Spaceflight Associated Neuro-ocular Syndrome
The Challenge
In several cases, astronauts have experienced lasting changes in their visual acuity when they returned to earth after long-duration spaceflight missions aboard the International Space Station. Referred to as spaceflight associated neuro-ocular syndrome (SANS), no clear explanation as to why such ophthalmic changes might occur in microgravity currently exists. It has been proposed by space medicine experts that the large displacement of body fluid toward the head in microgravity, via biomechanical pathways, may be a significant contributor to some of these ocular changes by influencing the way pressure is distributed in the cranium.
The Research
The Cross-cutting Computational Modeling Project (CCMP) has developed a suite of computational models to simulate the effects of fluid shift on the cardiovascular, central nervous and ocular systems to understand the cause of SANS syndrome. The models rely on fundamental research and development of lumped parameter, finite element, and computational fluid dynamic numerical modeling. These models will help identify critical parameter interactions, understanding of physiological responses and guide countermeasure development by characterizing the appropriate biomechanical response of the cardiovascular, central nervous and visual systems in microgravity.
The Progress
The CCMP has developed models of organ systems hypothesized to contribute to SANS syndrome. Models vary in the size resolution of the structures they model, the time step used to simulate changes within those systems, and the accuracy with which the model reproduces human anatomy. These models includethe whole body model, ans eye model. Together, these models provide information on contributions of the cardiovascular system (CVS), intracranial pressure (ICP), ocular blood flow, globe volume and intraocular pressure (IOP). In addition, the eye model (finite element) enhances understanding of biomechanical stress/strain and tissue remodeling that may occur during SANS. These models are used to examine key anatomical structures and physiological processes and to interpret experimental data generated to understand the cause of SANS.
Acronyms
CNS – Central Nervous System
CVS – Cardiovascular System
DAP – Digital Astronaut Project
HSE – Human Space Endeavours
ICP – Intracranial Pressure
IOP – (Intraocular Pressure)
SBMT – Society for Brain Mapping and Therapeutics
VIIP – Visual Impairment & Intracranial Pressure
Technical Data
- presentation_HSE_09182011_Final
- Myers_VIIP_abstract_draft20120510_Final
- 9th Annual SBMT – 10May2012 – compressed-FINAL
- Microgravity-induced fluid shift and ophthalmic changes
- Modeling the Effects of Spaceflight on the Posterior Eye in VIIP
- Numerical Modeling of Ocular Dysfunction in Space
- Biomechanics of the Optic Nerve Sheath in VIIP Syndrome
- Modeling and Simulation of Visual Impairment and Intracranial Pressure (VIIP) in Space
- Computational Models of the Eye and their Applications in Long Duration Space Flight
- An integrated biomechanical model for microgravity-induced visual impairment
Spaceflight Associated Neuro-ocular Syndrome Gaps
What is an HRP Gap?
Evidence from medical records, spaceflight operations and research findings provides the basis for identifying the most significant human risks in space exploration, including physiological and performance effects from hazards such as altered gravity, radiation, hostile/closed environments, isolation and distance. Each risk is assigned to an HRP Element (divisions of human research) to identify knowledge gaps, or the critical questions that must be answered, in order to mitigate the risk. These gaps become the focus of research conducted to reduce the likelihood and consequence of risks becoming a reality. To learn more about the Risk Identification and Mitigation process and the tasks developed to reduce those risks for the program please select the links below the for more information.
4.14 Ocular changes

Gallery
Cardiovascular Impacts
What are the in-flight alterations in cardiac structure and function?
Evidence from medical records, spaceflight operations and research findings provides the basis for identifying the most significant human risks in space exploration, including physiological and performance effects from hazards such as altered gravity, radiation, hostile/closed environments, isolation and distance. Each risk is assigned to an HRP Element (divisions of human research) to identify knowledge gaps, or the critical questions that must be answered, in order to mitigate the risk. These gaps become the focus of research conducted to reduce the likelihood and consequence of risks becoming a reality. To learn more about the Risk Identification and Mitigation process and the tasks developed to reduce those risks for the program please click on the link below the gap for more information.
