Contact Lenses That Dispense Drugs
Contact Lenses Could One Day Put Drugs Where Needed, Bypass Serious Side Effects
March 24, 2003 -- Drugs embedded in contact lenses could one day treat eye disorders like glaucoma.
A team of chemical engineers has found a way to mix a drug into contact lenses -- which allows the drug to slowly be released into the eye, directly where it's needed.
"One of the biggest problems with using eye drops to deliver medication to the eyes is that about 95% of the medication goes where it's not needed," says study author Anuj Chauhan, PhD, in a news release. Chauhan is an assistant professor of chemical engineering at the University of Florida in Gainesville. His findings were presented at the American Chemical Society meeting being held this week in New Orleans, La.
Dispensing eye medications through drops is a popular, but not very efficient, method because only about 5% of the drug penetrates into the eye. The problem is the drug mixes with tears, which then drain into the nasal cavity. From there, they go into the bloodstream and travel to other body organs -- which can cause serious side effects. For example, the drug Timolol -- which is prescribed to treat glaucoma -- can cause heart problems. .
But drugs contained in contact lenses could be released slowly enough to stay in the eye, says Chauhan. In theory, the disposable drug-laden contact lenses could be worn for up to two weeks. Rather than being exposed to a sudden high dose of medication -- from an eye drop -- the glaucoma patient gets the right amount of medicine all the time.
The contact lenses could also correct vision as they've always done, if necessary.
Researchers speculate that other drugs, like antibiotics, could also be incorporated into the contact lenses.
The drug-release contact lenses are still in very early engineering design stages, Chauhan says, and have not been tested on animals or humans.