Linking Diabetes & Dry Eye

By Jeffrey P. Gilbard, MD

If you have diabetes there is about a 50-50 chance you have dry eye. Dry eye is characterized by dryness, burning or sandy-gritty irritation in the eyes that gets worse as the day goes on. Dry eye in diabetes is a result of decreased corneal sensation or relative numbness of the surface of the eye. This relative numbness has also been associated with diabetic retinopathy.

What is dry eye, what causes it and what can be done about it? The tears on the surface of the eye are a salt solution. The surface of the eye needs these tears because the delicate living cells on the surface have no blood supply—it has a tear supply instead. So rather than getting important things like oxygen and electrolytes from the blood, it gets them from the watery layer of the tears. This watery layer is so important it is covered by a layer of oil produced by the oil glands in the eyelid that protects it from evaporation. The first thing that happens when an eye becomes dry is that the tears lose water and become too salty. Just like when you throw salt on a wound it causes stinging and burning, when your tears become too salty they cause stinging and burning of the eye surface.

As the eyes become drier this becomes a sandy-gritty irritation. Dry eye is one of the most common conditions affecting the eyes. It affects approximately 14% of people over the age of forty, and the prevalence increases with age. This is because there are many ways to get dry eye. Anything that decreases tear production or increases tear evaporation may cause dry eye. Long-term hard contact lens wear, LASIK eye surgery, certain viral infections of the cornea, and diabetes all may cause decreased corneal sensation and, with it, the decrease in tear production that results in dry-eye irritation.

Many choose to treat dry eyes with eye drops. It used to be that all artificial tears were pretty much the same. They were designed to cover up the dry spots that appear on the eye in advanced cases of dry eye. These drops were developed before it was realized that dry spots don’t cause dry eye but are a result of the tears becoming too salty. These drops would provide temporary relief of dry eye but the condition would never get better. Recently it was discovered that just as the electrolytes in the blood are biologically active, the electrolytes in the tear film are biologically active as well. It turns out that if the content of an artificial tear does not precisely match this electrolyte balance, the drop can “starve” the surface of the electrolytes it needs and decrease the quantity of lubrication. So in effect, with these drops, patients take one step forward, but also one step back.

There is another way to accelerate dry eye relief, and possibly even obtain complete dry eye relief. In a study of nearly 33,000 female health professionals, it was found that the more omega-3s they ate, the lower their risk for dry eye. There have actually been three studies that have linked dry eye to a dietary deficiency of omega-3s which are “essential fatty acids” that are scarce in the American diet. They can be obtained from salmon, sardines, herring, and tuna. Tuna is the number one source of omega-3s in the American diet, but now the FDA warns Americans not to eat it more than twice a week because of problems with its high mercury content.

The omega-3s are vital to eye care because first, they improve eye comfort by suppressing inflammation. Second, the oil glands in the eyelid use essential fatty acids to manufacture the oil layer of the tear film. Finally, the omega-3s work together to protect the tear gland and help it make more tear fluid.

Other benefits for diabetics: High dietary intake of omega-3s correlates with a lower incidence of type 2 diabetes, omega-3s have been shown to reduce elevated triglycerides in non-insulin dependent diabetics, and even more importantly, omega-3s reduce the risk of death from coronary heart disease and total mortality in diabetic women.

If you have dry eye and diabetes, you are not alone. There are excellent treatments available that can greatly add to your health and comfort.

Eye Facts

• Color blindness is more common among males, and occurs in about 8% of the male population.

• About 1.3 million U.S. residents are considered legally blind (American Foundation for the Blind).

• About 25.4% of U.S. residents are nearsighted (myopic) and 9.9% are farsighted (hyperopic), according to the National Eye Institute.

• The American Optometric Association says about 70% of people who use computers every day will develop vision problems such as dry eye.

• About 5.5 million U.S residents have cataracts severe enough to cause vision problems. About 400,000 new cases develop annually or about 1.35 million cataract surgeries each year (Univ. of Washington Dept of Ophthalmology).

• The Vision Council of America estimates that about 62% of U.S. residents have vision defects requiring correction.

For more information, call Jay Wilke at 727-443-7115, ext.223; email jayw@event-mangement.com; or visit website www.event-management.com

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