CONJUNCTIVA AND SUBCONJUNCTIVAL TISSUE IN PRIMARY OPEN-ANGLE GLAUCOMAAFTER LONG-TERM TOPICAL TREATMENT - AN IMMUNOHISTOCHEMICAL AND ULTRASTRUCTURAL-STUDY

Background: Primary open-angle glaucoma is commonly treated with long- term hypotensive medical therapy. When this approach becomes inadequat e, therapy proceeds with surgery. The present study investigates morph ological changes in the conjunctival and subconjunctival tissues induc ed by short- and long-term topical medical therapy of primary open-ang le glaucoma. Methods: Comparisons were made between biopsy specimens f rom glaucomatous patients, who received specific eyedrop therapy (timo lol and pilocarpine) for various periods of time, and control patients with no conjunctival pathology or topical treatment. Histological, im munohistochemical and ultrastructural parameters were investigated. Re sults: The morphometric analysis of histological sections and immunohi stochemistry (anti-fibronectin antibody) in medium- and long-term ther apy patients showed: (a) significant increases in the thickness and nu mber of epithelial cell layers; (b) significant increases in the fibro blast density in both subepithelial and deep connective tissue; and (c ) a more compact connective tissue, richer in collagen fibers arranged in whirls, with some inflammatory elements. These findings were confi rmed by the ultrastructural analysis. In the same patients, the other immunohistochemical parameters investigated (anti-HLA-DR, anti-CD1a, a nti-CD4, anti-CD8, anti-IL2 and C3b antibodies) revealed a tendency to chronic inflammation. Following specific surgery, this tendency manif ested itself in a diffuse immune response, especially in those patient s who underwent medium- and long-term medical therapy. Conclusion: Acc ording to these results, antiglaucomatous surgery should be rehabilita ted and considered as an alternative to long-term medical therapy in t he first-instance treatment of primary open-angle glaucoma.