Tackling HTLV-1 infection in ophthalmology: a nationwide survey of ophthalmic care in an endemic country, Japan

Introduction Japan is the most endemic of the developed nations in terms of human T-lymphotropic virus type 1 (HTLV-1) infection. Japan has been tackling HTLV-1 infection and has made remarkable progress. In ophthalmology, awareness of the association between HTLV-1 infection and uveitis has been increasing since the 1990s, when the relationship was first established. Here, we describe a nationwide survey and analysis of the current state of medical care for HTLV-1-associated uveitis (HAU) at ophthalmic facilities in Japan. Methods A questionnaire survey covered all university hospitals in Japan that were members of the Japanese Ophthalmological Society and all regional core facilities that were members of the Japanese Ocular Inflammation Society. Survey data were collected, and nationwide data on the state of medical care for HAU were tallied and analysed. Results Of the 115 facilities, 69 (60.0%) responded. HAU was most commonly diagnosed ‘based on blood tests and characteristic ophthalmic findings’. Overall, 86.8% of facilities perform testing for HTLV-1 antibodies during medical care for diagnosing uveitis, with 58.3% routinely performing testing. Facilities with experience in providing medical care for HAU accounted for 67.6%. The survey also revealed that 85.5% of facilities had seen no decrease in the number of patients with HAU. Conclusions In the two decades since the establishment of HAU as a pathological entity, the majority of facilities in Japan have started performing testing for HTLV-1 antibodies when considering differential diagnoses for uveitis. Our data suggest that providing information on HTLV-1 infection to ophthalmologists in Japan has been successfully implemented.