We found that pretangle forms of p-tau (at epitopes S202/T205, S214, S396, S404, T231, but not S199 and S212/T214), CitR209-tau, and T22+ Oligo-tau, as well as MC-1+ pretangle and mature tau tangles, are elevated in the retinas of patients with the earliest functional impairment (MCI due to AD). Here, MAPT is linked to Alzheimer disease.