CHANGES IN VISUAL FIXATION AND SACCADIC EYE-MOVEMENTS IN ALZHEIMERS-DISEASE

Visual fixation and saccadic eye movements were assessed in 31 mild to moderately demented patients with probable Alzheimer's disease (AD) a nd 31 age- and education-matched nondemented elderly control subjects. Seventeen AD and 17 matched control subjects were reassessed after a 9-month interval. On a fixation task, duration of fixation and number of intrusive saccades were not different between groups at baseline or follow-up. Both AD patients and control subjects showed more intrusiv e saccades at follow-up than at baseline. AD patients showed increased latency to initiation of saccades at baseline and on follow-up. Ampli tude and velocity of saccades were not different between groups at any visit. Changes in measures of fixation, but no saccade measure, corre lated with changes in MMSE scores over testing sessions. These data su ggest that fixation is more sensitive than are saccades to the progres sion of AD.