1. Department of Ophthalmology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan 704, Taiwan
2. Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 704, Taiwan
3. Department of Surgery, Chung Shan Medical University Hospital, Taichung 402, Taiwan
4. Department of Ophthalmology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807, Taiwan