Measuring VO2 inflight
What is VO2max in-flight and immediately post-flight?
Evidence from medical records, spaceflight operations and research findings provides the basis for identifying the most significant human risks in space exploration, including physiological and performance effects from hazards such as altered gravity, radiation, hostile/closed environments, isolation and distance. Each risk is assigned to an HRP Element (divisions of human research) to identify knowledge gaps, or the critical questions that must be answered, in order to mitigate the risk. These gaps become the focus of research conducted to reduce the likelihood and consequence of risks becoming a reality. To learn more about the Risk Identification and Mitigation process and the tasks developed to reduce those risks for the program please click on the link below the gap for more information.
Predicting Heart Disease
Can manifestations of sub-clinical or environmentally induced cardiovascular diseases during spaceflight be predicted?
Evidence from medical records, spaceflight operations and research findings provides the basis for identifying the most significant human risks in space exploration, including physiological and performance effects from hazards such as altered gravity, radiation, hostile/closed environments, isolation and distance. Each risk is assigned to an HRP Element (divisions of human research) to identify knowledge gaps, or the critical questions that must be answered, in order to mitigate the risk. These gaps become the focus of research conducted to reduce the likelihood and consequence of risks becoming a reality. To learn more about the Risk Identification and Mitigation process and the tasks developed to reduce those risks for the program please click on the link below the gap for more information.
Outcome of Medical Events
We do not know the quantified health and mission outcomes due to medical events during exploration missions.
Evidence from medical records, spaceflight operations and research findings provides the basis for identifying the most significant human risks in space exploration, including physiological and performance effects from hazards such as altered gravity, radiation, hostile/closed environments, isolation and distance. Each risk is assigned to an HRP Element (divisions of human research) to identify knowledge gaps, or the critical questions that must be answered, in order to mitigate the risk. These gaps become the focus of research conducted to reduce the likelihood and consequence of risks becoming a reality. To learn more about the Risk Identification and Mitigation process and the tasks developed to reduce those risks for the program please click on the link below the gap for more information.
Doctor on Board?
We do not know how the inclusion of a physician crew medical officer quantitatively impacts medical risk during exploration missions.
Evidence from medical records, spaceflight operations and research findings provides the basis for identifying the most significant human risks in space exploration, including physiological and performance effects from hazards such as altered gravity, radiation, hostile/closed environments, isolation and distance. Each risk is assigned to an HRP Element (divisions of human research) to identify knowledge gaps, or the critical questions that must be answered, in order to mitigate the risk. These gaps become the focus of research conducted to reduce the likelihood and consequence of risks becoming a reality. To learn more about the Risk Identification and Mitigation process and the tasks developed to reduce those risks for the program please click on the link below the gap for more information.
Microgravity Countermeasures
How does 1/6-g and 3/8-g influence countermeasures?
Evidence from medical records, spaceflight operations and research findings provides the basis for identifying the most significant human risks in space exploration, including physiological and performance effects from hazards such as altered gravity, radiation, hostile/closed environments, isolation and distance. Each risk is assigned to an HRP Element (divisions of human research) to identify knowledge gaps, or the critical questions that must be answered, in order to mitigate the risk. These gaps become the focus of research conducted to reduce the likelihood and consequence of risks becoming a reality. To learn more about the Risk Identification and Mitigation process and the tasks developed to reduce those risks for the program please click on the link below the gap for more information.
Efficient Exercise Regimen
Develop the most efficient and effective exercise program for the maintenance of muscle function.
Evidence from medical records, spaceflight operations and research findings provides the basis for identifying the most significant human risks in space exploration, including physiological and performance effects from hazards such as altered gravity, radiation, hostile/closed environments, isolation and distance. Each risk is assigned to an HRP Element (divisions of human research) to identify knowledge gaps, or the critical questions that must be answered, in order to mitigate the risk. These gaps become the focus of research conducted to reduce the likelihood and consequence of risks becoming a reality. To learn more about the Risk Identification and Mitigation process and the tasks developed to reduce those risks for the program please click on the link below the gap for more information.
