Tear film lipid layer (TFLL) and ocular surface (TFLL)

The tear film lipid layer (TFLL) is the outermost component of the precorneal tear film, primarily composed of non-polar and polar lipids secreted by the meibomian glands (Source: Willcox et al., 2017, TFOS DEWS II Tear Film Report). Its primary biological function is to stabilize the tear film by reducing the evaporation of the underlying aqueous layer and providing a smooth optical surface for light refraction (Source: StatPearls, Dry Eye Disease). The ocular surface, comprising the cornea and conjunctiva, relies on the TFLL to maintain a moist environment and protect against environmental pathogens and mechanical friction (Source: NIH, National Eye Institute). Dysfunction of this system, particularly through meibomian gland dysfunction (MGD), leads to evaporative dry eye disease, characterized by tear film instability and ocular surface inflammation (Source: Nelson et al., 2011, Investigative Ophthalmology & Visual Science). Therapeutic strategies include the use of lipid-replenishing drops like perfluorohexyloctane (Miebo) to reduce evaporation and anti-inflammatory agents like cyclosporine to treat the underlying ocular surface damage (Source: FDA, Miebo Prescribing Information).

Other names

Precorneal tear filmOcular surfaceMeibumTear filmCorneal epithelium

Lipid replenishment to reduce evaporation, reduction of surface tension, anti-inflammatory modulation of the ocular surface, and stimulation of natural tear production.