Researchers investigate the impacts of space travel on astronauts' eye health
Researchers at Texas A&M University, led by Dr. Ana Diaz Artiles, are conducting a study on the impacts of space travel on astronauts' eye health. Published in the journal npj Microgravity, their research is shedding light on the effects of altered gravity and fluid shifts on the cardiovascular system, particularly the vessels around the eyes. This was reported by SSPDaily.
As space travel becomes increasingly commonplace, not only astronauts but also individuals traveling with commercial space companies may be subjected to these physiological changes. Given that commercial space travelers may have different health conditions compared to astronauts, understanding the role of fluid shifts in cardiovascular and eye health becomes crucial.
When exposed to microgravity conditions, fluids within the body redistribute due to the absence of gravity's downward pull. In normal gravity, a significant portion of body fluids is stored in the legs, but in microgravity, they shift towards the upper body. This phenomenon of fluid shift may be connected to Spaceflight Associated Neuro-ocular Syndrome (SANS), which impacts astronauts' eyes and ocular perfusion pressure (OPP).
Dr. Diaz Artiles and her team are investigating possible countermeasures to address the headward fluid shifts associated with SANS. One study explored the use of lower body negative pressure (LBNP) as a potential aid in mitigating the effects of microgravity-induced fluid redistribution. The concept behind LBNP is to redirect fluid back into the lower body.
Although the exact link between OPP and SANS is yet to be determined, there is a hypothesis that microgravity exposure can elevate OPP compared to upright postures, potentially contributing to SANS development. However, the study found that while LBNP effectively induced fluid shift towards the lower body, it did not help reduce OPP. Therefore, if elevated OPP is definitively linked to SANS, LBNP may not be an effective countermeasure for this syndrome. Further investigation is needed to unveil the relationship between OPP, SANS, and the impact of LBNP as a countermeasure.
Dr. Diaz Artiles emphasizes that their research is only a part of a larger study investigating fluid shift and its connection to SANS. Previous experiments focused on cardiovascular effects through the use of a tilt table to mimic various altered gravity levels. The recently published study concentrated on LBNP as a countermeasure.
Future studies will explore the effects of a centrifuge as another countermeasure against fluid shift. Researchers aim to evaluate cardiovascular responses along with ocular perfusion pressure and other relevant cardiovascular functions affected by microgravity environments.
While these studies are currently conducted on Earth, the team intends to conduct future research in true microgravity conditions, such as parabolic flights. This will better represent the gravitational changes experienced during space flights and provide more accurate outcomes.
