1. Medical Education Department, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung City 83301, Taiwan
2. Department of Ophthalmology, Kaohsiung Chang Gung Memorial Hospital, College of Medicine, Chang Gung University, Kaohsiung City 83301, Taiwan
3. School of Medicine, College of Medicine, National Sun Yat-sen University, Kaohsiung City 80424, Taiwan
4. School of Medicine, Chang Gung University, Taoyuan City 33302, Taiwan