HISTOPATHOLOGY OF EPISCLERAL FIBROSIS AFTER TRABECULECTOMY WITH AND WITHOUT MITOMYCIN-C

Background: The aim of the study was to investigate the histopathologi c features of scar tissue which have proliferated at the site of trabe culectomy of surgical failures after procedures with and without the u se of the anti-metabolite mitomycin C (MMC). Methods: Wt obtained seve n surgical specimens after trabeculectomy without MMC and five specime ns after trabeculectomy with MMC, which were compared with 23 controls . Sections were stained with hematoxylin and eosin, Verhoeff-van Gieso n, Grocott methenamine silver, and alcian blue. An immunohistochemical stain was performed for alpha-smooth muscle actin. Results: Specimens from eyes operated without MMC showed dense scar tissue with many fib roblasts, much ground substance, parallel-oriented collagen fibers, an d contractile intracellular proteins within the Fibroblasts. Specimens from eyes operated with MMC consisted of tissue with only few fibrobl asts which did not exhibit contractile proteins. Collagen fibers were arranged randomly with less ground substance, Conclusion: Even after 1 -10 months, the scar tissue was distinctly different in the two groups . These results suggest that the use of MMC has long-term effects in v ivo, Surgical failures related to scar formation are possible and not reduced to zero.