Shedding Valuable Tears: Tear Fluid as a Promising Source of Disease Biomarkers

The simplicity of collecting and evaluating tear fluid (TF) can potentially provide a convenient non-invasive diagnostic tool that easily fits into a personalized approach to medicine based on risk assessment. Though, to date, most tear biomarkers are not yet ready for routine use due to problems with their clinical validation, given the huge clinical advantage of TF and the emerging advanced technical approaches developed for proteomic, lipidomic and metabolomic analysis of tears, TF studies will doubtless become a routine test for health monitoring in the near future. A number of associations between the levels of different substances in TF and the brain makes TF an invaluable source of brain disease biomarkers helpful in early diagnostics and personalized treatment. TF is a promising biological material, an invaluable source for predictive, diagnostic, prognostic, and mechanistic biomarkers.