Mitomycin C Injections Reduce Eye Pressure After Surgery

SAN FRANCISCO, California — In patients with glaucoma, mitomycin C administered with intra-Tenon injection results in lower intraocular pressure and fewer medications after surgery than mitomycin C administered with a sponge, according to new research.

"Our study suggests that mitomycin C injection leads to a reduction in medication use after surgery, and results in fewer tense or encapsulated blebs," said Michele Lim, MD, from the UC Davis Eye Center in Sacramento, California. "The injection method is also faster."

Dr. Lim presented the results here at the American Glaucoma Society 23rd Annual Meeting.

Her research team reviewed the outcomes of trabeculectomy in which mitomycin C was used. In 57 eyes, physicians used a sponge application; in 124, they used intra-Tenon injection.

At 1 month follow-up, investigators assessed complications; at 3-year follow-up, they assessed success and failure rates, intraocular pressure reduction, and the use of medications.

Trabeculectomy was more successful in the injection group than in the sponge group (80% vs 70%), although the difference was not significant. Success was defined as an intraocular pressure of 21 mm Hg or less or an intraocular pressure at least 20% below baseline without medications, additional surgery, or a devastating complication, according to Dr. Lim.

Intraocular pressure was significantly lower in the injection group than in the sponge group after trabeculectomy at 1 month (P = .03), 1 year (P = .008), 2 years (P = .003), and 3 years (P = .019).

Mitomycin C injection is a real advance for us.

Medication use was also significantly lower in the injection group than in the sponge group at 3 years (0.49 vs 0.94; P = .0328), Dr. Lim reported.

Tense, vascularized, or encapsulated blebs occurred more often in the sponge group than in the injection group 1 month or more after surgery (7% vs 0%; P = .009). However, early complications within 1 month of surgery were similar in the 2 groups.

"Mitomycin C injection is a real advance for us," session cochair Joel Schuman, MD, from the University of Pittsburgh in Pennsylvania, told Medscape Medical News. He said he has used mitomycin C injections in his glaucoma surgeries for more than a year.

The injection method "saves a significant amount of time, about 2 to 5 minutes per case," Dr. Schuman explained, improves outcomes, and "reduces exposure of operating room staff to mitomycin C."

Dr. Lim and Dr. Schuman have disclosed no relevant financial relationships.

American Glaucoma Society (AGS) 23rd Annual Meeting: Abstract 19. Presented March 2, 2013.