1. Department of Ophthalmology, Asan Medical Center, University of Ulsan College of Medicine, Seoul
2. Department of Ophthalmology, Myongji Hospital, Hanyang University College of Medicine, Goyang
3. Department of Clinical Epidemiology and Biostatistics, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
4. Clayton Eye Center, Morrow, GA