Episcleritis and Scleritis

Episcleritis

Localised, engorgement of the superficial episcleral plexus is the hallmark of this condition which may occur in isolation or together with uveitis or keratitis. Although normally benign, a small proportion of episcleritis cases may be associated with systemic inflammatory conditions such as rheumatoid arthritis, sarcoidosis and inflammatory bowel disease. Patients describe irritation, rather than pain, in the eye with a mild watery discharge and no disturbance of vision [13].

Patients should be reassured and advised that the condition is self-limiting. A topical non-steroidal anti-inflammatory agent may ease discomfort.

Scleritis

Scleritis is an inflammatory process involving the deep episcleral plexus and in 30-50% of cases [3] is associated with an underlying rheumatological disorder. Rheumatoid arthritis and Wegener’s granulomatosis are the most common connective tissue and vasculitic causes. Patients present with either localised or generalised bluish or violet discolouration and a deep dull aching pain in the eye. The pain is characteristically worse at night and may wake the patient from sleep. Vision may be affected and, as the extra-ocular muscles attach to the sclera, the pain is worse on movements of the eye. The eye is tender to touch through the closed eyelid [14].

Differentiation between episcleritis and scleritis may be difficult. However, instillation of 2.5% phenylephrine drops into the affected eye results in blanching of the superficial episcleral plexus after five minutes. Therefore, persisting vascular engorgement indicates scleritis.

All patients with suspected scleritis must be referred for an urgent ophthalmological assessment as, in severe cases; the inflammation may lead to thinning and ultimately, perforation of the globe.

Learning Bite

Blanching of the superficial episcleral plexus by topical phenylephrine is a useful indicator of episcleritis.