[1] Johns Hopkins Univ Sch Med, Wilmer Eye Inst, 600 North Wolfe St, Baltimore, MD 21287 USA
[2] Johns Hopkins Univ Sch Med, Dana Ctr Prevent Ophthalmol, Baltimore, MD USA
[3] Illinois Coll Optometry, Chicago, IL USA
[4] Massachusetts Eye & Ear Infirm, Harvard Med Sch, Boston, MA USA
[5] Johns Hopkins Univ, Berman Inst Bioeth, Baltimore, MD USA