Save your tears for another day — BYU researchers can use them to detect disease

It is said that tears of anger are salty and tears of joy are sweet. Regardless of whether this is actually the case or not, it is true that not all tears are created equal. The tears that come from chopping onions are different from the tears that come from pain—like stepping on a Lego in the middle of the night—as are those special basal tears that keep your eyes moist all day long. Each type of tear contains unique proteins that provide insight into health.

It’s clear that there is more to tears than meets the eye. In one new study published in Clinical proteomicsBYU biochemistry professor Kenneth Christensen and former graduate student Robert Roden describe a groundbreaking method of using soft contact lenses to collect proteins from basal cracks to detect disease early.

“How many people could be helped if doctors could detect illness before symptoms appear?” said Roden. “With this new lens method, we could potentially detect a range of health problems based on tear analysis.”

Body fluids such as tears or saliva contain proteins that are released at various locations in the body. The presence of certain proteins in biofluids may indicate health problems in the body. Proteins contained in tears are excellent for detecting eye diseases such as glaucoma and macular degeneration, but can also detect systemic diseases such as breast cancer or Alzheimer’s disease.

The problem is that collecting tears is notoriously difficult. Current methods of collecting tears are painful, irritating to the eye, and produce primarily a type of tear called reflex tears.

“When you poke yourself in the eye, you get a lot of reflex tears,” Christensen said. “But these tears are probably not the ones that indicate illness. Reflex tears would dilute indicator proteins linked to potential diseases in the body.”

Instead of invasive eye punctures, Roden wanted to use something more comfortable: a soft contact lens designed to naturally absorb proteins from the eye. Tests showed that lenses made from the Etafilcon-A hydrogel material had the highest levels of protein without causing irritation.

When these contact lenses were worn by volunteers for just five minutes, they absorbed nearly the same amount of proteins as traditional methods, but with less eye irritation to the patient. This new approach also allows patients to collect their own tears, eliminating the need for a trained optometrist.

Roden and Christensen both say their work on this project is far from over. In collaboration with Rocky Mountain University, the research team is conducting further clinical studies and using the contacts to link certain tear proteins to diseases such as macular degeneration and cancer. Ultimately, they hope this new method will be adopted in the practices of optometrists and oncologists.

“This project is very powerful in its scope,” Roden said. “Any disease your blood comes into contact with can show up in your tears. Hopefully this sampling can become a routine screening.”

Roden, now a professor at Rocky Mountain University, says completing his doctorate at BYU was both academically and spiritually fulfilling. He loves the bold marriage of science and religion promoted at BYU. He says he is grateful to study in a place where science and faith merge.

“Biochemistry is a witness to our Creator,” Roden said. “Our molecules proclaim that the Lord rules all life. Some people say that science and religion are contradictory, but I can’t find anything further from the truth. God’s fingerprint is everywhere in science.”

To read Roden and Christensen’s full publication, visit https://pmc.ncbi.nlm.nih.gov/articles/PMC10936081/