Inhibitory Effect of Anti-VEGF Drugs Bevacizumab (Avastin) on Corneal Neovascularization

The cornea is an avascular transparent structure normally. Corneal neovascularization may be initiated following infection, trauma, and inflammation, leading to decreased corneal transparency. Additionally, corneal neovascularization is a risk factor for graft rejection after allograft corneal transplantation. Vascular endothelium growth factor (VEGF) is known to have an important role in angiogenesis in the body. The anti-VEGF drugs have been proved to inhibit VEGF in previous reports on cancers and retina. In this study, we investigated the effects of anti-VEGF drug on corneal neovascularization in a rabbit model. Three models of corneal neovascularization in rabbits were used in this study, namely corneal micropocket, limbal stem cell insufficiency, and chemical burn. The anti-VEGF drug, bevacizumab (Avastin), was injected subconjunctivally for treating corneal neovascularization in these rabbit models. The maximal length and area of corneal neovascularization were measured and recorded. Histology analysis and immunochemical staining of the rabbit cornea were performed. Bevacizumab revealed inhibitory effect of corneal neovascularization in all of the three models. The treatment group showed lesser corneal neovascularization, inflammatory cells infiltration, and vascular endothelium cells by histology. Immunochemical stain revealed the expressions of the vascular endothelial cells and bevacizuzmab in cornea. In conclusion, subconjunctival injection of anti-VEGF drug, bevacizumab, can effectively suppress corneal neovascularization with no significant side effects based on this study. The dosage, administration routes, and efficacy in corneal diseases and allografts remains to investigate in the future.