Macias BR, Patel NB, Robert Gibson C, et al. - In this prospective study, researchers sought to quantitatively determine if changes in ocular structures that are hypothesized to be associated with the development of spaceflight-associated neuro-ocular syndrome occur on board the International Space Station (ISS) during 6-month missions. They examined the ocular structure of 11 astronauts [mean (SD) age of 45 (5) years, a mean (SD) height of 1.76 (0.05) m, and a mean (SD) weight of 75.3 (7.1) kg] before, during, and after a 6-month mission on board the ISS. According to findings, spaceflight-associated peripapillary optic disc edema and choroid thickening were noted bilaterally and occurred in both genders. Furthermore, they recorded substantial peripapillary choroid thickening during spaceflight, which has never been reported in a prospective study cohort population and which may be a contributing factor in spaceflight-associated neuro-ocular syndrome. Collecting data on spaceflight missions longer than 6 months can help to assess if the duration of the mission is correlated with exacerbating these observed visual structure or visual function changes.