Which is a listed cause of secondary MGD in humans?

• A. Graft-versus-host disease
• B. Surgical excision of the gland of the third eyelid
• C. Seasonal allergic conjunctivitis
• D. Atopic dermatitis

Answer: (A)

Secondary meibomian gland dysfunction arises when external factors damage or inflame the glands beyond usual aging changes. Graft-versus-host disease is a classic immune-mediated complication after bone marrow or stem cell transplantation that can target ocular adnexa, including the meibomian glands. This leads to reduced or altered lipid secretion, destabilizing the tear film and promoting evaporative dry eye—classic features of secondary MGD.

The other options aren’t typical listed causes in humans. The gland of the third eyelid is an anatomical structure largely discussed in veterinary contexts; its removal isn’t a standard human cause of secondary MGD. Seasonal allergic conjunctivitis and atopic dermatitis can inflame the eye and worsen dry eye symptoms, but they’re not classic listed etiologies of secondary meibomian gland dysfunction.