GFAP and Alzheimer disease: In total, only 4 out of 24 geo-layers reached significance, namely control mid-peripheral (~ 10 mm from ONH) INL (p < 0.01), AD central (~ 5 mm from ONH) INL (p < 0.01), AD central ONL (p < 0.05), and AD mid-peripheral RNFL (p < 0.05), indicating Aβ/GFAP co-localization was less prevalent than Aβ/TUBB3, described later.