Four-year evolution of the retinal microvasculature in an APOE ε4/ε4 cognitively normal individual.

Alzheimer's disease is a neurodegenerative disorder with a prolonged preclinical phase during which pathological changes begin 15-20 years before clinical presentation. We present longitudinal optical coherence tomography angiography (OCTA) images from a cognitively normal female with APOE ε4/ε4. Over a 4-year period, she demonstrated an accelerated rate of retinal microvasculature loss compared with that expected due to normal ageing, despite no significant changes in medical history and no development of cognitive symptoms. Four years after initial presentation, brain amyloid was detected on positron emission tomography while she remained cognitively normal. This accelerated retinal microvasculature loss may mirror the pathogenesis of cerebral amyloid angiopathy and may represent a hypothesis-generating observation supporting further study of OCTA-derived retinal microvascular metrics in genetically predisposed individuals.