The ABCs of MGD

Excerpted from page 37 of the July/August 2018 edition of AOA Focus.

A 2016 online survey showed that only 30% of doctors of optometry were routinely expressing the Meibomian gland during comprehensive eye examinations.

AOA Focus asked Jillian Ziemanski, O.D., M.S., clinical assistant professor, University of Alabama at Birmingham School of Optometry, what doctors should know about meibomian gland dysfunction. Among Dr. Ziemanski's teaching and research interests are MGD, dry eye and Sjögren's syndrome.  

Where are the meibomian glands located, and how do they contribute to eye health?

The meibomian glands are in the tarsal plate of the eyelids (both upper and lower). They are oriented vertically in the eyelids such that they open onto the surface of the lid margin. The primary function of the glands is to produce meibum, which is a mixture of mostly lipids and some proteins. The meibum is delivered to the eyelid margin and then spread across the surface of the eye upon blinking. Based on the polarity of aqueous tears and the mostly nonpolarity of the meibum, the lipids separate from the aqueous tears to form the outermost layer of the tears called the tear film lipid layer. The primary role of the lipid layer is to retard evaporation of the aqueous tears and promote tear stability.  

What are the signs and symptoms of MGD?

Symptoms of MGD are very similar to dry eye disease (burning, irritation, grittiness, foreign body sensation, itchiness, fluctuating vision, etc.), given that MGD is the most prevalent etiology of dry eye disease. Signs of MGD will consist of general dry eye findings (punctate epitheliopathy of the cornea and/or conjunctiva, reduced tear break-up time, etc.). MGD-specific signs may include meibomian gland dropout (visualized by meibography or transillumination of the eyelids), poor quality of meibum (turbid/white or thick like toothpaste), reduced expression of meibum (low amount of meibum delivery to the ocular surface), posterior lid margin hyperemia and anterior displacement of the mucocutaneous junction.  

Why is it so important to distinguish MGD from other types of dry eye?

It's important to understand the type of dry eye that each patient has so that treatment can be targeted to the underlying cause. Differentiating MGD from other types of dry eye really isn't all that difficult as long as you know what to look for.  

How is MGD treated?

Treatment options include warm compresses, oral antibiotics (tetracyclines, macrolides), lipid-based artificial tears, in-office warming procedures, therapeutic gland expression and intense pulsed light.  

How can MGD be prevented?

Warm compresses and lid hygiene may help to maintain the integrity and health of the glands/ocular surface. For those with frequent/prolonged computer or tablet use, incorporate deliberate blinking exercises (10 forceful blinks) at least every hour. The blinking promotes expression of meibum from the glands and may help to reduce stagnation. A 2016 online survey showed that only 30% of doctors of optometry were routinely expressing the Meibomian gland during comprehensive eye examinations.   AOA Focus asked Jillian Ziemanski, O.D., M.S., clinical assistant professor, University of Alabama at Birmingham School of Optometry, what doctors should know about meibomian gland dysfunction. Among Dr. Ziemanski's teaching and research interests are MGD, dry eye and Sjögren's syndrome.  

Where are the meibomian glands located, and how do they contribute to eye health?

The meibomian glands are in the tarsal plate of the eyelids (both upper and lower). They are oriented vertically in the eyelids such that they open onto the surface of the lid margin. The primary function of the glands is to produce meibum, which is a mixture of mostly lipids and some proteins. The meibum is delivered to the eyelid margin and then spread across the surface of the eye upon blinking. Based on the polarity of aqueous tears and the mostly nonpolarity of the meibum, the lipids separate from the aqueous tears to form the outermost layer of the tears called the tear film lipid layer. The primary role of the lipid layer is to retard evaporation of the aqueous tears and promote tear stability.