For patients recovering from eye surgery, "bandage" contact lenses may be a new way to get anesthetics and other drugs into the eye through the cornea.
Applied after a traumatic eye injury or surgery to protect a damaged cornea, the lenses can be used as an effective sustained-release drug delivery system, experts say.
Researchers at the University of Florida are working on a way to extend the release of drugs from silicone hydrogel contact lenses--the idea itself isn't new, but the length of time is significantly prolonged. By adding vitamin E to the process, the contact lenses are able to keep drugs in the eye for up to a week. Particularly in the case of glaucoma patients, more traditional treatments such as eyedrops tend to have a relatively poor compliance rate.
Speaking about the development at a January ophthalmic conference, Dr. Nicoletta Fynn-Thompson said the lenses allow for more thorough absorption of the drugs, increasing bioavailability about 50%, according to a Healio Ophthalmology report. Eye drops are much less efficient at conveying drugs to the cornea in particular.
UF's Anuj Chauhan said there are several lens-drug combinations in the works by his team and others and that drug-delivering contact lenses could be an important clinical step toward curing some ocular diseases.
"You could argue that any ocular disease can be cured by a contact lens," Chauhan told FierceDrugDelivery. "And for patients with diseases like glaucoma and cystinosis who constantly need drugs, the sustained-release contact lenses are a good answer."
As drug-delivery devices, Chauhan said, the contact lenses must strike a balance, to increase the duration of the drug release without compromising vision or preventing oxygen from reaching the eye.
- here's the Healio Ophthalmology report