Thinning of retinal nerve fiber layers (RNFLs) is associated with declining cognitive function in persons without neurodegenerative diseases, according to research published in JAMA Neurology.
A team of investigators from the United Kingdom conducted a community-based group observation analysis to assess the possibility of using RNFL thickness to determine cognition trends in healthy individuals.
Participants underwent physical examination and retinal optical coherence tomography imaging at the start of the study. They also completed a questionnaire that captured demographic, environmental, and personal information.
Four cognitive tests were conducted at start and completion of the study. The primary outcome was cognitive performance in the lowest fifth percentile for at least half of the cognitive tests or worsening results at follow-up for 1 or more tests.
A total of 32,038 participants were included in the study (average age, 56; 53.6% women). Worsening cognitive function was correlated with a thinner RNFL; individuals with the thinnest RNFL in the lowest fifth percentile were 11% more likely to fail a cognitive test. Follow-up test results for 1251 individuals suggest that those in the 2 groups with the thinnest RNFLs were nearly twice as susceptible to worse cognitive testing results at follow-up.
“A thinner RNFL is associated with worse cognitive function in individuals without neurodegenerative disease as well as greater likelihood of future cognitive decline,” the authors reported. “This preclinical observation has implications for future research, prevention, and treatment of dementia.”
Ko F, Muthy ZA, Gallacher J, et al; for the UK Biobank Eye & Vision Consortium. Association of retinal nerve fiber layer thinning with current and future cognitive decline: a study using optical coherence tomography [published online June 25, 2018]. JAMA Neurol. doi:10.1001/jamaneurol.2018.1578