Devin Mackay, United States of America
Indiana University School of Medicine OphthalmologyAuthor Of 1 Presentation
RELATIONSHIP OF RETINAL THICKNESS AND VISUAL CONTRAST SENSITIVITY WITH A/T/N NEUROIMAGING BIOMARKERS
Abstract
Aims
Objective: Visual system measures may represent potential biomarkers for Alzheimer’s disease (AD). Our goal was to investigate the relationship of two potential visual system biomarkers, retinal nerve fiber layer thickness (RNFL) and visual contrast sensitivity (CS), with neuroimaging biomarkers of amyloid (A), tau (T), and neurodegeneration (N).
Methods
Methods: 52 participants (25 cognitively normal, 14 subjective cognitive decline (SCD), 9 mild cognitive impairment (MCI), and 4 AD) underwent OCT to measure RNFL, frequency doubling technology to measure CS, amyloid PET, and MRI. A subset (n=44) underwent tau PET. A/T/N was measured continuously and dichotomously (cortical Centiloid (CL)/Aβ+ (CL>21), lateral temporal tau SUVR/tau+ (Braak stage>3), hippocampal volume (HV)/neurodegeneration+ (w-score<-1.5)). Continuous relationships were assessed using partial Pearson correlation, covaried for age, sex, and race/ethnicity, as well as ICV (MRI only). Stepwise logistic regression was used to predict dichotomous A/T/N positivity. Analyses were done in the full sample and in at-risk individuals only (SCD/MCI).
Results
Results: In continuous analyses, amyloid was associated with both CS and RNFL thickness (rp=-0.38, p=0.008; rp=-0.29, p=0.044, respectively), tau was associated with CS (rp=-0.59, p<0.001), and HV was associated with only RNFL (rp=0.32, p=0.028). Dichotomous analyses indicated that CS was associated with Aβ+ and tau+ (p=0.030, p=0.013, respectively), while RNFL showed a trend association associated with neurodegeneration+ (p=0.057). Similar results for A/T, but not N, were found when only including SCD/MCI (p<0.05).
Conclusions
Conclusion: Visual measures are promising biomarkers for A/T/N, with a combination of multiple visual measures may provide comprehensive prediction across pathologies. Future studies in larger samples are needed.