Measuring Blood Sugar: The Eyes Have It
June 24, 2001 (Philadelphia) -- Day in, day out, millions of diabetics prick their finger and squeeze a tiny drop of blood on a strip of paper to measure their blood sugar levels. It's part of the hassle of managing this chronic disease -- a real pain that soon may be a thing of the past if the latest research pans out.
In the not-too-distant future, bloodless, painless ways will be available for measuring and potentially even treating high levels of sugar, or glucose, in the blood, according to new research presented here Friday at the annual meeting of the American Diabetes Association (ADA). That will allow people with diabetes to monitor their sugars more often, leading to improved control and lower risk of diabetes complications, including nerve, eye, and kidney damage.
The first bloodless monitoring device for people with diabetes may be available as early as 2004, says David C. Klonoff, PhD, medical director the Dorothy L. and James E. Frank Diabetes Research Institute at Mills Health Center in San Mateo, Calif. It will work by casting an invisible light on either the skin or eye and measuring the interaction of the light with glucose. From there a computerized meter calculates glucose levels.
Also being previewed at the ADA meeting are contact lenses that measure glucose levels in tears. A person wearing the lenses presses a button on a small device that shines a light on the lens, and -- voila! -- a glow-in-the-dark phenomenon called fluorescence occurs, says Wayne F. March, MD, professor and chairman of ophthalmology at the University of Texas Medical Branch in Galveston, Texas.
"Tears contain glucose that's proportional to [the amount of] blood glucose," he tells WebMD, "and the contact lens can sense the glucose concentration on tears. The patient gets a reading and if the tear glucose is high, so is the blood sugar."
March and colleagues tested the new lenses on nine people with type 2 diabetes and three people without diabetes and found the contact not only corrected vision, but also accurately measured glucose. In the future, the same technology may be applied to eyeglass lenses, he says.
Ultimately, says Klonoff, "Where all this technology is eventually heading is toward an artificial pancreas."
The pancreas, the organ that produces the hormone insulin to metabolize glucose is not functional in people with diabetics. Creating a replacement organ is the Holy Grail of diabetes research. At the ADA meeting, French doctors reported early success in their bid to accomplish this.
"It's based upon an insulin pump that is surgically implanted under the skin in the abdomen wall, providing a two- to three-month supply of the hormone insulin," explains lead researcher Eric Renard, MD, of the Hopital Lapeyronie in Montpellier, France. "And a glucose sensor is implanted by the jugular vein."