Incidence of choroidal hemangioma in solitary cases and Sturge-Weber syndrome: a nationwide population-based study in Korea

To estimate the incidence of choroidal hemangioma in solitary cases and Sturge-Weber syndrome (SWS). Nationwide retrospective cohort study. Data were extracted from the Health Insurance Review & Assessment (HIRA) Service system in Korea between 2014 and 2023. Patients with a solitary choroidal hemangioma and SWS, as verified by both the SWS registration code (National Registry of Rare and Intractable Disease in Korea code Q85.8) and diagnostic code (International Statistical Classification of Diseases, 10th Revision code D18.08 / “choroidal hemangioma”), were included. During the 10-year observational period (excluding the 2014–2016 for wash out period), a total of 1999 individuals were diagnosed with solitary choroidal hemangioma from 2017 to 2023, and a total of 342 individuals were diagnosed with combined SWS and choroidal hemangioma. The period prevalence and the mean birth cohort incidence of a solitary choroidal hemangioma were 3.90 (95% CI 3.73–4.07) per 100,000population and 13.91 (95% CI 13.19–14.66) per 100,000 person-years, with a male-to-female ratio of 0.75:1, and that of SWS with choroidal hemangioma were 0.67 (95% CI 0.60–0.74) per 100,000 population, and 1.77 (95% CI 1.52–2.05) per 100,000 person-years with male-to-female ratio of 0.89:1 in South Korea. Among patients with solitary choroidal hemangioma, congenital non-neoplastic nevus (Q825) and epidermal cyst (L720) were most frequentlyobserved in 35 cases (1.75%) and 34 cases (1.70%), in contrast, SWS was most frequently accompaniedby Epilepsy (G4090 and G4020) in 28 cases (8.19%). This study identified the prevalence, birth-cohort incidence, and associated comorbidities of choroidal hemangioma with and without SWS in an East Asian population. These data could help to promote better understanding of the epidemiologic features of choroidal hemangioma and SWS patients.