Keiji Kataoka1, Satoru Kase2, Kousuke Noda1, Susumu Ishida1. 1. Department of Ophthalmology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan. 2. Department of Ophthalmology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan. Electronic address: kaseron@med.hokudai.ac.jp.