Atlas of Retinal Imaging in Alzheimer’s Study (ARIAS): SD‐OCT in Preclinical Alzheimer’s disease

Abstract

AbstractBackgroundARIAS is a preclinical Alzheimer’s disease (AD) cohort study, with the aim of following cognitively unimpaired (CU) older adults at high and low risk for AD and studying changes in retinal biomarkers over time. Here, we share baseline Spectral Domain Optical Coherence Tomography (SD‐OCT) data from ARIAS.MethodSD‐OCT was completed using the Heidelberg SPECTRALIS on 146 CU older adults (aged 55‐80), 83 high risk (APOE E4 carriers, first degree family history of AD), 63 low risk (APOE E4 non‐carriers, no first‐degree family history of AD). We took macular (30×25‐degree) and optic disc centered (radii of 3.5, 4.1, and 4.7 mm) SD‐OCT images. Vendor software was used to segment and compute average retinal thickness and volume in the 9 ETDRS maps for the macular and 7 glaucoma fields for the optic disk. ANCOVA (with age as a covariate) was used to compare retinal layer thickness and volume between the two groups. Bonferroni correction was used for multiple comparisons.ResultThe high risk group had significantly higher thickness/volume than the low risk group in the inner temporal quadrant of the ganglion cell layer (GCL, F(2, 144) = 3.67p<.05), the central quadrant of the inner nuclear layer (INL, F(2, 144) = 3.48,p<.05), the inner nasal quadrant of the outer plexiform layer (OPL, F(2, 144) = 7.35,p<.05). The peripapillary retinal nerve fiber layer (pRNFL) showed increased global thickness (F(2, 144) = 4.30, p<.05), and thickness in the nasal (F(2, 144) = 4.23, p<.05), nasal inferior (F(2, 144) = 3.34, p<.05), and temporal inferior (F(2, 144) = 3.61,p<.05) quadrants in the high risk group compared to the low risk group.ConclusionSD‐OCT can be applied to examine retinal thickness in preclinical AD. Thickness/volume of specific quadrants of the GCL, INL, and OPL differentiated high risk CU older adults from low risk CU older adults in a large preclinical cohort. pRNFL global thickness, and thickness in the nasal, nasal inferior, and temporal inferior quadrants, was increased in the high risk group. These results confirm and extend our prior findings of increased retinal layer thickness in preclinical AD. Longitudinal data will confirm whether these layers change over time in preclinical AD.