Legacy Eye Care
Modernized Optometry, Affordable Quality Care

Dry Eye

Dry Eye Syndrome

Dry eye is one of the most common reasons people visit their eye doctor and if left untreated, it can lead to serious complications, including vision loss.

Tears are extremely important to our eye's health and to our vision. Tears provide lubrication so the lids can blink smoothly over the corneas and the eyeballs can move freely around in their sockets. They also wash away dust particles and contain enzymes to help fight off infections. Clear vision is also dependent on a good tear film. Imagine how difficult it would be to see out of your car’s windshield if it was covered with dirty, oily water.

Dry eyes can be caused by:



Inadequate tear production

Tears are produced in the lacrimal gland located near the outside edge of the upper lid. Normal aging can cause a decrease in lacrimal gland secretions, as can systemic diseases such as rheumatoid arthritis, lupus, Sjögren's syndrome and ocular rosacea. Many medications can also cause the lacrimal glands to produce less tears; antihistamines, antidepressants and birth control pills to name a few. 

Poor tear quality

Tears are made up of 3 layers. The layer closest to the eye is a mucin layer. It is produced by goblet cells in the conjunctiva (the “Saran wrap” covering over the white part of the eye). This layer is responsible for attracting the liquid layer of the tears (the middle layer) to the otherwise water repelling corneal surface. Without it, the tears would very quickly roll off the surface of the eye.

As mentioned above, the middle tear layer (lacrimal layer) is predominately water. This layer contains salts, proteins, and lysozyme (an enzyme that protects us against bacteria) and has several functions: taking nutrients (such as oxygen) to the cornea, carrying waste products away from the cornea, helping to prevent corneal infection, and maintaining the tonicity of the tear film (important to keep the cornea from shriveling or swelling up). The lacrimal gland is primarily responsible for producing this layer of the tears.

The outermost layer of tears is an oily layer. Its purpose is to help prevent the tears from evaporating too quickly. Glands in the lids called the meibomian glands are responsible for this layer.

Environment

Dry, dusty, or smoke filled environments can be particularly difficult for people with less than adequate tear function. Anything irritating the eye needs to be washed away. If the tear film is not performing as it should, dry eye symptoms are certain to be a problem.

Anatomical

Sometimes the lids not working well will result in dry eye. They may be too loose against the cornea resulting in poor tear spread over the eye during blinks. In a condition called lagophthalmos, the lids do not close completely, especially when asleep, allowing the eyes to dry out. Floppy lid syndrome is characterized by upper lids that easily (and sometimes spontaneously) evert exposing the eye to drying and ocular surface injury. It is most ften seen in overweight, middle-aged males, although it may occasionally be encountered in women and non-obese individuals.

Diagnosis

Dry eye can be diagnosed a number of ways. Often, just listening to a patient’s complaints will clue the doctor that dry eye syndrome is a likely problem. Do you have a difficult time sitting under a ceiling fan or having air blow in your face? Do your eyes feel scratchy, like there are little hairs in them? Does your vision fluctuate and if so, does blinking seem to make it clearer? Do your eyes water all the time, especially when you read or work on the computer? A “Yes” answer to any of these questions can be significant for a diagnosis of Dry Eye Syndrome.

There are several tests a doctor might do to help diagnose dry eye. The tear break up time (TBUT) is a test that measures the time it takes for the tear film to break apart after a blink. The normal time before breakup is 10 seconds. Anything less than that is indicative of dry eye.

Dyes are used to assess the quality of health of our tears. Lissamine Green and Rose Bengal are used to highlight “dead” cells in the eye. While Fluorescein Sodium is used to study the tear break up time and quality of the tear film.

Your doctor may do a Schirmer test to determine the volume of tear production. Small strips of paper are hung from the bottom lids and after 5 minutes, the amount of paper that has been wet by the tears is measured. 10mm or more is considered normal.

Treatment: 

Treatment recommendations vary from person to person and, of course, takes into account the reasons for the dry eye. If the dry eye symptoms are mild, artificial tears may be all that are necessary. Most often, however, more aggressive treatment is necessary.

If the problem stems from a lack of tears (low Schirmer score), a drug like Restasis might be helpful.

If the dry eye is caused by meibomian gland dysfunction, lid scrubs, hot compresses, and a medication such as AzaSite or neutraceuticals such as HydroEye and Hydrate may be prescribed. Both the AzaSite and the oral supplements work to help the oils produced by the glands in the lids flow better.

(Click here for instructions on doing lid scrubs.)

(Click here for instructions on using hot compresses.)

If the dryness is caused by lagophthalmos or floppy lid syndrome, lubricating ointments often provide excellent relief. Tranquileyes is a sleep mask that provides warm moist heat to the eyes. Many patients also find running a humidifier near their bed helps as well.