Background: Effects of hypobarism and hypoxia on visual performance and mainly on contrast sensitivity (CS) are well known. The purpose of this study was to compare the adjustments of corneal thickness in hypobaric hypoxia conditions with changes in contrast sensitivity.
Methods: There were 12 healthy, emmetropic subjects assigned to the 14(th) Wing Aircrew based in Pratica di Mare AFB (Rome, Italy) who were evaluated for changes occurring in central corneal thickness (CCT), measured by portable ultrasonic pachymeter, and CS, assessed after reading the standard Pelli-Robson charts, during modification of atmospheric pressure and, therefore, of oxygen partial pressure.
Results: Hypobaric hypoxia conditions in pilots raised CCT (550 μm to 600 μm) and reduced CS (1.95 log to 1.05 log) in a statistically significant result.
Discussion: The study demonstrated that hypoxia and variations of atmospheric pressure may produce corneal edema, including changes of CCT and, correlatively, CS reduction.
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http://dx.doi.org/10.3357/AMHP.3938.2015 | DOI Listing |
Exp Eye Res
January 2025
Department of Ophthalmology, The Second Hospital &Clinical Medical School, Lanzhou University, Gansu, 730000, China. Electronic address:
The mechanisms underlying the low incidence of myopia at high altitudes remain unclear. Choroidal thickness and the dopaminergic system have been shown to be closely associated with myopia development. This study aimed to investigate the effects of high altitude exposure on choroidal thickness and the dopaminergic system.
View Article and Find Full Text PDFTissue Cell
January 2025
Department of Human and Animal Physiology, Yerevan State University, Yerevan, 1 Alek Manukyan St, Yerevan 0025, Armenia; Research Institute of Biology, Yerevan State University, Yerevan, 1 Alek Manukyan St, Yerevan 0025, Armenia. Electronic address:
High altitude characterized by the low partial pressure of the oxygen is a life-threatening condition that contributes to the development of acute pulmonary edema and hypoxic lung injury. In this study, we aimed to investigate the contribution of some inflammatory and oxidative stress markers along with antioxidant system enzymes in the pathogenesis of HAPE (high-altitude pulmonary edema) formation. We incorporated the study on 42 male rats to unravel the role of mast cells (MCs) and TNF-α in the lung after the effect of acute hypobaric hypoxia.
View Article and Find Full Text PDFCornea
January 2025
Department of Ophthalmology, Rothschild Foundation, Paris, France; and.
Purpose: The purpose of this study was to investigate the effect of hypoxia and hypobaric conditions on refraction and central corneal thickness on healthy corneas during an ascent without oxygen supplementation above 7000 m (23 000 ft).
Methods: Twelve multinational mountaineers were included in a prospective observational cohort study during an expedition to the Korzhenevskoi Peak (7105 m). The two patients excluded from the study had a history with keratoconus or were current wearers of rigid contact lenses.
Chronic exposure to high altitudes causes pathophysiological cardiac changes that are characterized by cardiac dysfunction, cardiac hypertrophy, and decreased energy reserves. However, finding specific pharmacological interventions for these pathophysiological changes is challenging. In this study, we identified tetramethylpyrazine (TMP) as a promising drug candidate for cardiac dysfunction caused by simulated high-altitude exposure.
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