[1] Johns Hopkins Univ, Sch Med, Wilmer Eye Inst, Dana Ctr Prevent Ophthalmol, Baltimore, MD 21205 USA
[2] Johns Hopkins Bloomberg Sch Publ Hlth, Dept Epidemiol, Baltimore, MD USA
[3] Johns Hopkins Bloomberg Sch Publ Hlth, Dept Int Hlth, Baltimore, MD USA
[4] Univ Penn, Dept Ophthalmol, Perelman Sch Med, Philadelphia, PA 19104 USA
[5] Univ Penn, Dept Biostat & Epidemiol, Perelman Sch Med, Philadelphia, PA 19104 USA
[6] Univ Penn, Ctr Clin Epidemiol & Biostat, Perelman Sch Med, Philadelphia, PA 19104 USA
[7] Univ Wisconsin, Dept Ophthalmol & Visual Sci, Fundus Photograph Reading Ctr, Madison, WI USA
[8] UCL Inst Ophthalmol, London, England
[9] Hammersmith Hosp, London, England
[10] Royal Surrey Cty Hosp UK, Surrey, England