What characterizes meibomian gland disease (MGD)?

• A. MGD is a multifactorial condition commonly characterized by meibomian gland orifice obstruction and metaplasia, reduced and altered meibum lipid profile, cystic dilation of the central duct, and acinar atrophy / dropout
• B. An autoimmune destruction of lacrimal glands
• C. Infection of the third eyelid gland leading to tear deficiency
• D. Overproduction of aqueous tear with lipid deficiency

Answer: (B)

Meibomian gland disease is a problem of the lipid-producing glands along the eyelid margin. The key feature is obstruction of the gland orifices with metaplasia of the ductal epithelium, which leads to reduced or altered lipid secretion. When the meibum is deficient or of poor quality, the tear film becomes unstable and evaporates more quickly, causing evaporative dry eye. Chronic changes can include dilation of the central duct and loss (dropout) of acinar cells, reflecting progressive gland dysfunction. Clinically, you may see plugged gland openings, lid margin inflammation, and signs of gland dropout on imaging of the meibomian glands.

In contrast, autoimmune destruction of the lacrimal glands describes a different disorder (aqueous tear deficiency from lacrimal gland loss), not primary meibomian gland dysfunction. Infection of the tear-producing third eyelid gland is not the same process as MGD, and overproduction of aqueous tears with lipid deficiency does not align with the typical lipid-dominant evaporative issue seen with MGD.