1. From the Singapore National Eye Centre, Singapore; 2Singapore Eye Research Institute, Singapore; 3Zhongshan Ophthalmic Centre, Guangzhou, China;
2. From the Singapore National Eye Centre, Singapore; 2Singapore Eye Research Institute, Singapore; 3Zhongshan Ophthalmic Centre, Guangzhou, China;4Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; and