RNFL thickness correlated to cognitive function
SEATTLE – Researchers reported here at the Association for Research in Vision and Ophthalmology meeting that a thicker retinal nerve fiber layer was associated with better performance on the mini mental state examination and reaction time.
Eneh Jones-Odeh, of King’s College, London, said she and her colleagues evaluated twins “to determine the relationship between RNFL and how well people perform in different cognitive tests.”
The researchers evaluated 823 sets of twins, 19 to 89 years old, who are participating in the Twin U.K. Cohort – a registry of twins who volunteer for research purposes, she said.
Jones-Odeh and colleagues found that the RNFL was thinner as patients aged and were more myopic. A thicker RNFL was associated with faster reaction time and a better score on the mini mental state examination (MMSE).
Thickness of the RNFL was “highly heritable, with additive genetic effects accounting for 82% of variance in the RNFL thickness,” according to the study, “while MMSE score and reaction time were moderately heritable, at 40% and 53%, respectively.”
“We found a strong genetic component in development of RNFL,” Jones-Odeh told Primary Care Optometry News. “The thicker the fiber layer, the better they performed.”
She said that they found a 94% genetic component, but the sample size needs to be bigger. A total of 12,000 sets of twins are in the U.K. cohort, so it is hoped that the sample size for this study can be doubled over the next year, she said.
“It’s been shown that the RNFL is thinner in patients with Alzheimer’s disease,” Jones-Odeh said, “and even thinner in patients with more severe disease.”
A larger cohort will allow the researchers to, “look at specific genes that account for the thickness of the RNFL,” she said. – by Nancy Hemphill, ELS, FAAO
Reference: Jones-Odeh E, et al. Is the relationship between retinal nerve fiber layer thickness and cognitive performance explained by genetic or environmental factors? A twin study. Presented at: Association for Research in Vision and Ophthalmology meeting; May 1-5, 2016; Seattle.
Disclosure: Jones-Odeh reports no relevant financial disclosures.