Lacritin: A Natural Tear Protein That Could Treat Dry Eye Disease

This was a narrative review examining the tear proteome — the complete set of proteins found in tears — with a focus on lacritin and lipocalin-1 biology. The authors synthesized findings from proteomic studies, functional assays, and preclinical experiments to discuss the therapeutic potential of tear protein replacement.

Current dry eye treatments are largely palliative, offering temporary relief without targeting the root cause. Identifying specific tear proteins that are depleted in dry eye opens the door to biotherapeutic approaches that could restore normal tear function rather than simply masking symptoms. This research shifts the treatment paradigm from generic lubrication to precision replacement of missing biological components.

This research sits at the intersection of proteomics and ophthalmology, part of a broader movement toward biologic therapies that replace what the body is missing rather than using synthetic substitutes. If tear protein replacement proves effective in clinical trials, it could fundamentally change how dry eye is treated — and the approach could extend to other mucosal surface diseases where specific protective proteins are depleted.

This is a review article, not a clinical trial, so it synthesizes existing evidence rather than presenting new patient data. The therapeutic potential of topical lacritin has been demonstrated in preclinical models but had not yet been validated in large-scale human clinical trials at the time of publication. The specific mechanisms by which protein-protein interactions in the tear film affect function are not fully understood.