Round silicone eye device releases drugs for six months, eliminating need for daily drops
Nearly half of glaucoma patients fail to take their daily eye drops as prescribed by an ophthalmologist, making them more vulnerable to vision loss and blindness. However, a new wearable time-release medication device could help solve this problem.
A new study shows that a medicated silicone ring placed on the eye can lower internal eye pressure by about 20 percent for half a year. Lowering internal eye pressure is the key to keeping glaucoma under control, as dangerously high eye pressure damages the optic nerve.
If the device is approved after more research, it could be a boon to the 3 million people who have glaucoma in the United States.
“In making effective treatments easier for patients, the hope is that we reduce vision loss from glaucoma, and possibly other eye diseases,” said study author James D. Brandt, M.D., director of the UC Davis Medical Center Glaucoma Service.
In a phase 2 clinical trial, ophthalmologists tested the device on 130 patients with glaucoma or ocular hypertension. Sixty-four patients wore the ring treated with glaucoma drug bimatoprost. An ophthalmologist placed the ring on the surface of the eye underneath the lids. No surgery is needed to install it. Those patients were also supplied artificial tears.
The control group of 66 patients wore a placebo ring treated with no medication, but twice a day took drops of another commonly prescribed glaucoma drug, 0.5 percent timolol.
Eye pressure in patients with the bimatoprost ring fell 3.2 to 6.4 mmHg over six months. Those in the timolol group had eye pressure that fell 4.2 to 6.4 mmHG. Overall, eye pressure decreased in the group wearing the bimatoprost ring by about 20 percent from the initial measurements over six months.
The ring itself seemed comfortable enough: only 6 percent wearing the device reported discomfort. The device became dislodged in 15 patients but was replaced each time. Some patients reported itchiness and eye redness, which is not unusual for patients taking glaucoma treatment drops. The ring can easily be removed if the patient wishes to discontinue treatment.
A phase 3 study of a larger group of patients is expected to begin later in 2016.
“What is exciting is that this is just one of several sustained-release drug delivery methods designed to help patients who have trouble taking daily eye drops,” Dr. Brandt said.
Researchers noted the device could be used for treating more than one eye condition at a time. If loaded with multiple medications, it could potentially treat eye allergies, dry eye and glaucoma simultaneously, eliminating the need for elderly patients to take multiple medications themselves for those issues.
The study was published in May online by Ophthalmology, the journal of the American Academy of Ophthalmology.