Less frequent rituximab retreatment maintains remission of neuromyelitis optica spectrum disorder, following long-term rituximab treatment. Issue 4 (21st June 2018) - Kim, Su-Hyun; Kim, Yeseul; Kim, Gayoung; Park, Na Young; Jang, Hyun-Min; Shin, Hyun-June; Hyun, Jae-Won; Kim, Ho Jin