Tear proteins and mucins

Tear proteins and mucins are a heterogeneous group of molecules that constitute the aqueous and mucous layers of the precorneal tear film. Mucins, such as the secreted MUC5AC and membrane-associated MUC1, MUC4, and MUC16, are essential for reducing friction during blinking and maintaining a stable, hydrophilic ocular surface [1][2]. Tear proteins, including lysozyme, lactoferrin, and secretory IgA, provide the primary innate and adaptive immune defense against ocular pathogens [3]. These components work synergistically to prevent desiccation and protect the corneal epithelium from environmental insults. In conditions like dry eye disease, the concentration and quality of these components are often diminished, leading to tear film instability and inflammation [1]. Pharmacological interventions like rebamipide and diquafosol target these components by stimulating their endogenous production to restore the ocular surface microenvironment [4][5].

Other names

Tear film componentsOcular surface mucinsLacrimal proteinsPrecorneal tear film glycoproteinsOcular glycocalyx components

Stimulation of mucin secretion from conjunctival goblet cells and upregulation of membrane-associated mucin expression to stabilize the tear film and protect the ocular surface.