Viewpoint

New thinking on dry eye and MGD

FROM THE CHIEF MEDICAL EDITOR

Larry E. Patterson, MD

Dry eye—traditionally, it’s not something that excites many of us. For years treatment has comprised mainly artificial tears and punctal occlusion. Often, we give out tear samples like “goody bags” at a kid’s birthday party—everyone feels better when they leave with a little gift. But dry eye is no gift. Numerous studies suggest that dry eye affects 15% of the population in the United States. And I’m seeing it in younger people all the time. Could it be that something has changed that caused us to have more dry eye than in the past?

First, we are aging. Two, “smart” devices have increased visual demands. And lots of medications can affect the tear film. But we also see more meibomian gland dysfunction, which many believe is the leading cause of dry eye disease worldwide. (Read Dr. Kendall Donaldson’s article on page 24.) What is causing MGD? Could dietary changes contribute? I think the answer is fast becoming “yes”.

THE CONNECTION BETWEEN DIET, DRY EYE AND MGD

The American diet has worsened, increasing the incidence of diabetes, hypertension and many other diseases. Processed foods and fast foods have led to higher levels of omega-6 fatty acids and a deficit of omega-3s. This may be why some patients have meibomian glands that look more like they are filled with toothpaste rather than olive oil. Omega-3s provide the raw material that leads to meibum production, and clinical reports have demonstrated thinner oils after treatment with omega-3 supplementation. One problem is that most people supplement their omega-3 with fish oil found in grocery stores, which is not only too low in dosage, but in the ethyl ester form, which has poor bioavailability.

Newer omega-3 fish oil supplements produced in the natural triglyceride form allow for much better absorption rates along with fewer gastrointestinal side effects. I have two staffers who couldn’t take fish oil because it upset their stomachs. But, with a triglyceride formulation in a much higher dosage, they had no side effects. A 2011 presentation by S. Gregory Smith, MD, from Wills Eye Hospital showed 82% of patients treated with one omega-3 formulation had a change in the meibum composition after eight weeks. More importantly, 100% had an improvement in symptoms, while 70% became totally asymptomatic. A combination of omega-3 and gamma-linolenic acid was shown to benefit patients who have dry eye in a 2013 study by John Sheppard, MD.

Dry eye isn’t quite as sexy or exciting as laser cataract surgery. But as Dr. Donaldson’s article points out, many new diagnostic tests and treatments are available to us. I’m looking forward to these and other advances coming down the pike that will help us treat this common, yet troublesome disease. OM