Poor eyesight unfairly mistaken for brain decline

Date:
May 9, 2022
Source:
University of South Australia
Summary:
Millions of older people with poor vision are at risk of being
misdiagnosed with mild brain decline due to cognitive tests that
rely on vision-dependent tasks.



FULL STORY ========================================================================== Millions of older people with poor vision are at risk of being
misdiagnosed with mild cognitive impairments, according to a new study
by the University of South Australia.


========================================================================== 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).

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 recognise faces. It has
no bearing on cognition.

UniSA 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 statistical difference with verbal fluency tests when using
the goggles.

The study has been published in Scientific Reports.

UniSA PhD candidate Anne Macnamara, who led the study, 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," Macnamara says.

"For example, if a mistaken score contributed to a diagnosis of mild
cognitive impairment, it could trigger psychological problems including depression and anxiety.

"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, the UniSA researchers say, with reduced vision underestimated in up to 50 per cent of older adults.

And with this figure expected to increase in line with an ageing
population, it is critical that neuro-degenerative researchers control
for vision when assessing people's cognition.

"Mobile apps can now be used to overlay simulated visual impairments
onto test materials when piloting their stimuli," Macnamara says.

"Also, researchers can incorporate quick and simple screening tasks
before getting people to do cognitive tests. Verbal tasks should always
be part of the assessment, too."

========================================================================== Story Source: Materials provided by University_of_South_Australia. Note: Content may be edited for style and length.


========================================================================== Journal Reference:
1. Anne Macnamara, Victor R. Schinazi, Celia Chen, Scott Coussens,
Tobias
Loetscher. The effect of age-related macular degeneration on
cognitive test performance. Scientific Reports, 2022; 12 (1) DOI:
10.1038/s41598- 022-07924-8 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2022/05/220509204939.htm

--- up 10 weeks, 10 hours, 50 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)