Tear film lipid layer and meibomian gland secretion (null)

The tear film lipid layer is the outermost component of the tear film, formed primarily from lipids produced and secreted by the meibomian glands located within the tarsal plates of the eyelids. Meibum, a complex mixture of wax esters, cholesterol esters, and other unique lipids, spreads over the aqueous layer of the tear film to form a hydrophobic barrier and minimize evaporation. This lipid layer plays an essential role in protecting the ocular surface, enabling clear vision, and preventing dry eye symptoms. Dysfunction of the meibomian glands (known as Meibomian Gland Dysfunction, MGD) alters secretion quality and quantity, leading to destabilization of the tear film and a range of ocular diseases including dry eye syndrome and blepharitis. Therapy focuses on restoring gland function and tear film properties but does not target a specific molecular entity.

Other names

Meibomian gland secretionsEyelid lipid secretionMeibumTear film lipid layer (TFLL)Tarsal gland secretion

Most drugs act indirectly: improve gland function, reduce inflammation, supplement tear composition; there is no direct "receptor-ligand" pharmacology for this layer