INTRODUCTION Spaceflight-associated neuro-ocular syndrome (SANS) describes structural and functional alterations of the eye that develop in many astronauts during long-duration spaceflight missions (>6 month). Understanding the consequences of the structural and functional changes to the eye and brain that endure long after return from spaceflight is essential for future exploration-class spaceflight missions.
PURPOSE The primary purpose of this project is to quantify long-term changes in ocular and brain structure that remain or develop long after spaceflight and to determine the functional consequences of those changes. Specifically, we will characterize the recovery and long-term structural and functional alterations to the eye and brain for 5 years following 6-month spaceflight missions. We will also characterize the structural and functional changes to the eye and brain, including cognitive changes, in crewmembers who have participated in past missions, calling them back several years after their most recent flights.
METHODS Advanced techniques will be used to study the eyes and brains of astronauts. For one set of experiments, preflight, inflight, and 5 years of postflight results from astronauts (n = 10) who have participated in =6-month missions will be compared to those from age and sex-matched non-astronaut control subjects (n=13). In a second set of experiments, outcomes from astronauts who had previously participated in =6-month missions (n=30) will be compared to control subjects that do not have standard duration spaceflight experience (n=30). In addition to characterizing the effects observed for individual variables, all data collected during the study will be analyzed using an integrative approach to identify relationships across ocular measures, brain measures, individual crewmembers, and time. Ocular structure and function will be evaluated using MRI and 3D structural analysis, optical coherence tomography (OCT), angiography, electroretinography (ERG), visual field analysis, pneumotonometry (intraocular pressure), visual field analysis, optical biometry, and dynamic vessel analysis. In collaboration with the integrated project team, MRI will be used to assess brain structural changes, and functional MRI (fMRI) and a series of cognitive batteries will be used to evaluate brain function. To better understand the neurophysiological mechanisms underlying anticipated changes, biomarkers associated with specific structural and functional brain alterations will be measured in blood samples. To complement the research measures, medically relevant test results already collected by the Space Medicine Operations Division will be shared.
PROGRESS DURING THIS REPORTING PERIOD This project is being combined with the work of three other Principal Investigators (PIs) who responded to the same solicitation with independent proposals. During this reporting period, the protocols and aims from all four PIs are being integrated into a revised integrated proposal that will be delivered to NASA Human Health Countermeasures (HHC) and NASA Human Factors and Behavioral Performance (HFBP) Element scientists in early 2022. To reach this goal, the research team determined how to combine MRI sessions from multiple PIs, identified and removed overlapping procedures, and made substantial progress towards having a single, integrated budget.
Abstracts for Journals and Proceedings
Issabekov G, Wood S, Pasternak O, Kernagis D, Iliff J, Rane S, Seidler R. "Recovery timeline of spaceflight-induced central nervous system changes." 2022 NASA Human Research Program Investigators’ Workshop, Virtual, February 7-10, 2022.
Abstracts. 2022 NASA Human Research Program Investigators’ Workshop, Virtual, February 7-10, 2022. , Feb-2022