Vertical saccades in senescence.

PURPOSE

To determine the metrics of vertical saccades in elderly subjects for comparison in neurologic disease.

METHODS

Sixteen elderly subjects, ten middle-aged subjects, and thirteen young subjects were examined using a magnetic search coil technique. Saccades were measured to predictable vertical target steps and maximal saccadic excursion was measured from primary position.

RESULTS

Maximal upward voluntary excursion was reduced in the elderly (mean 32.9 degrees) compared to young subjects (mean 43.1 degrees). Maximal downward voluntary excursion was also reduced in the elderly (mean 32.8 degrees), compared to young subjects (mean 46.8 degrees). The limited ocular motor range of the elderly was not increased by oculocephalic maneuvers. Individual young subjects had significantly larger downward than upward excursions, but elderly subjects generally had symmetrical upward and downward excursions. Asymptotic peak velocities were not significantly slower in the elderly. Individual young subjects made faster upward than downward saccades. Vertical saccade latencies were significantly prolonged and saccadic accuracy was reduced in the elderly compared to the young subjects.

CONCLUSIONS

The range and accuracy of upward and downward saccades decrease, and their latency increases in senescence. This quantitative study provides norms for the detection of brain or orbital disease in young, middle-aged, and elderly subjects.