[1] Univ Ulsan, Dept Ophthalmol, Asan Med Ctr, Coll Med, Seoul, South Korea
[2] Univ Ulsan, Asan Inst Life Sci, Asan Med Ctr, Clin Res Ctr,Coll Med, Seoul, South Korea
[3] Univ Ulsan, Dept Clin Epidemiol & Biostat, Asan Med Ctr, Coll Med, Seoul, South Korea