Drug-releasing contact lens may have overcome earlier problems

A group of scientists in Singapore have developed a contact lens capable of delivering ocular medication without some of the side effects seen with earlier versions of the device, according to a report in New Scientist.

Edwin Chow and colleagues at the Institute of Bioengineering and Nanotechnology created a technique in which medications can be mixed with a pre-polymer liquid. The liquid is then polymerized, creating a transparent contact lens material, according to the release.

If the drug is water-soluble, a network of interconnected, water-filled channels will hold the medication; if the drug is not water-soluble, it will be trapped in nano-spaces within the polymer matrix and slowly leach out into the channels, the scientists said.

Earlier versions of the contact-lens-based drug-delivery vehicle did not allow sufficient oxygen into the eye, but the new lens allows gases, salts and nutrients to “readily diffuse across,” Mr. Chow said.