Scientists from the University of South Australia found millions of older people with poor vision are at risk of being misdiagnosed with mild cognitive impairments.
They found cognitive tests that rely on vision-dependent tasks could be skewing results in up to a quarter of people aged over 50 who have undiagnosed visual problems such as cataracts or age-related macular degeneration (AMD).
The research is published in Scientific Reports and was conducted by Anne Macnamara et al.
Age-related macular degeneration is a leading cause of vision loss for older people.
It doesn’t cause complete vision loss, but severely impacts people’s ability to read, drive, cook, and even recognize faces. It has no bearing on cognition.
In the study, the researchers recruited 24 participants with normal vision to complete two cognitive tests—one involving vision-dependent reactive tasks and the other based on verbal fluency.
Using a set of goggles to simulate AMD, the participants scored far lower on the cognitive test involving reaction time tasks than without the goggles.
There was no big difference with verbal fluency tests when using the goggles.
The team says the results are a stark reminder that visual impairments—which affect approximately 200 million people worldwide over the age of 50—unfairly affect cognitive scores when tests involve visual abilities.
A mistaken score in cognitive tests could have devastating ramifications, leading to unnecessary changes to a person’s living, working, financial or social circumstances.
People with AMD are already experiencing multiple issues due to vision loss and an inaccurate cognitive assessment is an additional burden they don’t need.
Visual impairments are often overlooked in research and clinical settings, with reduced vision underestimated in up to 50 percent of older adults.
The team says with this figure expected to increase in line with an aging population, it is critical that neuro-degenerative researchers control for vision when assessing people’s cognition.
If you care about eye health, please read studies about diet linked to blinding eye diseases in older people, and vitamin B3 that could help treat common blinding eye disease.
For more information about health, please see recent studies that pure cocoa may improve your eye sight in daylight.
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