NEW ORLEANS (American Chemical Society) -- Eye diseases like glaucoma could one day be treated by pharmaceuticals delivered through contact lenses. Chemical engineers from the University of Florida say they've been able to make soft contact lenses containing tiny embedded particles that slowly release drugs directly where they're needed.
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March 26, 2003
By Robert H. Shmerling, M.D.
Harvard Medical School
How does this article relate to me?
If you have ever tried to use eye drops and wondered if any of the drops were actually getting into the eye, you are not alone. But even if you've never used eye drops and never had any eye problems, news of a novel way to deliver medications into the body could someday affect you directly.
These researchers describe a contact lens that has medication imbedded within it, designed to gradually and continuously deliver the drug just where it's needed. If proven safe, reliable and effective, it may do more than just make it easier to take the medication. It could be more effective than eye drops and reduce side effects for people with glaucoma or other eye problems.
Because eye drops are often used intermittently up to several times a day, the eye is exposed to a relatively large dose of medication, some of which is absorbed into the bloodstream and carried throughout the body. Side effects may follow as the medicine winds up far from its intended target. For example, a common glaucoma medication, timolol, may slow the rate at which the heart pumps. If a lower amount of the medication were continuously delivered by wearing a contact lens, side effects might be eliminated. This system could also deliver the medicine more reliably and eliminate the need to remember several doses each day.
What changes do I need to make?
If you have glaucoma, don't ask your eye doctor for the contact lenses described in this article — they are not yet available and much more study will be required before they are.
For now, if you have glaucoma or any other disorder of the eye, it is important to take your medications regularly, carefully following the instructions on the prescription. It is also important to have frequent checkups with your ophthalmologist. Just as high blood pressure may silently lead to serious problems over time, glaucoma may gradually lead to vision loss without warning symptoms.
Routine eye examinations typically include a pressure measurement that screens for glaucoma. Screening is specifically recommended for people 40 or older, African-Americans, who have a higher than average risk of the disease, or if there is a family history of glaucoma.
What can I expect in the future?
Only a few years ago, the options for taking a medication were much more limited. Increasingly, medicines are delivered in new ways, such as through the skin, by nasal spray or inhaler. Perhaps we will soon consider the "medicated contact lens" as a routine way to treat glaucoma or other disorders of the eye. It is likely that such innovations will first be applied to the administration of well-established medications. Over time, however, new ways to deliver a drug could lead to the discovery of entirely new drugs that take advantage of the new means of administration.
Although this article describes a potentially exciting new way to treat eye disease, the researchers have not yet tested it in animals or people. It may be years away, but expect to hear more about studies that evaluate how medications delivered through contact lenses can treat eye diseases in people. In addition, you can expect to hear about other innovative ways to administer medicines that improve convenience, effectiveness and safety.
Related Areas:
Drug Resource Center
Glaucoma
