Meibomian gland dysfunction (MGD)
also called... MGD, meibomitis, meibomianitis, lid margin disease
WHAT IT IS Your oil glands have gone on strike!
The meibomian glands
are located in the eyelids. Secretions from these glands comprise the lipid
(oily) layer of the tear film which is so crucial in preventing rapid evaporation of the tears. Failure of these glands to produce or secrete oil - due to chronic blockage, thickening of the meibum, etc. will affect the quality and stability of the tear film
, which in turn will produce classic dry eye symptoms
even in people whose dry eye test results appear normal. A TBUT
should show whether the oil layer of the tear film is adequate or not.
Meibomian gland dysfunction is quite common and unfortunately it often goes undiagnosed. Even when diagnosed is often not treated or is not treated effectively until it has become chronic or severe.
MGD may be inflammatory (often as a result of blepharitis) or atrophic.
For more non-technical background to put MGD in context, please read Dry Eye for Dummies
CAREFUL! MAY BE CONFUSED WITH... "Dry eye"
(in the aqueous deficiency
sense): Many people who have dry eye symptoms are treated as though the cause is aqueous deficiency, e.g. with artificial tear supplementation and punctal plugs, when in fact their primary problem is meibomian gland dysfunction. Some researchers believe that up to 70% of chronic dry eye may actually be MGD, not "classic" dry eye.
Blepharitis is related because chronic blepharitis will cause chronic meibomian gland dysfunction, which in turn will cause dry eye symptoms. But blepharitis should not be confused with meibomian gland dysfunction. Keep in mind that you may clear up the bleph and still have MGD.
TREATMENT Typical treatments for MGD may include, depending on specifics of the condition: