A discovery that could rethink the diagnostic process.
At the beginning of omissions then more serious memory losses, from distraction trends … Alzheimer’s disease gradually affects all cognitive functions. If most of the diagnoses are established around 65, research is working to detect the illness earlier and earlier to better combat its evolution. English researchers have found that testing people’s sight as aging could help the early diagnosis of this incurable disease.
They carried out their research on more than 8,000 subjects aged 48 to 92. The latter have passed different cognitive tests including the VST to assess the visual processing speed, HVLT, a verbal memory test, and SF-EMSE for a global assessment of cognitive functions. For the VST visual test, participants had to press a computer key as soon as they detect a triangle on the screen (Simple VST). The second version of the test involved clicking on a triangle (pointing up or down) made up of points in constant moving, anywhere and randomly in the visual field (VST complex). The reaction time has been recorded each time.
The results of the study shared in the journal “Neurology” show that a slowdown in visual treatment (ability to see the triangle more or less quickly) was associated with “A strong probability” dementia in the future. The average time between the date of the cognitive test and the date of the diagnosis was 9.6 years, with a median of 9.8 years or almost 10 years. “Visual disorders can be an early indicator of cognitive decline because toxic amyloid plates associated with Alzheimer’s disease can first affect the brain areas associated with vision, while the brain areas associated with memory are damaged as the disease progressesexplain the authors in The Conversation. Vision tests can therefore detect deficits before memory tests. “
Other aspects of vision are affected by Alzheimer’s disease. For example, the ability to perceive the contours of objects, or to distinguish faces but also certain colors such as blue and green. Patients also seem to have trouble ignoring visual distractions, which can manifest itself by eye movements control disorders. Even if conventional cognitive tests remain very good predictors of Alzheimer’s disease, scientists hope that in the long term, the visual test can be used as a diagnostic supplement.