Novel punctal plug approach to glaucoma drug delivery well-tolerated, lowers IOP

ATLANTA — Using a punctal plug to deliver glaucoma medication could safely reduce the need for patient compliance while enhancing overall drug delivery.

"Punctal plug delivery represents a novel approach to problems of medication compliance by delivering medication over 3 months," Richard A. Lewis, MD, said at the American Academy of Ophthalmology meeting.

The punctal plug delivery system works by eluting latanoprost from a core in the punctal plug. Dr. Lewis and colleagues conducted an open-label, uncontrolled pilot study and a randomized phase 2 study examining IOP reduction and tolerability using the punctal plugs.

The pilot study examined 3-month drug release results of 10 eyes of five patients with primary open-angle glaucoma or ocular hypertension. Pressure was reduced by 30%, Dr. Lewis said, and the device was well-tolerated and had no side effects.

However, the retention rate using a commercial plug was not optimal, at 63%, he said.

The second phase of the study is examining 61 glaucoma patients. Preliminary results showed a statistically significant drop in mean IOP from baseline, he said.

This is some very important work in an area of glaucoma that we all are concerned about, and that is compliance with medical therapy. This is an innovative, novel drug delivery system … with a punctal plug with a drug-eluting core. Certainly the results of his pilot study of five patients warranted a more extensive study that combines a larger population. He nicely identified the biggest problem, which is extrusion of the punctal plug in about a third of the patients. It was not unexpected – we all have this problem when we’re treating our dry eye patients with punctal plugs.

Stephen Gedde, MD
Bascom Palmer Eye Institute, Miami, U.S.A.