Retinal vessel oxygen saturation and vessel diameter in healthy individuals during high‐altitude exposure

2018 ◽  
Vol 97 (3) ◽  
pp. 279-286 ◽  
Author(s):  
Yiquan Yang ◽  
Diya Yang ◽  
Yunxiao Sun ◽  
Yuan Xie ◽  
Zheng Zhang ◽  
...  
Keyword(s):  
Oxygen Saturation ◽  
High Altitude ◽  
Retinal Vessel ◽  
Vessel Diameter ◽  
Healthy Individuals ◽  
Altitude Exposure

Retinal vessel oxygen saturation and vessel diameter in high myopia

2015 ◽  
Vol 35 (5) ◽  
pp. 562-569 ◽  
Author(s):  
Qishan Zheng ◽  
Yao Zong ◽  
Li Li ◽  
Xia Huang ◽  
Leilei Lin ◽  
...  
Keyword(s):  
Oxygen Saturation ◽  
High Myopia ◽  
Retinal Vessel ◽  
Vessel Diameter

Retinal Vessel Oxygen Saturation in Healthy Individuals

2012 ◽  
Vol 53 (9) ◽  
pp. 5433 ◽  
Author(s):  
Asbjorg Geirsdottir ◽  
Olafur Palsson ◽  
Sveinn Hakon Hardarson ◽  
Olof Birna Olafsdottir ◽  
Jona Valgerdur Kristjansdottir ◽  
...  
Keyword(s):  
Oxygen Saturation ◽  
Retinal Vessel ◽  
Healthy Individuals

Retinal Vessel Oxygen Saturation and Vessel Diameter in Inactive Graves Ophthalmopathy

2017 ◽  
Vol 33 (6) ◽  
pp. 459-465 ◽  
Author(s):  
Xiaonan Yang ◽  
Danping Huang ◽  
Siming Ai ◽  
Xuanwei Liang ◽  
Jing Zhao ◽  
...  
Keyword(s):  
Oxygen Saturation ◽  
Retinal Vessel ◽  
Vessel Diameter ◽  
Graves Ophthalmopathy

scholarly journals Automation improves repeatability of retinal oximetry measurements

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0260120
Author(s):  
Robert Arnar Karlsson ◽  
Olof Birna Olafsdottir ◽  
Vedis Helgadottir ◽  
Soumaya Belhadj ◽  
Thorunn Scheving Eliasdottir ◽  
...  
Keyword(s):  
Oxygen Saturation ◽  
Intraclass Correlation ◽  
Retinal Vessel ◽  
Vessel Diameter ◽  
Automated Measurements ◽  
Automation Of Measurements ◽  
Image Pairs ◽  
The Right ◽  
Measurement Area ◽  
Retinal Oximetry

Purpose Retinal oximetry is a technique based on spectrophotometry where images are analyzed with software capable of calculating vessel oxygen saturation and vessel diameter. In this study, the effect of automation of measurements of retinal vessel oxygen saturation and vessel diameter is explored. Methods Until now, operators have had to choose each vessel segment to be measured explicitly. A new, automatic version of the software automatically selects the vessels once the operator defines a measurement area. Five operators analyzed image pairs from the right eye of 23 healthy subjects with semiautomated retinal oximetry analysis software, Oxymap Analyzer (v2.5.1), and an automated version (v3.0). Inter- and intra-operator variability was investigated using the intraclass correlation coefficient (ICC) between oxygen saturation measurements of vessel segments in the same area of the retina. Results For semiautomated saturation measurements, the inter-rater ICC was 0.80 for arterioles and venules. For automated saturation measurements, the inter-rater ICC was 0.97 for arterioles and 0.96 for venules. For semiautomated diameter measurements, the inter-rater ICC was 0.71 for arterioles and venules. For automated diameter measurements the inter-rater ICC was 0.97 for arterioles and 0.95 for venules. The inter-rater ICCs were different (p < 0.01) between the semiautomated and automated version in all instances. Conclusion Automated measurements of retinal oximetry values are more repeatable compared to measurements where vessels are selected manually.

