Late onset of sequential multifocal bleb leaks after glaucoma filtration surgery with 5-fluorouracil and mitomycin C

PURPOSE: To describe the late onset of sequential multifocal bleb leaks as a postoperative complication after filtering surgery with antimetabolites. MATERIALS: Retrospectively, 385 consecutive eyes (304 patients) undergoing trabeculectomy with 5-fluorouracil (5-FU) or mitomycin C (MMC) from 1989 to 1994 were reviewed. Eyes with filtration bleb leak occurring 6 months or more after trabeculectomy were analyzed, and clinical characteristics of the filtration bleb, response to treatment, and bleb histopathology from eyes undergoing bleb excision were analyzed. RESULTS: In seven (1.8%) of 385 consecutive eyes from 304 patients undergoing glaucoma filtration surgery with 5-FU or MMC, repetitive bleb leaks in different locations of the bleb were observed from 9 to 44 months (mean, 20.4 months) after the procedure. One hundred ninety-three eyes (50%) were treated with 5-FU and the remaining eyes, with MMC. All eyes had transparent, avascular, lobular, cystic blebs. Bleb leaks occurred in five eyes treated postoperatively with subconjunctival 5-FU and in two eyes in which MMC was used intraoperatively. Three eyes (all treated with 5-FU) required surgical excision, and four eyes healed with soft contact lens, cyanoacrylate glue, or intrableb injection of autologous blood. Histopathology of the bleb leak sites demonstrated focal epithelial thinning and interruption with subjacent hypocellularity and stromal collagen degeneration. CONCLUSION: Late sequential multifocal bleb leaks may occur after glaucoma filtration surgery with administration of antimetabolites (5-FU or MMC) and are associated with epithelial break down, hypocellularity, and stromal collagen necrosis in the filtration bleb.