July 15 (HealthDay News) -- A new testing device may give doctors early warning of eye disease, especially vision trouble linked to diabetes, researchers say.

The device is able to capture images of the eye that reveal metabolic stress and tissue damage, even before the first signs and symptoms of disease appear, says a team at the University of Michigan. The technology measures a phenomenon called flavoprotein autofluorescence (FA), which is thought to be a reliable indicator of eye trouble.

"The concept behind measuring FA in the retina is to determine whether there's a metabolic dysfunction in the retinal tissue," explained lead researcher Dr. Victor M. Elner, a professor in the University's Department of Ophthalmology and Visual Sciences.

"Our objective in performing this study was to determine whether we could detect abnormal metabolism in the retina of patients who otherwise would remain undiagnosed based on clinical examination alone," Elner added.

The report is published in the July issue of the Archives of Ophthalmology.

In the study, Elner's team measured FA levels in 21 people with diabetes and compared those results with data from people who did not have the disease.

People with diabetes had significantly higher levels of FA compared with nondiabetics, the researchers report. "The diabetics demonstrated consistently abnormal metabolism when compared to the control individuals without disease," Elner said.

His group also measured FA levels in patients with and without diabetic retinopathy. Diabetic retinopathy, which can eventually lead to blindness, is a common complication of diabetes.

"Patients with retinopathy had significantly more abnormality to their readings than patients without retinopathy," Elner said. "This indicated that we can actually use the method to monitor the severity of the disease."

There are a number of advantages to FA testing, Elner said.

"FA testing is less invasive, rapid and gives a test result within five minutes," Elner said. "It compliments glucose tolerance testing in that it actually tells us about tissue dysfunction in the retina, which is indicative of how the whole body is doing."

In addition, because of its rapid, noninvasive nature, the new test can be used to screen patients at risk for a variety of different diseases, Elner said. "Diabetes is the best example of that because of the prevalence of the disease in our population. But the technique is also capable of screening other diseases such as glaucoma or age-related macular degeneration," he added.

Elner has a financial interest in this technology, and started a company to make it commercially available.

There are some 24 million Americans with diabetes and 57 million more who have pre-diabetes, according to the U.S. Centers for Disease Control and Prevention. In addition, 4.1 million people over 40 suffer from diabetic retinopathy.

SOURCES: Victor M. Elner, M.D., Ph.D., professor, department of ophthalmology and visual sciences, University of Michigan Medical School, Ann Arbor; July 2008 Archives of Ophthalmology