Diabetes & The Body

Diabetics and dry eye syndrome

Dry eye syndrome is a disease of the surface of the eye that causes burning, stinging, grittiness and discomfort. This disease is very common in the general population with estimates of up to 28% of adults having the disease. It is also true that patients with diabetes have this disease more often than those without diabetes.

Because diabetes can affect the nerves of the ocular surface and cause a reduced sensitivity, diabetic patients can have this disease and not know that they do have it. It is therefore important that people with diabetes are aware of this potential problem and that they make sure that their eye doctor looks carefully at their ocular surface.

What is dry eye?

Although the term dry eye suggests that a reduced tear flow is the sole cause of the problem, there are many ways that dry eye can occur. The normal tear film on the surface of the eye is a very complex structure that is secreted by a number of glands around the ocular surface and lids. The tear film is replenished by each blink and the used tears are pumped into the small holes in the upper and lower lids near the nose. They then pass through a small canal and flow into the nose and eventually down the throat.

If any of these glands malfunction because of inflammation or lack of blood supply or improper nerve stimulation, the tear film becomes thin or has a poor composition and this is called a dry eye. Also if the lids do not blink fully, or if they remain partially open during sleep, dry eye can result. The patient with dry eye will feel uncomfortable and the doctor evaluating the dry eye will see dead and dry cells on the surface of the eye and often lid redness and crusting.

What Causes Dry Eyes?

Tears bathe the eye, washing out dust and debris and keeping the eye moist. They also contain enzymes that neutralize the microorganisms that colonize the eye. Tears are essential for good eye health.

In dry eye syndrome, the eye doesn't produce enough tears, or the tears have a chemical composition that causes them to evaporate too quickly.

Dry eye syndrome has several causes. It occurs as a part of the natural aging process, especially during menopause; as a side effect of many medications, such as antihistamines, antidepressants, certain blood pressure medicines, Parkinson's medications, and birth control pills; or because you live in a dry, dusty or windy climate. If your home or office has air conditioning or a dry heating system, that too can dry out your eyes. Another cause is insufficient blinking, such as when you're staring at a computer screen all day.

Dry eyes are also a symptom of systemic diseases such as dry mouth, and several forms of ulcerative skin disease.

Long-term contact lens wear is another cause; in fact, dry eyes are the most common complaint among contact lens wearers. Recent research indicates that contact lens wear and dry eyes can be a vicious cycle. Dry eye syndrome makes contact lenses feel uncomfortable, and the rubbing of the lenses against the conjunctiva seems to be a cause of dry eyes.

Incomplete closure of the eyelids, eyelid disease and a deficiency of the tear-producing glands are other causes. Tears are composed of three layers: the outer, oily, lipid layer; the middle, watery, lacrimal layer; and the inner, mucous or mucin layer. Each layer is produced by a different part of the eye (the lacrimal gland produces the lacrimal layer, for example), so a problem with any of those sources can result in dry eyes.

Dry eye syndrome is more common in women, possibly due to hormone fluctuations. Recent research suggests that smoking and taking multivitamins can increase your risk of dry eye syndrome, and that eating a lot of omega-3 fatty acids (found in cold-water fish) may decrease your risk.

Dry Eye Syndrome Symptoms and Signs

Persistent dryness, scratching and burning in your eyes are signs of dry eye syndrome. These symptoms alone may be enough for your eye-care practitioner to diagnose dry eye syndrome. Sometimes he or she may want to measure the amount of tears in your eyes. A thin strip of filter paper placed at the edge of the eye, called a Schirmer test, is one way of measuring this.

Some people also experience a "foreign body sensation," the feeling like there's something in the eye. And, it may seem odd, but sometimes watery eyes can result from dry eye syndrome, because the excessive dryness works to over-stimulate the watery component of your eye's tears.

How do we treat dry eye disease?

Dry eye syndrome is an ongoing condition that may not be cured (depends on the cause), but the accompanying dryness, scratching and burning can be managed. Your eye care practitioner may prescribe artificial tears, which are lubricating eye drops that may alleviate the dry, scratching feeling.

Restasis eyedrops (cyclosporine in a castor oil base) go one step further: they help your eyes to increase tear production. Restasis treatment is the first of its kind.

If the problem is environmental, you should always wear sunglasses when outdoors, to reduce exposure to sun, wind, and dust. Indoors, an air cleaner can filter out dust and other particles from the air, while a humidifier adds moisture to air that's too dry because of air conditioning or heating.

Temporary or permanent silicone plugs in the tear ducts keep tears in your eye from draining away as quickly. Called lacrimal plugs or punctal plugs, they can be inserted painlessly while you're in the eye doctor's office and are normally not felt once inserted.

A new type of punctal plug made of acrylic is a small rod that becomes a soft gel when exposed to your body heat after insertion. It is designed to accommodate to the size of any punctum canal. Advantages of this type of plug are that one size fits all so measurement is unnecessary, and nothing protrudes from the tear duct that could potentially cause irritation.

Sometimes, however, the tear ducts need to be closed surgically.

Doctors sometimes recommend special nutritional supplements for dry eyes. Studies have found that supplements containing certain essential fatty acids can decrease dry eye symptoms.

If medications are the cause of dry eyes, discontinuing the drug generally resolves the problem. But in this case, the benefits of the drug must be weighed against the side effect of dry eyes. Sometimes switching to a different type of medication alleviates the dry eye symptoms while keeping the needed treatment. In any of the following cases, never switch or discontinue your medications without consulting with your doctor first!

• Effect of use of contact lens
• Eye irritation due to computer use
• Omega-3 fatty acids and your eyes
• Are your dry eyes due to inflammation of the eyelids characterized by redness and swelling and dried crusts

Treating any underlying eyelid disease, such as blepharitis, helps as well. This may call for antibiotic or steroid drops plus frequent eyelid scrubs with an antibacterial shampoo.

