Thinner RNFL may predict cognitive decline
A thinner retinal nerve fiber layer may predict cognitive decline, according to a study on a large cohort of healthy individuals.
Previous studies using OCT imaging demonstrated a correlation between thinner retinal nerve fiber layer (RNFL) and cognitive impairment. This study, using data from the U.K. Biobank, a community-based cohort of 502,656 U.K. residents 40 to 69 years old, investigated RNFL thickness as a predictor of brain degeneration leading to cognitive impairment in people without a degenerative disease at baseline.
“Our aim was to examine whether the known RNFL-cognition relationship in dementia held true in the early stages of cognitive decline,” co-author Paul J. Foster, PhD, told Primary Care Optometry News. “Between 2002 and 2012, 99% of clinical trials into treatments for Alzheimer’s disease failed. Treatments were being tested on those who already have severe damage to the brain,”
Repeated assessment of cognitive function was performed over 4 years using touch screens. It included tests on prospective memory, pairs matching, numeric and verbal reasoning, and reaction time. A selected subgroup also underwent OCT imaging. A total of 32,038 subjects who scored all the tests and had high-quality imaging results on OCT were included in the study.
A thinner baseline RNFL was associated with worse performance on baseline cognitive tests. Subjects in the thinnest RNFL quintile who failed at least two of four cognitive tests were almost double those in the thickest RNFL quintile. Multivariate regression analysis showed that those in the lowest two quintiles had twice the likelihood of developing decline of cognitive functions over a 3-year follow up than those in the top RFNL quintile.
“Our findings show that a thinner RNFL is a potential indicator for current impaired cognition and may have a potential role in screening for those at an increased risk of a future decline in cognitive function,” the authors wrote.
“Identifying predictors of future cognitive decline is a priority for developing treatment and prevention strategies for dementia. OCT measures will help identify those at highest risk of early cognitive changes. This will help to develop better clinical trials and pull through new treatments more rapidly,” Foster said. – by Michela Cimberle
Disclosures: Ko reported no relevant financial disclosures. Foster receives personal fees from Allergan, Google/DeepMind, Santen and Zeiss and grant support from Alcon. Please see the study for the other authors’ financial disclosures.