The sclera is the white outer portion of the eye and is composed of a fibrous material called collagen. The episclera is a thin, normally clear layer of tissue, which covers the sclera. The sclera and episclera function to protect the delicate structures inside the eye and provide structural support to the globe (eyeball).
Episcleritis and scleritis are conditions in which the outer wall of the eye is inflamed. This inflammation can be due to a localized process or be secondary to an underlying systemic disease such as rheumatoid arthritis, lupus erythematosus, sarcoidosis, colitis, etc. Other manifestations of these systemic conditions may exist simultaneously with the ocular inflammation.
Both conditions present with redness, either unilaterally or bilaterally. Pain is usually mild with episcleritis, but may be deep seated and severe with scleritis. Both conditions may have a smoldering course or be recurrent. Episcleritis tends to be a self-limiting, benign condition as compared with scleritis which can be very serious and complicated by tissue destruction both outside and inside the eye. Untreated scleritis can lead to blindness.
Management involves a careful review of the patients’ medical history to determine if there are any predisposing conditions (i.e., chemical exposure, medical problems) that may be contributing to this problem and which can be modified. In many cases of scleritis a systemic workup may be coordinated with an internist, rheumatologist or other specialist.
Treatment is focused primarily on the inflammatory reaction: If relatively mild, without evidence of a threat to the health of the eye, no treatment or relatively conservative treatment with an oral nonsteroidal anti-inflammatory agent (aspirin-type medication) is usually the primary approach. If the inflammation is severe, however, strong immunosuppressive therapy with systemic steroids or other immunomodulators may be initiated. These medications may be associated with serious side effects necessitating regular monitoring by an internist or rheumatologist. The risks and benefits of treatment must be carefully weighed in each case against the potential risks of permanent damage to the eye from these inflammatory conditions. The duration and severity of the ocular inflammation, the patient's general health and age, and the status of the other eye are some of the factors that have to be taken into consideration when determining how to best treat episcleritis and scleritis.