Association of Exercise and Swimming Goggles With Modulation of Cerebro-ocular Hemodynamics and Pressures in a Model of Spaceflight-Associated Neuro-ocular Syndrome.

Autor:	Scott JM; Universities Space Research Association, Houston, Texas.; Memorial Sloan Kettering Cancer Center, New York, New York., Tucker WJ; Integrated Cardiovascular Exercise Physiology and Rehabilitation Laboratory, College of Nursing and Health Innovation, University of Texas at Arlington, Arlington., Martin D; KBRWyle, Houston, Texas., Crowell JB; MEI Technologies, Houston, Texas., Goetchius E; KBRWyle, Houston, Texas., Ozgur O; New York Eye & Ear Infirmary, New York., Hamilton S; New York Eye & Ear Infirmary, New York., Otto C; Universities Space Research Association, Houston, Texas.; Memorial Sloan Kettering Cancer Center, New York, New York., Gonzales R; MEI Technologies, Houston, Texas., Ritter M; KBRWyle, Houston, Texas., Newby N; KBRWyle, Houston, Texas., DeWitt J; KBRWyle, Houston, Texas., Stenger MB; National Aeronautics and Space Administration Johnson Space Center, Houston, Texas., Ploutz-Snyder R; Universities Space Research Association, Houston, Texas.; Applied Biostatistics Laboratory, Department of Systems, Populations, and Leadership, University of Michigan, Ann Arbor., Ploutz-Snyder L; Universities Space Research Association, Houston, Texas.; School of Kinesiology, University of Michigan, Ann Arbor., Morgan WH; Lions Eye Institute, Nedlands, Western Australia, Australia., Haykowsky MJ; Integrated Cardiovascular Exercise Physiology and Rehabilitation Laboratory, College of Nursing and Health Innovation, University of Texas at Arlington, Arlington.
Jazyk:	angličtina
Zdroj:	JAMA ophthalmology [JAMA Ophthalmol] 2019 Jun 01; Vol. 137 (6), pp. 652-659.
DOI:	10.1001/jamaophthalmol.2019.0459
Abstrakt:	Importance: Astronauts on International Space Station missions demonstrate adverse neuro-ocular changes. Reversing a negative translaminar pressure gradient (TLPG) by modulating cerebral blood flow, decreasing intracranial pressure, or increasing intraocular pressure (IOP) has been proposed as potential intervention for spaceflight-associated neuro-ocular syndrome (SANS). Objective: To examine whether exercise (resistance, moderate-intensity aerobic, and high-intensity aerobic) or artificially increasing IOP is associated with modulated cerebro-ocular hemodynamic and pressure changes during head-down tilt (HDT), an analogue of spaceflight, in healthy adults. Design, Setting, and Participants: A single-center investigation was conducted at Johnson Space Center, Houston, Texas, from January 1, 2014, to December 31, 2016, in 20 healthy men. Exposure: On 3 separate days, participants rested supine, were tilted to -15° HDT, and then completed 1 of 3 experimental exercise conditions (moderate-intensity aerobic, resistance, or high-intensity interval aerobic). A subset of 10 participants wore swimming goggles on all days. Main Outcomes and Measures: Applanation rebound tonometry was used to noninvasively assess IOP, and compression sonography was used to assess internal jugular venous pressure (IJVP). Estimated TLPG was calculated as the difference between IOP and IJVP. Cerebral inflow and outflow were measured in extracranial arteries using color-coded duplex ultrasonography. Results: Twenty men participated in the study (mean [SD] age, 36 [9] years). Compared with supine IOP (mean [SD], 19.3 [3.7] mm Hg), IJVP (mean [SD], 21.4 [6.0] mm Hg), and estimated TLPG (mean [SD], -2.1 [7.0] mm Hg), -15° HDT was associated with increased IOP (mean difference, 2.3 mm Hg; 95% CI, 1.4-3.3 mm Hg; P < .001) and IJVP (mean difference, 10.5 mm Hg; 95% CI, 8.9-12.2 mm Hg; P < .001) and with decreased TLPG (mean difference, -8.2 mm Hg; 95% CI, -10.1 to -6.3 mm Hg; P < .001). Exercise (regardless of modality) at -15° HDT was associated with decreased IOP (mean difference, -1.6 mm Hg; 95% CI, -2.6 to -0.6 mm Hg; P = .002) and TLPG (mean difference, -3.5 mm Hg; 95% CI, -6.2 to -0.7 mm Hg; P = .01) compared with rest. Both IOP (mean difference, 2.9 mm Hg; 95% CI, 0.7-5.1 mm Hg; P = .01) and TLPG (mean difference, 5.1 mm Hg; 95% CI, 0.8-9.4 mm Hg; P = .02) were higher in participants who wore swimming goggles compared with those not wearing goggles. Conclusions and Relevance: In this study, exercise was associated with decreased IOP and estimated translaminar pressure gradient in a spaceflight analogue of HDT. The addition of swimming goggles was associated with increased IOP and TLPG in HDT. Further evaluation in spaceflight may be warranted to determine whether modestly increasing IOP is an effective SANS countermeasure.
Databáze:	MEDLINE
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