally every 2 days in group 2, 10 mg bevacizumab subconjunctivally every 2 days in group 3 and 0.2 cc of normal saline in the same way in group 4 (control group). All eyes were treated for 7 days. Then the animals were killed and corneal specimens sent for histopathological analysis. Tear film and aqueous humour samples were obtained to assess vascular endothelial growth factor (VEGF) levels. Seven days after topical bevacizumab treatment the neovascular index in group 1 was lower than that in the control group (P = 0.028). In groups 2 and 3 the neovascular index was lower 2 days after subconjunctival bevacizumab treatment than that in control group (P = 0.009 and P = 0.009, respectively). In the control group the VEGF level in aqueous humour increased by 66% from day 7 to 14. In groups 1-3 it decreased by 49.80%, 70.20% and 76.44%, respectively (P = 0.043). The VEGF level in tear film of the control group increased by 35.23% from day 7 to 14, which was not significant (P = 0.893), while in groups 1-3 it decreased by 57.26%, 34.59% and 67.97%, respectively, which was only significant in groups 1 and 3 (P = 0.043). Subconjunctival 5 mg/mL bevacizumab is effective in reducing corneal neovascularization in animal models and in reducing VEGF levels. Further research is needed to assess the potential side effects and minimal effective dose.