Epidemiological survey of intraocular inflammation in Japan.

PURPOSE: To report the frequency and trend of intraocular inflammation based on a survey of new ophthalmology patient visits to university hospitals throughout Japan during 2002. METHODS: A questionnaire was sent to the departments of ophthalmology in 110 university hospitals nationwide to survey the total number of new patients who visited the outpatient clinics for the first time between 1 January and 31 December 2002, and also the number of patients diagnosed with intraocular inflammation during this period. RESULTS: The surveys completed by 41 university hospitals were analyzed in this study. During 2002, a total of 151 299 new ophthalmological patients presented at the 41 institutions, and 3060 (2.2%) of the new patients were diagnosed as having intraocular inflammation. The most frequent intraocular inflammatory disease identified was sarcoidosis (13.3%), followed by Vogt-Koyanagi-Harada (VKH) disease (6.7%), Behçet disease (6.2%), bacterial endophthalmitis (3.8%), herpetic iridocyclitis (3.6%), diabetic iritis (1.6%), human leukocyte antigen-B27-associated uveitis (1.5%), acute retinal necrosis (1.3%), ocular toxoplasmosis (1.1%), ocular toxocariasis (1.1%), uveitis associated with human T lymphotropic virus-1 (also known as HAU) (1.1%), and others. Infectious intraocular inflammation accounted for 16% of all uveitis cases. CONCLUSIONS: Through the collaboration of a large number of institutions, some aspects of the epidemiology of intraocular inflammation in Japan were elucidated. However, the disease concept and diagnostic criteria remain ambiguous for a considerable number of diseases within the spectrum of intraocular inflammation, and the possibility that such factors may bias the present findings cannot be denied. In the future, a prospective survey based on well-defined, common diagnostic criteria is required to obtain more precise epidemiological data.