meibomian gland dysfunction
noun. refers to the condition where the glands are not secreting enough oil or when the oil they secrete is of poor quality
Meibomian glands are the tiny oil glands which line the margin of the eyelids (the edges which touch when the eyelids are closed). These glands secrete oil which coats the surface of our eyes and keeps the water component of our tears from evaporating (drying out). Together, the water and the oil layer make up the tear film.
The tear film lubricates and keeps the surface of our eyes healthy; it also affects how we see. If either the water or oil layer is decreased, or is of poor quality, we may have symptoms of irritation and/or blurred vision.
Often, the oil gland openings get plugged up so that less oil comes out of the glands. The oil that does make it out of the glands can be granular (crusty) or otherwise unhealthy and can cause irritation.
MGD is very common. In the early stages, patients are often asymptomatic, but if left untreated, MGD can cause or exacerbate dry eye symptoms and eyelid inflammation. The oil glands become blocked with thickened secretions. Chronically clogged glands eventually become unable to secrete oil which results in permanent changes in the tear film and dry eyes.