Microgravity and Astronauts: Do Spacewalks Cause Optical Abnormalities?


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Are spacewalks dangerous? Image courtesy of NASAAstronaut Vision Exams: What Inspired the Study?

This research may be critical to the future of the space program, as well as the health of astronauts. So, how did it all start?

Dr. Kramer: I was contacted to evaluate a symptomatic Astronaut with choroidal folds on eye examination to better define the clinical findings using high resolution magnetic resonance imaging. This resulted in the discovery of additional findings not apparent on neuro-ophthalmogic examination. More astronauts followed and a pattern of imaging abnormalities emerged that suggested elevated intracranial pressure. Two focused conference sessions with NASA officials followed. By this point the pattern was well defined and I felt compelled to document observations as a baseline study for future research and possibly improve our understanding of a clinical entity on earth referred to as idiopathic intracranial hypertension which share similar imaging findings including optic nerve swelling.

Next Steps for Spaceflight

What’s next for spaceflight? According to Dr. Kramer, “The next step is confirming the findings, defining causation and working towards a solution based on solid evidence. I would also suggest that defining biologic risks factors is also critical since not all astronauts showed evidence of abnormalities. Hopefully, through earlier identification of asymptomatic changes in spaceflight with the deployment of advance technologies on board the ISS, medical protocols could be initiated as needed to mitigate symptoms. I would suspect “the whether it is possible and how” is under active discussion and investigation by NASA officials but remains unknown to best of my knowledge.”


Kramer, L., Sargsyan, A., Hasan, K., Polk, D., Hamilton, D. Orbital and Intracranial Effects of Microgravity: Findings at 3-T MR Imaging. (2012). Radiology. Accessed March 12, 2012.

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