Sarah Hamm-Alvarez, PhD: Importance of a Tear-Based Parkinson Biomarker

Newly presented research shows early promise in the development of a biomarker for earlier detection of Parkinson disease. Investigators at the Keck School of Medicine of USC studied the proteins found in basal and reflex tears of patients with Parkinson disease and those without.

Sarah Hamm-Alvarez, PhD, Professor of Ophthalmology at the USC Roski Eye Institute at the Keck School of Medicine of USC, presented the research at the 2019 Annual Meeting of the Association for Research in Vision and Ophthalmology (ARVO) in Vancouver, BC.

Hamm-Alvarez told MD Magazine® that a tear-based biomarker that she and her team are investigating could be both simple for use in screening and inexpensive.

The biomarker test is something that “could be applied on a routine screening basis to anybody who would be in a neurology clinic who would have a certain constellation of symptoms,” she noted.

In part 1 of the interview, Hamm-Alvarez introduced the study and the team’s reasons for investigating tears for a Parkinson biomarker. In part 2, she described the study methods and the differences they found in basal and reflex tears. Part 3 covers the collaborative process of developing this Parkinson biomarker.

Why is the search for a Parkinson biomarker important?

What would be the advantages of a tear-based Parkinson biomarker?

Well I think that this is one of the most exciting things for anybody who works in this Parkinson's disease space. So, some of the drugs that are commonly used in Parkinson's disease are the same drugs that have been used for the past 40 years and it's very difficult to develop new drugs if you can't identify patients at a stage where you can still make an intervention and then have a biomarker that provides a readout that that intervention has, obviously, had a therapeutic effect. So, obviously, any diagnostic biomarker that could provide [diagnosis of] patients at an earlier state would be potentially of great benefit whether it is a biomarker in bio fluid like tears or saliva or cerebrospinal fluid. We're very excited about the potential for any biomarker to be able to be paired to new therapies.One of the advantages that we would see if we're able to advance this as a potential biomarker is that a tear-based biomarker is so simple, and it could potentially be so inexpensive. This could be something that is non-invasive, we use the word atraumatic. So, this is not something that requires advanced instrumentation, fancy imaging, invasive cerebrospinal fluid analysis, and so it's something that could be applied on a routine screening basis to anybody who would be in a neurology clinic who would have a certain constellation of symptoms.