Which change initiates the obstructive pathway in MGD?

• A. Hyperkeratinization & hypertrophy of duct epithelium
• B. Increased tear lipid synthesis
• C. Direct acinar hypertrophy
• D. Hypersecretion of meibum

Answer: (A)

The initiating change in the obstructive pathway of MGD is hyperkeratinization and hypertrophy of the duct epithelium. When the duct lining becomes thickened and the epithelium grows, the duct orifice narrows or plugs up, which blocks the flow of meibum. This stagnation causes the secretions to become inspissated and further blocks the duct, setting off the cascade of obstruction that characterizes MGD. Over time, continued blockage and pressure can lead to ductal dilation and eventual acinar atrophy, but the first step that starts the obstruction is that epithelial change. Parameters like increased tear lipid synthesis or hypersecretion of meibum would not initiate the blockage; they relate more to the tear film environment or secretory state rather than the initial ductal obstruction. Direct acinar hypertrophy is not the initiating event either, since the obstruction comes from the ductal narrowing.