Common Eye Disorders
Dry Eye
What is Dry Eye?
Dry Eye or Dry Eye Syndrome is one of the most common eye problems, and affects over thirty million Americans. It is often caused by a problem with the quality of the tear film that lubricates the eyes. Each time a person blinks, a film of tears spreads over the eye leaving the surface of the eye smooth, clear and protected. Without our tear film, good vision would not be possible.
Tears are more complex than one might expect. A healthy tear actually contains three layers.
- The mucin layer coats the cornea, the eye's clear outer window, forming a base so the tear film can adhere to the eye.
- The middle aqueous layer (made up of 98% water) provides moisture and other important nutrients to the cornea.
- The outer lipid layer is an oily film that seals the tear film on the eye and controls evaporation.
Tears are produced by two different methods. One method produces tears at a slow, steady rate and is responsible for normal eye lubrication as described above (and the tear film). The other method produces large quantities of tears in response to eye irritation or emotions.
In dry eye, sometimes excess tearing may occur. Excess tearing from "dry eye" may sound odd, but if the tears responsible for safeguarding lubrication do not keep the eye wet enough, the eye becomes irritated. When the eye is irritated, the lacrimal gland produces a large volume of tears.
What Are the Symptoms of Dry Eye?
Typical symptoms include:
- Stinging, burning or 'scratchy' eyes;
- Stringy mucus in or around the eyes;
- Severe eye irritation from smoke or wind;
- Excessive tearing;
- Difficulty or discomfort wearing contact lenses.
What Causes Dry Eye?
Dry eye syndrome has many causes. One of the most common reasons for dryness is simply as a result of the normal aging process, however there are others:
- Dry environment or workplace (wind, air conditioning)
- Sun exposure
- Smoking or second-hand smoke exposure
- Cold or allergy medicines
- An eye injury or other problem with your eyes or eyelids (like a drooping eyelid or bulging eyes)
- Sjogren's syndrome -- includes dry eyes, mouth, and mucus membranes, and often rheumatoid arthritis or other joint disorder
Detection and Diagnosis
There are several methods to test for dry eyes. The eye doctor will perform an eye exam, and may perform certain tests to determine the level of tear production, as well as the quality of the tear. One test is known as Schirmers test. A Schirmers test is used to determine whether the eye produces enough tears to maintain adequate moisture. The test is performed by placing filter paper inside the lower lid of the eye. After a few minutes, the paper is removed and tested for its moisture content. A special type of dye called "fluorescein" may also be used to test for dry eye.
How is Dry Eye Treated?
Dry Eye Syndrome is an ongoing condition that may not be cured, but the accompanying dryness, scratching and other irritations, may be managed. Your eye care professional may recommend artificial tear medications, which are lubricating eye drops that may help to alleviate the
symptoms. A prescription product that addresses the underlying inflammation associated with
dry eye is also available from your eye care professional.
A more permanent treatment option that may be considered depending on the severity
of the condition is what is called "punctal or punctum plugs." Punctal or punctum plugs
are soft silicone plugs, about the size of a sesame seed. They are non-surgically
placed into the natural punctal opening (located at the nasal margins of the upper and
lower eyelids through which tears drain from the eye). Punctal plugs allow natural
tears to be retained on the eye longer. The entire procedure can be performed in
an eye doctor's office within a few minutes. Although considered a more
permanent treatment for Dry Eye, punctal/punctum plugs can be removed if
problems arise. |
