[1] Sun Yat Sen Univ, Sch Publ Hlth, Guangzhou, Peoples R China
[2] Hebei Med Univ, Hosp 2, Dept Gen Practice, Shijiazhuang, Peoples R China
[3] Univ Edinburgh, Usher Inst, Deanery Mol Genet & Populat Hlth Sci, Edinburgh, Scotland
[4] Sun Yat Sen Univ, Zhongshan Ophthalm Ctr, State Key Lab Ophthalmol, Guangzhou, Peoples R China
[5] Chinese Univ Hong Kong, Fac Med, JC Sch Publ Hlth & Primary Care, Hong Kong, Peoples R China
[6] Hong Kong Med Journal, Hong Kong, Peoples R China