Notably, Spearman’s correlation analysis indicated that retinal T22+ Oligo-tau strongly and positively correlates with brain NFTs burden (Fig. 2d, rS = 0.66, P < 0.0001), Braak staging—a parameter of tauopathy spread across brain regions during AD progression (Fig. 2e, rS = 0.71, P < 0.0001), CAA severity (rS = 0.69, P < 0.0001), and the A(amyloid-beta plaque) B(NFT stage) C(Neuritic plaque)—ABC scores (Table 3). Here, MAPT is linked to tauopathy.