Affiliations: [a] Bobby R. Alford Department of Otorhinolaryngology and Communicative Sciences, Baylor College of Medicine, Houston, TX, USA | [b] Life Sciences Research Laboratories, NASA Johnsn Space Center, Houston, TX, USA | [c] Wyle Life Sciences, Houston, TX, USA
Note: [*] Reprint address: Jacob J. Bloomberg, PhD, NASA Johnson Space Center, Mail Code: SD3, Houston, TX 77058. Tel.: +281 483 0436; Fax: +281 244 5734; E-mail: jbloombe@ems.jsc.nasa.gov
Abstract: We describe a new, objective, easily administered test of dynamic visual acuity (DVA) while walking. Ten normal subjects and five patients with histories of severe bilateral vestibular dysfunction participated in this study. Subjects viewed a visual display of numerals of different font sizes presented on a laptop computer while they stood still and while they walked on a motorized treadmill. Treadmill speed was adapted for 4 of 5 patients. Subjects were asked to identify the numerals as they appeared on the computer screen. Test results were reasonably repeatable in normals. The percent correct responses at each font size dropped slightly while walking in normals and dropped significantly more in patients. Patients performed significantly worse than normals while standing still and while walking. This task may be useful for evaluating post-flight astronauts and vestibularly impaired patients.
