Tear film lipid and mucin layers

The tear film lipid and mucin layers are integral components of the precorneal tear film, essential for maintaining ocular surface homeostasis and optical quality. The lipid layer, primarily produced by the Meibomian glands, forms the outermost interface to prevent tear evaporation and provide structural stability (TFOS DEWS II, 2017). The mucin layer, consisting of glycoproteins like MUC5AC secreted by conjunctival goblet cells, acts as a surfactant to spread the aqueous layer over the hydrophobic corneal epithelium (StatPearls, 2023). Deficiencies in these layers are central to the pathogenesis of dry eye disease, leading to tear film instability and ocular surface damage. Pharmacological targeting involves lipid-replenishing drops, such as perfluorohexyloctane, or mucin secretagogues like rebamipide and diquafosol (PubMed, 2021). These therapies aim to restore the protective barrier and improve patient symptoms of irritation and blurred vision.

Other names

Precorneal tear filmOcular surface filmTear filmLipid-mucin complexTear film lipid layerTear film mucin layer

Therapeutic agents target these layers by supplementing deficient lipids to reduce evaporation, stimulating goblet cells to increase mucin secretion, or providing mucoadhesive polymers to stabilize the tear film structure (TFOS DEWS II, 2017).