According to recent studies, analyzing a person's tears could eventually pave the way for cheaper screening, earlier diagnosis, and potential treatment that can fight Parkinson's disease. By studying the alpha-synuclein level in patients with the disease, researchers found that they have five times more of the protein molecule found in the brain that causes nerve damage.

The study's author, Dr. Mark F. Lew of the Keck School of Medicine at the University of Southern California has said that their research is "the first to show that tears may be a reliable, inexpensive and non-invasive biological marker of Parkinson's disease."

By analyzing tears, doctors can set up biological markers that can be beneficial in studying the disease as Parkinson's is known to take its time in affecting a patient, even as symptoms appear earlier on. Dr. Lew's study also predicts that the abnormal protein molecules can also be found outside the brain, because Parkinson's affects the nerve signals in the body, as well as the brain.

From a pool of 55 patients with the long-term degenerative disease and 27 individuals without it, tear samples were collected and compared. Levels of healthy, non-clumped alpha-synuclein strains were found to be lower in patients with Parkinson's. However, they tallied higher levels of the unhealthy form of the molecule, called oligomeric alpha-synuclein. This strain is the one that forms aggregates, which makes it more associated with nerve damage.

Dr. Lew explains, "Knowing that something as simple as tears could help neurologists differentiate between people who have Parkinson's disease and those who don't in a non-invasive manner is exciting."

As with early studies for various types of diseases, further plans for research are underway, with a larger group targeted as sample. The aim for the future study is to detect the changes in protein-levels before other symptoms can even manifest in a patient.

The study will still be presented in the annual meeting of the American Academy of Neurology in Los Angeles on April 21-27. It is also still set to be peer-reviewed in a medical journal.