1. Department of Ophthalmology, Tung Wah Eastern Hospital, Hong Kong, China
2. Department of Ophthalmology and Visual Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
3. Department of Ophthalmology, Salmaniya Medical Complex, Government Hospitals, Manama 323, Bahrain
4. Department of Ophthalmology and Visual Sciences, Prince of Wales Hospital, Hong Kong, China
5. Hong Kong Eye Hospital, 147K Argyle Street, Kowloon, Hong Kong, China