We’ve talked briefly about Meibomian gland dysfunction and how this aspect of dry eyes can impact vision. But even while knowing the basics, it can be difficult to understand how Meibomian gland dysfunction (MGD) plays such a large role in dry eye symptoms. Symptoms such as burning and irritation are easily understood as symptoms of dry eyes, but it may be confusing how watery and runny eyes can also be indicative of dry eye disease worsened by MGD. Here, we will break down Meibomian glands and their role in the tear film so you can really understand the symptoms of your dry eyes.
The Basics of Tears
The tear film is one of the most important aspects of ocular health. It provides the front surface of the eye with vital oxygen and nutrients. Without a healthy and durable tear film, the eye is susceptible to damage. Our tears are comprised of three layers, and each of them play an equally important role. The innermost layer is the mucin layer. This layer, which is in direct contact with the corneal surface, helps spread the tears evenly and keeps them adhered to the surface of the eye. The middle watery aqueous layer makes up the largest portion of the tear film, and is vital in keeping the front of the eye moist and lubricated. This layer of the tear film is released by the lacrimal gland, which lies above the upper corner of our eyes. The outermost lipid layer is what is released by Meibomian glands. The lipid layer of the tear film keeps the tears stable and prevents them from immediately evaporating when exposed to air. If the lipid layer is not adequate, the tears will quickly disperse, leaving the corneal surface exposed.
In aqueous deficient dry eye disease, the lacrimal gland does not release enough of the aqueous layer of the tears. This can result in areas of the cornea being unlubricated, causing symptoms of dryness and irritation. In Meibomian gland dysfunction, the lipid layer is not being adequately released, causing an unstable tear film that is quick to evaporate. This can also cause dry, gritty eyes. Additionally, it may result in the production reflex tears. In an attempt to keep the eye lubricated, the lacrimal gland makes an excess of watery tears. However, without an adequate lipid layer to keep these tears stable, they either evaporate or run off the eye. This is when watery or runny eyes can be indicative of Meibomian gland dysfunction and dry eye disease.
How to Treat MGD and Watery Eyes
Treating Meibomian gland dysfunction requires restoring the lipid layer of the tears. In some cases of early or mild MGD, this can be done using warm compresses and lid scrubs, which aim to unclog the Meibomian glands and promote proper release of the lipid layer. There are also specially formulated artificial tears which help promote a more stable lipid layer and prevent tear evaporation. In more moderate or severe cases of MGD, options like Lipiflow are an option which can provide long-term relief of symptoms. Your doctor can recommend the treatment option that is most appropriate for you.