Prevalence and Incidence of Keratoconus in South Korea: A Nationwide Population-based Study

PURPOSE: To determine the prevalence and incidence of keratoconus in South Korea. DESIGN: A nationwide, population-based, retrospective study of keratoconus in the entire South Korean population (N = 47 990 761) from 2009 to 2014 was conducted using data from the Korean Health Insurance Review and Assessment (HIRA) database. METHODS: We identified patients with ophthalmologist confirmed keratoconus using the HIRA database, and estimated keratoconus prevalence and incidence rates, both overall and according to age and sex. RESULTS: Of 47 990 761 subjects, 17 931 had keratoconus during the 6-year period. The prevalence in the general population was 37.4 cases (95% confidence interval [CI]: 36.8-37.9) per 100 000 people. After exclusion of an initial 1-year washout period, 13 343 cases of incident keratoconus were identified during the final 5-year period (2010-2014). The incidence rate in the general population was 5.56 cases (95% CI: 5.47-5.66) per 100 000 person-years. Incidence peaked among men in their late 20s and among women in their early 20s. The overall male-to-female incidence rate ratio was 1.00, meaning there was no sex predisposition. CONCLUSION: Estimates of the nationwide, population-based prevalence and incidence of keratoconus may help deepen our understanding of the pathophysiology of the disease and allow appropriate healthcare system planning. (C) 2018 Elsevier Inc. All rights reserved.