Epidemiology of Episcleritis and Scleritis in Urban Australia

Importance The epidemiology of episcleritis and scleritis in Australia is largely unknown. Background To determine the incidence, prevalence and clinical characteristics of episcleritis and scleritis in Melbourne. Design Retrospective longitudinal study. Participants Patients aged >= 18 years with episcleritis or scleritis seen at the Royal Victorian Eye and Ear Hospital from November 2014 to October 2015. Methods Medical record review confirmed clinical diagnosis and characteristics. Incidence and prevalence were calculated using estimates of the adult population in areas of Melbourne with >= 30 ocular presentations/year to the emergency department. Main Outcome Measures Diagnosis of active episcleritis or scleritis, aetiology, ocular complications and treatments. Results From a general population of 3 408 068, we confirmed 149 new and 23 pre-existing cases of active episcleritis, and 35 new and 23 pre-existing cases of active scleritis. Incidence per 100 000 person-years was 4.4 (95% confidence interval [CI] 3.7-5.1) for episcleritis and 1.0 (95% CI 0.7-1.4) for scleritis, while 12-month prevalence was 5.1 (95% CI 4.3-5.9) and 1.7 (1.3-2.2) per 100 000 persons, respectively. Systemic disease was associated with 10% of episcleritis compared with 34% of scleritis (P < .001). Ocular complications were seen in 3% (6/184) of episcleritis eyes and 44% (32/72) of scleritis eyes, with the commonest being anterior uveitis (12/72) and ocular hypertension (14/72). At presentation, scleritis patients were commonly treated with oral non-steroidal anti-inflammatory drugs (60%) and prednisolone (19%). By 12 months, 24% of scleritis patients required immunosuppressants. Conclusions and Relevance Rates of episcleritis and scleritis in our single-centre Australian study were low. Episcleritis was usually benign, whereas scleritis had increased ocular complications and systemic disease.