Scientists have devised contact lenses that not only correct vision but also deliver drugs straight to the retina.

Dr. Ciolino holding the medicine dispensing contact lens he and colleagues made. Credit:
John Earle Photography

The lenses developed at Massachusetts Eye and Ear aren’t exactly groundbreaking. Scientists have been experimenting with contact lenses that double as drug delivery agents for some time now, but unlike previous efforts, these contact lenses dispense medicine gradually instead of dumping it all at once.

By gradually releasing the drugs, the new lenses might become useful in treating ophthalmological illnesses like glaucoma.

The researchers lined normal contact lenses with peripheral latanoprost, a glaucoma medication that’s typically delivered as eye drops. The medicine is encased in slow-dissolving polymers allowing for a steady release into the patient’s retina. In this case, the patients were four monkeys which served as test subjects.

Results suggest that these lenses with lower doses of latanoprost deliver the same amount of eye pressure reduction as the eye drop version. The lenses fitted with a higher dose of the drug had better pressure reduction, the team reported in Ophthalmology. 

“Instead of taking a contact lens and allowing it to absorb a drug and release it quickly, our lens uses a polymer film to house the drug, and the film has a large ratio of surface area to volume, allowing the drug to release more slowly,” said senior author Daniel S. Kohane, M.D., Ph.D., director of the Laboratory for Biomaterials and Drug Delivery at Boston Children’s Hospital.

Some might find it silly to go about such a complicated route when you have eyedrops in the first place. If it only were that simple, though. Previous research suggests one in two glaucoma patients don’t use their prescribed eye drops, either due to sheer forgetfulness, or to avoid the uncomfortable pain of applying the drops.

“This promising delivery system removes the burden of administration from the patient and ensures consistent delivery of medication to the eye, eliminating the ongoing concern of patient compliance with dosing,” said Janet B. Serle, M.D., a glaucoma specialist at Icahn School of Medicine at Mount Sinai.

“If we can address the problem of compliance, we may help patients adhere to the therapy necessary to maintain vision in diseases like glaucoma, saving millions from preventable blindness,” said Joseph B. Ciolino, M.D., an ophthalmologist at Massachusetts Eye and Ear and an Assistant Professor of Ophthalmology at Harvard Medical School. “This study also raises the possibility that we may have an option for glaucoma that’s more effective than what we have today.”