Novel Lens Delivers Controlled Doses of Medicine

A contact lens-based system that uses a strategically placed drug polymer film to deliver medication gradually to the eye was shown to be as effective as daily eye drops in a preclinical model for managing glaucoma. In a study supported by a grant from the Boston Children's Hospital, the effect of the drug-eluting contact lens was assessed in four glaucomatous monkeys. The researchers showed that the contact lens with lower doses of latanoprost delivered the same amount of eye pressure reduction as the eye drop version of the medication. The lenses delivering higher doses of latanoprost had better pressure reduction than the drops.

The novel contact lens design contains a thin film of drug-encapsulated polymers in its periphery. The drug-polymer film slows the drug coming out of the lens.

A contact lens designed to deliver medication gradually to the eye may improve outcomes for patients who struggle with imprecise, difficult-to-self-administer eye drops. Courtesy of John Earle Photography.

Because the film is on the periphery, the center of the lens remains clear, allowing for normal visual acuity, breathability and hydration. The lenses can be made with no refractive power or with the ability to correct the refractive error in nearsighted or farsighted eyes.

"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 Daniel S. Kohane, M.D., director of the Laboratory for Biomaterials and Drug Delivery at Boston Children's Hospital.

"We found that a lower-dose contact lens delivered the same amount of pressure reduction as the latanoprost drops, and a higher-dose lens, interestingly enough, had better pressure reduction than the drops in our small study," said Joseph B. Ciolino, M.D., an ophthalmologist at Massachusetts Eye and Ear and an assistant professor of ophthalmology at Harvard Medical School. "Based on our preliminary data, the lenses have not only the potential to improve compliance for patients, but also the potential of providing better pressure reduction than the drops."

Contact lenses have been studied as a means of ocular drug delivery for nearly 50 years, yet many such lenses are ineffective because they dispense the drug too quickly.

The research was published in Ophthalmology (doi: 10.1016/j.ophtha.2016.06.038).