| Title: |
Hypoxic, hypercapnic, and hyperoxic responses of the optic nerve head and subfoveal choroid blood flow in healthy humans |
| Authors: |
Gallice, Mathilde; Zhou, Thierry; Aptel, Florent; Verges, Samuel; Riva, Charles; Geiser, Martial; Chiquet, Christophe |
| Source: |
http://arodes.hes-so.ch/record/9671. |
| Publication Year: |
2022 |
| Collection: |
Hes-so: ArODES Open Archive (University of Applied Sciences and Arts Western Switzerland / Haute école spécialisée de Suisse occidentale) |
| Description: |
Purpose: To investigate the impact of different gas mixtures (hyperoxia, hypoxia, and hypercapnia) on the optic nerve head (ONH) and choroidal (Ch) hemodynamics. Methods: Twenty-three healthy subjects (28 ± 6 years) took part in the study. Variations in inspired oxygen and carbon dioxide fraction were produced by a gas mixing device. Arterial oxygen saturation (SpO2) was measured continuously using a transcutaneous sensor and end-tidal carbon dioxide partial pressure by capnography. The experiment comprised three successive periods: 3-minute baseline (room air breathing), 15-minute gas mixture inhalation (normocapnic hypoxia, hypercapnia, or hyperoxia), and 15-minute recovery (room air breathing). Laser Doppler flowmeter parameters—velocity (VEL), volume (VOL), and flow (BF) of red blood cells—were measured. Two-way ANOVAs were performed for statistical analysis. Results: In response to hyperoxia, ONHBF significantly decreased by −18% ± 6% (P = 0.04) from baseline, due to significant changes in VEL (−12% ± 3% P = 0.0002). During hypoxia at 85% SpO2, ONH VEL increased by +12% ± 3% (P = 0.0009), whereas VOL and BF did not change significantly. ChBF significantly increased by +7% ± 2% (P = 0.004) in response to hypoxia, due to significant changes in VEL +5% ± 2% (P = 0.03). Both Ch and ONHBFs did not vary significantly in response to hypercapnia. Conclusions: The magnitude of the blood flow response is the most significant during hyperoxia for ONH and hypoxia for ChBF. For ONHBF, a 37% difference between hyperoxia and hypoxia can be useful when vasoreactivity to O2 will be tested in patients. |
| Document Type: |
text |
| Language: |
English |
| DOI: |
10.1167/iovs.17-21855 |
| Availability: |
https://doi.org/10.1167/iovs.17-21855; http://arodes.hes-so.ch/record/9671 |
| Accession Number: |
edsbas.8C3AADB6 |
| Database: |
BASE |