What Causes Iritis?

What is iritis?

The colored part of the eye is called the iris. When the iris gets inflamed, the condition is called iritis, which is also called anterior uveitis. The muscles present in the iris help in pupil contraction and relaxation. The anterior and posterior chambers of the eye are also divided by these muscles. 

People of all ages can be affected by iritis. It may occur due to an unknown cause or an underlying medical condition,  such as a systemic inflammatory disease or autoimmune disease, which can be acute or chronic. Individuals with iritis tend to be photosensitive along with experiencing pain and redness in their eye. Iritis could lead to glaucoma or blindness if it is left untreated. 

Symptoms of Iritis

In people with iritis, one or both of their eyes may be affected. Children with iritis may have the following symptoms:

• Eye pain
• Red eye
• Headache
• Irregular shape of pupils
• Decreased visual clarity
• Light sensitivity

In most cases, juvenile idiopathic arthritis (JIA)-associated iritis is symptomatic until after vision impairment has already occurred. It is one of the reasons why rheumatologists and ophthalmologists recommend frequent routine eye exams. To detect or monitor this condition, people can take eye exams as often as four times in 12 months. 

Iritis generally affects one eye, which can quickly develop along with experiencing any or all of the following signs and symptoms:

• Eye or brow pain
• Worsening pain in the eye in bright light
• Eye redness
• Blurry vision
• Headache
• Pupil irregularity

Causes of Iritis

In most cases, iritis has no identifiable cause. However, juvenile idiopathic arthritis (JIA) is often associated with iritis in children. Kids who have this condition are required to undergo routine screenings to detect eye inflammation. Iritis is also linked to genetic factors, eye trauma, and certain medical conditions. 

• Eye Injuries: Acute iritis can be caused by a penetrating or blunt trauma or from a chemical or fire burn. 

• Genetic Susceptibility: Autoimmune diseases caused by a gene alteration might also cause acute iritis in certain people. These diseases include inflammatory bowel disease (IBD), Reiter's syndrome, ankylosing spondylitis, and psoriatic arthritis.

• Infections: Iritis can also occur due to certain infections, such as shingles (herpes zoster) on the face, syphilis, histoplasmosis, tuberculosis, and toxoplasmosis. 

• Behcet's Disease: Also called Behcet's syndrome, is a rare cause of acute iritis in the West. This disorder also causes symptoms, which include genital sores, mouth sores, and joint problems. 

• Sarcoidosis: This inflammatory disease is associated with the growth of granulomas in the body, including the eyes. 

• Certain Medications: Another rare cause of iritis is the intake of certain drugs. They include certain medications for HIV infections, such as cidofovir and the antibiotic called rifabutin (Mycobutin). Iritis symptoms usually go away after stopping these medications. 

Risk Factors

A person's risk of developing iritis may increase with the following factors:

• Tobacco Smoking - A study suggests that smokers have a two-fold chance of developing new-onset iritis compared to nonsmokers. 

• Sexually Transmitted Infections: These infections include syphilis and HIV/AIDS. 

• Genetic Alteration: The presence of HLA-B27 in the blood may indicate a higher risk of developing certain autoimmune diseases. 

• Autoimmune Disease or a Weakened Immune System: It often includes reactive arthritis and ankylosing spondylitis 

Diagnosing Iritis

Iritis is usually diagnosed by an ophthalmologist. The condition can be confirmed by the following eye exams:

• External Eye Examination: In an external examination, the doctor observes the pattern of eye redness, which can be in one or both eyes. The doctor also looks for any eye discharge. A penlight might be used by the doctor to check your pupils. 

• Visual Acuity Test: In this test, the doctor checks the clarity and sharpness of your vision by using a standardized chart held 20 feet away.  

• Slit-Lamp Exam: This eye examination involves the use of eye drops to dilate the pupils. It uses a special microscope with light to give doctors a closer look at the different structures of the eye. 

If a certain disease is causing a patient's iritis, an eye doctor may work with the patient's primary care provider to help identify the exact cause. In such cases, other tests may be recommended to rule out certain conditions. Tests may include X-rays and blood tests. 

Treating Iritis

The main goal of iritis treatment is to reduce pain, inflammation, and redness along with preserving the patient's vision. If iritis is due to an underlying medical condition, treatment for such condition is also required. Iritis treatment may involve the use of the following:

• Dilating Eye Drops: Pain caused by iritis can be relieved through the use of dilating eye drops. They can also help prevent complications, which can impair the pupil's function. 

• Ophthalmic Steroids: Steroid medications in the form of eye drops can help reduce inflammation. 

• Oral Medication: For worsening symptoms, oral medications, such as steroids and other anti-inflammatory drugs may be prescribed. Oral medications also depend on the patient's overall condition.

Eye drops and oral medications should only be used according to your ophthalmologist's prescription and instruction since the incorrect use or intake of these medications can cause serious side effects, such as cataracts and/or glaucoma. 

Complications

Iritis usually clears up without any problems with prompt treatment. However, some people may experience complications, especially when iritis is left untreated. Some of the potential complications of iritis may include: 

• Optic nerve damage
• Retinal inflammation
• Glaucoma (elevated pressure inside the eye)
• Cataracts (clouding of the eyes' lens)
• Macular edema (fluid buildup in the macula)
• Band keratopathy (deposits of calcium on the cornea)
• Synechiae (abnormal iris adhesion to other structures of the eye)

In severe cases, these complications can lead to partial or total loss of vision. These complications can be prevented when iritis is promptly treated using medications that reduce inflammation. However, surgery may be required when treatment involves repairing the cornea or removing a cataract. The risks of developing complications also vary depending on a person's other medical condition, age, and the specific cause of iritis. 

When to Seek Medical Help

Consult an eye doctor if you develop any of the following signs and symptoms of iritis:

• Blurry vision
• Eye redness near the iris
• Eye pain that is associated with bright light

You can also go to the nearest hospital emergency department to seek immediate medical help if there is no eye doctor available in your area. 

Outlook for Iritis

Traumatic iritis often resolves within 7-14 days. On the other hand, it may take weeks or even months for nontraumatic iritis to resolve. Iritis that is associated with 

People who have a higher risk of having recurrent iritis may be instructed by their eye doctor to have steroid eye drops on hand, so they can use it whenever signs of a recurrence occur.