1. Department of Ophthalmology, Korea University College of Medicine, Seoul, Republic of Korea
2. Department of Public Health, Graduate School, Korea University, Seoul, Republic of Korea
3. Health Insurance Policy Research Institute, National Health Insurance Service, Wonju, Republic of Korea
4. Medical Research Institute and Department of Anatomy, College of Medicine, Ewha Womans University, Seoul, Republic of Korea
5. Department of Preventive Medicine, Korea University College of Medicine, Seoul, Republic of Korea