CONJUNCTIVITIS
Excerpted from Triad's Eye Care Notes © 1989-2005 by Triad Publishing Co.

At one time or another, nearly everyone has had pink eye, or conjunctivitis (kon-junk-tih-VI-tiss). In fact, this is one of the more common reasons people go to an eye doctor. "Conjunctivitis" means inflammation of the conjunctiva (kon-junk-TI-vuh). The conjunctiva is the thin membrane that covers the white part of the eye (sclera) and the undersurface of the eyelids. "Inflammation" means that this membrane is red, irritated, or swollen.

Conjunctivitis is not a disease; it is simply a reaction to something that is irritating the eye. There are many conditions that can result in a reddened eye. Usually, it means a viral or bacterial infection, but conjunctivitis can also be caused by allergy, irritants such as air pollution, smoke or noxious fumes, or minor trauma as from contact lenses, a scratch, or even a loose eyelash. An eye can also look red as the result of something more serious, such as corneal infection or foreign body, or even be a sign of certain inner eye diseases.

Why Is Your Eye Red?

Healthy conjunctiva is transparent. It only looks white because the sclera under it is white. (On the undersides of the lids it looks pink because the tissues under it are pink.) Buried within the conjunctiva are many tiny blood vessels that normally don't show. When there is a conjunctival inflammation or irritation, the blood flow to these vessels is increased, engorging them and making them visible against the white background -- thus the term "pink eye." The reddish color is almost never due to actual bleeding.

Is Pink Eye Contagious?

Sometimes yes; sometimes no. It depends on what is causing it. Infectious conjunctivitis (caused by bacteria or viruses) can be contagious; if the cause is an allergy or irritant, it is not. Any time you aren't sure, it is a good idea to assume it's contagious. That means not touching your other eye after rubbing the pink eye, washing your hands after touching the eye or lids, not sharing towels or washcloths, and disposing of tissues used to wipe the eye.

What Should You Do? Do You Need To See a Doctor?

If your eye feels scratchy and uncomfortable, it's all right to try a mild over-the-counter lubricant for a few days, which may provide temporary relief. But do not use any product that contains a steroid, because if you have an infection, steroids can make it worse.

If the eye redness and irritation come on when you or a family member has or has recently had an upper respiratory infection (cold, fever, runny nose), the culprit is likely to be the same "bug." If it's a virus, treatment will not usually be helpful.

But for a bacterial infection, which often causes a pus-like discharge or a crusty mattering on the lids, a doctor may need to prescribe an antibiotic eyedrop or ointment for you.

When both eyes are red, an allergy or atmospheric irritant may be the cause. Be alert to this possibility and you may be able to identify and avoid the offending substance. A seasonal allergy is likely if the eyes get red and itchy around the same time each year. If you are bothered a lot, medication can be prescribed to relieve the symptoms.

If you wear contact lenses and develop conjunctival irritation and redness that doesn't clear up in several hours after removing the lenses, they might be the cause of a problem that requires treatment.

Sudden, profuse tearing with lids that tend to want to close suggests a foreign body, a scratch, or a corneal infection. If these symptoms don't subside within a few hours, your eye should be examined. The same holds true if your child comes running in from outdoors with a red, tearing eye. This almost certainly means that the eye has been scratched or that there is a small foreign body in it.

Conjunctivitis can occur in association with certain systemic diseases. And sometimes a red eye is not conjunctivitis at all, but a sign of a corneal problem or an internal eye condition that needs prompt medical attention. This includes iritis and uveitis (inflammations deep within the eye), and one uncommon type of glaucoma.

Most causes of conjunctivitis are not serious and tend to clear up on their own. Some go away after a few days, viral infections may last several weeks, and an allergic reaction may go on for months. Do not ignore a persistently red eye in the hope that it will go away. If the symptoms are irritating and last for more than a few days, or especially if your eye is painful or if there is a lot of discharge, the problem may not be trivial. Any time you are not sure whether a red or pink eye is serious, it is always better to be safe and have your eye examined.

Excerpted from Triad's Eye Care Notes © 1989-2005 by Triad Publishing Co.

Patients: for more information about your eyes, see: Taking Care of Your Eyes: A Collection of the Patient Education Handouts Used by America's Leading Eye Doctors