The role of Cetuximab and Bevacizumab in experimental corneal angiogenesis

Introduction and Aim: Angiogenesis is defined as the formation of new blood vessel derived as extensions from existing vasculature. In order to accurately establish the molecular structure of angiogenesis, many studies are carried out on experimental angiogenesis models. In our study, we also investigated the role of cetuximab, which is an anti-EGF agent, and of bevacizumab, which is an anti-VEGF monoclonal antibody, on the inhibition of rat alkali burn model.Mateials and Methods: In the study, a total of 28 Spraque-Dawley rats were used. Right eyes of all the rats cauterized by silver nitrate stick for 8 seconds. After the formation of alkali burn corneal angiogenesis model, the rats were divided into four equal groups: In right eyes af all the rats,three doses of injection were given subconjunctivally on days 1,4 and 7. At each dose, while 0.15ml saline was given subconjunctivally to the control group, 0.1ml bevacizumab was given to bevacizumab group, and lastly 0.15ml(0.1ml bevacizumab+0.05ml cetuximab) was administered to bevacizumab+cetuximab group. On day 8, before they were sacrificed, cornea were biomicroscopically examined, and corneal angiogenesis was assessed, and then the photographs of cornea were taken. Following enucleation of rats sacrificed with high dose of anaesthesia, the cornea were dissected and embedded in parafin as a routine follow-up procedure. Then, for histochemical and immunuhistochemical analyses, the sections were taken and prepared. After the corneal sections obtained were assessed histopathologically, images were taken.Results: According to the biomicroscopical, histopathological and immunohistochemical findings obtained from the present study, the amount of angiogenesis was determined to have decreased considerably in both bevacizumab and cetuximab groups. In group bevacizumab+cetuximab, relatively less inhibiton was observed.Conclusion: As a result, we concluded, in our study, that bevacizumab, the efficiacy of which has been established in many earlier studies, produced effective results on the inhibition of angiogenesis. Cetuximab, which has not been previously used for the inhibition of corneal angiogenesis was also determined to be as effective as bevacizumab. However, we are of the opinion that the combined administration of both drugs subconjunctivally is not effective for the inhibition of angiogenesis.Key words: Angiogenesis, cornea, cetuximab, bevacizumab