Definition

Iritis is the inflammation of the iris, the colored circle surrounding the pupil (the black hole in the center of the eye). The iris gives the eye its color due to its pigment content and controls the amount of light entering the pupil by adjusting its muscle fibers. This action causes the pupil to shrink in bright light and widen in dim light. The exact cause of iritis is often unknown, but genetic factors are known to play a role in its development.

Causes

Often, the cause of iritis is unknown. In some cases, iritis is related to eye injury, genetic factors, or certain diseases, especially autoimmune diseases. Causes of iritis include:

• Eye injury. Blunt injuries, sharp wounds, chemical burns, or fire can cause acute (new) iritis.
• Infections. Viral infections of the face can cause iritis. Infections in other parts of the body associated with iritis include tuberculosis (infection with Mycobacterium tuberculosis), syphilis (a sexually transmitted infection caused by Treponema pallidum), or toxoplasmosis (infection with the parasite Toxoplasma gondii).
• Genetic factors. People with certain autoimmune diseases (diseases that attack the immune system) due to gene mutations can experience acute iritis. These autoimmune diseases include psoriatic arthritis, ankylosing spondylitis (inflammation of the joints in the spine), and inflammatory bowel disease.
• Behcet's disease. This is a rare cause of acute iritis, characterized by joint problems, mouth ulcers, and genital sores.
• Juvenile rheumatoid arthritis. Chronic iritis can develop in children with this condition.
• Sarcoidosis. Inflammation affects various parts of the body, such as the lungs, lymph nodes, eyes, and skin. This autoimmune disease can cause collections of inflammatory cells in areas of the body, including the eyes.
• Kawasaki disease. This involves inflammation of the walls of blood vessels.
• Ulcerative colitis. This is inflammation of the large intestine.
• Certain medications. Some medications, such as the antibiotic Rifabutin and the antiviral drug Cidofovir used to treat HIV infection, can cause iritis. Bisphosphonates, drugs for osteoporosis, can also cause iritis. Stopping these medications usually alleviates the iritis symptoms.

Risk Factor

Risk of developing iritis will increase if you:

• Have certain gene mutations. People with mutations in genes important to the immune system are more likely to develop iritis.
• Have a sexually transmitted infection, such as syphilis or HIV/AIDS.
• Have a compromised immune system or immune system disorders, including ankylosing spondylitis and arthritis.
• Smoke. Studies have shown that smoking can increase the risk of developing iritis.

Symptoms

Iritis can occur in one or both eyes. It usually appears suddenly and can persist for up to three months. Signs and symptoms include:

• Eye redness
• Pain or discomfort in the eyes
• Headache, the pain can be felt especially around the eyes
• Sensitivity to light
• Irregular pupil shape
• Decreased vision if chronic (lasting a long time)

Iritis lasting a few days is called acute iritis, while iritis persisting for more than three months is chronic iritis.

Diagnosis

To diagnose iritis, an ophthalmologist will conduct an interview and complete physical examination of the eyes. The interview includes questions about signs and symptoms and medical history. Afterward, the doctor will perform the following eye examinations:

• Outer eye examination. The doctor will use a flashlight to examine your pupils, look for redness patterns in your eyes, and check for excess discharge.
• Visual acuity test. The doctor will test your visual acuity using a special chart and standard tests.
• Examination with slit lamp. The doctor will look inside your eyes using a special microscope. By dilating your pupils with eye drops, the doctor can see inside your eyes better.

If the doctor suspects a disease or condition causing your iritis, they will work with other specialists to determine the cause. Further tests such as blood tests or X-rays may be needed to find or rule out the cause of your iritis.

Management

Treatment for iritis aims to preserve vision and relieve pain and inflammation. For iritis associated with other diseases, treating the underlying disease will aid the healing process.

Medications commonly prescribed by ophthalmologists include anti-inflammatory eye drops and pupil dilators to reduce pain. Pupil dilators also protect the eyes from complications that can interfere with pupil function. If symptoms persist or worsen, your doctor may prescribe oral medications appropriate for your condition. In serious cases or if complications arise, surgery may be considered as another treatment option.

After receiving treatment from an ophthalmologist, there are steps to treat the condition at home, include:

• Following the medication usage rules as directed by your doctor
• Wearing dark glasses if light hurts your eyes.
• Taking painkillers if needed.

If iritis is caused by an eye injury, it usually heals within 1-2 weeks. In other cases, healing may take weeks to months.

Complications

If not treated properly, iritis can cause the following complications:

• Cataracts. Clouding of the lens of the eye, especially if the inflammation lasts for a long time.
• Irregular pupil shape. Scar tissue from inflammation can cause the iris to stick to the lens or cornea, making the pupil shape irregular and slowing the iris's reaction to light.
• Glaucoma. Increased intraocular pressure and nerve damage, leading to vision loss.
• Calcium buildup on the cornea (band keratopathy). This causes corneal damage and can reduce vision.
• Swelling of the retina. This swelling can reduce the central vision area.

Prevention

Preventing iritis is difficult because most cases have no known cause. However, early detection and prompt treatment can reduce the risk of permanent vision loss. Additionally, treating underlying diseases, such as autoimmune diseases, can help prevent the onset of iritis.

When to See a Doctor?

Consult an ophthalmologist as soon as possible if you have symptoms of iritis. Prompt treatment can help prevent serious complications. If you experience eye pain and vision problems along with other signs and symptoms, you may need immediate medical attention. Iritis has a high recurrence rate, so if you experience similar symptoms to those of previous iritis episodes, consult a doctor immediately.

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