[A nation-wide survey on the occurrence of Vogt-Koyanagi-Harada disease in Japan].

A nation-wide survey was performed to estimate the frequency and distribution of Vogt-Koyanagi-Harada's disease (Harada's disease hereinafter). A questionnaire was mailed to the departments of ophthalmology in hospitals with at least 200 beds. The response rate was 489 out of 1,077 institutions, or 45.4%. The annual prevalence was estimated to be 15.5 per million and the incidence was 6.5 per million, based on the number of reported cases and the response rate per prefecture. It was estimated that 1,800 patients were treated for this disease annually and that there were about 800 new cases. Geographical distribution showed no special characteristics such as these seen with Behçet's disease. The results of the analysis of 1,833 cases showed that females were slightly more affected than males, with an age distribution on first visit which showed a peak in the fourth decade and with the median age being 42.3 years.