What is the primary function of Meibomian glands in the eyelids?

What is the primary function of Meibomian glands in the eyelids?

• A. Produce aqueous humor to nourish cornea
• B. Secrete meibum to prevent evaporation
• C. Secrete mucin to lubricate conjunctival surface
• D. Produce tears that wash debris

Answer: (B)

Meibomian glands provide the lipid component of the tear film. Their primary job is to secrete meibum, an oily substance that forms the outermost lipid layer of the tear film. This lipid layer slows evaporation of the underlying aqueous tears, helping the tear film stay stable on the eye and maintain a smooth ocular surface for comfortable vision. If this lipid layer is deficient or the glands are blocked, tears evaporate more quickly, leading to evaporative dry eye and related discomfort. The other statements refer to different structures: aqueous humor is produced to nourish the cornea by the ciliary body, mucin from goblet cells helps lubricate the conjunctival surface, and tears that wash debris are produced by the lacrimal glands. Thus, the correct function is secretion of meibum to prevent evaporation.

Meibomian glands provide the lipid component of the tear film. Their primary job is to secrete meibum, an oily substance that forms the outermost lipid layer of the tear film. This lipid layer slows evaporation of the underlying aqueous tears, helping the tear film stay stable on the eye and maintain a smooth ocular surface for comfortable vision. If this lipid layer is deficient or the glands are blocked, tears evaporate more quickly, leading to evaporative dry eye and related discomfort. The other statements refer to different structures: aqueous humor is produced to nourish the cornea by the ciliary body, mucin from goblet cells helps lubricate the conjunctival surface, and tears that wash debris are produced by the lacrimal glands. Thus, the correct function is secretion of meibum to prevent evaporation.