In space no one can see you scream: investigations of cerebrovascular and retinal haemodynamics in response to spaceflight-relevant stimuli

Endothelial dysfunction may contribute to oedema associated with the ocular condition spaceflight associated neuro-ocular syndrome (SANS). This thesis investigated spaceflight-relevant retinal and cerebrovascular haemodynamic changes through computational fluid dynamics simulations. Findings showed microgravity increased haemodynamic metrics towards the eye. Separate simulation and ultrasound methods verified cerebrovascular responses under spaceflight-relevant conditions. In a tail suspension mouse model, elevated retinal haemodynamics were linked to endothelial dysfunction. Human studies showed environmental heat and exercise modulated blood flow, potentially reducing retinal haemodynamics. These insights suggest spaceflight haemodynamic responses may contribute to endothelial dysfunction. Future work could utilise these methods in further spaceflight contexts.