Background/aims We wished to determine whether the pupillary light reaction can differentiate preclinical Alzheimer’s disease (AD) subjects from normal ageing controls. We performed a prospective study evaluating the pupillary light reaction in a cohort of well-characterised subjects with preclinical AD versus normal ageing controls.
Methods We recruited 57 subjects from our institution’s Memory and Aging Project, part of our Alzheimer’s Disease Research Center. All subjects completed PET-PiB imaging, cerebrospinal fluid analysis and at least 1 neuropsychiatric assessment after their baseline assessment. All participants were assigned a clinical dementia rating and underwent a complete neuro-ophthalmic examination. Participants were divided into a dementia biomarker+ (preclinical AD) and biomarker– (normal ageing) group based on preclinical risk for Alzheimer’s dementia. Pupillometry measurements were performed by using the NeurOptics PLR-200 Pupillometer.
Results A total of 57 subjects were recruited with 24 dementia biomarker+ and 33 dementia biomarker- individuals. A variety of pupil flash response (PLR) parameters were assessed. Comparisons between groups were analysed using generalised estimating equations. None of the pupillary parameters showed a significant difference between groups.
Conclusions We found no significant differences in PLR between preclinical AD subjects and normal ageing controls. This suggests that the disease effect on the PLR may be small and difficult to detect at the earliest stages of the disease. Future studies could include larger sample size and chromatic pupillometry.
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Contributors GPVS, Y-BS and LB collected data for this study. GPVS, Y-BS and LB were all involved in the design and development of this study. GPVS and LB contributed to writing and editing the manuscript. MG and JH were involved in data analysis and biostatistics.
Funding This study was funded by Research to Prevent Blindness (Grant Number: P30 EY02687). This study was supported by the Knight Alzheimer's Disease Research Center, and the following grants: P50 AG05681; PO1 AG03991; PO1 AG026276.
Disclaimer The funding organisations had no role in the design or conduct of this research.
Competing interests None declared.
Patient consent Not required.
Ethics approval Washington University Human Research Protection Office.
Provenance and peer review Not commissioned; externally peer reviewed.
Data sharing statement For any additional data, please contact: GPVS, MD firstname.lastname@example.org.
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