Changes in colour perception in Alzheimer's disease continuum

Abstract

Aims/Purpose: The progression of Alzheimer's disease (AD) manifests from a preclinical stage, characterized by asymptomatic pathological alterations, to an advanced stage of AD accompanied by cognitive impairment. The aim of this study was to explore visual function along the entire AD continuum, from individuals with a high genetic predisposition to those in the moderate phase of the disease.Methods: All participants underwent a visual examination and had to be visually healthy to be included. The study contained five groups: controls (n = 53), individuals with a positive family history of AD (HF+) (n = 13), mild cognitive impairment (MCI) (n = 23), mild AD (n = 25) and moderate AD (n = 21). The study analysed the results of errors in colour perception.Results: A significant increase in the total number of errors was observed between the control group and the moderate AD group. And also when comparing the FH+ group with the MCI group, the mild AD group and the moderate AD group. Significant differences were found on the tritan axis between the control group and the mild AD group, as well as in the moderate AD group. Significant differences were observed between the FH+ group and the mild AD group, as well as in the moderate AD group. A significant increase in the number of errors on the deutan axis was observed between the control group and both the mild and moderate AD groups. In addition, a statistically significant increase was observed when comparing the FH+ group with the moderate AD group. The test correlated with the MMSE score and also showed good predictive value when memory impairment was present.Conclusions: Understanding the importance of changes in colour perception in AD continuum can aid in the early detection and treatment of AD, potentially improving patient outcomes and facilitating targeted interventions.