[1] Natl Univ Singapore, Dept Ophthalmol, Singapore 119260, Singapore
[2] Natl Univ Singapore, Singapore Natl Eye Ctr, Singapore 119260, Singapore
[3] Univ Wisconsin, Dept Ophthalmol, Madison, WI USA
[4] Johns Hopkins Univ, Sch Publ Hlth, Dept Epidemiol, Baltimore, MD 21205 USA
[5] NHLBI, Bethesda, MD 20892 USA
[6] Univ N Carolina, Chapel Hill, NC USA
[7] Penn State Univ, Coll Med, Dept Hlth Evaluat Sci, Hershey, PA USA
[8] Univ Mississippi, Med Ctr, Dept Med, Jackson, MS 39216 USA