Wednesday 9 March 2011

Eye Allergies and Contact Lens Wear

Seasonal allergies affect about 20 percent of Americans. A significant portion of these people experience eye allergies, which can cause visual impairment and discomfort. Proper care, however, can limit or prevent the effects of eye allergies.

There are approximately 40 million contact lens wearers in the United States; the American Optometric Association estimates that about 75 percent of them report eye pain and irritation caused by allergies.

An eye allergy is a reaction to allergens or non-parasitic antigens. Pollen, mold, or dust mites are common allergens that can get into the eye and create an inflammation in the conjunctiva. The conjunctiva is a tissue that lines the inner eyelid and the cornea. It also helps to keep the eye moist. Eye allergies can be hereditary, but are not contagious.

Allergens are attracted to contact lenses. The lens can function like a sponge and attract deposits and allergens, making it crucial for wearers to thoroughly clean and disinfect their lenses and follow the guidelines given to them by their eye care practitioner.

Symptoms of eye allergies include red, itchy, burning, tearing, swollen eyes, and the feeling that something is in the eyes. Some eye allergy sufferers experience blurry vision or feel distracted and tired.

There are three common allergic conditions - giant papillary conjunctivitis, vernal keratoconjunctivitis and atopic keratoconjunctivitis. Giant papillary conjunctivitis (GPC) is the most common allergic condition in contact lens wearers. Generally, the condition causes the eye to feel itchy and irritated. GPC is caused either by an allergic reaction to the preservatives used in contact lens solutions or by lens deposits accumulated on the lens.

If the contact lens wearer continues with wear even when experiencing GPC, symptoms such as itchiness, redness and irritation frequently occur. These symptoms can sometimes continue after the lenses have been removed. Those who continue with contact lens wear in the presence of GPC also report that their lenses ride up on the eye when blinking, which can cause the onset of papillae or red bumps to form, especially on the under side of the upper eyelid.

Treating GPC most commonly involves suspending contact lens wear while the condition improves.

Tips

- Don't rub your eyes; this will make it worse. Try placing a cool cloth on your eyes to ease the itching.
- Frequently wash hands with soap and water.
- Wash bedding in hot water to reduce allergens.
- Avoid wearing eye makeup.
- Never share contact lenses or eye makeup with anyone.
- Limit the length of time lenses are worn.
- Try wearing lenses part time and glasses part time.
- Discuss with your eye care professional a cleansing and replacement schedule that will best suit your needs.
- Use eye drops as recommended by your eye care professional.
- Use a rinsing and storage solution that does not contain known allergenic ingredients such as thimerosal.

Daily disposable lenses avoid the buildup of allergens on the lens surface and also eliminate exposure to disinfecting solutions and lens cleaning products that may also lead to allergic reactions.

Allergies to preservatives in contact lens solutions

The body's response to allergens causes nearby cells to release chemicals that result in inflammation. Some substances found in contact lens solutions can lead to this response, causing redness, itching, and discomfort.

Preservatives in contact lens solutions can remain on the contact lens surface and/or within the lens matrix even after the lens has been cleaned and disinfected. These preservatives may cause an allergic reaction. The chemical Thimerosal is most commonly associated with eye allergies, though other chemicals can also cause an allergic response. Reactions can develop at any time, even after several months or years using a solution.

To avoid an allergic reaction to contact lens solutions, it is wise to use products labeled "sensitive eyes" or "thimerosal free." Check the product label to ensure that the solution does not contain chemicals you may be allergic to.

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