Optical coherence tomography angiography reveals structural and hemodynamic remodeling of cerebral penetrating vessels owing to aging

Aging induces structural and functional changes in the cerebral microvasculature. However, in vivo characterization of remodeling in cerebral penetrating vessels (PVs) remains limited. In this study, we employed optical coherence tomography angiography (OCTA) to investigate age-related alterations in cortical PVs in adult (2-4 months) and aged (15-16 months) mice. Using three-dimensional OCTA imaging, we quantified PV tortuosity and local flow dynamics through Doppler frequency variance (DFV) mapping. PV tortuosity was slightly but significantly increased in aged mice, reflecting geometric remodeling of the vertical microvascular network. DFV in aged PVs decreased by more than 15% relative to adults, suggesting reduced flow complexity that may be associated with increased vascular stiffness and altered perfusion dynamics. These findings provide in vivo evidence that aging alters the geometry and hemodynamics of PVs and support the use of OCTA-derived metrics as noninvasive biomarkers of cerebrovascular aging.