Glaucoma Shunt Outcomes Improve With Addition of Mitomycin C

Mitomycin C augmentation improves Baerveldt shunt outcomes and reduces the need for postoperative medications in patients with glaucoma, according to research published in Ophthalmology Glaucoma. 

Researchers conducted a retrospective comparative case series to evaluate whether intra-operative mitomycin C augmentation influences the success of Baerveldt aqueous shunts in patients with glaucoma.

The team reviewed medical records of consecutive patients who underwent standalone Baerveldt aqueous shunt implantation at a single center. They categorized patients according to whether mitomycin C was used intraoperatively (mitomycin-C group, received 0.2-0.4 mg/ml of mitomycin C) or not (control group).

The study’s main outcome was Baerveldt aqueous shunt survival, defined as an intraocular pressure (IOP) greater than 6 mm Hg and no more than 21 mm Hg, or no more than 18 mm Hg and a more than 20% IOP reduction from baseline. Secondary outcomes included difference in IOP, number of glaucoma medications, postoperative complications, rate of intraluminal ripcord removal, and interventions. The researchers assessed outcomes at baseline and postoperative months 1, 3 and 6 and years 1 through 5.

A total of 88 patients, 55 in the mitomycin-C group (mean age, 55.9 years; 65% men and 35% women) and 33 in the control group (mean age, 54 years; 55% men and 45% women), were included in the study. The average follow-up duration was 4.7±1.4 years. 

At year 5, the investigators found the mitomycin-C group compared with the control group had a significantly higher rate of complete success at the 21 mm Hg or lower threshold (39.3% vs 17.8%; log rank P =.016) and of final complete success at the 18 mm Hg or lower threshold (38 % vs 15.6%; log rank P =.0042). The researchers report no significant difference in qualified success between mitomycin-C group and control group at the 21 mm Hg or lower threshold (82% vs 93%; log rank P =.29) or 18 mm Hg or lower threshold (70.3% vs 79.3%; log rank P =.44). 

The team found use of mitomycin C was correlated with a lower number of glaucoma medications between postoperative month 3 and year 2 (P <.001) and with a lower rate of intraluminal ripcord removal at all assessed timepoints (P <.001). They observed a higher incidence of transient hypotony at year 1, but not of prolonged hypotony, in the mitomycin-C group compared with the control group (P =.049).

“This study suggests that [mitomycin C] augmentation of Baerveldt aqueous shunts reduces the number of glaucoma medications postoperatively, but that is associated with a small increase in rate of late hypotony,” concluded the researchers.

Limitations of the study included the retrospective design, small sample size, and lack of randomization.