Astronauts who spend time aboard the International Space Station return to Earth with changes to the structure of their eyes which could impact their vision. NASA has studied the phenomenon, known as space flight-associated neuro-ocular syndrome (SANS), for several years, and now a University of Houston optometrist has quantified some of the changes using optical coherence tomography imaging, reporting his findings in JAMA Ophthalmology.
“We studied pre-flight and post-flight data from 15 astronauts who had spent time aboard the space station and detected changes in morphology of the eyes,” said Nimesh Patel, assistant professor. All of them had good vision before and after the flight, but many of them had a change in structures of their eyes.
Patel created customized programs to study data from optical coherence tomography, a noninvasive clinical test that offers cross-section pictures of the retina. His algorithms showed that following prolonged space flight, three major changes occur.
“The findings of this study show that in individuals exposed to long-duration microgravity, there is a change in the position of the Bruch membrane opening, an increase in retinal thickness closer to the optic nerve head rim margin, and an increase in the proportion of eyes with choroidal folds,” said Patel.
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Image: University of Houston optometrist Nimesh Patel studies the vision of returning International Space Station astronauts and proves a structural change to their eyes. (Credit: University of Houston)