Which test best assesses meibomian gland function in blepharitis?

• A. Slit-lamp depth measurement
• B. Meibomian gland expression
• C. Intraocular pressure
• D. Fluorescein angiography

Answer: (B)

Meibomian gland expression directly tests how well the eyelid glands are functioning by assessing the ability to express the meibum and the quality of what is produced. Gently pressing on the eyelid margins yields secretions that reveal expressibility and the nature of the lipid. Normal glands express clear, fluid to mildly viscous secretions with good expressibility. In blepharitis with meibomian gland dysfunction, glands may be obstructed or produce turbid, thick, or toothpaste-like secretions, and expressibility is reduced. This direct assessment of gland function makes it the best test for evaluating meibomian glands in blepharitis.

Other tests don’t target gland function. Slit-lamp depth measurement isn’t a functional test of the glands, intraocular pressure relates to glaucoma risk, and fluorescein angiography examines ocular blood vessels rather than the lid glands.