PSEN1 and amyloidosis: Within the primary visual system, V1 and the retina exhibited earlier pathological changes—specifically, earlier amyloid pathology, both detectable at 6 months—suggesting a potential synchrony between the emergence of retinal Aβ plaques and brain plaques during disease progression; notably, one study reported retinal Aβ plaques at 2.5 months in APP/PS1 mice [12], 2–3 months earlier than in the brain, a discrepancy that may reflect methodological differences in Aβ labeling (curcumin-based probes visualizing Aβ and its isomers in that study versus conventional Aβ antibodies in ours).