Iritis is a condition causing inflammation of the iris. It is the most common form of uveitis, accounting for an estimated 60% of all cases in the Western countries.
The iris is the colored ring that surrounds the pupil. Inflammation can occur suddenly over hours/days (acute iritis) or can develop gradually. The condition is said to be chronic when it persists longer than 6 weeks.
Also Known As
Sometimes referred to as anterior uveitis.
- Acute iritis
- Chronic iritis
Causes and Risk Factors
Iritis can occur due to issues such as:
- Infections – Inflammation can be caused by infections such as the virus responsible for Herpes Simplex.
- Trauma- Both blunt and penetrating traumas can cause swelling of the iris. Burn injuries caused by fire or chemicals are also known causes.
- Autoimmune disorders – Disorders such as Reiter's syndrome, inflammatory bowel disease, sarcoidosis and Behcet's disease are associated with iritis.
- Drug-induced allergies – Individuals may react to some medications with inflammation of the iris. These drugs include Mycobutin and Cidofovir used by HIV patients.
The risk factors for development of iritis include:
- Gender predisposition – Individuals with a specific change in the gene, labelled HLA-B27 are more likely to develop iritis than those without.
- Compromised immune system – Those with a weakened immune system due to conditions such as HIV or autoimmune disorders are at a higher risk.
- Habits such as tobacco smoking
- Female gender
Signs & Symptoms
Iritis can affect one or both eyes. Patients present symptoms such as:
- Brow/Eye pain
- Diminished vision
- Sensitivity to light (Photophobia)
- Watering/Excess tearing
- Partial/Complete loss of vision
The eye professional will perform a number of tests to diagnose iritis. He/she may also check for underlying conditions. The tests may include:
- Slit lamp exam – The test involves use of a microscope to magnify the view of the eye. Where there’s iritis, it will show white blood cells (WBCs) and protein particles in the aqueous humor. This is usually a definitive test for iritis.
- Staining – The professional may stain the ocular surface with dye to assess other structures such as the cornea.
- Blood tests – They are useful in identifying the underlying cause of iritis. Blood tests can reveal presence of an autoimmune disease or an infection such as the Herpes Simplex Virus.
- Imaging tests – Chest X-rays or CT scan to check for sarcoidosis.
Treatment majorly focuses on the underlying cause. It is aimed at reducing the inflammation.
- Antibiotics – Pills may be issued to treat iritis caused by bacterial infections.
- Antivirals – In the case of viruses such as Herpes Simplex Virus, the eye doctor may prescribe Aciclovir to treat the condition first. The inflammation should resolve with proper treatment of the infection.
- Steroid drugs – They can be administered in the form of eye drops, pills or injections. The drugs work to reduce inflammation.
Surgeons will rarely perform operations for iritis. However, in the case of certain complications such as cataracts, a surgery may be necessary to remove it.
Home care involves taking drugs as prescribed. Patients should also wear dark glasses to reduce the effect of light on the eyes.
Generally, patients respond well to treatment. The condition goes away within a week or two. Non-traumatic iritis may however take longer to resolve. Those caused by systemic diseases such as sarcoidosis could also be chronic, taking much longer.
Complications may come about if the condition is not treated early. These include:
- Cataracts – This is clouding of the lens. It is treated surgically by removing the cataract.
- Irregular pupil – It is caused by adhesion of the swollen iris to other structures. As a result, the pupil changes shape and becomes irregular.
- Calcium accumulation on cornea (band keratopathy) - Occurs especially in chronic iritis.
- Optic nerve damage
- Elevated intraocular pressure that results in glaucoma
- Swelling of the macular retina – Fluid filled cysts may develop in the retina at the back of the eye, what is referred to as cystoid macular edema.
- Loss of vision
Measures that can be taken to prevent iritis include:
- Taking medications as prescribed by the doctor
- Going for regular eye check ups
- Wearing eye protection when in hazardous environment