[Effect of mitomycin C on aqueous humor flow after trabeculectomy]

The intraoperative application of the antimetabolite mitomycin C has been recommended extensively in the literature for trabeculectomy in eyes with poor prognosis glaucoma. The modulation of wound healing with the antimetabolite mitomycin C has increased the success and predictability of filtration surgery. However, eyes in which mitomycin C is applied topically via a sponge during surgery bear the risk of developing postoperative hypotony and a decrease in visual acuity. Anterior chamber fluorophotometry (Fluorotron Master II, Coherent, Palo Alton) was used to study the effect of trabeculectomy with and without mitomycin C on the aqueous humour dynamics in glaucomatous eyes 6 months postoperatively. A 0.5-mg/ml solution of mitomycin C was applied topically via a sponge under the conjunctival flap. In a second group the same type of limbus-based flap was performed without the use of mitomycin C. The subsequent procedure was identical in both groups. Six months after surgery the eyes without mitomycin C revealed normal aqueous humour flow during the afternoon hours, comparable with the unoperated fellow eyes (mean 2.1 microliters/min). Eleven eyes treated with mitomycin C showed a reduction of aqueous humour flow of about 56% (mean 0.9 microliter/min) when compared with the unoperated contralateral eye and an age-, race- and sex-matched group. The fluorophotometric data suggest that the significant reduction of aqueous humour flow is the reason for the hypotony seen in glaucomatous human eyes following trabeculectomy with mitomycin C.