Minimum Exercise Needed?
What is the minimum exercise regimen needed to maintain fitness levels for tasks?
Evidence from medical records, spaceflight operations and research findings provides the basis for identifying the most significant human risks in space exploration, including physiological and performance effects from hazards such as altered gravity, radiation, hostile/closed environments, isolation and distance. Each risk is assigned to an HRP Element (divisions of human research) to identify knowledge gaps, or the critical questions that must be answered, in order to mitigate the risk. These gaps become the focus of research conducted to reduce the likelihood and consequence of risks becoming a reality. To learn more about the Risk Identification and Mitigation process and the tasks developed to reduce those risks for the program please click on the link below the gap for more information.
Exercise Hardware
Identify and validate exploration countermeasure hardware for the maintenance of muscle function.
Evidence from medical records, spaceflight operations and research findings provides the basis for identifying the most significant human risks in space exploration, including physiological and performance effects from hazards such as altered gravity, radiation, hostile/closed environments, isolation and distance. Each risk is assigned to an HRP Element (divisions of human research) to identify knowledge gaps, or the critical questions that must be answered, in order to mitigate the risk. These gaps become the focus of research conducted to reduce the likelihood and consequence of risks becoming a reality. To learn more about the Risk Identification and Mitigation process and the tasks developed to reduce those risks for the program please click on the link below the gap for more information.
Time Course of Changes in Muscle
Characterize the time course of changes in muscle protein turnover, muscle mass, and function during long duration space flight.
Evidence from medical records, spaceflight operations and research findings provides the basis for identifying the most significant human risks in space exploration, including physiological and performance effects from hazards such as altered gravity, radiation, hostile/closed environments, isolation and distance. Each risk is assigned to an HRP Element (divisions of human research) to identify knowledge gaps, or the critical questions that must be answered, in order to mitigate the risk. These gaps become the focus of research conducted to reduce the likelihood and consequence of risks becoming a reality. To learn more about the Risk Identification and Mitigation process and the tasks developed to reduce those risks for the program please click on the link below the gap for more information.
Bone Health Standard
A new acceptable bone health standard using an expanded surrogate for bone health needs to be defined for the flight environment.
Evidence from medical records, spaceflight operations and research findings provides the basis for identifying the most significant human risks in space exploration, including physiological and performance effects from hazards such as altered gravity, radiation, hostile/closed environments, isolation and distance. Each risk is assigned to an HRP Element (divisions of human research) to identify knowledge gaps, or the critical questions that must be answered, in order to mitigate the risk. These gaps become the focus of research conducted to reduce the likelihood and consequence of risks becoming a reality. To learn more about the Risk Identification and Mitigation process and the tasks developed to reduce those risks for the program please click on the link below the gap for more information.
Osteoporosis & Fractures
What is the incidence & prevalence of early onset osteoporosis or fragility fractures due to exposure to spaceflight.
Evidence from medical records, spaceflight operations and research findings provides the basis for identifying the most significant human risks in space exploration, including physiological and performance effects from hazards such as altered gravity, radiation, hostile/closed environments, isolation and distance. Each risk is assigned to an HRP Element (divisions of human research) to identify knowledge gaps, or the critical questions that must be answered, in order to mitigate the risk. These gaps become the focus of research conducted to reduce the likelihood and consequence of risks becoming a reality. To learn more about the Risk Identification and Mitigation process and the tasks developed to reduce those risks for the program please click on the link below the gap for more information.
Ocular changes
We do not know the etiological mechanisms and contributing risk factors for ocular structural and functional changes seen in-flight and post-flight.
