Overview of Alzheimer’s
The need for early detection
Using eye-tracking for early diagnosis of Alzheimer’s
Last year, researchers from Loughborough University found that patients with mild cognitive impairment (MCI) related to memory loss are more likely to develop Alzheimer’s disease. They achieved this by studying how people with Alzheimer’s, amnesic MCI, non-amnesic MCI, and healthy controls performed on anti-saccade tasks. Anti-saccades are a form of oculomotor testing that allows researchers to assess whether someone has a frontal lobe dysfunction. They found that patients who had amnesic MCI had the highest error rates, which were most similar to patients with Alzheimer’s. Their findings were consistent with previous studies which showed that erroneous saccades and increased latency are useful biomarkers for Alzheimer’s disease.
Other studies demonstrated that patients with Alzheimer’s have longer fixation periods compared to healthy controls in visual search tasks and experience difficulty in switching attention and processing stimuli in their field of vision. As a result, this makes it difficult for patients to detect peripheral stimuli in visual search tasks. This can cause patients to overlook important information in their vision.
To elucidate these findings, scientists from the University of College London analyzed the relationship between oculomotor tests and standard cognitive tests in younger individuals with early symptoms of Alzheimer’s. Their results confirmed that eye-tracking metrics are a powerful marker in determining visual cognitive decline. Furthermore, fixation, pro-saccade and smooth pursuit tests were important markers to detect Alzheimer’s.
Overall, eye movement analysis in Alzheimer’s disease is a promising road for early diagnosis. By identifying biomarkers for Alzheimer’s, scientists could establish protocols that will help clinicians to not only detect the disease, but also monitor it’s progression. In addition, oculomotor exercises could be used to target and improve cognitive domains that are affected by Alzheimer’s. Lastly, eye-tracking technology has become widely available, and its simplicity in collecting quality data makes it the best candidate for a non-invasive, inexpensive, early diagnostic tool for Alzheimer’s.