Iritis, also called “anterior uveitis” is an inflammatory disorder of the iris, the colored portion of the eye that surrounds the pupil. The symptoms generally include pain in the eye, light sensitivity (photophobia), and blurry vision. Sometimes the pupil is small and the eye is red, although there is no discharge. Often patients see “floaters” in the field of vision. Usually only one eye is involved, although it is possible to have iritis in both eyes. The symptoms iritis typically appear suddenly and develop over a few hours or days.
Iritis is an “inflammatory” condition of the eye. It is usually not caused by bacterial or viral infection. In many cases the cause of the inflammation cannot be determined. Most often, though, it is associated with a concomitant autoimmune disease such as rheumatoid arthritis, systemic lupus erythematosus, Reiter’s disease, ankylosing spondylitis, among others. In autoimmune diseases the person’s own immune system attacks its own organs and tissues. In many cases the eye becomes a target of the antibodies, thus causing an inflammatory reaction.
Iritis may occur only once, but it is frequently a recurring problem. After a few times experiencing the disorder, patients become very adept at recognizing the symptoms and are quick to seek medical attention. If left untreated, iritis becomes very painful and can lead to vision loss. Treatment usually involves corticosteroid eye drops and, in some cases, eye drops to dilate the pupils. Typically, initial treatment is aggressive, often with dosing several times a day in order to suppress the inflammation. After that, the steroid drops are tapered gradually in order to prevent a rebound effect.
The critical message to take from this is that iritis is not a benign condition that will go away by itself. It won’t, it will only get worse. The appropriate action to take is to go to an ophthalmologist as soon as possible and begin treatment.
As the name implies, the inflammation occurs in the posterior or rear of the eye. It is characterized by inflammation of the layer of blood vessels beneath the retina. The symptoms of posterior uveitis include blurred vision, distortion of the size and shape of objects, and floating black spots in the visual field.
About 25% of cases of posterior uveitis are of unknown cause. Generally though, it may be cause by bacterial or viral infection, tuberculosis, HIV, herpes virus, and many others.
The disorder is treated systemically, either with tablets or injection rather than locally with eye drops. This is because, unlike anterior uveitis, the inflammation is located at the back of the eye and the drops simply would not reach the affected area.