1. Department of Ophthalmology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
2. Department of Ophthalmology, Kyungpook National University Hospital, Daegu, Korea.
3. Department of Ophthalmology, SMG-SNU Boramae Medical Center, Seoul, Korea.
4. Department of Ophthalmology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.