The critical role of the eyelid
The eyelid’s primary function is to protect the eye from injury and provide a moist cavity for the normal functioning of the conjunctiva and cornea.
The eyelids contain muscles that enable them to open and close, and are covered with skin. The inner lid is lined with mucous membrane, while the outer lid is lined with eyelashes.
The edges of the upper and lower lids are lubricated by an oily secretion produced by the meibomian glands. This oily secretion contributes to the makeup of the tear film, and serves to decrease the rate at which the tears evaporate.
What are meibomian glands?
Meibomian glands are the oil glands that line the edge of your eyelids, near your eyelashes. Around 25 to 40 meibomian glands line the upper eyelid and 20 to 30 line the lower eyelid. These glands secrete the oil that coats the eyes and tear film, to prevent the tears from evaporating too quickly.
A closer look at the tear film
Tears consist of three layers that function to protect and nourish the surface of the eye.
Oil layer– prevents evaporation of the water layer
Water layer– sustains the eye
Mucus layer– spreads tears to cover the entire surface of the eye
The tears lubricate our eyes and help to keep our eyes healthy. If there is a problem with any of the layers within the tear film, it can cause irritation, dry eyes, or blurred vision.
What is meibomian gland dysfunction?
Meibomian gland dysfunction (MGD) is a common condition that occurs when the meibomian glands don’t produce enough oil (meibum), or the oil is of poor quality.
MGD is a common underlying cause of dry eye syndrome and blepharitis.
A study including 233 adults found that 59% showed at least one symptom of MGD.
This condition occurs when the oil glands become blocked with thick secretions. This prevents a normal flow of oil and leads to a reduced quantity. The oil that successfully flows through the glands can be crusty or poor in quality and may cause irritation.
Meibomian gland dysfunction often does not present with any symptoms in its early stages. However, if the condition progresses without treatment, it can cause dry eye symptoms and/or inflammation of the eyelid.
When MGD becomes a chronic problem, and the glands are constantly blocked or clogged, oil secretion is impossible and can cause permanent damage in the tear film as well as dry eye syndrome.
The risk of developing MGD increases with age— with increased prevalence among those age 40 and older.
Additionally, women who wear eye makeup have a greater risk of developing MGD.
Common symptoms of MGD
Dryness
Burning
Itching
Redness
Crusty discharge
Watery eyes
Blurred vision
Light sensitivity
Chalazions/styes
Foreign body sensation
How is MGD diagnosed?
Through a comprehensive eye exam, your eye doctor can determine if you are suffering from MGD.
Your eye doctor may apply pressure to your eyelid to observe the secretions that are expressed. The quality, quantity, and stability of your tears will likely be evaluated as well.
The tear breakup time (TBUT) test is a common, painless procedure that your eye doctor may recommend to determine the stability of your tear film. This test involves placing a drop of dye on the front surface of your eye to be absorbed by the tear film. Your doctor will then examine your eye with a blue light which causes your tears to glow. If your tear film has reduced stability, it will be evident through this test, as the tears will break up quickly on your eye.
If you experience MGD symptoms contact us at (804) 217-9883 for treatment options.
