Corneal Neovascularization: Review Article

Corneal neovascularization occurs through inordinate wound healing after infection, injury or surgery. Neovascularization is formation of new vascular structures in the locations which had not already vessels. The two overlapping mechanisms including vasculogenesis and angiogenesis are probably involved in neovascularization process, and the last mechanism is more involved in tumor growth and corneal and retinal disorders. In fact, corneal neovascularization is a visual threatening status that usually occurs along with inflammatory or infectious disorders of the eye surface. The studies of angiogenesis-related cancer showed that there is a balance between angiogenic factors (such as VEGF and FGF) and antiangiogenic molecules (such as angiostatin, endostatin and pigment epithelium-derived factor; EPDF) in cornea. Problems such as inflammation, infection, injury and lesions result in corneal neovascularization, which are due to stimulation of angiogenesis in this tissue. Corneal neovascularization may be influenced by matrix metalloproteinase (MMPs) and other proteolytic enzymes. The application of new medical and surgical therapies such as angiostatic steroids, non-steroidal anti inflammatory drugs, argon laser photocoagulation and photodynamic therapy (PDT) in animal models had been efficient to some extent for inhibition of corneal neovascularization. In this study we reviewed neovascularization-dependent corneal disorders and molecular processes involved in this disorder, and also their potential therapies.