Abstract
Abstract: :
Purpose: To investigate a novel method of treatment for leaking filtration blebs and, secondarily, shed light on the role of antimetabolite as a causative agent. Other investigators have observed that wound leaks are commonly associated with small filtration blebs ringed by fibrous tissue, and have advocated the creation of larger blebs to decrease hydrostatic pressure on the bleb surface. If this inhibition of lateral flow is the cause of the leak, in blebs that are already leaking, increasing the size of the bleb should eliminate leakage. Methods: Appropriate informed consent was obtained from all patients. Twenty-three patients were enrolled. All had Seidel positive blebs occurring an average of 2.4 years following filtration surgery. All underwent slit lamp revision of their blebs in order to increase the lateral expanse of their blebs. Subconjunctival injection of Mitomycin C (22 cases) or 5FU (1 case) was used in all cases to help maintain the newly expanded bleb. Results: Following slit lamp revision of their filtration blebs augmented by additional antimetabolite, 20 of 23 patients had cessation of the leak. No filter failed. There were no cases of hypotony maculopathy. In two of the failures, the blebs could not be expanded laterally. One patient contracted endophthalmitis before his leak sealed.Average follow-up was 414 days. Conclusion: Slit lamp revision augmented by antimetabolite is a highly effective method of treating leaking filtration blebs while preserving filter function. This study supports the theory that leaking filtration blebs are caused by limited bleb surface area, not simply by direct effect of antimetabolites on tissue. Since additional antimetabolite application led to cessation of the bleb leaks, this study casts doubt on the theory that direct drug toxicity is the cause of leaking blebs, and in fact implies that it is an insufficiency of antimetabolite during surgery that eventually leads to bleb leakage.
Keywords: 631 wound healing • 353 clinical (human) or epidemiologic studies: outcomes/complications • 390 drug toxicity/drug effects