This article is more than 5 years old. Information may no longer be current.
Intra-Tenon’s injection of MMC for trabeculectomy may lead to better blebs
Click Here to Manage Email Alerts
SAN FRANCISCO — A newer method of applying mitomycin C may create more ideal trabeculectomy blebs by better diffusion of the antimetabolite, according to a presenter here.
“The ideal bleb is diffuse with normal vascularity. The scary bleb is focal, cystic and avascular; it is prone to leaks, blebitis and endophthalmitis,” Michele C. Lim, MD, said at the American Glaucoma Society annual meeting.
Lim and colleagues retrospectively reviewed outcomes of 57 eyes undergoing trabeculectomy in which MMC was instilled via sponge and 125 eyes that received MMC by injection.
Michele C. Lim
“Our hypothesis was that injecting mitomycin would lead to lower pressures, and we also wanted to look at the complication profiles to see if they were different,” she said.
Trabeculectomies were performed with either limbus-based or fornix-based conjunctival flaps, and for the sponge application, a standard MMC dose of 0.1 mg/mL to 0.4 mg/mL was applied for 3 minutes. For the injection technique, 0.1 mL of MMC was injected into the superior fornix, and a muscle hook was used to spread the medication diffusely. MMC concentration for injection was weaker than that used for sponge application.
The study found no difference in IOP change from baseline between MMC sponge and injection groups. Medication use was significantly lower in the MMC injection group 36 months after trabeculectomy, and a tense, vascularized or encapsulated bleb was more likely to form in the MMC sponge group than in the MMC injection group.
“The injection method may lead to possible reduction in medication burden; it is definitely faster than applying mitomycin by sponge. The injection method may be associated with less bleb failure from scarring. And, last but not least, the injection method appears to be safe,” Lim said.