Bleb oozing more frequent with 5-FU use than with MMC

TOKYO — Late-onset bleb oozing occurs more frequently following trabeculectomy with 5-fluorouracil than trabeculectomy with mitomycin-C, according to researchers here. It remains unclear which agent is a greater risk for overall bleb leak, however.

“Antimetabolites may be too effective in some cases, but not in some others,” Hiroshi Matsuo, MD, told Ocular Surgery News. “Consequently, it is ideal to take into consideration characteristics of the conjunctiva or Tenon's capsule before or during surgery and to individualize the dose of antimetabolites. At present, no other evidence-based antiproliferative agents are available, so it is important to use mitomycin-C or 5-fluorouracil adequately.”

Researchers here at the University of Tokyo Graduate School of Medicine performed a cross-sectional study evaluating the prevalence of aqueous humor oozing and point leak in 403 eyes of 403 patients with functional blebs at least 3 months after undergoing trabeculectomy with adjunctive use of 5-FU or MMC. They found that 48 eyes (11.9%) had oozing and eight eyes (2%) had point leak. While the researchers did not find any significant differences in intraocular pressure between eyes with point leak or oozing, IOP in eyes with either oozing or point leak was significantly lower than IOP in eyes without leak or oozing.

Point leak was also associated with a larger avascular area, and the avascular area was significantly larger after MMC use than 5-FU use. Dr. Matsuo pointed out that a greater prevalence of point leak might be detected in the MMC group if the study population was larger and a longer postoperative history was taken.

Dr. Matsuo said ways to avoid late-onset oozing or leak when performing a trabeculectomy with antimetabolites are not currently known.

“We want our results to be of some help in establishing such a way,” he said.

For more details on Dr. Matsuo's study, see the June 15 print edition of Ocular Surgery News.