1. Division of Gastroenterology, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, 325, Sec 2, Cheng-Kung Road, Taipei Neihu 114, Taiwan
2. Department of Ophthalmology, China Medical University Hospital, School of Medicine, College of Medicine, China Medical University, Taichung City 404, Taiwan
3. Department of Medical Research, Tri-Service General Hospital, Taipei 114, Taiwan
4. School of Public Health, National Defense Medical Center, Taipei 114, Taiwan