Prior to the appearance of classic movement abnormalities like tremor and slowness, those with Parkinson's suffer from non-motor symptoms, such as altered function of the gastrointestinal tract, depression and changes in the sense of smell. The secretion of specific proteins into tears may be regulated by similar changes in nerve function that are seen in these other affected systems. Thus, an analysis of alterations in the secretion of proteins into tears may lead to the identification of a reliable biomarker (tracks disease activity) for Parkinson's disease (PD).
As PD affects multiple non-motor systems, tear secretion in those with Parkinson's will be altered to exhibit a characteristic or diagnostic biomarker profile that will be reflected in changes in the protein composition of tear fluid, which can be measured relatively easily, cost-effectively and non-invasively.
Tear fluid samples will be collected from participants with Parkinson's, and, through biochemical assays, the profile of proteins in tears will be characterized and compared to those from control participants. The profiles will be analyzed with respect to differences between participants with Parkinson's and control participants. If differences are found, the levels of these potential biomarkers in Parkinson's will be analyzed with respect to disease severity.
Impact on Diagnosis/Treatment of Parkinson's Disease:
There are currently no biomarkers for the detection of Parkinson's. Identification of reliable biomarkers for PD would allow for earlier detection and treatment of and monitoring of drug-based interventions, potentially leading to better outcomes.
Next Steps for Development:
Biomarkers for Parkinson's, if present in tears, may be used to screen for early detection of the disease, to monitor the course of disease and to measure the effectiveness of potential therapeutic treatments. These evaluations will be non-invasive, relatively easy to perform and cost-effective.