Impaired vision can be one of the earliest signs of cognitive decline, and loss of visual sensitivity can indicate impending dementia years in advance.
In a recent study, a British research team from Loughborough University examined whether visual processing speed is suitable for predicting the risk of later dementia. The study results were published in the specialist magazine “Scientific Reports”.
Connection between dementia and vision problems
In recent years, there has been increasing evidence of a possible connection between impaired vision and dementia. For example, a recent study came to the conclusion that certain visual symptoms can be an early warning sign of Alzheimer's.
In addition, when examining people with dementia, deficits in visual processing were often found, report the experts at Loughborough University. This suggests a potential benefit of measures of visual processing to support dementia screening.
Visual processing speed examined
In the study, the researchers used data from 8,623 participants in the EPIC-Norfolk Prospective Population Cohort Study to investigate what role visual processing speed can play in identifying the risk of later dementia.
The visual processing speed was determined at the beginning of the study using the so-called Visual Sensitivity Test (VST). For the test, participants had to press a button as soon as they saw on a screen that a triangle was forming in a field of moving dots, the team explains.
The researchers compared the test results with the probability of developing dementia over the course of the study period, with 537 participants suffering from dementia at the end of the study.
Connection with the risk of dementia
The data analysis showed that people with lower visual processing speed scores were significantly more likely to be diagnosed with dementia in the future, the team reports.
“Our latest study shows that loss of visual sensitivity can predict dementia as early as 12 years before diagnosis,” the researchers said in a press release about the study results.
Improved dementia screening
Overall, a reduced complex visual processing speed is significantly associated with a high probability of a future dementia diagnosis and the combination of visual processing tests with other neuropsychological tests could significantly improve the possibilities for early detection of dementia, the researchers conclude. (fp)
