Study shows limited efficacy of third IOP-lowering agent

MILAN — Washout from topical medications in glaucoma patients before micro-stent implantation provided evidence of the effects of single or combined medical therapy on IOP.

IOP-lowering topical medications are the mainstay of glaucoma therapy. In 50% of patients, two or more medications are prescribed. The additive effect of a second agent is well-established by several studies, but there is some question about the added effect of a third agent, Brian Flowers, MD, said at the annual joint meeting of Ocular Surgery News and the Italian Society of Ophthalmology.

Brian Flowers

In the COMPASS phase 3 randomized, controlled study of the CyPass micro-stent (Transcend Medical), patients underwent washout of all medications 2 to 4 weeks before randomization.

"We looked at this as an opportunity to assess the relative effect of being on one, two or three meds in a real-world environment," Flowers said.

There were 128 patients; the majority were on one or two medications, while some were on no medications or three medications.

"Results were partly expected and partly unexpected," Flowers said.

After the washout period, patients on no medications had no change in IOP. Patients on one medication had a mean pressure rise of 5.3 mm Hg, and patients on two medications had an IOP increase of 7.4 mm Hg. However, an interesting finding was that patients who were on three medications had a similar rise of 7.5 mm Hg.

"This makes the argument for minimally invasive procedures. Once you get to two meds and then need a further IOP-lowering effect, it’s good to have surgical alternatives that work better than a third added agent," Flowers said.

Disclosure: Flowers is a consultant for Transcend Medical.