Epidemiology of macular dystrophy in Japan (2011-2020): a nationwide population-based study.

PURPOSE: To describe the characteristics and prevalence of macular dystrophy using a comprehensive national claims database in Japan. STUDY DESIGN: Population-based retrospective study using a nationwide claims database. METHODS: Approximately 126 million individuals covered by Japan's universal health coverage system were included. Health insurance claims from 2011 to 2020 stored in the National Database of Health Insurance Claims (NDB) of Japan were analyzed. Patients with macular dystrophy, including best vitelliform macular dystrophy (BVMD), Stargardt disease (STGD), cone/cone-rod dystrophy, or central areolar choroidal dystrophy (CACD), were identified using diagnostic codes recorded in the database. The population-based prevalence of diagnosed macular dystrophy was calculated, and age-standardized rates were derived using the WHO standard world population. RESULTS: Between 2011 and 2020, 1,268 patients with BVMD, 460 with STGD, 5758 with cone/cone-rod dystrophy, and 280 with CACD were identified in the NDB. As of October 1, 2020, the corresponding prevalence rates were 10.05, 3.65, 45.65, and 2.35 per 1,000,000 persons, respectively. CONCLUSION: This nationwide study provides updated epidemiological estimates of macular dystrophy in Japan. These findings may inform clinical management, healthcare planning, and future research on macular dystrophy.