Immunohistochemical expression of angiogenesis markers in human pterygium

Human pterygium is a common ocular surface disorder that is associated with chronic UV exposure. Histopathologically, this lesion is characterized by proliferation, inflammation, fibrosis, extracellular matrix remodelling and excessive angiogenesis, a process of new blood vessels formation from pre-existing vasculature that underlies a large number of physiological processes, such as growth and differentiation, wound healing, and abnormal conditions, such as neoplasia. Nestin is a intermediate filament (IF) protein originally described as a neuronal stem cell marker. Nestin is also expressed in newborn vascular endothelial and therefore recognized as a specific marker for newly formed blood vessels in normal and various tumor tissues. Notch1, a type 1 transmembrane protein, is associated whit a variety of cellular events, including cell fate determination, cellular differentiation, proliferation and apoptosis. This protein has also a important role in vascular development, including proliferation and migration of endothelial cells. The aim of this study is to evaluate, by immunohistochemistry on formalin–fixed and paraffin embedded sections, nestin and notch1 expression in the epithelial and endothelial cells of primary pterygium compared to normal conjunctival tissue, in order to determine whether these factors may participate in the development of pterygium via angiogenesis process. The results will be discussed