Intracranial Pressure And Its Effect On Vision In Space And On Earth Vision Impairment In Space

Fluid distribution during spaceflight and impact on brain and vision health is an emerging field of high-priority research in the NASA human space program. International Space Station astronauts have developed ocular refraction changes during prolonged spaceflight. Within this book, experts review current data related to fluid shifts during microgravity exposure and the impact of fluid shifts on astronaut health. This work also compares current astronaut health problems with Earth-based health conditions such as elevated intracranial pressure and glaucoma. Chapters include discussion of altered fluid distribution, including intracellular and extracellular fluid shifts, eye morphology and vision disturbances, and intraocular pressure. In addition, chapters will include a discussion of advanced non-invasive technologies to investigate the abovementioned fluid volume and pressure variables. As such, the book aims to bridge health professionals, researchers, and science professionals by a presentation of ophthalmology topics critical to future human space exploration, thus providing new perspectives to solve emerging brain and eye disease on Earth and in Space.

"Fluid distribution during spaceflight and impact on brain and vision health is an emerging field of high-priority research in the NASA human space program. International Space Station astronauts have developed ocular refraction changes during prolonged spaceflight. Within this book, experts review current data related to fluid shifts during microgravity exposure and the impact of fluid shifts on astronaut health.This work also compares current astronaut health problems with Earth-based health conditions such as elevated intracranial pressure and glaucoma. Chapters include discussion of altered fluid distribution, including intracellular and extracellular fluid shifts, eye morphology and vision disturbances, and intraocular pressure. In addition, chapters will include a discussion of advanced non-invasive technologies to investigate the abovementioned fluid volume and pressure variables.As such, the book aims to bridge health professionals, researchers, and science professionals by a presentation of ophthalmology topics critical to future human space exploration, thus providing new perspectives to solve emerging brain and eye disease on Earth and in Space"--

Fluid distribution during spaceflight and impact on brain and vision health is an emerging field of high-priority research in the NASA human space program. International Space Station astronauts have developed ocular refraction changes during prolonged spaceflight. Within this book, experts review current data related to fluid shifts during microgravity exposure and the impact of fluid shifts on astronaut health. This work also compares current astronaut health problems with Earth-based health conditions such as elevated intracranial pressure and glaucoma. Chapters include discussion of altered fluid distribution, including intracellular and extracellular fluid shifts, eye morphology and vision disturbances, and intraocular pressure. In addition, chapters will include a discussion of advanced non-invasive technologies to investigate the abovementioned fluid volume and pressure variables. As such, the book aims to bridge health professionals, researchers, and science professionals by a presentation of ophthalmology topics critical to future human space exploration, thus providing new perspectives to solve emerging brain and eye disease on Earth and in Space.

Recent missions on board the International Space Station have revealed previously unreported physiological consequences of long duration space flight, particularly in eyesight, and in this Brief Dr. Seedhouse reviews the existing theories on what causes this degeneration and how long it will last. Notably, 60% of long-duration crews have reported subjective degradation in vision, a clear indication that further study is necessary before astronauts embark on even longer-term space missions. Decreased near-visual acuity was reported in 46% of ISS/Mir crewmembers, resulting in a change of up to 2 dioptres in their refractive correction. It is possible that ophthalmic changes have been present since the first days of spaceflight, but had been attributed to other causes; this approach to the issue as well as other hypotheses are all presented in full to give a broad foundation of the existing knowledge on the topic. The changes have occurred at various times during a mission with varying degrees of visual degradation. Some cases resolved on return to Earth, but several crewmembers have not regained pre-flight visual acuity, indicating the damage may be permanent. One explanation of the syndrome has been attributed to hyperopic shift due to aging, but onboard analysis techniques, including visual acuity assessments, retinal imagery, and ultrasound examination of the eye, has led to the acceptance of a wider syndrome. In addition to vision changes, studies have reported flattening of the globe, swelling of the optic disc (papilledema), choroidal folds in the retina, swelling of the optic nerve sheath, and visual field defects. It is widely hypothesized that this spectrum of symptoms may be explained by an elevation of intracranial pressure (ICP). Establishing the provenance of this medical problem, monitoring its occurrence and resolving the symptoms for future long term space missions is a key challenge for space medicine. With this book, readers have an entry point for understanding the full scope of the problem and its possible origins.

