This New Technique Can Help Detect Eye Diseases, Diabetes From Your Tears

Tears, whether of joy or sadness, offers a peek into a person's emotional being. But they are a lot more than that. These droplets can be used to spot eye diseases and diabetes, thanks to a newly developed technique.

The new technique, called iTEARS, applies nanotechnology to quantify the composition of tears. Tears are made up of small sacs called exosomes, which contain molecular messages from the body. If we intercept these messages and identify them correctly, we can look into the human body and detect diseases like diabetes, according to a study published in ACS Nano.

A hurdle on the researchers' path was the minute quantity of tears when compared to other bodily fluids like urine and saliva, as well as its low recovery and long processing time. To overcome this, tear samples were collected and mixed with a solution. Next, the solution was added to a device with a couple of nanoporous membranes. When the membranes were vibrated, the solution got sucked in, leaving behind only the sacs.

Researchers say the process takes just five minutes.

Study co-author Fei Liu, a biomedical engineer at China's Wenzhou Medical University, is hoping to use this novel technique to develop self-testing kits that people can use in their homes.

"We wanted to demonstrate the potential of using tears to detect disease," he said.

Dry-eye diseases leave behind different molecular fingerprints in people's tears. The research team was able to identify 426 proteins associated with dry-eye disease during their study.

Scientists also found some biomarkers which change during diabetic retinopathy development. This information can be used to track diabetes progression in people.

"This is just the beginning," said study co-author Luke Lee, a bioengineer at Harvard Medical School. "Tears express something that we haven't really explored."

The researchers now want to use tears to identify other diseases along with depression or emotional stress.