FRIDAY 20 May 2022 (HealthDay News) – Poor visibility makes it harder to read and easier to travel. But it can also lead to a misdiagnosis of mild mental retardation in older people, according to a new, small study.
That can happen when someone’s thinking abilities are assessed using vision-dependent tests, researchers explained.
They noted that as many as 1 in 4 people over the age of 50 have undiagnosed vision problems such as cataracts or age-related macular degeneration (AMD), which can skew visual assessments of their mental acuity.
AMD does not cause complete vision loss, but does affect the ability to read, drive, cook, and even recognize faces. It has no effect on mental function (cognition).
Visual limitations affect over 200 million seniors worldwide, said study leader Anne Macnamara, a Ph.D. candidate at the University of South Australia.
“An incorrect score in cognitive tests can have devastating consequences, leading to unnecessary changes in a person’s living, working, financial or social circumstances,” Macnamara warned in a university news report.
For example, if a wrong score contributes to a diagnosis of mild cognitive impairment, it can trigger psychological problems, including depression and anxiety, Macnamara explained.
This study included 24 participants with normal vision who were asked to complete two cognitive tests, one dependent on vision and one dependent on verbal skills. They did the tests with and without glasses to simulate AMD.
While wearing the glasses, participants had much lower scores on the vision-dependent test, but no significant change in scores on the verbal proficiency test, according to the study. The results were recently published in the journal Scientific reports,
“People with AMD are already experiencing multiple problems due to vision loss, and an incorrect cognitive assessment is an additional burden they do not need,” Macnamara noted.
The authors of the study added that vision problems are often overlooked by health care providers and researchers.
“Researchers can take on quick and easy screening tasks before people do cognitive tests. Verbal tasks should also always be part of the assessment,” Macnamara said.
The US National Eye Institute has more on poor vision.
SOURCE: University of South Australia, news release, 9 May 2022