Experimental contact lenses deliver eye medication in controlled doses
November 15, 2011
We've had our eyes on contact lenses which aim to deliver medicine for several years. Now, a team of biomedical and chemical engineers from Alabama's Auburn University (AU) claims to have designed the first disposable lenses capable of delivering controlled doses of medication for as long as they're being worn.
One incentive for developing these wearable drug-delivery devices (they can be corrective or merely transparent) is the short-lived nature of medication in drop form. Typically, drugs applied to the eyes in that manner are largely washed out after only thirty minutes or so, whereas "wearing your meds" can be far more effective. Certainly, it makes sense that chronic dosing would yield more benefits than sporadic, not to mention the added convenience of potentially being able to forget about medicating for days at a time.
The AU team, led by chemical engineer Mark Byrne, has developed daily-use lenses that can be worn a full 24 hours and extended-wear versions which can conceivably be left in for as long as 30 days. That can spell measurable relief for those who might otherwise have to administer antibiotics, anti-inflammatories and/or anti-allergy drugs several times daily.
Because of this added efficacy, Byrne believes eye drop use may soon begin to, well, drop. "Results indicate that our lenses release a constant drug concentration for the entire time the lens is worn. This is about 100 times better than the conventional therapy, which consists of drug delivery via eye drops. With numbers that impressive, this technology is a real game-changer."
"Eye drops and ointments make up more than 90 percent market share, but are an inefficient, inconvenient method," Byrne continued. "Our lenses offer the increased efficacy and efficiency of drug delivery, which translates to better eye health." With less drugs used overall, that could translate to substantial relief for the wallet, as well.
It's remarkable enough that these new lenses, essentially hydrogels molecularly imprinted with therapeutic agents, can transmit light unhindered, but that property, coupled with a readily-tailored, consistent drug-delivery rate, belies the complexity of the new lenses.
"These aren't contacts soaked in a medication that only release for a very short time," Byrne said. "We are administering a drug through controlled release by creating drug memory in the lens structure while maintaining all of the other lens properties." Hopefully, FDA approval, marketing and availability won't be too far behind. We'll be keeping our eyes peeled.
Source: Auburn University
Watch the video below to learn more about these contact lenses: