Clinical features of HTLV-I associated uveitis determined in multicenter collaborative study. Study Group for HTLV-I Associated Ocular Diseases.

The elucidation of the clinical features of human T-lymphotropic virus type I (HTLV-I) associated uveitis (HAU) was advanced by the results of a multicenter study performed by the collaboration of university hospitals throughout Kyushu and Okinawa and two institutions in the Tokyo-Yokohama metropolitan areas of Japan. A total of 426 cases of endogenous uveitis were registered during the five-month study period between September 1992 and January 1993. The etiology and clinical entity remained unknown for about half of these cases. A series of 50 cases of HTLV-I seropositive, entity-undefined uveitis were suspected to be HAU, and analyses of these cases provided the following clinical features of this recently defined uveitis entity. 1) middle-aged adult of either sex develops acute, inflammatory uveal disease and presents with visual haze or floaters, or both; 2) active disease consists of granulomatous or nongranulomatous reactions accompanied by vitreous opacities and retinal vasculitis with rare retinochoroidal exudative changes; 3) the disease resolves with response to corticosteroids, although leaving sequelae in occasional cases; 4) the disease affects one or both eyes, and up to half of cases show recurrent disease within years; 5) the visual outcome is usually favorable; 6) the disease occurs as an isolated disorder, but may sometimes be complicated by HTLV-I associated myelopathy. Hyperthyroidism is also associated in occasional cases; 7) the titer of serum HTLV-I antibodies is significantly high compared with that of HTLV-I carriers, suggesting an immune mechanism as the pathogenesis of HAU.