Retinal vessel regulation at high altitudes1
| Autor: | Stefan Drinda, Thomas Neumann, Andreas Brückmann, Michael Baertschi, Gunter Wolf, Marcus Franz, Walthard Vilser, Christian Jung |
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| Rok vydání: | 2016 |
| Předmět: |
Adult
Male medicine.medical_specialty Physiology 030204 cardiovascular system & hematology Constriction 03 medical and health sciences chemistry.chemical_compound Young Adult 0302 clinical medicine Physiology (medical) Internal medicine medicine Humans Macitentan Oxygen saturation (medicine) Aged business.industry Endothelin receptor antagonist Altitude Retinal Vessels Retinal Hematology Effects of high altitude on humans Hypoxia (medical) Middle Aged Cell Hypoxia Retinal vessel chemistry Cardiology Female medicine.symptom Cardiology and Cardiovascular Medicine business 030217 neurology & neurosurgery |
| Zdroj: | Clinical hemorheology and microcirculation. 63(3) |
| ISSN: | 1875-8622 |
| Popis: | PURPOSE To measure static and dynamic changes of retinal vessels in response to normobaric hypoxia (NH, study A) and hypobaric hypoxia (HH, study B). METHODS Study A included 10 healthy individuals exposed to a simulated altitude of 5500 meters in a NH chamber; study B included 17 individuals studied after ascent to 3000-meter altitude. Retinal vessel diameter, response to flicker light, retinal oxygen saturation and retinal venous pressure were measured at baseline, under the corresponding hypoxia condition. The effects of macitentan, an endothelin receptor antagonist, were examined in study B. RESULTS The mean age of participants was 34.6±9.3 years in study A and 36.7±10.8 years in study B. Retinal arterial and venous diameter increased, arterial and venous response to flicker light decreased, while retinal oxygen saturation remained stable under both experimental conditions. Retinal venous pressure increased in six individuals after ascent to 3000 meters and normalized after macitentan treatment. The occurrence of acute mountain sickness (AMS) correlated only with the decrease of arterial constriction after ascent to 3000 meters. CONCLUSIONS Retinal arterial and venous vessels react to NH and HH with a diameter increase and an impaired response to flicker light. Macitentan was capable to normalize the increased retinal venous pressure observed at high altitudes. |
| Databáze: | OpenAIRE |
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