Ocular surface mucins and tear film components

Ocular surface mucins and tear film components comprise a complex, multi-layered system essential for maintaining the health, protection, and optical clarity of the eye. This system is traditionally described as having three primary layers: an inner mucin layer (consisting of membrane-associated mucins like MUC1, MUC4, and MUC16, and secreted mucins like MUC5AC), a middle aqueous layer containing water, electrolytes, and proteins, and an outer lipid layer produced by the meibomian glands. These components work synergistically to provide lubrication, prevent epithelial desiccation, protect against environmental pathogens, and create a smooth refractive surface for vision. In pathological conditions such as Dry Eye Disease (DED) and Meibomian Gland Dysfunction (MGD), the homeostasis of these components is disrupted, leading to tear film instability, hyperosmolarity, and chronic inflammation. Therapeutic interventions target these components through various mechanisms, including mucin secretagogues like rebamipide, P2Y2 receptor agonists like diquafosol to stimulate secretion, and lipid stabilizers like perfluorohexyloctane to reduce evaporation. Additionally, anti-inflammatory agents such as cyclosporine and lifitegrast are used to restore the biological environment necessary for healthy tear film production.

Other names

Tear filmPrecorneal tear filmOcular mucinsLacrimal functional unit componentsMuco-aqueous layer

Mucin secretagogue, P2Y2 receptor agonist, Calcineurin inhibitor, Lymphocyte function-associated antigen-1 (LFA-1) antagonist, Lipid layer stabilizer, Nicotinic acetylcholine receptor agonist