Researchers Develop Drug-Eluting Contact Lens

Captured using scanning electron microscopy, the image above shows an antibacterial agent suspended in a biodegradable polymer that can be inserted into a contact lens. Image courtesy of MIT.

From the Wire: A startup company known as Eyenovations has developed contact lenses that can deliver drugs to the eye for a month or longer. The company is developing the technology to make it easier for patients with glaucoma to receive medicine without relying on frequent eyedrops. The company believes that the lenses could prove useful for treating several other eye conditions and for delivering antibiotics following eye surgery.

Daniel Kohane, director of the Laboratory for Biomaterials and Drug Delivery at Children’s Hospital in Boston, first developed this drug-delivering contact lens while collaborating with ophthalmologists seeking a better way to deliver antibiotics to patients who had received a prosthetic cornea. With the help of a research team, Kohane developed a hydrogel lens with a polymer film inside that contains the medication. The medication is released from the contact gradually, and the rate of release can be controlled by altering the properties of the polymer film and the lens. In future models, it may be possible to infuse the medication directly into the hydogel material of the lens.

Several other research groups have explored contact lenses that carry medications, but they have struggled to achieve extended release of the drugs. The Eyenovations team found a way to make their lens deliver high doses of medication for up to 100 days–a process they are now patenting. They plan to develop commercial lenses, using materials approved by the US FDA, that deliver drugs for up to 30 days. The group reports that it has begun animal testing and plans clinical testing soon.

The company’s first focus will be developing a lens that delivers medication for glaucoma. Many patients are prescribed eyedrops in the early stages of the disease, but because they have few symptoms and must take up to eight drops per day, between one-quarter and more than half of all patients fail to follow their medication schedules.

“A drug-eluting contact lens has tremendous potential,” says James Chodosh, an ophthalmologist at Massachusetts Eye and Ear Infirmary, who was not involved in the work. The technology would be particularly useful for elderly or handicapped patients who have difficulty adhering to a frequent-dosing regimen, he says.

Chodosh adds that others have experimented for many years with different ways of delivering drugs to the eye. For example, small devices can be placed in the eye, but these are not widely used. Contacts, which many people already wear, could have a much easier time gaining acceptance by ophthalmologists. But to be clinically useful, Chodosh says, the lenses will have to fit well, allow proper flow of oxygen to the eye, and not interfere with vision.

Kreitel believes that the Eyenovations technology could also prove useful for dry eye, another widespread condition that requires regular drops, as well as for other diseases that require medication at the front of the eye. He adds, “There are also several medicines that people suspect are good for treating eye conditions, but they can’t be put into drops.” In addition, says Kohane, it may be possible to create a medicated lens with vision correction for those who already wear contacts. And medicated contacts could be a more efficient way to deliver eye medications to people in remote or resource-poor areas.

More information is available from the Technology Review.

Tags: contact lens, Drug delivery, Eyenovations