Effect of aging on horizontal smooth pursuit.

Quantitative infrared oculographic study of horizontal pursuit in young and elderly normal subjects showed significantly lower smooth pursuit velocities in the elderly when tracking triangular waveform targets of 20 degrees amplitude at velocities of 10 degrees/sec and over. Latencies for initiation of smooth eye movements were significantly prolonged in older subjects. The reduced velocity responses of the pursuit system indicate that the diagnosis of abnormal pursuit must be qualified by the age of the patient. Smooth pursuit is an age-dependent motor system.