Tear samples likely next screening method for peripheral neuropathy among diabetics

A new Australian study has suggested that tear samples might be the next screening method to screen diabetic patients for peripheral neuropathy. The study conducted by Sydney-based University of New South Wales (UNSW) has stated that tear-testing may be used to screen diabetic patients for diabetic peripheral neuropathy, a debilitating condition that affects them.

The study, recently published in the Ocular Surface journal, is the first to show that peripheral nerve damage, often the earliest sign of the condition, can be traced in tear film. “We found that people with type 1 diabetic peripheral neuropathy – which can result in recurring ulcers of the feet and in severe cases require amputation – have reduced levels of a protein known as ‘substance P’ in their tear film,” Maria Markoulli, a senior author of the study, said.

“Almost 119,000 Australians have type 1 diabetes. In the future, they may be able to have a quick tear sample collected either at their optometrist, the chemist, GP or endocrinologist, and be told whether they are at risk,” she said. Peripheral neuropathy is the most common complication of diabetes affecting almost 50 per cent of diabetics and occurs when chronically high blood sugar damages the nerves connecting the brain and spinal cord to the rest of the body.

Symptoms include pain, numbness, imbalance, weakness, pins and needles, and recurring foot ulcers. While nerve damage cannot be reversed, early detection can help patients better manage the condition and prevent further complications. However, current early testing options are limited to invasive examinations, such as skin biopsies.

“What we're proposing with this method is something that will be done quickly, non-invasively, and potentially could be done even by a non-specialist,” Markoulli said. She said peripheral neuropathy is notoriously difficult to detect early on and requires special training.

"What we're proposing with this method is something that will be done quickly, non-invasively, and potentially could be done even by a non-specialist,” according to the researchers. During the study, which consisted of 100 participants, the researchers tested the concentration of two proteins (called neuropeptides) in the tear film of people with type 1 and type 2 diabetes compared to control groups.

While the researchers found that those with type 1 diabetic peripheral neuropathy had less ‘substance P’ protein in their tear film, the results did not suggest that type 2 diabetes have the same biomarkers. “This is perhaps because these diseases have different pathologies and risk factors,” a lead author of the study, S S Tummanapalli said.

“It tells us that the two disease processes are quite different,” the researcher said. While the results are promising for those with type 1 diabetes, further study is required before tear testing becomes available clinically.

In particular, the researchers hope to study substance P loss over time according to varying severities of peripheral neuropathy.

(This story has not been edited by Devdiscourse staff and is auto-generated from a syndicated feed.)