Peripapillary retinal nerve fiber layer and macular outer retinal layers are reduced in cognitively unimpaired older adults at high risk of AD. Preliminary results from a five ‐year longitudinal study

Background The retina, an extension of the central nervous system, shows promise for development non-invasive, low cost AD risk screening biomarkers. Most studies do not answer question whether retinal biomarkers are useful in pre-symptomatic phase assessment early disease risk. In this study1, we investigated structural changes neural layers between and high cognitively unimpaired (CU) older adults using Spectral Domain Optical Coherence tomography (SD-OCT). Method These data were provided from ongoing trial that will conclude enrolment summer 2022.1 Macular (30×25-degree) optic disc centered (radii 3.5, 4.1, 4.7 mm) SD-OCT images 13 CU (age mean: 67 years; range: 56-75 years) 60 at 66 55-81 no significant difference age two groups, p = 0.43) acquired Spectralis imaging device. Participants had MoCA score ≥ 26, RBANS-U DMI 85. Vendor software was used to segment compute average thickness 9 ETDRS maps macular 7 glaucoma fields disk. Independent sample t test compare layer groups. A p-value < 0.05 assessed statistical significance. Cohen’s d served as effect size measure. Result region, there reduced volume/thickness measurements vs. (outer plexiform volume inner inferior region; 0.054 0.062 mm3, 0.047, 0.62; outer nuclear layer, ONL thickness; 97 102 µm, 0.041, 0.64; volume; 0.076 0.16 0.023, 0.71). peripapillary nerve fiber (RNFL) temporal region (3.5 mm radius; 66.7 75.6 0.011, 0.80; 4.1 59.7 68.3 0.006, 0.87; 54.2 62.2 0.87). Conclusion Our initial analysis RNFL group.