Prolonged microgravity exposure during long-duration spaceflight (LDSF) produces unusual physiologic and pathologic neuro-ophthalmic findings in astronauts. These microgravity-associated findings collectively define the Spaceflight Associated Neuro-ocular Syndrome (SANS). In this book, the editors compare and contrast prior published work on SANS by the National Aeronautics and Space Administration’s (NASA) Space Medicine Operations Division with retrospective and prospective studies from other research groups. The book describes the possible mechanisms and potential etiologies for SANS, and provides an update and review on the clinical manifestations of SANS including: unilateral and bilateral optic disc edema, globe flattening, choroidal and retinal folds, hyperopic refractive error shifts, and focal areas of ischemic retina (i.e., cotton wool spots). The ocular imaging findings (e.g., retinal nerve fiber layer, optic disc, and choroidal changes on optical coherence tomography) of SANS is also described, including the intraorbital and intracranial findings on orbital ultrasound and magnetic resonance imaging. The knowledge gaps for in-flight and terrestrial human research including potential countermeasures for future stud is also explored, including reports on the in-flight and terrestrial human and animal research being investigated by NASA and its partners to study SANS both prospectively and longitudinally and in preparation for future long duration manned missions to space including the moon, the asteroid belt, or Mars. We think this is a unique topic and hope that NASA and its research partners continue to study SANS in preparation for future longer duration manned space missions. Written in an easy-to-read manner, the book adopts a translational approach and explores the science and the clinical manifestations of Space flight associated neuro-ocular syndrome. It is also multi-disciplinary and suitable for both clinicians and researchers in ophthalmology, neurology, and aerospace medicine interested in SANS SANS is a unique space flight disorder that has no terrestrial equivalent. The book involves contributions from international experts across multiple disciplines to tackle the problem of SANS Summarizes and reviews the current findings of SANS, including possible mechanisms and potential etiologies, clinical manifestations, current reports on the in-flight and terrestrial human and animal research, and ocular imaging findings

This book consolidates the current knowledge of how short and long-duration spaceflight affects the anatomy and physiology of the central nervous system. It also incorporates the methodology and constraints of studying the central nervous system in space. Chapters detail advances in imaging techniques available to assess intracranial and intraocular pathology as well as translational medicine with an emphasis on brain cancer and neurodegenerative disease in spaceflight. Additionally, the book offers theoretical background information, tested laboratory protocols, and step-by-step methods for reproducible lab experiments to aid neuroscientists and neurobiologists in laboratory testing and experimentation. Spaceflight and the Central Nervous System is the first to comprehensively include all aspects of spaceflight-induced changes in the central nervous system. It is an invaluable resource for basic and clinical laboratory trainees and researchers in aerospace medicine and physiology or for those looking to gain specific knowledge in spaceflight neuroscience.

Natural elements and cosmic phenomena in space, such as asteroids, comets, meteors, black holes and super bubbles pose a threat to the planet Earth and spacefarers in the near-Earth environment. Terrestrial and Extraterrestrial Space Dangers describes these dangers in the near-Earth outer space environment. The uniquely risky nature of rocket transportation is documented and quantified. The human health consequences for vision, muscles, and the neurovestibular system, for instance, on exposure to an outer space environment, are also explained in this book. Readers will benefit from the extensive information offered within this text which is also accompanied with a bibliography of references. This book offers a comprehensive primer for anyone interested in space travel and associated risk assessment.

Physiology in extreme conditions can reveal important reactions of the human body, which help our assessment of limits emerging under healthy conditions and critical signals of transition toward disease. While many mechanisms could simply be associated with adaptations, others refer to unexpected reactions in response to internal stimuli and/or external abrupt changes.