Dry Eye

Dry eye is a condition in which there are insufficient tears to lubricate and nourish the eye. Tears are necessary for maintaining the health of the front surface of the eye and for providing clear vision. People with dry eyes either do not produce enough tears or have a poor quality of tears. Dry eye is a common and often chronic problem, particularly in older adults.

With each blink of the eyelids, tears are spread across the front surface of the eye, known as the cornea. Tears provide lubrication, reduce the risk of eye infection, wash away foreign matter in the eye, and keep the surface of the eyes smooth and clear. Excess tears in the eyes flow into small drainage ducts, in the inner corners of the eyelids, which drain in the back of the nose.

Dry eyes can result from an improper balance of tear production and drainage.

• Inadequate amount of tears – Tears are produced by several glands in and around the eyelids. Tear production tends to diminish with age, with various medical conditions, or as a side effect of certain medicines. Environmental conditions such as wind and dry climates can also affect tear volume by increasing tear evaporation. When the normal amount of tear production decreases or tears evaporate too quickly from the eyes, symptoms of dry eye can develop.
• Poor quality of tears – Tears are made up of three layers: oil, water, and mucus. Each component serves a function in protecting and nourishing the front surface of the eye. A smooth oil layer helps to prevent evaporation of the water layer, while the mucin layer functions in spreading the tears evenly over the surface of the eye. If the tears evaporate too quickly or do not spread evenly over the cornea due to deficiencies with any of the three tear layers, dry eye symptoms can develop.

The most common form of dry eyes is due to an inadequate amount of the water layer of tears. This condition, called keratoconjunctivitis sicca (KCS), is also referred to as dry eye syndrome.

People with dry eyes may experience symptoms of irritated, gritty, scratchy, or burning eyes, a feeling of something in their eyes, excess watering, and blurred vision. Advanced dry eyes may damage the front surface of the eye and impair vision.

Treatments for dry eyes aim to restore or maintain the normal amount of tears in the eye to minimize dryness and related discomfort and to maintain eye health.

What causes dry eyes?

The majority of people over the age of 65 experience some symptoms of dry eyes.

The development of dry eyes can have many causes. They include:

• Age – dry eye is a part of the natural aging process. The majority of people over age 65 experience some symptoms of dry eyes.
• Gender – women are more likely to develop dry eyes due to hormonal changes caused by pregnancy, the use of oral contraceptives, and menopause.
• Medications – certain medicines, including antihistamines, decongestants, blood pressure medications and antidepressants, can reduce the amount of tears produced in the eyes.
• Medical conditions – persons with rheumatoid arthritis, diabetes and thyroid problems are more likely to have symptoms of dry eyes. Also, problems with inflammation of the eyelids (blepharitis), inflammation of the surfaces of the eye, or the inward or outward turning of eyelids can cause dry eyes to develop.
• Environmental conditions – exposure to smoke, wind and dry climates can increase tear evaporation resulting in dry eye symptoms. Failure to blink regularly, such as when staring at a computer screen for long periods of time, can also contribute to drying of the eyes.
• Other factors – long term use of contact lenses can be a factor in the development of dry eyes. Refractive eye surgeries, such as LASIK, can cause decreased tear production and dry eyes.

How are dry eyes diagnosed?

Dry eyes can be diagnosed through a comprehensive eye examination. Testing, with special emphasis on the evaluation of the quantity and quality of tears produced by the eyes, may include:

• Patient history to determine any symptoms the patient is experiencing and the presence of any general health problems, medications taken, or environmental factors that may be contributing to the dry eye problem.
• External examination of the eye, including lid structure and blink dynamics.
• Evaluation of the eyelids and cornea using bright light and magnification.
• Measurement of the quantity and quality of tears for any abnormalities. Special dyes may be instilled in the eyes to better observe tear flow and to highlight any changes to the outer surface of the eye caused by insufficient tears.

Using the information obtained from testing, your optometrist can determine if you have dry eyes and advise you on treatment options.

How are dry eyes treated?

One of the primary approaches used to manage and treat mild cases of dry eyes is adding tears using over-the-counter artificial tear solutions.

Dry eyes can be a chronic condition, but your optometrist can prescribe treatment to keep your eyes healthy, more comfortable, and prevent your vision from being affected. The primary approaches used to manage and treat dry eyes include adding tears, conserving tears, increasing tear production, and treating the inflammation of the eyelids or eye surface that contributes to the dry eyes.

