1. From the State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, People's Republic of China;
2. the Department of Optometry and Vision Science, Faculty of Science, The University of Auckland, Auckland, New Zealand;
3. the School of Optometry, and the 4The Hong Kong Jockey Club Sports Medicine and Health Sciences Centre, Faculty of Health and Social Sciences, The Hong Kong Polytechnic University, Hong Kong SAR, China; and
4. the Department of Ophthalmology, McGill University, Montreal, Quebec, Canada.
5. the School of Optometry, and