3 National Centre for Infectious Diseases, Singapore; Tan Tock Seng Hospital, Singapore; Lee Kong Chian School of Medicine, Singapore.
4 National Centre for Infectious Diseases, Singapore; Tan Tock Seng Hospital, Singapore; Lee Kong Chian School of Medicine, Singapore; Yong Loo Lin School of Medicine, Singapore.
5 Duke-NUS Medical School, Singapore; Tan Tock Seng Hospital, Singapore; Lee Kong Chian School of Medicine, Singapore; Yong Loo Lin School of Medicine, Singapore; Moorfields Eye Hospital, NHS Foundation Trust, London, UK. Electronic address: [email protected].