Evidence from medical records, spaceflight operations and research findings provides the basis for identifying the most significant human risks in space exploration, including physiological and performance effects from hazards such as altered gravity, radiation, hostile/closed environments, isolation and distance. Each risk is assigned to an HRP Element (divisions of human research) to identify knowledge gaps, or the critical questions that must be answered, in order to mitigate the risk. These gaps become the focus of research conducted to reduce the likelihood and consequence of risks becoming a reality. To learn more about the Risk Identification and Mitigation process and the tasks developed to reduce those risks for the program please click on the link below the gap for more information.
Medical Event Risk Metrics
We need to characterize the medical conditions that can occur during exploration missions and their relevant associated end states, management options, and the capabilities necessary to manage them (what can happen, how bad could it be, what can we do to improve it?).
Evidence from medical records, spaceflight operations and research findings provides the basis for identifying the most significant human risks in space exploration, including physiological and performance effects from hazards such as altered gravity, radiation, hostile/closed environments, isolation and distance. Each risk is assigned to an HRP Element (divisions of human research) to identify knowledge gaps, or the critical questions that must be answered, in order to mitigate the risk. These gaps become the focus of research conducted to reduce the likelihood and consequence of risks becoming a reality. To learn more about the Risk Identification and Mitigation process and the tasks developed to reduce those risks for the program please click on the link below the gap for more information.
Integrated Exploration Medical System Models
We need to develop integrated exploration medical system models for the Moon and Mars.
Evidence from medical records, spaceflight operations and research findings provides the basis for identifying the most significant human risks in space exploration, including physiological and performance effects from hazards such as altered gravity, radiation, hostile/closed environments, isolation and distance. Each risk is assigned to an HRP Element (divisions of human research) to identify knowledge gaps, or the critical questions that must be answered, in order to mitigate the risk. These gaps become the focus of research conducted to reduce the likelihood and consequence of risks becoming a reality. To learn more about the Risk Identification and Mitigation process and the tasks developed to reduce those risks for the program please click on the link below the gap for more information.
Cardiovascular Impacts from Weightlessness
Determine whether long-duration weightlessness induces cardiovascular structural and functional changes and/or oxidative stress & damage (OSaD)/inflammation, that can contribute to development of disease.
Evidence from medical records, spaceflight operations and research findings provides the basis for identifying the most significant human risks in space exploration, including physiological and performance effects from hazards such as altered gravity, radiation, hostile/closed environments, isolation and distance. Each risk is assigned to an HRP Element (divisions of human research) to identify knowledge gaps, or the critical questions that must be answered, in order to mitigate the risk. These gaps become the focus of research conducted to reduce the likelihood and consequence of risks becoming a reality. To learn more about the Risk Identification and Mitigation process and the tasks developed to reduce those risks for the program please click on the link below the gap for more information.
Fluid Intake
Is it necessary to increase crew fluid intake and, if possible, to what extent will it mitigate stone formation?
Evidence from medical records, spaceflight operations and research findings provides the basis for identifying the most significant human risks in space exploration, including physiological and performance effects from hazards such as altered gravity, radiation, hostile/closed environments, isolation and distance. Each risk is assigned to an HRP Element (divisions of human research) to identify knowledge gaps, or the critical questions that must be answered, in order to mitigate the risk. These gaps become the focus of research conducted to reduce the likelihood and consequence of risks becoming a reality. To learn more about the Risk Identification and Mitigation process and the tasks developed to reduce those risks for the program please click on the link below the gap for more information.
Frequency of formation
What is the frequency of post-flight stone formation; the incidence and types of stones; and the time course of stone formation? How does stone formation correlate with food intake and hydration status?
Evidence from medical records, spaceflight operations and research findings provides the basis for identifying the most significant human risks in space exploration, including physiological and performance effects from hazards such as altered gravity, radiation, hostile/closed environments, isolation and distance. Each risk is assigned to an HRP Element (divisions of human research) to identify knowledge gaps, or the critical questions that must be answered, in order to mitigate the risk. These gaps become the focus of research conducted to reduce the likelihood and consequence of risks becoming a reality. To learn more about the Risk Identification and Mitigation process and the tasks developed to reduce those risks for the program please click on the link below the gap for more information.