Analysis of Gaze Shift in Depth in Alzheimer's Disease Patients

Kenya UOMORI  Shinji MURAKAMI  Mitsuho YAMADA  Mitsuru FUJII  Hiroshi YOSHIMATSU  Norihito NAKANO  Hitoshi HONGO  Jiro MIYAZAWA  Keiichi UENO  Ryo FUKATSU  Naohiko TAKAHATA  

IEICE TRANSACTIONS on Information and Systems   Vol.E76-D   No.8   pp.963-973
Publication Date: 1993/08/25
Online ISSN: 
Print ISSN: 0916-8532
Type of Manuscript: PAPER
Category: Medical Electronics and Medical Information
Alzheimer's disease,  depth perception,  convergent eye movement,  conjugate eye movement,  saccade,  

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To clarify the stereopsis disturbance in patients with Alzheimer's disease (AD), we analyzed binocular eye movement when subjects shifted their gaze between targets at different depths. Subjects are patients with Alzheimer's disease, Mluti-infarct dementia (MID), or Olivopontocerebellar atrophy (OPCA), and healthy controls. Targets are arranged in two ways: along the median plane and asymmetrically crossing the median plane, at distances from the eyes of 1000 mm and 300 mm. When the targets are switched at the onset of a beep, the subjects shifted their gaze to the lit target. The experiment is conducted in a dimly lit room whose structure is capable of providing good binocular cues for depth. In AD subjects, especially in the subjects whose symptoms are moderate (advanced stage), vergence is limited and the change in the convergence angle is small, unstable, and non-uniform. These results are different from those of other patients (MID) and OPCA) or healthy controls and suggest a disturbance of stereopsis in the parietal lobe where AD patients typically have dysfunctions.