MAPT and Alzheimer disease: An early accumulation of APP/Aβ and tau hyperphosphorylation, two hallmarks of brain neurodegeneration, also occur in retinas of experimental AD models and patients suffering from AD (Oddo et al., 2003; Javaid et al., 2016; Czakó et al., 2020; Mei et al., 2020; Schultz et al., 2020; Gupta et al., 2021; Latina et al., 2021a).