Meibomian Gland Dysfunction (Dry Eye) Explained
What Are the Meibomian Glands?
In the 1600s, Heinrich Meibom named these special type of sebaceous glands in the deeper layer of the upper and lower eyelids that normally secrete a clear oil that prevents the evaporation of the eye’s watery layer of tears. This lipid secretion is referred to as “meibum” and serves to make the eyelid seal tight and stop the water from spilling over the eyelid margin. Ninety different proteins have been identified in this complex oil layer.
Why Is It Important for the Meibomian Glands to Function Well?
Consider this analogy: Picture two glasses of water with a blow dryer on top. One glass just has water in it and the other has a ¼ inch layer of olive oil riding on top of the water. If you blow-dry both glasses of water, the one with no oil in it will permit the water to evaporate, while the oil-topped water glass will not allow the water to evaporate. In this same manner, the oily layer of the tears called meibum will protect the watery aqueous layer from evaporating and causing what we know today as a dry eye.
Meibomian Gland Dysfunction
The oil in the oil glands can harden like butter does in the refrigerator. It hardens over time because of chronic inflammation of the eyelids called blepharitis and poor blinking habits like incomplete blinking. An infection or inflammation of the eyelids called blepharitis can happen when bacteria over-populate the eyelid margins and can even have mites called Demodex contribute to the breakdown of the oil gland function. Long-term inflammation ensues and the glands just stop functioning and will start to atrophy. Once the 25 oil glands in the lower lids and 50 in the upper lids no longer secrete oil and start to disappear, the eye is said to have meibomian gland dysfunction or MGD. You may not even be aware that anything is wrong due to the chronic and progressive nature of the disease. The day after you get your haircut, you know you don’t need one. But, in a few weeks, you may realize that small changes every day can sneak up on you. Patients with MGD often suffer from dry eyes and easily get eyelid infections, styes, and cysts, called chalazions, in the lids.
Related Read: Do You Have Dry Eye Syndrome? Signs to Look For
Can MGD Cause Watery Eyes as well as Dry Eyes?
The answer is yes! Again, this may be tricky, since eyes that are dry will often have a component of “reflex tearing” and appear to be watering constantly. That is why your eye doctor may say you have a dry eye when you complain of excessive watering, often known as “epiphora.” Since epiphora can be caused by a blockage of the lacrimal drainage system, it is important to have an official diagnosis of why your eyes are symptomatically too dry or too wet.
Will MGD Interfere with my Contact Lens Wear?
Yes, again! Most patients who complain of repeated contact lens intolerance and unsuccessful wear have MGD to blame. Many times, a patient who experiences chronic contact lens failure and has tried numerous contact lens technologies and gone to many doctors will discover that the problem is not the lenses, but rather his/her eyes. You must root out the cause of the MGD-induced dry eye before you can to get on the path of successful contact lens wear.
What Can Be Done about MGD?
The first step is to get a diagnosis. The diagnosis should be made scientifically by a knowledgeable doctor, not one who just says, “I know a dry eye when I see it.” The analysis involves laboratory tests and clinical observations, some of which are:
- Tear Lab test of tear osmolarity to analyze inflammation
- Meibomian Gland Evaluator calibrated expression test
- Zone Quick test of tear volume over time
- LipiView2 for blink pattern, lipid layer thickness, blink rate, and infrared photography (meibography) of the meibomian glands
- Tests for complete eyelid closure and eyelid seal
- Tear film breakup time test
- Vital stains like lissamine green and fluorescein to disclose inflammation
- Observations of the tear lake along the eyelid margin
- Tests of lid wiper epitheliopathy and keratitis (inflammation of the cornea)
- Standard Evaluation of Eye Dryness (SPEED) survey
- Corneal topography to see tear-film-caused corneal irregularities.
Related Read: Dry Eye Syndrome – The Sneakiest Eye Disease We Know
Standard Treatments for MGD
The standard treatment of MGD has typically involved rubbing a warm washcloth along the eyelid with baby shampoo. Your doctor may have already recommended this home remedy. From conclusive studies by researchers Don Korb and Carolyn Blackie, we know that this does not work and could be damaging. The blocked oil glands are positioned in the rear of the eyelid and encased in the cartilaginous rigid “tarsal plate” of the eyelid. The heat from a washcloth is dissipated by the lid skin, muscle layer, vascular layer and the tarsal plate. The temperature required to melt down the blocked oil is 108.5 degrees Fahrenheit or 42.5 degrees Celsius. (Think of how cold hard butter won’t melt in a pan unless it gets to about 95 degrees Fahrenheit.) Meibum melts at about 10 degrees warmer than our body temperature. Prolonged heating of the outside of the eyelid can result in adversely altering the shape of the cornea at the front of the eye and blur our vision correction, according to Korb and Blackie.
LipiFlow Is the Only Modern FDA Approved Treatment for MGD
Glandular structure and function have been shown to deteriorate over time if nothing is done to restore and maintain the health of freely flowing oil glands. These chronic cystic conditions cause MGD, evaporative dry eye, and lipid-deficiency dry eye. Once the oil glands are blocked, fluctuating vision, contact lens discomfort and worsening symptoms following ocular surgery can result. Once the oil glands are lost, they do not regenerate. LipiFlow allows for calibrated vectored thermal pulsation–heat applied to the inside of the eyelid directly next to the meibomian oil glands with simultaneous external pressure to the outside of the lids–to remove gland blockages and restore oil flow into the tear film.
At Brill Eye Center, this treatment is at the core of our Dry Eye Spa, because it is very much a comfortable spa-like treatment. Relief can be instant after this 12-minute experience. As of November 2015, LipiFlow is the only electronic device cleared by the US Food and Drug Administration for the safe and effective treatment of MGD. Dr. Brill has been enthusiastically performing LipiFlow since 2014 with amazing patient outcomes.
Schedule your dry eye evaluation to see if you have MGD and to find out if you are a candidate for the 12-minute root cause treatment called LipiFlow. It could be just what you need to improve your quality of life and stop suffering.