Assessment of the visual acuity, contrast sensitivity, color vision and visual integration in the Alzheimer's Disease progression according to the scale GDS

Abstract

PurposeAlzheimer's disease (AD) is characterized by an accumulation of abnormal plaques and tangles in the brain with cortical atrophy most pronounced in the medial temporal and posterior temporoparietal regions. The process is estimated to begin years before the appearance of clinical symptoms. The aim of this work was to investigate the potential use of ophthalmological psychophysical tests as AD follow‐up.MethodsTwenty‐six mild AD patients, 12 moderate AD and 32 controls underwent visual acuity (VA), contrast sensitivity (CS), colour perception tests and perception visual test (PDT). All patients were classified according the Global Deteriorate Scale (GDS).ResultsIn comparison with control: i) patients with mild AD presented a significant decrease in the VA, in the CS (for all the spatial frequencies), in the blue colour perception and in PDT; ii) patients with moderate AD showed the same result as the mild AD, compared with controls, furthermore a significant increase of the total number of errors in the colour test (p < 0.05 in all instances). In comparison with mild AD, moderate AD patients had no statistical differences in CS, VA and PDT (p > 0.05) but significant differences in the colour perception (total number of errors and unspecific blue axis errors) (p < 0.05).ConclusionsIn comparison with the control group, patients with mild and moderate AD presented a statistically significant decrease in CS, for all the spatial frequencies (the higher the spatial frequency, the greater the loss of CS perception), and in the colour perception. Therefore AD patients, show alterations in the M, P, and K visual pathways. Psychophysical tests could be useful tools to diagnose support and follow‐up in mild AD.