Episcleritis ----------- General Information The sclera is the outer covering of the eyeball. The outer thin layer of the sclera is called the episclera. Episcleritis is an inflammation of the episclera. It appears as a small, immovable lump or nodule around the margin of the clear cornea. It may also be more generalized and appear as a swelling around the corneal margin. The cause of episcleritis is believed to be due to a complex allergic reaction. If the reaction is severe enough, small blood vessels may grow into the cornea and cause it to become cloudy. Episcleritis is significant since it not only resembles tumors, but also is potentially serious. Even though episcleritis rarely causes permanent damage to the eye, it can be irritating to the patient. Important Points in Treatment 1. A thorough eye examination is essential before treatment. A sample (biopsy) of the tissue may be required to determine if any cancerous tissue is present. 2. Though episcleritis generally responds to treatment, it may recur, and treatment may have to be extended or reinstated. Notify the Doctor if Any of the Following Occur: * The disorder remains the same or worsens. * The eye appears painful or irritating to your pet. * You cannot apply the prescribed medication.