MGD: Meibomian Gland Dysfunction

Eyelid disease can cause a variety of symptoms. Guntars Grebezs

Meibomian Gland Dysfunction, or MGD, is an eye condition that is so common that even doctors tend to forget to address it even when patients are experiencing symptoms. MGD is a type of blepharitis. Blepharitis is a term that describes an inflammatory and sometimes infectious condition of the eyelid. Blepharitis is categorized as anterior or posterior blepharitis. Anterior blepharitis affects the front part of the eyelid and the eyelashes.

Anterior blepharitis causes eyelid thickening, redness and crusty eyelashes and is typically caused more by staphylococcus bacteria that we all have on our bodies. It tends to accumulate on the eyelids and lashes in some individuals. Posterior blepharitis is referred to as meibomian gland dysfunction.

There are about 40-50 meibomian glands on the upper eyelids and 20-25 glands on the lower eyelids. Meibomian glands are large sebaceous glands that secrete oil or meibum. Everytime we blink, these glands secrete meibum and it is spreads over the surface of the tears. This layer of oil prevents tear film evaporation and helps to keep our eyes lubricated.

In MGD, these glands become inflamed. Over time, the chemical makeup of this oil-like secretion changes and sometimes becomes too thick. In some cases, the meibum is over-produced and there is too much of it. This condition is called meibomian seborrhea.

MGD causes an unstable tear film. The tear film that coats our eye is quite complicated and if it becomes unstable or of poor quality, the surface of the eye begins to become inflammed. The eyes become red, irritated, dry and may cause vision to fluctuate on a daily basis.

Chronic MGD can cause the glands to become blocked, impacted and infected.

When it becomes infected, it is called a hordeolum or a stye. When a hordeolum does not heal properly and persists for weeks, it can sometimes turn into a chalazion.

Symptoms of MGD

People with MGD complain of:

  • red-rimmed eyelid margins
  • dry eyes
  • sandy, gritty sensation
  • fluctuating vision

Interestingly, many patients complain upon stepping out of a hot shower. They say their eyes become extremely red and they sometimes feel pinpoint, stabbing eye pain. This is usually because there is a sudden change in the humidity in the bathroom and the tear film becomes unstable very quickly. The eye dries out and the cornea, the clear dome-like structure on the front part of the eye, is not lubricated properly and dries out.

How does an optometrist diagnose MGD?

Eye doctors diagnose the condition first based off of patient symptoms. Under the microscope, doctors will see that the eyelid margin appears red, vascularized and the meibomian glands may appear to be plugged up. The tear film is unstable. Doctors measure something called the TBUT-tear film break up time.

If the oily layer on the surface is not intact, people will have a reduced TBUT. A normal TBUT is about 10 seconds. The meibomian glands can be expressed and a thicker than normal meibum is seen. The tear film will sometimes appear too oily. Other times, the tears will have a frothy, bubbly appearance.

How is MGD treated?

Treatment of meibomian gland dysfunction varies depending on the severity.

  • Lid Hygiene - Many doctors will first recommend warm compresses every day followed by some type of lid hygiene eyelid scrubs. Commercially available surfactant eyelid scrub preparations are available over the counter. Newer biochemicals such as hypochlorous acid solution have been found to be extremely beneficial as well.
  • Antibiotics - Tetracycline and tetracycline derivatives such as doxycycline or minocycline have been shown to have a dual therapeutic effect. They decrease the amount of bacteria present in the gland and also have been shown to have an anti-inflammatory effect on the glands. Sometimes patients may need to use them for several weeks to months. Recently, azithromycin given for only six days has been shown to mimic the same therapeutic effect as tetracycline given for a much longer period of time. Its benefit is controversial among eye care practitioners
  • Topical antibiotics - Azithromycin is also available as a topical gel, called Azasite (Akorn Pharmaceutical) Some practitioners will prescribe Azasite to be applied to the eyelid margin directly every night. This may be prescribed anywhere from 10-30 days.
  • Topical steroids - Topical steriod eye drops are also given in combination when MGD causes excessive inflammation.
  • Omega 3 supplements - Omega 3 fatty acids when given in therapeutic doses have been shown to normalize the meibomian glands.

What happens if MGD is not treated properly?

If MGD is not treated, a more severe form of ocular surface disease can develop and can display symptoms that can alter quality of life. Because MGD causes evaporative dry eye, the cornea can become desiccated and dry to a point where scar tissue can form. If MGD is chronic, it can cause the meibomian glands to actually atrophy. Once they are atrophied, it is very difficult to make them function normally again. MGD can develop into ocular rosacea, which can require more aggressive medical treatment.


Kashkouli MB, Fazel AJ, Kiavash V, et al. Oral azithromycin versus doxycycline in meibomian gland dysfunction: a randomised double-masked open-label clinical trial. Br J Ophthalmol. 2015 Feb;99(2):199-204.

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