K Z Li1, C S Tan2,3. 1. National Healthcare Group Eye Institute, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore, 308433, Singapore. 2. National Healthcare Group Eye Institute, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore, 308433, Singapore. Colintan_eye@yahoo.com.sg. 3. Fundus Imaging Reading Center, National Healthcare Group Eye Institute, Singapore, Singapore. Colintan_eye@yahoo.com.sg.