Abstract
Abstract: :
Purpose: Pterygium is histologically composed of fibrovascular tissue. This study is to test the hypothesis that decreased angiogenic inhibitors may contribute to the pterygium formation and to compare the expression levels of pigment epithelium-derived factor (PEDF), a potent angiogenic factor, in pterygium and normal human conjunctiva. Methods: The normal human conjunctiva obtained from donor eyes without any diagnosed ocular diseases (8 cases, age 29-60) and the pterygial tissue excised from therapeutic surgery (9 cases, age 37-66 ) were used for this study. The tissues were immediately fixed with formaldehyde, embedded with paraffin and sectioned (4 µm) for immunohistochemistry using a monoclonal antibody specific to human PEDF by immunofluorescence and the avidin-biotin complex method. Results: All of the 8 independent normal conjunctival specimens showed high expression of PEDF. The PEDF expression was predominantly detected in the epithelium of the conjunctiva. Under the same immunostaining conditions, however, all of the 9 pterygia lacked the PEDF staining in the epithelium or fibroangiogenic mass. Conclusion: These results provided the first evidence that PEDF is expressed at a high level in normal human conjunctiva, and lack of PEDF expression may play an important role in the formation and progression of pterygium. Anti-angiogenic treatment using angiogenic inhibitors may have therapeutic potential in the treatment of pterygium.
Keywords: 532 Pterygium • 365 conjunctiva • 320 antigen presentation/processing