Angiogenesis in the pathogenesis of pterygium.

Pterygium represents an epithelial hyperplasia associated with fibro-vascular growth. It is an active process, associate with cellular proliferation, remodeling of the connective tissue, angiogenesis and inflammation. The aim of this study consists of emphasizing angiogenesis involvement in the pterygium pathogeny. The material used for this study consisted of 21 pterygion fragments surgically removed in the Ophthalmology Clinic of the Emergency County Hospital, Craiova. Nine patients were men, 22 were women, and they were aged between 58 and 81 years. Ten fragments of epibulbar conjunctiva from the vicinity of the sclero-corneal limbus were used as control tissue. They were initially histological processed by paraffin inclusion. The immunohistochemical processing was made in the Histological, Histopathological and Immunohistochemical Techniques Laboratory of the University of Medicine and Pharmacy of Craiova. The working technique used was ABC÷HRP (Avidin complexed with biotinylated peroxidase). Angiogenesis in the pterygion was investigated with CD31 marker that allows the identification of the vascular endothelium and the establishment of the vascular microdensity and with VEGF, which allowed the identification of the main source of proangiogenic factors in pterygium. Our study emphasized the existence of a much richer vascularization at the level of the pterygium, compared with the one of the normal conjunctiva. The respective blood vessels were best represented in the subepithelial conjunctive, due to the increased necessities of the proliferating pterygium epithelium. The morphology of the blood vessels is specific for the neoformation vessels, which have a small caliber, are branched and have a rarely visible lumen. The investigation of the vascular microdensity has shown the existence of an intense angiogenesis process at the level of the pterygium and the overexpression of the VEGF, mainly in the proliferating structures of the pterygium, plead for the pathogenic involvement of this growth factor in the development of the pterygium.