Dry Eye Syndrome
More than 10 million Americans suffer from dry eye syndrome each year. It is caused by a deficiency in the quality and/or quantity of the tear film that lubricates the surface of the eye.
Your tear film is made up of three layers:
- The mucous layer coats the cornea (the eyes clear window), forming a foundation so the tear film can adhere to the eye.
- The middle, aqueous layer which is 98 percent water provides moisture and supplies oxygen and other important nutrients to the cornea.
- The outer lipid layer is an oily film that sits on the watery layer to prevent evaporation of the tears.
Tears are formed by several glands around the eye. With each blink, the eyelids spread the tears over the surface of the eye. Tears exit the ocular surface via two tiny drainage ducts located in the inner corner of the eye near the nose.
Causes of Dry Eye Syndrome
Dry eye syndrome has many causes. One of the most common reasons for dryness is simply the normal aging process. As we grow older, our bodies produce less oil (60 percent less at age 65 then at age 18). This is more pronounced in women who tend to have dryer skin than men. The oil deficiency also affects the tear film. Without enough oil to seal the watery layer, the tear film evaporates much faster, leaving dry areas on the cornea which causes irritation.
Several other factors, such as hot, dry or windy climates, high-altitude, air-conditioning and cigarette smoke also cause dry eyes. Many people also find their eyes become irritated when reading or working on a computer. During these tasks, we tend to blink less, and our eyes dry out. Stopping periodically to rest and blink helps to keep the eyes more comfortable.
Contact lens wearers may also suffer dryness because soft contact lenses stay soft by absorbing your tears. If your eyes are already a little short on tears, this may cause a dry eye problem. By covering the cornea, less oxygen is able to reach the corneal surface.
In addition, certain medications can cause dehydration and lead to ocular dryness. Thyroid conditions, vitamin A deficiency, or diseases such as Parkinson’s and Sjogren’s syndrome can also cause dryness. Women frequently experience problems with dry eyes as they enter menopause due to hormonal changes.
Some of the symptoms of dry eyes include:
- A foreign body sensation
- Blurry vision which improves with blinking
- Excess tearing or discomfort after using the eyes while reading, watching television or working on a computer
There are several methods to test for dry eyes. Your doctor should first determine the underlying cause by measuring the tear production, the evaporation rate and quality of the tear film.
When it comes to treating dry eyes, everyone’s needs are different. Many people find relief by using artificial tears on a regular basis. Some of these products are watery and help temporarily alleviate symptoms; others are thicker and adhere to the eye longer. Avoidance of products that “whiten the eye” is important. These contain chemicals which harm the blood vessels on the surface of the eye and may lead to chronic redness.
Occluding the tear drain in the eyelid with special inserts called punctal plugs is another option. This works like closing a sink drain with a stopper. The special microscopic sized plugs help keep the tears on the surface of the eye, keeping it moist. This may be done on a temporary basis with a dissolvable collagen plug or permanently with a silicone plug.
Restasis, a medicated eye drop available by prescription, has helped many dry eye sufferers. It functions by decreasing the inflammation associated with dry eyes and actually helps the eye produce more tears. Several other eye drops are currently being tested before approval by the FDA and may be available soon.
There are also simple lifestyle changes that can significantly improve dry eyes. Drinking a lot of water keeps the body hydrated and flushes impurities. You should also make a conscious effort to blink frequently, especially when reading, watching television and working on a computer.
Treating dry eye problems is important not only for comfort but also for the health of your eyes. If you think you have dry eyes, contact Eye Physicians of Central Florida to schedule an examination.