1. Department of Ophthalmology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807, Taiwan
2. School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
3. Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University Irving Medical Center, New York, NY 10032, USA