Yi-Hsun Huang1, Jia-Horung Hung2,3. 1. Department of Ophthalmology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, No.1, University Road, Tainan 701, Taiwan. 2. Department of Ophthalmology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, No.1, University Road, Tainan 701, Taiwan. hungjh@mail.ncku.edu.tw. 3. Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan. hungjh@mail.ncku.edu.tw.