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Decrease in visual chromatic sensitivity as a potential biomarker for early detection of mild cognitive impairment – a pilot study
Author(s)
Date Issued
2023
Conference
Citation
Choi, K. Y., Lam, Y. H., & Chan, H. L. (2023 Nov 18). Decrease in visual chromatic sensitivity as a potential biomarker for early detection of mild cognitive impairment – a pilot study. 30th Annual Congress of Gerontology, The Hong Kong Polytechnic University.
Type
Conference Paper
Abstract
Purpose
Vision is essential to maintain daily activities and quality of life for the elderlies. Studies have suggested
that elderlies with cognitive impairment would also face visual challenges. In particular, colour vision
requires an intact visual pathway, starting from the retina to the brain, and a good brain function for
colour information processing. In this pilot study, we conducted comprehensive eye examinations for
elderlies of different cognitive capabilities, and revealed the possibility of utilizing chromatic sensitivity
as a biomarker for the early detection of mild cognitive impairment (MCI).
Method
Sixty elderlies were recruited, and 56 completed all the measurements (aged 73.5 ± 8.2, range 60 – 91
years old, 44 female & 12 male). Eye examination included, but not limited to, visual acuity (VA),
external and internal ocular health assessments. Additionally, contrast sensitivity (CS) and colour vision
(CV) were also evaluated. To assess the cognitive function of the elderlies, the Cantonese version of
the Mini-Mental State Examination (MMSE) was conducted.
Results
Of the participants, 42.9% had MCI based on the MMSE (cutoff score 24/25), having a mean score of
24.52 ± 4.73 out of 30. The VA and CS were significantly better in normal than MCI participants (p
<0.05). Interestingly, MCI participants were subjectively more aware of a reduced vision (p <0.05).
Despite the statistical insignificance, MCI participants had a consistently higher rate of having problems
on ocular health issues, e.g., cataract and macular degeneration. In particular, the MMSE score was
positively correlated with the CV, even after controlling for covariates, indicating that CV is an
independent factor in relation to cognitive function.
Conclusion
MCI is difficult to detect when the symptoms are mild. On the other hand, patients are more aware of
a reduced vision, which may be indicative of an impaired cognitive ability. Changes of colour vision
may be a potential sign for the early detection of MCI for elderlies. Regular eye examination is
recommended to the public to early reveal visual and cognitive impairments.
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