A call for neurovascular monitoring in an era of longer missions and broader spaceflight participation

Spaceflight-Associated Neuro-ocular Syndrome (SANS) has emerged as a critical neuroophthalmic risk for human space exploration, particularly as mission duration increases and access to space expands. Current spaceflight ocular surveillance and research protocols have prioritized structural imaging and selected neuroimaging/physiological assessments. However, accumulating evidence suggests that SANS is not confined to the posterior pole as a purely structural optic nerve head phenomenon but may also involve vascular and hemodynamic alterations. At the same time, structural changes at the optic nerve head may not fully capture the functional integrity of the afferent visual pathway. We therefore propose to define a more targeted extension of current SANS surveillance protocols incorporating ultra-widefield swept-source optical coherence tomography angiography (UWF-SS-OCTA), visual evoked potentials (VEPs) and pattern electroretinogram (ERG) into standardized pre-flight, in-flight (when feasible), and post-flight assessments. Beyond its relevance to astronaut health, this topic may also be of translational interest to the broader scientific and clinical community.