Iritis (i-RYE-tis) is inflammation that affects the colored ring around your eye's pupil (iris). The iris is a part of the middle layer of the eye (uvea), so iritis is a type of uveitis, also known as anterior uveitis.
Iritis, the most common type of uveitis, affects the front of your eye. The cause is often unknown. It can result from an underlying systemic condition or genetic factor.
If untreated, iritis could lead to glaucoma or vision loss. If you have symptoms of iritis, see your doctor as soon as possible.
Iritis can occur in one or both eyes. It usually develops suddenly, and can last six to eight weeks. Signs and symptoms of iritis include:
- Eye redness
- Discomfort or achiness in the affected eye
- Sensitivity to light (photophobia)
- Decreased vision
Iritis that develops suddenly, over hours or days, is known as acute iritis. Symptoms that develop gradually or last longer than six weeks indicate chronic iritis.
When to see a doctor
See an eye specialist as soon as possible if you have symptoms of iritis. Prompt treatment helps prevent serious complications. If you have eye pain and vision problems with other signs and symptoms, you might need urgent medical care.
Often, the cause of iritis can't be determined. In some cases, iritis can be linked to eye trauma, genetic factors or certain diseases. Causes of iritis include:
- Injury to the eye. Blunt force trauma, a penetrating injury, or a burn from a chemical or fire can cause acute iritis.
- Infections. Shingles (herpes zoster) on your face can cause iritis. Other infectious diseases, such as toxoplasmosis, histoplasmosis, tuberculosis and syphilis, can be linked to other types of uveitis.
- Genetic predisposition. People who develop certain autoimmune diseases because of a gene alteration that affects their immune systems might also develop acute iritis. Diseases include ankylosing spondylitis, Reiter's syndrome, inflammatory bowel disease and psoriatic arthritis.
- Behcet's disease. An uncommon cause of acute iritis in Western countries, this condition is also characterized by joint problems, mouth sores and genital sores.
- Juvenile rheumatoid arthritis. Chronic iritis can develop in children with this condition.
- Sarcoidosis. This autoimmune disease involves the growth of collections of inflammatory cells (granulomas) in areas of your body, including your eyes.
- Certain medications. Some drugs, such as the antibiotic rifabutin (Mycobutin) and the antiviral medication cidofovir, that are used to treat HIV infections can be a rare cause of iritis. Stopping these medications usually stops the iritis symptoms.
Your risk of developing iritis increases if you:
- Have a specific genetic alteration. People with a specific change in a gene that's essential for healthy immune system function are more likely to develop iritis. This change is labeled HLA-B27.
- Develop a sexually transmitted infection. Certain infections, such as syphilis or HIV/AIDs, are linked with a significant risk of iritis.
- Have a weakened immune system or an autoimmune disorder. This includes conditions such as ankylosing spondylitis and reactive arthritis.
- Smoke tobacco. Studies have shown that smoking contributes to your risk.
If not treated properly, iritis could lead to:
- Cataracts. Development of a clouding of the lens of your eye (cataract) is a possible complication, especially if you've had a long period of inflammation.
- An irregular pupil. Scar tissue can cause the iris to stick to the underlying lens or the cornea, making the pupil irregular in shape and the iris sluggish in its reaction to light.
- Glaucoma. Recurrent iritis can result in glaucoma, a serious eye condition characterized by increased pressure inside the eye and possible vision loss.
- Calcium deposits on the cornea (band keratopathy). This causes degeneration of your cornea and could decrease your vision.
- Swelling within the retina (cystoid macular edema). Swelling and fluid-filled cysts that develop in the retina at the back of the eye (macular retina) can blur or decrease your central vision.