• Adding tears – Mild cases of dry eyes can often be managed using over-the-counter artificial tear solutions. These can be used as often as needed to supplement natural tear production. Preservative-free artificial tear solutions are recommended because they contain fewer additives that could further irritate the eyes. However, some people may have persistent dry eyes that don’t respond to artificial tears alone. Additional steps need to be taken to treat their dry eyes.
• Conserving tears – An additional approach to reducing the symptoms of dry eyes is to keep natural tears in the eyes longer. This can be done by blocking the tear ducts through which the tears normally drain. The tear ducts can be blocked with tiny silicone or gel-like plugs that can be removed, if needed. A surgical procedure to permanently close tear ducts can also be used. In either case, the goal is to keep the available tears in the eye longer to reduce problems related to dry eyes.
• Increasing tear production – Prescription eye drops that help to increase production of tears can be recommended by your optometrist, as well as omega-3 fatty acid nutritional supplements.
• Treatment of the contributing eyelid or ocular surface inflammation – Prescription eye drops or ointments, warm compresses and lid massage, or eyelid cleaners may be recommended to help decrease inflammation around the surface of the eyes.

Self Care

Steps you can take to reduce symptoms of dry eyes include:

• Remembering to blink regularly when reading or staring at a computer screen for long periods of time.
• Increasing the level of humidity in the air at work and at home.
• Wearing sunglasses outdoors, particularly those with wrap around frame design, to reduce exposure to drying winds and sun.
• Using nutritional supplements containing essential fatty acids may help decrease dry eye symptoms in some people. Ask your optometrist if the use of dietary supplements could be of help for your dry eye problems.

Avoiding becoming dehydrated by drinking plenty of water (8 to 10 glasses) each day.

Keep an Eye on Harmful UV Rays

Ultraviolet (UV) radiation is a concern for many Americans, but most people are thinking about protecting their skin, not their eyes. Whether it’s a cloudy or sunny day, summer or winter, the American Optometric Association (AOA) reminds Americans to take specific measures to protect their eyes from the sun’s UV rays in order to decrease the risk of vision disorders.

The sun’s primary danger is in the form of UV radiation. UV radiation is a component of solar radiation, but can be given off by artificial sources like tanning beds.

According to the AOA’s 2008 American Eye-Q® survey, which identified Americans’ attitudes and behaviors regarding eye care and related issues, only 49 percent of Americans said UV protection was the most important factor when purchasing sunglasses. Respondents said that the price and style of sunglasses were among the most important factors to them.

“Overexposure to UV rays has been linked to a variety of problems, including age-related cataracts and degeneration of the cornea,” said Gregory W. Good, O.D., PhD, optometrist and AOA’s UV Protection Expert. “Other disorders that can occur are abnormal growths on the eye’s surface and even sunburn of the eyes. These conditions can cause blurred vision, irritation, redness, tearing, temporary vision loss and, in some instances, blindness.”

According to Dr. Good, the effects of solar radiation are cumulative; therefore optometrists recommend parents purchase proper eyewear for young children and teenagers. The longer the eyes are exposed to solar radiation, the greater risk a person has for developing conditions later in life such as cataracts or macular degeneration.

It is not clear how much exposure to solar radiation will cause damage, so the AOA recommends wearing quality sunglasses that offer proper UV protection and a wide-brimmed hat whenever people spend time outdoors. Also, certain contact lenses incorporate an ultraviolet blocker in the lens, which helps further reduce exposure to UV light that eventually can cause cataracts and other eye problems. Patients can ask their optometrist for additional information about these contact lenses.

The following top five tips from the American Optometric Association can help prevent eye damage from exposure to UV radiation:

1. Wear protective eyewear any time the eyes are exposed to UV rays, even on cloudy days and during the winter.
2. Look for quality sunglasses or contact lenses that offer good protection. Sunglasses or protective contact lenses should block out 99 to 100 percent of UV-A and UV-B radiation and screen out 75 to 90 percent of visible light.
3. Check to make sure sunglass lenses are perfectly matched in color and free of distortions or imperfections.
4. Purchase gray-colored lenses because they reduce light intensity without altering the color of objects to provide the most natural color vision.
5. Don’t forget protection for young children and teenagers, who typically spend more time in the sun than adults and thus are at greater risk for damage.

Additionally, be sure to schedule periodic comprehensive eye exams with an eye doctor. It’s a good way to monitor eye health, maintain good vision, and keep up-to-date on the latest in UV radiation protection.

Other interesting facts from the American Eye-Q® survey include:

• 46 percent of survey respondents have worn lenses (contacts lenses or regular glasses) that provide UV protection.
• 35 percent of respondents wear prescription sunglasses.
• Some respondents understand that dry eye (32 percent), temporary blindness (30 percent), and sunburn (29 percent) can result from overexposure to UV rays.
• By comparison, fewer respondents link eye diseases such as cataracts (24 percent), eye cancer (24 percent), macular degeneration (19 percent); and glaucoma (17 percent) to overexposure to solar rays. (17 percent) to overexposure to solar rays.
• 67 percent of parents purchase sunglasses for their children; however, 13 percent of parents do not check to make sure the glasses protect against UV rays.

For additional information on UV protection, please visit: http://www.aoa.org/x4735.xml. Or to view a copy of the AOA’s Shopping Guide for Sunglasses, please visit: http://aoa.org/documents/SunglassShoppingGuide0810.pdf.