[1] Univ Ulsan, Coll Med, Asan Med Ctr, Dept Ophthalmol, Seoul 138736, South Korea
[2] Univ Ulsan, Coll Med, Asan Med Ctr, Dept Clin Epidemiol & Biostat, Seoul 138736, South Korea
[3] Carl Zeiss Meditec Inc, Dublin, CA USA
[4] Konyang Univ, Kims Eye Hosp, Dept Ophthalmol, Myung Gok Eye Res Inst, Seoul, South Korea