Tears and ocular surface disorders: Usefulness of biomarkers.

INTRODUCTION: Corroborating data suggest that the analysis of tear fluid might represent an additional tool in the ophthalmological practice. AREAS COVERED: The purpose of this review was to sum up the tear protein profiles in healthy and diseased ocular surface and to highlight biomarker usefulness in the early diagnosis as well as at follow-up. This analysis encompasses a deep examination of the protein profile expression under physiological and pathological conditions. Tear protein profile analysis will allow in the near future discriminating between different grades of inflammation, from acute trauma toward immune-, endocrine-, and nervous-related disorders of the ocular surface. CONCLUDING REMARKS: The review provides an overview of old and recent findings about inflammatory mediators identified at the ocular surface, under physiological and pathological conditions. To date, the analysis of tear fluid represents a new additional approach for diagnosis and management of ocular surface diseases. Understanding the pathophysiological mechanism could also offer significant advantages to develop strategies addressed to better clarify some complex ocular surface disorders. To sum up, the possibility to provide selective biomarkers as a future target of specific diseases should be considered for supporting diagnosis and management of ocular surface diseases.