Glaucoma drug-dispensing silicone ring eye insert shows promise
A medicated silicone ring that rests on the surface of the eye reduced eye pressure in glaucoma patients by about 20 percent over six months.
The thin silicone ring made by ForSight Vision5 is suffused with medication that slowly releases over time, and it is designed to be replaced by an ophthalmologist every six months. This eliminates the need for glaucoma patients to regularly instill medicated eye drops themselves.
Ophthalmologists at 10 sites nationwide tested the ring in a Phase 2 clinical trial on patients with glaucoma or ocular hypertension. In the study, 64 patients received the topical ocular insert containing bimatoprost (Lumigan, Allergan). Patients were also supplied with artificial tears. The control group of 66 patients wore an insert treated with no drug but twice a day used 0.5 percent timolol (Timoptic, Merck) drops, the regulatory benchmark for glaucoma drugs. Intraocular pressure (IOP) in the bimatoprost group fell 3.2 to 6.4 mm Hg over six months, in comparison to 4.2 to 6.4 mm HG for the timolol group. Overall, IOP decreased in the group wearing the bimatoprost ring by about 20 percent from the initial measurements over six months.
Researchers said the device was well tolerated and safe with a high retention rate of 89 percent for both groups at six months. The ring became dislodged in 15 patients but was replaced each time, allowing therapy to continue. Some patients experienced itchiness and eye redness, which is not unusual for patients taking glaucoma medication.
“Some sort of slow-releasing device such is this one will definitely come to fruition one day,” says Optometry Times Editorial Advisory Board member Ben Casella, OD, FAAO, “and studies show that compliance goes down when more drops are needed in one’s regimen. State associations should examine their laws with respect to the ability to prescribe sustained release inserts in preparation for therapies such as this.”
A Phase 3 study of a larger group of patients is expected to begin later in 2016. The study authors noted the device could also be used for non-glaucoma medications, with potential applications for dry eye, allergies, and inflammation. In addition, the non-invasive nature of the device and its relatively large surface area make this technology a potential candidate for delivering multiple ocular drugs at once, further reducing the burden of self-administration on patients.