[Causes and prevalence of visual impairment in Japan].

PURPOSE: To investigate the causes of visual impairment in Japan. METHODS: The documents of 4,852 individuals with authorization of visual impairment registered between April 2007 and March 2010 in 7 randomly selected regions were reviewed. RESULTS: The major causes of visual impairment were glaucoma (21.0%), diabetic retinopathy (15.6%), retinitis pigmentosa (12.0%), macular degeneration (9.5%) and chorioretinal atrophy (8.4%). Individuals over 70 years of age were predominant for glaucoma, those aged 50-69 years for diabetic retinopathy and those under 40 years of age for retinitis pigmentosa. Sixty-one percent of persons affected by glaucoma were severely handicapped. Macular degeneration increased with age especially in individuals over 80 years of age. CONCLUSION: There was no difference in the order of major causes as compared with a previous report in 2001-2004. It is important to establish a central database system so that the data can be surveyed to provide more relevant information to understand current issues for handicapped persons and develop new prophylactic and therapeutic modalities.