Effects of Venoconstrictive Thigh Cuffs on Dry Immersion-Induced Ophthalmological Changes

Autor: Marc Kermorgant, Ayria Sadegh, Thomas Geeraerts, Fanny Varenne, Jérémy Liberto, François-Philippe Roubelat, Noémie Bataille, Marie-Pierre Bareille, Arnaud Beck, Brigitte Godard, Adrianos Golemis, Nathalie Nasr, Dina N. Arvanitis, Ophélie Hélissen, Jean-Michel Senard, Anne Pavy-Le Traon, Vincent Soler
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Frontiers in Physiology, Vol 12 (2021)
Druh dokumentu: article
ISSN: 1664-042X
DOI: 10.3389/fphys.2021.692361
Popis: Neuro-ophthalmological changes named spaceflight associated neuro-ocular syndrome (SANS) reported after spaceflights are important medical issues. Dry immersion (DI), an analog to microgravity, rapidly induces a centralization of body fluids, immobilization, and hypokinesia similar to that observed during spaceflight. The main objectives of the present study were 2-fold: (1) to assess the neuro-ophthalmological impact during 5 days of DI and (2) to determine the effects of venoconstrictive thigh cuffs (VTC), used as a countermeasure to limit headward fluid shift, on DI-induced ophthalmological adaptations. Eighteen healthy male subjects underwent 5 days of DI with or without VTC countermeasures. The subjects were randomly assigned into two groups of 9: a control and cuffs group. Retinal and optic nerve thickness were assessed with spectral-domain optical coherence tomography (OCT). Optic nerve sheath diameter (ONSD) was measured by ocular ultrasonography and used to assess indirect changes in intracranial pressure (ICP). Intraocular pressure (IOP) was assessed by applanation tonometry. A higher thickness of the retinal nerve fiber layer (RNFL) in the temporal quadrant was observed after DI. ONSD increased significantly during DI and remained higher during the recovery phase. IOP did not significantly change during and after DI. VTC tended to limit the ONSD enlargement but not the higher thickness of an RNFL induced by DI. These findings suggest that 5 days of DI induced significant ophthalmological changes. VTC were found to dampen the ONSD enlargement induced by DI.
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