Visual impairment confused with brain deterioration

Visual impairment confused with brain deterioration

Credit: Unsplash/CC0 Public Domain

A new study by the University of South Australia has revealed that millions of older adults with low vision are at risk of being misdiagnosed with mild cognitive impairments.

Cognitive tests that rely on vision-based tasks may skew results in up to a quarter of people over 50 who have undiagnosed vision problems such as cataracts or age-related macular degeneration (AMD).

Age-related macular degeneration is a leading cause of vision loss in the elderly. It does not cause complete vision loss, but it severely affects people’s ability to read, drive, cook and even recognize faces. It has no effect on cognition.

UniSA researchers recruited 24 participants with normal vision to complete two cognitive tests – one involving vision-based interactive tasks and the other based on verbal fluency.

Using a set of glasses to simulate AMD, participants scored significantly lower on a cognitive test that includes reaction time tasks compared to without the goggles. There was no statistical difference with verbal fluency tests when protective eyewear was used.

The study was published in Scientific Reports.

UniSA Ph.D. Candidate Anne McNamara, who led the study, says the results are a stark reminder that visual impairments – which affect nearly 200 million people worldwide over the age of 50 – unfairly affect cognitive scores when tests involve visual abilities.

“A false result on cognitive tests can have devastating repercussions, leading to unnecessary changes in a person’s living, working, financial, or social conditions,” says McNamara.

For example, if a false result contributes to a diagnosis of mild cognitive impairment, it may lead to psychological problems including depression and anxiety.

“People with AMD already have multiple problems due to vision loss and inaccurate cognitive assessment presenting an additional burden that they don’t need.”

UniSA researchers say that visual impairments are often overlooked in research and clinical settings, with reduced vision in up to 50 percent of older adults.

With this number expected to increase in line with an aging population, it is critical that neurodegenerative researchers control vision when assessing people’s cognition.

“Mobile apps can now be used to overlay simulated visual impairments on test subjects when experiencing their stimuli,” says McNamara.

“Also, researchers can incorporate quick and simple screening tasks before having people take cognitive tests. Verbal tasks should always be part of the assessment as well.”

Hearing and vision impairment associated with serious cognitive impairment in the elderly

more information:
Ann McNamara et al, The effect of age-related macular degeneration on cognitive test performance, Scientific Reports (2022). DOI: 10.1038 / s41598-022-07924-8

Offered by the University of South Australia

the quote: Unfairly impaired vision due to brain deterioration (2022, May 10) Retrieved May 10, 2022 from

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2022-05-10 07:39:49

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