[1] Univ Hong Kong, LKS Fac Med, Dept Ophthalmol, Room 301,Block B,Cyberport 4, Hong Kong, Peoples R China
[2] Univ Hong Kong, LKS Fac Med, Dept Microbiol, Hong Kong, Peoples R China
[3] Chinese Univ Hong Kong, Dept Ophthalmol & Visual Sci, Hong Kong, Peoples R China
[4] Univ Hong Kong, LKS Fac Med, Sch Publ Hlth, Hong Kong, Peoples R China