Scleritis and episcleritis

From the earliest available descriptions of episcleritis (Slade, 1838; Rognetta, i844; Desmarres, 1847) a confusion has existed between scleritis and episcleritis. This has led to contradictory views on the relative severity and prognosis of these conditions, and the erroneous belief that episcleritis is accompanied by serious complications (Viswalingham, 1936; Wood, 1936; Mann and Markson, I950; Clavel and Teulieres, 1958). While Slade (I838), Rognetta (i844), and Desmarres (I847), thought that episcleritis was both common and severe, Mackenzie (i 830) considered it to be neither and gave at the same time a vivid and accurate description of scleritis. This confusion still persists today. In an attempt to clarify the position we have been studying patients with scleritis and episcleritis in a special clinic at Moorfields Eye Hospital during the past io years. Of these, 207 patients (30I eyes) with episcleritis and 159 patients (2I7 eyes) with scleritis were analysed in depth.§ The results reported below have led us to conclude that scleritis and episcleritis are clinically distinct, with a different symptomatology and prognosis and requiring different management. The incidence of these conditions is not known, but Williamson (1974) suggested that it was about o-o8 per cent of hospital new patient referrals. Our series is from highly selected patients, all being referred from elsewhere, often where there was difficulty in diagnosis, and with unusual problems. This is reflected in the fact that go per cent of the patients who had rheumatoid arthritis were seen within a year of the start of the special clinic.