Compensatory Saccades Are Associated with Physical Performance in Older Adults: Data from the Baltimore Longitudinal Study of Aging

Objective: To determine whether compensatory saccade metrics observed in the video head impulse test, specifically saccade amplitude and latency, predict physical performance. Study Design: Cross-sectional analysis of the Baltimore Longitudinal Study of Aging, a prospective cohort study. Setting: National Institute on Aging Intramural Research Program Clinical Research Unit in Baltimore, Maryland. Patients: Community-dwelling older adults. Intervention(s): Video head impulse testing was performed, and compensatory saccades and horizontal vestibulo-ocular reflex (VOR) gain were measured. Physical performance was assessed using the Short Physical Performance Battery (SPPB), which included the feet side-by-side, semitandem, tandem, and single-leg stance; repeated chair stands; and usual gait speed measurements. Main Outcome Measure(s): Compensatory saccade amplitude and latency, VOR gain, and SPPB performance. Results: In 183 participants who underwent vestibular and SPPB testing (mean age 71.8 yr; 53% females), both higher mean saccade amplitude (odds ratio [OR] =1.62, p = 0.010) and shorter mean saccade latency (OR = 0.88, p = 0.004) were associated with a higher odds of failing the tandem stand task. In contrast, VOR gain was not associated with any physical performance measure. Conclusion: We observed in a cohort of healthy older adults that compensatory saccade amplitude and latency were associated with tandem stance performance. Compensatory saccade metrics may provide insights into capturing the impact of vestibular loss on physical function in older adults.