Author(s):Chen Y, Hetzel S, Pinto AA, Paulsen AJ, Schubert CR, Hancock LM, Klein BE, Merten N, Cruickshanks KJ. The pupil constriction to light is associated with cognitive measures in middle-aged and older adults. Aging Clin Exp Res. 2022 Mar 10. doi: 10.1007/s40520-022-02097-w. [Epub ahead of print] PMID 35267180
Journal: Aging Clinical And Experimental Research, Mar 2022
AIMS The evidence relating the pupil light reflex (PLR) and cognition have been inconsistent. In this cross-sectional study, we evaluated the association between the PLR and cognition in community-dwelling middle-aged and older individuals.
METHODS Pupil reactivity was recorded in a subgroup of 403 participants (mean age 60.7 years, 57.3% females) in an epidemiologic study of aging. Ten pupil parameters were calculated to describe pupil constriction to light stimuli. A principal component analysis (PCA) score was used to calculate an overall performance over four cognitive testings. Linear regression was used to assess the association between pupil parameters and PCA scores, adjusting for age, sex, education, medications, health-related quality of life questionnaire, and systemic and ocular comorbidities.
RESULTS The PCA scores decreased by 0.039 [95% CI (- 0.050, – 0.028)] per year increase in age and were lower in males than females by 0.76 [95% CI (- 0.96, – 0.55)] (p < 0.001). Pupil constriction amplitude in millimeters and the duration from stimulus onset to maximal constriction velocity were significantly associated with cognition after adjusting for (1) age and sex and (2) age, sex, and multiple covariates (p < 0.05).
CONCLUSIONS In this study, we provided moderate evidence suggesting the association between PLR and neuropsychological cognitive measures. The findings suggest the potential of pupil reactivity to serve as a biomarker of brain aging and warrant further longitudinal study to assess if changes in the PLR can predict cognitive decline over time.