Update: April, 2005- Dr. Geddes' research has generated so much interest that Discovery Canada has aired a web video about it. After a quick visit on April 22, with a camera man and sound tech, the video appeared on Discovery Canada's web site on April 28, 2005. Check it out at http://www.exn.ca/news/video/exn2005/04/28/exn20050428-contact.asx . The seeming interview was not exactly as it looks. Dr. Geddes says that the questions that were asked are the same but he never talked with Jay Ingram, the host of the show!

December, 2004- A potentially revolutionary approach to sugar monitoring for diabetic patients has recently been invented. Dr. Chris D. Geddes , Associate Professor at UMBI's Medical Biotechnology Center and head of the Institute of Fluorescence , has developed contact lenses capable of measuring glucose in tears, which reflect blood glucose levels. This non-invasive and continuous technique, using innovative fluorescent probes embedded into commercially available lenses, may eliminate the necessity of repeated blood sampling currently used to monitor sugar levels in diabetics. The contact lens changes color in relation to the amount of sugar in tears and can be monitored by the wearer simply looking into a mirror. This work, done in conjunction with Dr. Ramachandram Badugu and Dr. Joseph R. Lakowicz from the Center for Fluorescence Spectroscopy, University of Maryland, Baltimore, was recently reviewed in Nature Materials 3, 76 (2004).

While no human trials have begun, tests with custom-built laboratory "eyes" have shown great promise in being able to accurately sense glucose levels under physiological conditions. The lenses would also make it easier for care-givers to determine glucose levels in the elderly or in children.

Diabetes is the cause of a myriad of long-term health problems, including vascular diseases, blindness, and kidney failure. Its incidence is increasing with increased prevalence of obesity. Long-term effects can be minimized with strict management of glucose levels, but the current, painful blood testing regimens are difficult to follow, especially for children. A non-invasive and continuous monitor of glucose levels will be an incredible breakthrough for the management of this chronic disease.

This work was supported out of special funds from the Medical Biotechnology Center.

Figure 1: Experimental lenses: With no glucose the lens is red; with glucose the lens becomes pink.