Meibomian Gland Dysfunction (MGD) and dry eye

The normal tear film has three layers made in several places on and around the eye. The top layer is an oily substance produced in the Meibomian glands that sit near the base of the eyelashes. There are approximately 15 glands on each upper and lower lid. This oily layer maintains a stable tear film and reduces evaporation of the tears. Research over the last couple of years has pointed to poor oily layer production as a leading cause or contributor to dry eye.

The normal secretion should be a clear free flowing substance that looks like oil (of course)! Meibomian Gland Dysfunction occurs when this oily secretion is in some way decreased. Some people have only slightly altered production which appears as small particles within the mostly clear fluid. Others have significantly decreased production which appear more like butter or Crisco than oil. The image below shows a thick white secretion from one of the lower meibomian glands.

This gland is plugged and cannot secrete the normal oil. Treatment for this condition is targeted at improving the quality of gland production, ideally restoring it to the original oily state. Many treatments target this condition and are discussed in my book. 

If you have dry eye it is important to see your eye care professional to determine if this condition exists.