Topography of the age-related decline in motion sensitivity.

PURPOSE

We examined whether the decline in motion sensitivity in the elderly is equivalent for different visual field locations.

METHODS

High velocity (28 degrees/s) random dot kinematograms (RDK's) were used to measure direction discrimination thresholds for 5 locations in the visual field (1 position centered on fixation and 4 locations each centered 18 degrees from fixation in the nasal, temporal, superior, and inferior quadrants). Differential luminance sensitivity was assessed by automated perimetry. Younger (N = 15, mean age = 22.9 +/- 1.3 years) and older (N = 13, mean age = 66.6 +/- 4.5 years) subjects were studied.

RESULTS

Motion sensitivity varied with test location for both younger and older subjects, but sensitivity was significantly lower in older individuals. The largest age-related reduction in sensitivity was in the central location, whereas the smallest decline was in the superior position. No significant correlations between motion and differential luminance sensitivity were evident.

CONCLUSIONS

There is a significant age-related deterioration in visual sensitivity to motion which is more pronounced in the central visual field than in some regions of the more peripheral field. Although both motion and differential luminance sensitivity decrease with age, the rate and the magnitude of the loss differ for these two visual functions.