What is the primary mechanism of lipid therapy for the tear film?

• A. Augments the deficient lipid component of the tear film.
• B. Reduces tear production by the lacrimal gland.
• C. Increases mucin production on the corneal surface.
• D. Stimulates blinking to distribute tears more evenly.

Answer: (A)

The main idea is that lipid therapy works by replenishing the lipid layer of the tear film. The outer lipid layer, produced by the Meibomian glands, acts as a hydrophobic barrier that reduces evaporation of the underlying aqueous layer. When this lipid component is deficient or abnormal—as in Meibomian gland dysfunction—adding lipids helps rebuild that barrier, slow evaporation, and stabilize the tear film, improving tear break-up time and comfort.

Other options don’t fit because reducing tear production would worsen dryness, increasing mucin production targets the inner mucous layer rather than the lipid layer, and stimulating blinking helps distribute tears but doesn’t address the lipid barrier that prevents evaporation.