Which ocular condition is LEAST likely to affect meibomian glands?

• A. Ocular rosacea
• B. Chalazion
• C. Internal hordeolum
• D. External hordeolum (stye)

Answer: (D)

Meibomian glands sit deeper in the eyelid within the tarsal plate and supply the oily layer of the tear film. When these glands are involved, you see conditions like an internal hordeolum, which is an infection of the meibomian gland, or a chalazion, which is a blockage and granulomatous reaction of the gland. Ocular rosacea is also commonly associated with meibomian gland dysfunction, leading to chronic lid inflammation and tear film instability. An external stye, however, arises from infection of the lash follicle or glands at the eyelid margin (glands of Moll and Zeis) rather than the meibomian glands themselves. Because of this anatomical distinction, an external stye is least likely to affect the meibomian glands.