The iris is the colored part of the eye you look at when you say a person has blue or brown eyes. Its function is to change the size of the pupil, the black-looking opening in the center that allows light to enter the eye. Iritis is an inflammation of the iris. It can occur in one eye or, less commonly, in both. Iritis is a serious condition, so do not treat it casually or ignore it, hoping it will go away by itself.
Symptoms
There may be no symptoms at all. Or, an eye with iritis may look “bloodshot” and may be extremely uncomfortable in bright light, sunlight, or the glare of automobile headlights. Pain or aching in the eye or brow can occur from the tightening of inflamed muscles as they constrict the pupil in bright light. The red color comes from congestion of blood vessels on the outside surface of the eye, which is a reaction to the inflammation. There may also be some blurring of vision.
What Causes Iritis?
Although there are many possible causes, most of the time the exact reason cannot be identified. Iritis can occur independently or in association with inflammations elsewhere in the body, such as in the joints (arthritis or spine spondylitis), teeth or sinuses, or bowels (colitis). Usually, it is not due to an infection, is not contagious, and is not related to infectious “pink eye”.
Why Is Iritis Serious?
If iritis is not treated promptly, there can be complications that threaten vision. These complications occur because the inflamed iris gets “sticky” and adheres to the lens, which lies directly behind it, or to the cornea, which is in front of it. The areas of stickiness, called synechiae, are dangerous because they may block the normal channels for fluid flow within the eye and lead to secondary glaucoma, a serious condition that can lead to blindness. Other complications of iritis are cataract, retinal swelling, and other internal eye damage.
Treatment
If the iritis is severe, the intraocular muscles must be rested with cycloplegic (or dilating) eye drops. These help relieve much of the pain because they allow the iris to rest by preventing their normal constriction, especially in bright light. The dilation also keeps the iris away from the lens and cornea so that synechiae are less likely to form and, if already present, pull free those that are not firmly attached. Even though cycloplegic drops blur your vision, which can be annoying and make it difficult to see well enough to read or even drive a car, they are very important and should not be discontinued until you have been told that it is safe to do so.
Other treatments include steroid eye drops or oral anti-inflammatory agents. Medications may produce very rapid relief at first, but the complete control of an iritis attack tends to be a slow process. As the inflammation subsides, you will given instructions for reducing the medications gradually. Stopping treatment suddenly can result in a flare-up of the attack.
Recurrence
An iritis attack may be completely cleared by treatment and may never occur again. However, once you have had iritis, a red eye even years later could indicate another attack. If at any time you think an attack may be starting, see your eye doctor right away. Be sure to tell any doctor who is treating you for any type of eye problem that you have a history of iritis.
