Ocular surface mucin and glycocalyx

The ocular surface mucin and glycocalyx layer is a complex, multi-component structure that coats the corneal and conjunctival epithelia, playing a vital role in maintaining ocular surface health and tear film stability (Uchino, 2018; Gipson, 2004). It consists of membrane-associated mucins (MUC1, MUC4, MUC16) that form the glycocalyx and secreted gel-forming mucins (primarily MUC5AC) produced by conjunctival goblet cells (Argueso et al., 2021; Willcox, 2014). This layer provides essential lubrication, facilitates surface wetting, and acts as a robust physical and chemical barrier against pathogens, allergens, and environmental toxins (Uchino, 2018; Gipson, 2004). In diseases such as dry eye disease (DED), Sjögren's syndrome, and ocular surface inflammation, the expression and glycosylation of these mucins are significantly altered, leading to barrier disruption and epithelial damage (Uchino, 2018; Argueso et al., 2021). Therapeutic agents like rebamipide and diquafosol target this layer by stimulating mucin production and secretion, thereby restoring the protective glycocalyx and improving tear film quality (Uchino, 2018; BenchChem, 2026).

Other names

Tear film mucin layerCorneal glycocalyxConjunctival glycocalyxMucous layer of the tear filmOcular surface mucinsTear film mucin/glycocalyx layer on corneal and conjunctival epithelium

Stimulation of mucin secretion from goblet cells (mucin secretagogues), upregulation of membrane-associated mucin expression in epithelial cells via EGFR or P2Y2 pathways, and provision of mucin-mimetic lubrication and barrier support.