Visual Function is a Stronger Predictor of Mobility Performance for Women than for Men

Abstract

Abstract: : Purpose: Last year at ARVO, we reported a gender difference in a population of older adults with regard to the travel time and number of orientation errors while navigating a mobility course. Some studies with younger subjects have suggested that women use a landmark strategy to navigate and men, an orientation strategy (Moffat et al., Evol Hum Behav, 1998, 19:73-87; Sandstrom et al., Cogn Brain Res, 1998, 6:351-360). A differential weighting of sensory and/or cognitive information for the purpose of navigation would underlie a difference in strategy and account for the performance difference. In this study we determine whether visual function has a gender-specific effect on mobility performance. Methods: A population-based sample of 1505 persons between the ages of 72 – 92 was enrolled in the third round of SEE. Visual function was assessed with a battery of tests including (static) visual acuity, dynamic visual acuity, contrast sensitivity, and visual fields. Travel time and number of orientation errors were measured as subjects navigated a circuitous, 32.8-m course seeded with obstacles. Linear regressions by gender were performed, adjusting for age and cognition. Results: Age and cognition accounted for 20% of the variance in travel time for both the women and men. For the women, dynamic visual acuity, log contrast sensitivity, and visual fields were significant predictors of travel time. The vision measures accounted for an additional 7% of the variance. Conversely, none of the visual function measures reached significance for the men, and the vision measures accounted for less than a half percent of the variance in travel time. These findings were corroborated by a multivariate regression analysis that revealed significant gender by visual function interactions (F=5.74, p <.0001). Visual function did not predict the number of orientation errors for women or men. Conclusions: Vision function is a stronger predictor of mobility performance for women than for men. This might be an important consideration for orientation and mobility training.

Keywords: aging: visual performance • vision and action • clinical (human) or epidemiologic studies: ris