The iris is the circular, colored portion of the front of the eye with the dark pupil in the center.
The iris is made up of muscular fibers that control the amount of light entering the pupil so that we can see clearly. The iris accomplishes this task by making the pupil smaller in bright light and larger in dim light.
The iris is the front part of the uveal tract of the eye (the iris in the front and the ciliary body and uveal tract behind it). In some people, the iris can become inflamed. This is termed iritis.
Inflammation of the front part of the eye is referred to as anterior uveitis or iritis, whereas inflammation behind this is known as posterior uveitis.
Iritis usually develops quickly and generally affects only one eye.
Signs and symptoms may include any or all of the following:
- pain in the eye or brow region. An exception to this is iritis in patients with juvenile rheumatoid arthritis since they often do not have pain. Due to the lack of pain it may be confused with minor irritation ("pink eye") of the eye and should not be ignored in these patients;
- worsened eye pain when exposed to bright light;
- reddened eye, especially adjacent to the iris;
- small or irregularly shaped pupil;
- blurred vision;
- increased tear production in the eye;
- iritis may result in glaucoma and/or cataracts, leading to a marked decrease of vision.
Iritis may be a consequence of trauma (traumatic iritis) or non traumatic causes. In a significant number of cases, no cause for the iritis is found.
- Blunt trauma to the eye can cause traumatic inflammation of the iris.
- Non traumatic iritis is frequently associated with certain systemic diseases (diseases that affects multiple locations throughout the body), such as ankylosing spondylitis, Reiter syndrome, sarcoidosis, tuberculosis, inflammatory bowel disease and psoriasis. Noteworthy of special attention is iritis associated with juvenile rheumatoid arthritis.
- Infectious causes may include Lyme disease, tuberculosis, toxoplasmosis, syphilis and herpes simplex and herpes zoster viruses.
First, we try to find a cause. Causes such as trauma, inflammatory eye disease, or an eye infection are often apparent. Treatment is then directed at the underlying cause. In many cases, no cause is detected. There are no natural remedies for iritis.
Specific treatment is usually antiinflammatory cortisone (steroid) eyedrops, often accompanied by drops to enlarge (the pupil). This serves two purposes: (1) it relieves some of the pain (2) the drops keep the pupil dilated to avoid it becoming scarred down and adherent to the focusing lens (behind the pupil) of the eye.
If the drops are not successful, injections of steroids around the eye or steroid (cortisone) pills may be necessary.
How long does iritis last?
Usually, iritis clears in days, but it may last for months or may become chronic and recurrent.
What are complications of iritis?
Blindness is the ultimate but relatively rare complication. Recurrent pain and blurring of vision may occur. If the pupil becomes scarred, it is unable to react, thereby losing some of the ability to adjust to different light conditions.
Glaucoma secondary to iritis may cause pain and result in blindness.
What is the prognosis for iritis?
In most cases, iritis responds to a short course of steroid eyedrops and dilating drops. In the case of recurrences, each new episode increases the possibility of scarring, glaucoma, cataract, and other serious eye damage.
What research is being done for iritis?
Since iritis usually responds so well to treatment, the research is primarily concerned with the management of cases which recur frequently or do not respond to conventional treatment. Besides looking for more effective medications, research also is concerned with looking for the best way of delivering medications to the eyedrops, pills, or injections.