Currently, two companies—Mati Therapeutics and Ocular Therapeutix—are performing clinical trials of punctal plug delivery systems for glaucoma medications.
The Mati Therapeutics platform (Evolute) has an L-shaped design and is inserted into the nasolacrimal duct. The device is cosmetically invisible, but can be easily seen with eversion of the lower lid.
The device that was studied for glaucoma has a core of latanoprost-polymer matrix that is surrounded by silicone, and it delivers the medication into the tear film at a constant rate.
In a phase II clinical trial, the latanoprost punctal plug was found to be comfortable. It was associated with a 20% lowering from baseline IOP over a 3-month period, and in two separate clinical trials, it had a retention rate of 92% and 96%, respectively.