Which sequence describes the obstructive pathway in meibomian gland disease?

• A. Hyperkeratinization & hypertrophy of duct epithelium → damming of lipid secretions → upstream cystic ductal dilation → acinar atrophy → meibomian gland dropout
• B. Damming of lipid secretions → hyperkeratinization of duct epithelium → acinar atrophy → gland dropout
• C. Increased mucin production → lipid layer stabilization → gland dropout
• D. Increased intraglandular pressure → Inhibition of lipid secretion → acinar atrophy

Answer: (A)

The obstructive pathway in meibomian gland disease starts with blockages at the duct, driven by ductal epithelial changes. Hyperkeratinization and hypertrophy of the duct epithelium form a barrier that impedes lipid flow. Secretions back up, causing damming within the duct. This stagnation drives upstream dilation of the ducts (cystic dilation proximal to the blockage) as the lipids accumulate. Over time, the chronic obstruction and accompanying inflammation lead to acinar atrophy, and the gland ultimately undergoes dropout as functional tissue is lost.

This sequence fits the idea that obstruction begins with epithelial changes, then secretions back up and dilate the ducts, followed by loss of acinar tissue and gland dropout. Other options don’t match the initiating event or the downstream consequences as well: starting with damming before epithelial change, or focusing on mucin production or increased intraglandular pressure as the primary driver, doesn’t reflect the classic obstructive cascade.