Retinal vessel diameter affects oxygen saturation measurements

2010 ◽  
Vol 88 ◽  
pp. 0-0
Author(s):  
SH HARDARSON ◽  
HR BERGVINSSON ◽  
E STEFANSSON
Keyword(s):  
Oxygen Saturation ◽  
Retinal Vessel ◽  
Vessel Diameter ◽  
Retinal Vessel Diameter

scholarly journals Physiology in Medicine: Acute altitude exposure in patients with pulmonary and cardiovascular disease

2014 ◽  
Vol 116 (5) ◽  
pp. 478-485 ◽  
Author(s):  
Leigh M. Seccombe ◽  
Matthew J. Peters
Keyword(s):  
Cardiovascular Disease ◽  
High Altitude ◽  
Cardiac Disease ◽  
Healthy Individuals ◽  
Commercial Aircraft ◽  
Altitude Exposure ◽  
Rapid Access

Travel is more affordable and improved high-altitude airports, railways, and roads allow rapid access to altitude destinations without acclimatization. The physiology of exposure to altitude has been extensively described in healthy individuals; however, there is a paucity of data pertaining to those who have reduced reserve. This Physiology in Medicine article discusses the physiological considerations relevant to the safe travel to altitude and by commercial aircraft in patients with pulmonary and/or cardiac disease.

scholarly journals Retinal vessel oxygen saturation and vessel diameter in retinitis pigmentosa

2014 ◽  
Vol 92 (5) ◽  
pp. 449-453 ◽  
Author(s):  
Thor Eysteinsson ◽  
Sveinn H. Hardarson ◽  
David Bragason ◽  
Einar Stefánsson
Keyword(s):  
Retinitis Pigmentosa ◽  
Oxygen Saturation ◽  
Retinal Vessel ◽  
Vessel Diameter

scholarly journals UBC-Nepal expedition: markedly lower cerebral blood flow in high-altitude Sherpa children compared with children residing at sea level

2017 ◽  
Vol 123 (4) ◽  
pp. 1003-1010 ◽  
Author(s):  
Daniela Flück ◽  
Laura E. Morris ◽  
Shailesh Niroula ◽  
Christine M. Tallon ◽  
Kami T. Sherpa ◽  
...  
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Oxygen Saturation ◽  
High Altitude ◽  
Sea Level ◽  
Vessel Diameter ◽  
Cerebral Hemodynamic ◽  
Hemodynamic Pattern ◽  
End Tidal

Developmental cerebral hemodynamic adaptations to chronic high-altitude exposure, such as in the Sherpa population, are largely unknown. To examine hemodynamic adaptations in the developing human brain, we assessed common carotid (CCA), internal carotid (ICA), and vertebral artery (VA) flow and middle cerebral artery (MCA) velocity in 25 (9.6 ± 1.0 yr old, 129 ± 9 cm, 27 ± 8 kg, 14 girls) Sherpa children (3,800 m, Nepal) and 25 (9.9 ± 0.7 yr old, 143 ± 7 cm, 34 ± 6 kg, 14 girls) age-matched sea level children (344 m, Canada) during supine rest. Resting gas exchange, blood pressure, oxygen saturation and heart rate were assessed. Despite comparable age, height and weight were lower (both P < 0.01) in Sherpa compared with sea level children. Mean arterial pressure, heart rate, and ventilation were similar, whereas oxygen saturation (95 ± 2 vs. 99 ± 1%, P < 0.01) and end-tidal Pco2 (24 ± 3 vs. 36 ± 3 Torr, P < 0.01) were lower in Sherpa children. Global cerebral blood flow was ∼30% lower in Sherpa compared with sea level children. This was reflected in a lower ICA flow (283 ± 108 vs. 333 ± 56 ml/min, P = 0.05), VA flow (78 ± 26 vs. 118 ± 35 ml/min, P < 0.05), and MCA velocity (72 ± 14 vs. 88 ± 14 cm/s, P < 0.01). CCA flow was similar between Sherpa and sea level children (425 ± 92 vs. 441 ± 81 ml/min, P = 0.52). Scaling flow and oxygen uptake for differences in vessel diameter and body size, respectively, led to the same findings. A lower cerebral blood flow in Sherpa children may reflect specific cerebral hemodynamic adaptations to chronic hypoxia. NEW & NOTEWORTHY Cerebral blood flow is lower in Sherpa children compared with children residing at sea level; this may reflect a cerebral hemodynamic pattern, potentially due to adaptation to a hypoxic environment.

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