[1] Univ Texas Med Branch, Sch Hlth Profess, Div Rehabil Sci, 301 Univ Blvd, Galveston, TX 77555 USA
[2] Univ Texas Med Branch, Sealy Ctr Aging, 301 Univ Blvd, Galveston, TX 77555 USA
[3] Univ Michigan, Dept Ophthalmol & Visual Sci, Kellogg Eye Ctr, 100 Wall St, Ann Arbor, MI 48105 USA
[4] Univ Texas Med Branch, Sch Med, Dept Family Med, 301 Univ Blvd, Galveston, TX 77555 USA
[5] Univ Texas Med Branch, Sch Med, Dept Neurol, 301 Univ Blvd, Galveston, TX 77555 USA