Tear film aqueous-mucin layer

The tear film aqueous-mucin layer is a complex physiological compartment essential for maintaining the health and optical clarity of the ocular surface. Modern research describes it as a unified mucoaqueous gradient where mucins, produced by conjunctival goblet cells and corneal epithelium, are interspersed with the aqueous component secreted by the lacrimal glands [1][2]. This layer provides a smooth refractive surface for vision, lubricates the eyelids during blinking, and contains essential nutrients, electrolytes, and antimicrobial proteins like lysozyme and lactoferrin [3]. It also serves as a physical and chemical barrier against environmental pathogens and debris. Dysfunction of this layer, characterized by decreased volume or altered biochemical composition, is the primary driver of Dry Eye Disease (DED) [4]. Such deficiencies lead to tear hyperosmolarity, which triggers a cascade of ocular surface inflammation and epithelial damage [5]. Therapeutic interventions focus on supplementing the layer with artificial lubricants or stimulating the endogenous production of water and mucins through secretagogues [5]. Additionally, anti-inflammatory agents are used to break the "vicious circle" of dry eye and restore the natural homeostasis of the tear film [5].

Other names

Aqueous-mucin layerMucoaqueous layerTear film aqueous layerTear film mucin layerPrecorneal tear film

Lubrication, osmotic stabilization, and stimulation of endogenous secretion to restore tear film homeostasis.