A clinically oriented approach to secondary saccades

Abstract

Secondary saccades bring the fovea on the target missed by primary saccades. The authors studied secondary saccades in the responses recorded from 76 healthy subjects during a normal refixation paradigm, focusing their attention on their latency (L2). L2 proved to be negatively related to target amplitude and positively to precision and latency of the corresponding primary saccade; the authors were not able to find any linear relationship with subject's age. On the basis of these relationships, they determined a three-class L2 distribution: decreased, normal and increased L2. A subject can be reliably evaluated comparing (chi-square test) his own frequency of L2 values belonging to each class with the frequencies observed in the controls; if a difference exists, the Kimball test enables the identification of the class from which this difference possibly arises.

Key Words:

• secondary saccades
• latency
• clinical application