TY - CHAP

T1 - Glymphatic system and Spaceflight Associated Neuro-Ocular Syndrome

AU - Wostyn, Peter

AU - Nedergaard, Maiken

N1 - Publisher Copyright: © 2022 Elsevier Inc. All rights reserved.

PY - 2022

Y1 - 2022

N2 - A spectrum of ophthalmic abnormalities, including optic disc edema, globe flattening, chorioretinal folds, and hyperopic refractive error shifts, has been observed in astronauts during and after long-duration spaceflight. An increased understanding of factors contributing to this syndrome, initially termed “visual impairment and intracranial pressure syndrome” and recently renamed "Spaceflight Associated Neuro-Ocular Syndrome" (SANS), is currently a top priority for space agencies. At present, the exact mechanisms causing SANS are not completely understood. Elevated intracranial pressure and compartmentalization of cerebrospinal fluid within the orbital optic nerve sheath have been proposed as possible explanations for SANS. A novel potential mechanism of microgravity-induced optic disc edema pertains to the “ocular glymphatic system” concept and proposes that it may result, at least partly, from an imbalance of glymphatic fluid transport at the level of the optic nerve head. We propose that additional studies will play a critical role in understanding the contribution of the ocular glymphatic system in optic disc edema in SANS.

AB - A spectrum of ophthalmic abnormalities, including optic disc edema, globe flattening, chorioretinal folds, and hyperopic refractive error shifts, has been observed in astronauts during and after long-duration spaceflight. An increased understanding of factors contributing to this syndrome, initially termed “visual impairment and intracranial pressure syndrome” and recently renamed "Spaceflight Associated Neuro-Ocular Syndrome" (SANS), is currently a top priority for space agencies. At present, the exact mechanisms causing SANS are not completely understood. Elevated intracranial pressure and compartmentalization of cerebrospinal fluid within the orbital optic nerve sheath have been proposed as possible explanations for SANS. A novel potential mechanism of microgravity-induced optic disc edema pertains to the “ocular glymphatic system” concept and proposes that it may result, at least partly, from an imbalance of glymphatic fluid transport at the level of the optic nerve head. We propose that additional studies will play a critical role in understanding the contribution of the ocular glymphatic system in optic disc edema in SANS.

KW - Astronaut

KW - Cerebrospinal fluid

KW - Intracranial pressure

KW - Ocular glymphatic system

KW - Optic disc edema

KW - Spaceflight Associated Neuro-Ocular Syndrome

KW - Trans-lamina cribrosa pressure difference

U2 - 10.1016/B978-0-323-91524-3.00016-8

DO - 10.1016/B978-0-323-91524-3.00016-8

M3 - Book chapter

AN - SCOPUS:85142754075

SN - 9780323915250

SP - 67

EP - 76

BT - Spaceflight Associated Neuro-Ocular Syndrome

PB - Elsevier

ER -