Quite a few products are in testing for possible dry eye treatment. For example, trehalose (a carbohydrate) improved dry eye symptoms in small studies, but further testing is needed.

If contact lens wear is the cause of your dry eyes, your eye-care practitioner may want to switch you to a different lens or have you wear your lenses for fewer hours each day. In a few cases, it is recommended that contact lens wear be discontinued altogether until the dry eye problem is cleared up.

If you are considering LASIK (a surgical procedure intended to reduce a person's dependency on glasses or contact lenses), be aware that dry eyes may disqualify you for the surgery, at least until the problem is resolved. Dry eyes increase your risk for poor healing after LASIK, so most surgeons will want to treat the dry eyes first, to ensure a good LASIK outcome. This goes for other types of vision correction surgery, as well.

The good news about dry eye disease is that the condition almost never leads to loss of vision. It does however leave the patient more open to irritation and infection. Since people with diabetes may have more problems healing from infections, it is important that they understand the treatment and use them routinely and appropriately.

One of the most natural treatments for dry eye is simply blinking. Studies have shown that computer use and intense near work cause the blink rate to slow to about one half of the normal rate. Dry eye patients are encouraged to take the time to think about blinking regularly during the day and to even squeeze blink a few times to encourage the oil glands in the lids to secrete more.

If the lids are red and the meibomian glands are not secreting well, lid treatments may be prescribed. The procedures include washing the lid margins and using hot soaks to encourage proper gland flow. Sometimes an antibiotic will be prescribed.

Drops for the ocular surface are the next form of treatment. There are many drops available. Some have preservatives that may be irritating to the eye if used more than 4 times a day. Ophthalmic decongestants, known as drops promoted to “get the red out”, should not be used as dry eye treatments as they may cause more redness after prolonged use. Dry eye patients should use their drops routinely or as prescribed by their health professional. Routine use of drops will prevent problems later in the day when symptoms are likely to be stronger.

Those patients with more severe dry eye may be given preservative-free artificial tears for daytime relief, and/ or ointments to be used at night. These should be used just before sleep as they will blur vision. Other available treatments for severe dry eye include punctal occlusion. Silicone plugs may be suggested to block the outflow of tears from the surface of the eye. Oral medications may help promote secretion from the lacrimal gland. Humidity shields can be fitted to glasses to prevent evaporation from the surface of the eye.

Practical efforts can help as well. Humidifying the home and work environment, keeping the car vents aimed at the feet so that the air currents do not interfere with your tear film, and avoiding smoky rooms when possible can help keep the eyes comfortable.

Maintaining good nutrition and a healthy lifestyle will certainly help diabetics’ condition and may help with their dry eye condition as well. Eating many fruits and vegetables, drinking 8 glasses of water a day, exercising regularly and avoiding excess coffee and alcohol and not smoking can only help tear glands to perform at their best.

Dry eye disease is a common complication of diabetes. Patients should be aware of this and be sure to have routine checkups that include careful observations of the eye surface tissue. Maintaining a healthy lifestyle, eating well, keeping the lids clean and the routine use of lubricants will help to keep your patients’ eyes healthy.

Dry eye occurs most often in the elderly, and the institute reports that nearly 75 percent of people over age 65 will experience dry eye syndrome. Although the cause of dry eye syndrome is unknown, it tends to occur more often in women, especially those who are pregnant or postmenopausal. An even more pervasive problem, eye allergies affect an estimated 80 million Americans. Not to be confused with dry eye syndrome, eye allergies are a reaction to substances in the environment that can result in some of the same types of discomforts associated with eye dryness. To learn more about how eye allergies are diagnosed and treated, visit the “Ocular Allergies” topic at this Web site.

When you have dry eye syndrome, either you don't produce enough tears, or you have poor quality tears and excessive tear evaporation. It most commonly occurs in both eyes. Either problem causes your eyes to sting or burn, feel scratchy, become irritated and excessively tear. People with dry eyes have difficulty wearing contact lenses. A recent study has shown that allergic and inflammatory processes may be involved. They also may develop stringy mucus in or around their eyes. There can be pain and redness in the eye, a feeling of heavy eyelids, or blurred, changing or decreased vision. Severe cases of dry eye often are also sensitive to light. Although eye infections are possible with dry eye syndrome, vision loss from dry eye is rare. Most people with dry eye find the condition to be an uncomfortable nuisance.

Dry eye occurs most often in older women after menopause. Information gathered from the Women's Health Study, a large cohort study in which 25,665 postmenopausal women provided information about the use of hormone replacement therapy (HRT), suggests that those who use HRT, particularly estrogen alone, are at increased risk of dry eye syndrome. The disorder when associated with rheumatoid arthritis or dry mouth is called Sjogren’s syndrome, an autoimmune disease that attacks the body's lubricating glands, such as the tear and salivary glands. Allergies can also contribute to eye dryness, causing additional eye discomforts such as itchiness, redness, swelling and wateriness. (For more information, visit the “Ocular Allergies” topic at this Web site.

Conclusion

Although dry eye syndrome has no cure, its symptoms can be treated. Over-the-counter artificial tears that lubricate the eye are the main treatment. Sterile artificial eye ointments are sometimes used at night to help lubricate the eye during sleep and to treat the scratchy eye feeling that many dry eye sufferers have when they wake up. Avoiding anything that can cause eye dryness — such as hair dryers, rooms with low humidity, air conditioning in cars (especially when vents are positioned directly at your face) wind and cigarette smoke — is recommended. In cases of moderate to severe dry eye, tears can be conserved by placement of a temporary or permanent plug into the channel at the inner corner of the eyelid where tears drain into the nose and the back of the throat.