Tear film and ocular surface epithelium

The tear film is a structured, multilayered fluid (lipid, aqueous/mucin, and mucin/glycocalyx) that overlays the ocular surface epithelium, which is composed primarily of the corneal and conjunctival epithelial cells. The tear film ensures optical clarity, lubrication, and protection of the ocular surface, while the epithelium maintains a barrier and provides the foundation for epithelial renewal and wound healing. Disruption of either component can result in dry eye, inflammation, pain, visual disturbance, or increased susceptibility to infection. The system is a focus of therapies aimed at restoring homeostasis in ocular surface diseases, but it is not itself a single molecular drug target.

Other names

Precorneal tear filmOcular surfaceCorneal epithelium and conjunctival epithelium

Lubrication and hydration (artificial tears/lubricants); Modulation of inflammation (anti-inflammatories); Anti-infective action (antibiotics); Promotion of epithelial healing (growth factors)