Incidence and causes of visual impairment in Japan: the first nation-wide complete enumeration survey of newly certified visually impaired individuals

Purpose: To investigate the visual impairment certification status in Japan. Study design: Observational cross-sectional study. Methods: We asked all welfare offices throughout Japan to submit data concerning age, sex, causative diseases, and visual impairment grades for newly certified visually impaired individuals aged ≥ 18 years in the fiscal year of 2015. The certification was based on criteria of the Act on Welfare of Physically Disabled Persons. Results: In total, data were collected for 12,505 newly certified visually impaired individuals. The most common age group for these individuals was 80-89 years (29.6%), followed by 70-79 (26.3%) and 60-69 (17.3%) years. The most common causative disease was glaucoma (28.6%), followed by retinitis pigmentosa (14.0%), diabetic retinopathy (12.8%), and macular degeneration (8.0%). Glaucoma was the most common causative disease in both sexes (30.2% in men and 27.0% in women). The most common impairment grade was grade 2 (31.8%), followed by grades 5 (24.3%) and grade 1 (16.1%). The number of visually impaired individuals with underlying glaucoma had increased in comparison with the number in the most recent surveys (from fiscal years 2007 to 2009), whereas the number of individuals with underlying diabetic retinopathy and macular degeneration had decreased. Conclusion: To our knowledge, this is the first nation-wide complete enumeration survey of newly certified visually impaired individuals in Japan. These findings may contribute to administrative activities concerning medical welfare as well as educational activities for preventing visual impairment.