MAPT and Alzheimer disease: Notably, the levels of retinal Aβ42 also correlated with the extent of pS396-tau or Oligo-tau-laden RGCs (not shown; rP=0.69 and rP=0.67, respectively; P = 0.003), as well as RGC integrity, suggesting that retinal Aβ may drive RGC tauopathy and degeneration, similar to the interactions between Aβ and the spread of tau in neurons of AD brains [18, 134].