Meibomian Gland Dysfunction (MGD), The Most Prevalent Type of Dry Eye

Meibomian Gland Dysfunction (MGD)

• What is it?

Meibomian gland dysfunction (MGD) is the most prevalent type of dry eye. It is also called evaporative dry eye. This condition is caused by inactive use of special oil glands located within your eyelids called meibomian glands. This leads to a tear imbalance and quick evaporation of your tears. Common symptoms include; burning, itchy, red, watery eyes and fluctuating vision.

• What is a meibomian gland?

The meibomian glands are vertical glands located within your upper and lower eyelids that, when activated, secrete a special oil called meibum into your tears. These glands activate upon complete blinks when the two eyelids (upper and lower) touch. The mild compression of the lids stimulates these glands to pump oil (meibum) into your tears.
 

• Why is meibum important?

Let’s go back to basic chemistry. We know that oil floats/sits on top of water. The same rules apply to your tears. You can visualize your tears to having 2 distinct layers, an oil/lipid layer (meibum) and an aqueous layer, that is the watery portion of the tears. Oil does not evaporate the same way water does and as a result, the lipid layer of your tears acts as a sealant to prevent your tears from evaporating too quickly. If your tears take longer to evaporate then they can allow for a better tear balance and functionality.

• What is the importance of a balanced tear film?

Your tears do much more than simply keep your eye moisturized. They also contain antibodies to prevent infection and protect the ocular surface. Additionally your tears collect oxygen and other essential nutrients that your eye needs, especially for your cornea (the front clear dome of the eye) that is avascular (no blood vessels). The cornea is only able to get oxygen from what your tears collect. If you can’t maintain tears on your eyes due to evaporation, then your eye will lack access to adequate oxygen.
 

• How does meibomian gland dysfunction occur?

Most of us are on electronic devices, screens, or doing other activities that involve heavy focus. By doing activities involving heavy focus (even reading paper books, sewing, crafts etc…) we are blinking less and less. Additionally the average individual’s quality of blinking has degraded. Many of us are not performing complete blinks and instead just move our upper eyelid downward without making contact to the lower eyelid. Over a prolonged period of time, poor quality blinks and less frequent blinking leads to inactivity of the meibomian glands. This leads to the meibum (oil) in these glands to solidify and eventually clog these glands. Once the glands become clogged, no amount of quality blinking will allow them to express oil into your tears. This leads to a cycle of less and less use of these meibomian glands, resulting in MGD.
 

• What are the dangers of meibomian gland dysfunction (MGD)?

Individuals with MGD eventually will continue to use their meibomian glands less and less. Eventually if these glands are not used routinely and become inactive, they will begin to undergo atrophy (death of the glands). Once these glands die off, they cannot be regenerated or recovered. This is why dry eye often starts asymptomatic. Many patients may be undergoing the early phases of MGD but don’t feel the symptoms of dry eye due to their normal functional glands compensating for the work of the inactive glands. However as this condition progresses, the amount of healthy functional meibomian glands will begin to decline and eventually they will not be able to keep up with maintaining a good tear balance. Loss of a healthy lipid layer in your tears will result in the inability of your eyes to maintain a well lubricated surface, the inability of your cornea to have access to oxygen and the inability of your eyes to properly fight off infections.
 

• How do we treat MGD?

In the past we didn’t have good treatment methods. In many cases, patients were told to use artificial tears and warm compresses. Although these methods may provide temporary relief, they do not treat the underlying cause of the dry eye and are often only able to provide relief for minutes to hours.
 

Newer advances in technology as well as our understanding of this condition have lead to in office procedures that can be done to truly treat the underlying cause of MGD. These procedures improve the overall functionality as well as health of meibomian glands. These technologies include IPL (Intense Pulsed Light), RF (Radio Frequency) and manual expression of the meibomian glands. For the majority of patients who undergo multiple treatments using these technologies (usually 3-5 treatment sessions), significant improvement is seen in both patient symptoms as well as the functionality of their meibomian glands. Ask your doctor about these treatment methods to see if they may be right for you.