Dry eye and meibomian gland dysfunction: what is actually happening

Dry eye is one of the most common complaints we see at Cedar Vision Works, and it is also one of the most misunderstood. Many patients arrive having used lubricating drops for months with limited improvement, not knowing that the drops may be addressing the wrong part of the problem. The tear film has three layers, and the one that is most often disrupted is the one that drops do not replace.

The three layers of the tear film ¶

The tear film that covers the surface of the eye is not simply water. It has three layers: a mucin layer that helps the tear film adhere to the corneal surface, an aqueous layer that provides the bulk of the volume, and a thin oily layer on top produced by the meibomian glands in the eyelids.

The oily layer slows evaporation. Without it, the aqueous layer evaporates quickly, leaving the corneal surface exposed. This is the most common form of dry eye, called evaporative dry eye, and it is caused by meibomian gland dysfunction rather than insufficient tear production.

How we assess meibomian gland function ¶

At Cedar Vision Works, the dry eye assessment includes meibography, which uses infrared imaging to photograph the meibomian glands through the eyelid. Healthy glands appear as long, regular structures. Glands that have become atrophied or distorted show up clearly on the image.

We also assess the tear film break-up time, which measures how quickly the tear film destabilises after a blink, and look at the lid margins for signs of blepharitis or lid margin disease, which often accompanies meibomian gland dysfunction.

What treatment looks like ¶

For most patients with meibomian gland dysfunction, the first-line treatment is a warm compress routine applied to the closed eyelids for 10 minutes each morning. The warmth softens the thickened meibum in the glands, making it easier to express. We show patients how to do this properly, because the technique matters.

If a lubricating drop is appropriate, we recommend one that contains a lipid component rather than a purely aqueous drop, as this better addresses the evaporative component. We do not sell drops in the practice; we recommend what is available over the counter and explain why.

If you have been managing dry eye symptoms for more than a few months without much improvement, a dedicated assessment is likely to be more useful than another bottle of drops. The dry eye assessment at Cedar Vision Works is £55 and takes 30 minutes.