TRABECULECTOMY WITH MITOMYCIN-C - AN ELECTRON-MICROSCOPIC AND CLINICAL-STUDY

A prospective and randomized clinical trial was conducted to investiga te the pressure-lowering effect of mitomycin C-aided trabeculectomy in the Turkish population. The scleral tissues excised during the operat ion were examined by light and electron microscopy. The study populati on consisted of 26 patients undergoing mitomycin C-aided trabeculectom y and another 26 patients subjected to trabeculectomy without mitomyci n C serving as controls. The treatment groups consisted of primary ope n-angle and closed-angle glaucomas, congenital glaucomas, various type s of secondary glaucomas and prior failed trabeculectomies. The decrea se in IOP was more marked (P < 0.01) and the number of additional medi cations needed post-operatively was less in the mitomycin C group (P < 0.01). There were no serious complications except for transient hypot ony in one mitomycin-treated eye. Transmission electron microscopic ex aminations showed differences between the control and mitomycin applie d trabecular blocks. At the scleral dissection plane where mitomycin w as applied, collagen fibrils were frayed with a loss of proteoglycan c ross-links. Fibroblasts demonstrated pyknotic nuclei and loss of cell processes. In the control group, active fibroblasts and regular collag en structure were observed at this level. The middle and inner scleral layers were generally unaffected except for minor changes in some of the mitomycin-treated eyes. Our study showed mitomycin C to be safe an d effective as adjunct to trabeculectomy in both primary open-angle, p rimary angle-closure, various secondary glaucomas and prior failed tra beculectomies. Transmission electron microscopic examinations of excis ed blocks showed disruption in collagen organization and cytopathic ef fects to fibroblasts. Mitomycin seemed to affect the proteoglycan cros s-links between collagen fibrils after its application.