The iris is an important structure of the eye that contains muscular fibers that react to the amount of light entering the pupil. The pupil becomes smaller in bright light and larger in dim light. The iris is the colored ring structure around the pupil. Iritis occurs when the iris tissue becomes inflamed. Inflammation can occur either in the front part of the eye (anterior uveitis) or back (posterior uveitis). Anterior uveitis is by far the more common of the two, and is a common form of intraocular inflammation.
In ititis, white blood cells called leukocytes exude into the anterior chamber (fluid-filled space between the iris and the cornea of the eye. Through a slit-lamp examination, an ophthalmologist can view the inflammatory cells floating in the convection currents of the aqueous humor (space between the lens and the cornea). The severity of the disease is made based on the concentration of inflammatory cells. Adhesion between the iris and lens may result from scarring. Iritis will usually occur in one eye at a time. In acute iritis, treatment should start quickly to avoid complications. In chronic iritis, inflammation may be resistant to therapy and may even cause visual impairment can occur from glaucoma, macular swelling or cataracts. Patients with iritis may experience cloudy vision, redness of the eye, headaches, pain in the eye or surrounding the eyes (brow region), and in irregular scarred pupils. No cause for iritis can be found in a large number of cases. In others, trauma to the eye as well as several inflammatory and infectious diseases can be the culprit. Crohn’s disease, arthritis and inflammatory bowel disease are just a few autoimmune diseases known to cause iritis or uveitis. Lyme disease, tuberculosis, syphilis and multiple forms of herpes (herpes simplex, herpes zoster viruses) are among several other infectious causes tied of iritis. After diagnosis by an ophthalmologist, treatment is usually started with corticosteroid and dilating eye drops. In some cases medications are used by mouth. Rarely chemotherapeutic agents are required to control inflammation. Infectious causes of iritis are treated. These medications relieve inflammation and pain while also working to reduce scarring. It’s much more common to find a systemic medical cause for iritis in patients with both eyes affected. A minority of patients with red eyes are found to have iritis. It’s important to treat iritis soon after symptoms appear as each new episode increases chances of scarring, cataracts, glaucoma and other serious eye damage. If the pupil becomes scarred, it will lose some of its ability to adjust to different light conditions.
