Department of Psychiatry, PC Sint-Amandus, Beernem, Belgium.
Colonel, US Army (retired), Moab, UT, USA.
Eye (Lond). 2019 Oct;33(10):1519-1524. doi: 10.1038/s41433-019-0453-8. Epub 2019 May 7.
Ophthalmic abnormalities including unilateral and bilateral optic disc edema, optic nerve sheath distention, globe flattening, choroidal folds, and hyperopic shifts have been observed in astronauts during and after long-duration spaceflight. An increased understanding of factors contributing to this syndrome, termed spaceflight-associated neuro-ocular syndrome, is currently a top priority for the ESA and NASA, especially since this medical obstacle could impact the visual health of astronauts as well as the success of future missions, including continued trips to the International Space Station, a return to the moon, or a future human mission to Mars. Currently, the exact mechanisms causing this neuro-ocular syndrome are not fully understood. In the present paper, we propose a hypothetical framework by which optic disc edema in astronauts may result, at least partly, from the forcing of perioptic cerebrospinal fluid into the optic nerve and optic disc along perivascular spaces surrounding the central retinal vessels, related to long-standing microgravity fluid shifts and variations in optic nerve sheath anatomy and compliance. Although this hypothesis remains speculative at the present time, future research in this area of investigation could not only provide exciting new insights into the mechanisms underlying microgravity-induced optic disc swelling but also offer opportunities to develop countermeasure strategies.
在长期太空飞行期间和之后，宇航员会出现眼部异常，包括单侧和双侧视盘水肿、视神经鞘扩张、眼球扁平、脉络膜皱褶和远视移位。目前，欧洲航天局和美国宇航局的当务之急是更深入地了解导致这种综合征（称为航天相关神经眼综合征）的因素，特别是因为这种医疗障碍可能会影响宇航员的视觉健康以及未来任务的成功，包括继续前往国际空间站、重返月球或未来人类前往火星的任务。目前，导致这种神经眼综合征的确切机制尚未完全阐明。在本文中，我们提出了一个假设框架，根据该框架，宇航员的视盘水肿至少部分可能是由于眶周脑脊液沿着围绕中央视网膜血管的血管周围空间被迫进入视神经和视盘所致，这与长期微重力下的液体转移以及视神经鞘解剖结构和顺应性的变化有关。虽然目前这一假设仍具有推测性，但未来在这一研究领域的研究不仅可以为微重力引起的视盘肿胀的机制提供令人兴奋的新见解，还为开发对策策略提供机会。
