Behçet's disease (BD) is an important cause of visual morbidity throughout the world, but shows striking differences in racial predilection. Despite important advances in the therapeutic management of acute intraocular inflammation, the long-term impact of these new strategies on visual outcome of BD and their efficacy in different ethnic groups is unknown. A comparative study of patient characteristics, clinical ocular features and inflammatory score, and current therapy was undertaken on all patients fulfilling the International Study Group criteria for Behçet's disease and the Behçet's Disease Research Committee of Japan, who attended the Uveitis Clinics of Moorfields Eye Hospital (n=19) and Kurume University School of Medicine (KUS) (n=35) during a continuous consecutive four-week period. Japanese patients were significantly older (43.2+/-11.8 years) than the patients seen in London (35.4+/-8. 9 years). There was a predominance of male patients in both groups. All patients seen in KUS were Japanese, while the patients in London included 12 Caucasians, five Middle Eastern, one African, and one Asian. No significant differences were seen between the two populations in the duration of systemic disease or systems affected by the disease, such as mouth ulcers, genital ulcers, skin lesions including erythema nodosum, or arthritis. The duration of ocular disease was similar in both centres: around seven years. There was, however, a significant difference in the number of eyes with active anterior uveitis (59.7% KUS vs 18.4% London (chi-square: 5.4; p=0.006)) and/or posterior uveitis (31.3% KUS vs 18.4% London (chi-square: 5.42; p<0.02)). No significant differences were found in the number of eyes with optic disc swelling or optic atrophy and in each centre the number of eyes with vision greater than 6/9 or worse than 6/60 were the same. The treatment schedules were very different between the two centres. More patients were treated with topical steroids in Japan (68.7% KUS vs 10.5% London (chi-square: 30.5; p=0.001), but a similar number used concomitant intraocular pressure-lowering agents. More patients received systemic steroids in London (84.2% London vs 17% KUS (chi-square: 20.25; p<0.001)). Three patients received systemic steroids alone, five had prednisolone and cyclosporin, four had prednisolone and azathioprine, and four had triple therapy with prednisolone, cyclosporin, and azathioprine. Only one patient used colchicine. Cyclosporin use was similar in London and KUS (47.4% and 42.8%, respectively). In Japan, three patients used prednisolone alone and three tacrolimus (FK506). In addition, two patients, who were on steroids alone, took colchicine as well. More patients in Japan had undergone surgery for cataract and glaucoma (chi-square: 4.0; p=0.045). In KUS, seven of 67 eyes had cataract surgery. A further three eyes had visually significant cataract and two eyes had undergone glaucoma surgery. In contrast, no patients in London had undergone any surgery up to and including this period.