There are abnormalities in eye movements in individuals with Alzheimer's disease, which are related to oculomotor frontal-subcortical circuit dysfunctions.

The aim of the study is to compare the parameters of saccadic eye movements in individuals with Alzheimer's disease with those in older adults without dementia.

31 individuals with mild and intermediate Alzheimer's dementia (MMSE > 13) (26 women, mean age 76.8 ± 6.41 and 5 men, mean age 79.1 ± 5.21) and 30 individuals without symptoms of dementia (matched for age) were examined.

The parameters of saccadic eye movements were measured with the use of Saccadometer Advanced. Two experiments were performed: Latency Trials (LAT) and Reflexive with Gap (RXG). Saccadic latency [ms], the reaction time [ms] and the number of executed saccades were measured.

Results:

LAT:

Statistically significant differences in the number of saccades (α = 0.05, p = 0.000024) and in average latency [ms] (α = 0.05, p = 0.039) between the individuals with AD and the healthy ones were found.

RXG:

Statistically significant differences were found in all the variables tested: number of executed saccades (α = 0.05, p = 0.0265), average latency [ms] (α = 0.05, p = 0.043) and average duration [ms] (α = 0.05, p = 0.000035) between persons from the control group and those from the experimental group.

It was found that the level of oculomotor efficiency in mild and intermediate Alzheimer's disease is significantly lower in relation to older people without dementia.