Evaporative Dry Eye or Lack of Tears

If your skin stays chapped and dry for long, it becomes red, irritated, itchy, and vulnerable to scrapes and cuts that can be a portal for infection. The same thing can happen to your eyes. If they are chapped and dry because they aren’t continuously bathed in a layer of protective tears, they become irritated, itchy, and red, and their surface becomes prone to cuts. Dry eye syndrome may be the culprit.

Millions of people have dry eye syndrome (also known as keratoconjunctivitis sicca), and it's one of the most common reasons for visits to eye doctors. Dry eyes can disrupt a person’s quality of life. In some cases, the eyes can be so dry that it's difficult to read, drive, or carry on with activities of daily living. 

One type of dry eye that has been receiving more attention in recent years is evaporative dry eye caused by meibomian gland dysfunction.

The Tear Film

To understand evaporative dry eye, you need to know a little about what your tears are actually made of. The tear film is thought to be made up of a mucin or mucus layer that coats the surface of the cornea and makes tears "stick" to the eye.

The next layer is composed of water and oil. Oil helps to prevent tear film evaporation. When your eye is open to the atmosphere throughout the day, tears evaporate and are lost through drainage. The longer your eyes are open, the more evaporation occurs. If your tear film lacks oil, your tears evaporate very rapidly, especially when exposed to an atmosphere that promotes evaporation.

If your eyes aren't constantly bathed in just the right mixture of lubricating "ingredients," symptoms of dry eye syndrome develop. It’s a delicate and critical balance. If the dryness continues and becomes severe, ulcers and scars can form on the cornea. Infection and even some loss of vision can develop.

Causes of Inadequate Tears

The eyelid contains several tiny glands—called meibomian glands—that contribute oils to the normal tear film. The glands are located inside the eyelid and have an opening on the eyelid margin. In some people, these glands are susceptible to clogging or not functioning correctly on a chronic basis.

Meibomian gland dysfunction is very common. Mild cases often go undiagnosed or are not treated properly.

Diagnosis

Evaporative dry eye is diagnosed by examining the eye under a slit lamp biomicroscope. Under high magnification, your healthcare provider can see the individual openings of the meibomian glands. Sometimes the glands will be plugged up. When meibomian gland dysfunction is chronic, the glands can actually atrophy.

The consistency and quantity of the tears can also be examined. If evaporative dry eye is present, the tears may seem thick or frothy.

Treatment 

A variety of approaches can be tried at home to help treat mild cases of dry eyes, including lifestyle changes, natural remedies, medications, and surgery.

Lifestyle Measures

Here are several simple things you can do to help keep your eyes moist and protect them from dirt and debris: 

• Keep the air in your home humidified, especially in the winter. A humidifier or a pan of water on a radiator can help.
• Try to take regular breaks from your computer screen.
• Protect your eyes from smoke, wind, and drafts—from a hairdryer or air conditioner, for instance. Wrap-around sunglasses can help.
• Remember to drink water (try for at least six glasses a day) and try to get at least seven hours of sleep.

Home Remedies

Some home remedies might help soothe dry, red, and itchy eyes:

Warm compresses. Try applying a clean, warm, wet washcloth to the eyelids for three to four minutes once or twice a day. Gentle pressure can warm the meibomian glands and help them express their content, and also keep the lids and eyelashes free of debris.

Lid massage. Gentle, light pressure to the lid margins with your fingertip can also encourage meibomian gland function. As you roll your finger upward on your lower lid, look up. Then roll your finger downward on your upper lid as you look down. 

Lid scrubs. With your fingertips or a warm wet washcloth, gently wash your top and bottom eyelids at least once a day. This keeps your lids free of debris and bacteria that can block meibomian gland secretions. You can use a mild soap (such as baby shampoo) that won’t irritate your eyes, followed by rinsing with water.

Omega-3 fatty acids. You can also try adding flaxseed oil and fish oil to your diet. Both are good sources of omega-3 fatty acids, which some think can help the meibomian glands produce better and more consistent oil.

Eye drops. You can buy artificial tears, moisturizing gels, and ointments at your local pharmacy without a prescription. These products are commonly used to soothe mildly dry eyes, though their effect is only temporary.

Office Treatments

If home remedies aren't working, your healthcare provider can offer a variety of options. These include:

Topical ointments. Topical cyclosporine A, an immunomodulatory medication with anti-inflammatory properties, has long been prescribed for dry eyes. However, it can have side effects such as itching, redness, and blurry vision, and it is relatively expensive.

Mechanical pressure therapy. Some clinicians believe that in-office expression of oil from the meibomian glands helps promote a healthy tear film. This involves gently squeezing the eyelids to help expel the material from inside the glands.

Thermal pulsation. Eyelid thermal pulsation is an in-office treatment option. The pulsation device (called LipiFlow or iLUX) applies heat to the meibomian glands in the upper and lower eyelids while it simultaneously compresses them to express their contents. Side effects, such as eye and eyelid discomfort, appear to be minimal and resolve quickly. The process is expensive, however, and is not covered by most insurance. 

A Word From Verywell

If you think that you may have dry eyes, it is important that you discuss it with your healthcare provider. Not only is it uncomfortable, but it can also cause complications that can permanently affect your vision. Getting the right diagnosis is the first step in making sure that you can find an effective treatment for your dry eyes.