A Cataract Lens That Doubles as Glaucoma Medicine? New Study Shows It's Possible
Millions of older adults rely on daily medicated eye drops to treat their glaucoma. But it's a well-documented fact that most patients don't use their medication as prescribed. Reasons why abound: challenging multi-drop routines or multiple daily applications, cost, side effects, and poor eye drop technique resulting in little to no medication entering the eye.
A new study presented on Sunday at the 130th annual meeting of the American Academy of Ophthalmology suggests that for patients who already need cataract surgery, there might be a better way to treat their glaucoma during cataract surgery.
The Phase 1/2 trial included 106 adults with glaucoma or ocular hypertension who were scheduled for cataract surgery. Researchers replaced each patient's clouded natural lens with an artificial one carrying small pads of bimatoprost, a widely used glaucoma drug. The pads release the medication gradually inside the eye. After 12 months, eye pressure had fallen to about the same level as in patients who received a standard lens plus twice-daily timolol drops. More than 95 percent of those with the drug-releasing lens were free of glaucoma medication.
"Imagine being able to treat two of the most common eye diseases, cataract and glaucoma, in one sitting," said Jeffrey A. Kammer, MD, an ophthalmologist and investigator in the trial. "There is simply nothing like it in development."
The problem with drops
Glaucoma damages the optic nerve, most often because pressure inside the eye is too high. Lowering that pressure is the only proven way to slow the disease, and daily drops are the usual first tool. But drops only work if patients use them, and many struggle to do so consistently.
"Daily eye drops can be challenging to administer consistently," Dr. Kammer said. "The idea of a drug-eluting lens that could provide sustained medication after cataract surgery is particularly compelling."
Cataract surgery offers a natural opening. It is one of the most commonly performed and predictable operations in the world, and glaucoma and cataracts often strike the same aging eyes.
What the trial found
The study enrolled adults with mild-to-moderate open-angle glaucoma or ocular hypertension who were scheduled for cataract surgery. Participants were randomly assigned, in a 2:1:1 ratio, to one of three groups: a lens delivering a higher dose of bimatoprost (78 micrograms), a lower dose (39 micrograms), or a standard commercial lens followed by timolol 0.5 percent drops. Patients and evaluators were masked to the assignments.
Before treatment, average eye pressure ranged from 24.6 to 26.3 mmHg across the groups. At 12 months, average pressure had dropped to 15.9 mmHg in the higher-dose group, 14.8 mmHg in the lower-dose group and 15.7 mmHg in the timolol group.
The pressure reductions in both implant groups were statistically indistinguishable from those achieved with timolol drops. The difference was in the daily burden: more than 95 percent of patients with the drug-releasing lens needed no glaucoma medication at one year.
Vision and safety held up as well. Every eye that received the implant could see 20/32 or better with correction at 12 months, and safety was comparable across all three groups. No serious adverse events were reported.
Echoing earlier results
The findings mirror a smaller first-in-human study of the implant. That earlier work showed roughly a 37 percent reduction in eye pressure over three years, a 95 percent medication-free rate, corrected vision of 20/32 or better in every patient, and safety comparable to routine cataract surgery.
"I was more encouraged than surprised by how closely the interim 12-month findings aligned with the first-in-human results," Dr. Kammer said. "Seeing similar outcomes across these studies provides reassuring evidence that the treatment effect is being replicated as the program progresses."
A new way to deliver therapy
This isn’t the first time ophthalmologists have thought about treating glaucoma during cataract surgery. Combing cataract surgery with the implantation of tiny drainage devices known as Minimally Invasive Glaucoma Surgery (MIGS) has been shown effective. But Dr. Kammer said those procedures have not caught on as widely as many expected.
A drug-releasing lens, he says, could be easier for surgeons to adopt because it slips into a procedure they already perform. "This technology is forcing us to rethink how we deliver glaucoma therapy," he said. He pointed to the lens's ease of implantation, its low side-effect profile and its seamless fit into the operation as reasons more ophthalmologists may be comfortable using it.
What comes next
The results are an interim look, and important questions remain, mainly how long the drug keeps working and whether safety holds over time. Patients in the Phase 1/2 trial will be followed for three years. Two larger Phase 3 trials are now underway.
"Longer-term follow-up will be important for understanding the durability of pressure control as well as safety," Dr. Kammer said. For patients, he added, the direction is promising: "Glaucoma treatment is moving toward solutions that could make managing the disease simpler."
