Ocular surface physical coating

The ocular surface physical coating refers to the protective and lubricating layer, primarily the precorneal tear film, that covers the cornea and conjunctiva. This structure is vital for maintaining ocular health, providing a smooth optical surface for light refraction, and protecting the eye from environmental irritants and pathogens (StatPearls, 2023). It is traditionally described as a trilayered structure comprising an inner mucin layer, a middle aqueous layer, and an outer lipid layer, though modern models suggest a more integrated mucoaqueous gradient (National Eye Institute, 2023). In diseases such as dry eye syndrome or keratoconjunctivitis sicca, the stability of this coating is compromised, leading to increased evaporation, hyperosmolarity, and inflammation (Mayo Clinic, 2023). Therapeutic strategies targeting this structure are typically physical rather than molecular, involving the application of lubricants, artificial tears, or moisture-retaining inserts to supplement the natural barrier and reduce mechanical friction during blinking (PubMed, 2017).

Other names

Tear filmPrecorneal tear filmOcular surface barrierCorneal coating

Physical lubrication, tear film stabilization, and reduction of evaporative water loss.