Approximately half of the people who have had type 2 diabetes for over 10 years experience a decrease in nerve function, which typically begins in their feet. Because this can result in wounds and even amputations, it's important to know when it's starting – and a simple eye test may be all that's required to find out.

The small peripheral nerve fibers that are affected by the disease are found not only in the skin, but also in the eye's cornea. Because the cornea is transparent, it can be more easily examined than the skin.

With this in mind, an Umeå University research team led by Prof. Olov Rolandsson used a laser-scanning microscope to perform eye exams on 82 test subjects all aged around 69, from the Swedish city of Skellefteå. Approximately half of those people had type 2 diabetes, and half did not.

What the scientists found was that corneal nerve density was lower in the diabetics than in the healthy subjects, and it was particularly low in people who had been diabetic for over 10 years.

The test is non-invasive and takes just 10 minutes to perform. Additionally, the team has created a computer program that automatically assesses the degree of nerve damage, based on the corneal nerve density.

"Although there is currently no cure, it's always an advantage to detect changes in the nerves early," says Rolandsson. "Therefore, it's valuable to find a fast and safe diagnostic method."

A paper on the research was recently published in the journal Investigative Ophtalmology & Visual Science.

Source: Umeå University