Epidemiology and Clinical Characteristics of Episcleritis and Scleritis in Olmsted County, MN.

PURPOSE: To determine the population-based incidence and disease associations of episcleritis and scleritis in a Midwestern US population.

DESIGN: Population-based retrospective cohort study.

METHODS: All residents of Olmsted County, MN from 2006-2015 were identified using the Rochester Epidemiology Project. 223 episcleritis cases and 77 scleritis cases were identified. We assessed incidence and disease associations of episcleritis and scleritis, as well as scleritis recurrence rates, treatment, and complications.

RESULTS: The incidence rates for episcleritis and scleritis were 15.39 and 5.54 per 100,000 per year, respectively. Females accounted for 60.1% of episcleritis and 51.9% of scleritis cases. The mean age at diagnosis was 40.2 years for episcleritis and 48.8 years for scleritis. In the episcleritis cases, the incidence in females was higher (p=0.01). There was no significant difference between genders for scleritis incidence (p=0.75). 23.4% of scleritis patients had an associated systemic disease. Patients with systemic disease had a trend towards an increased risk of recurrence, but it was not statistically significant. There was a slightly decreased risk of scleritis recurrence with older age at diagnosis (HR 0.73, p=0.058, 95% CI 0.52 - 1.01). At last follow up, most eyes with scleritis (90.4%) had good visual acuity (better than 20/40), and 92.3% had stable or improved visual acuity.

CONCLUSION: The Olmsted County, MN population had a lower incidence of episcleritis and a higher incidence of scleritis compared to previous studies. The population-based results from this study may provide information that is more applicable to a primary eye care setting.