scholarly journals Assessment of Acute Mild Hypoxia on Retinal Oxygen Saturation Using Snapshot Retinal Oximetry

2013 ◽  
Vol 54 (12) ◽  
pp. 7538 ◽  
Author(s):  
Tushar R. Choudhary ◽  
Derek Ball ◽  
Javier Fernandez Ramos ◽  
Andrew I. McNaught ◽  
Andrew R. Harvey
Keyword(s):  
Oxygen Saturation ◽  
Mild Hypoxia ◽  
Retinal Oximetry

Retinal Oxygen Saturation and Metabolism: How does it Pertain to Glaucoma? An Update on the Application of Retinal Oximetry in Glaucoma

2013 ◽  
Vol 23 (4) ◽  
pp. 465-472 ◽  
Author(s):  
Leslie A. Tobe ◽  
Alon Harris ◽  
Anne Schroeder ◽  
Austin Gerber ◽  
Stephen Holland ◽  
...  
Keyword(s):  
Oxygen Saturation ◽  
Retinal Oximetry

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.

Hemoglobin Oxygen Saturation with Mild Hypoxia and Microgravity

2017 ◽  
Vol 88 (6) ◽  
pp. 527-534
Author(s):  
Johnny Conkin ◽  
James H. Wessel ◽  
Jason R. Norcross ◽  
Omar S. Bekdash ◽  
Andrew F. J. Abercromby ◽  
...  
Keyword(s):  
Oxygen Saturation ◽  
Hemoglobin Oxygen Saturation ◽  
Mild Hypoxia

scholarly journals Changes in retinal venular oxygen saturation predict activity of proliferative diabetic retinopathy 3 months after panretinal photocoagulation

2017 ◽  
Vol 102 (3) ◽  
pp. 383-387 ◽  
Author(s):  
Thomas Lee Torp ◽  
Ryo Kawasaki ◽  
Tien Yin Wong ◽  
Tunde Peto ◽  
Jakob Grauslund
Keyword(s):  
Diabetic Retinopathy ◽  
Oxygen Saturation ◽  
Proliferative Diabetic Retinopathy ◽  
Panretinal Photocoagulation ◽  
Wide Field ◽  
Non Invasive ◽  
Venous Oxygen Saturation ◽  
Treatment Naïve ◽  
Angiographic Findings ◽  
Retinal Oximetry

Background/AimsProliferative diabetic retinopathy (PDR) is a severe blinding condition. We investigated whether retinal metabolism, measured by retinal oximetry, may predict PDR activity after panretinal laser photocoagulation (PRP).MethodsWe performed a prospective, interventional, clinical study of patients with treatment-naive PDR. Wide-field fluorescein angiography (OPTOS, Optomap) and global and focal retinal oximetry (Oxymap T1) were performed at baseline (BL), and 3 months (3M) after PRP. Angiographic findings were used to divide patients according to progression or non-progression of PDR after PRP. We evaluated differences in global and focal retinal oxygen saturation between patients with and without progression of PDR after PRP treatment.ResultsWe included 45 eyes of 37 patients (median age and duration of diabetes were 51.6 and 20 years). Eyes with progression of PDR developed a higher retinal venous oxygen saturation than eyes with non-progression at 3M (global: +5.9% (95% CI –1.5 to 12.9), focal: +5.4%, (95% CI –4.1 to 14.8)). Likewise, progression of PDR was associated with a lower arteriovenular (AV) oxygen difference between BL and 3M (global: –6.1%, (95% CI –13.4 to –1.4), focal: –4.5% (95% CI –12.1 to 3.2)). In a multiple logistic regression model, increment in global retinal venular oxygen saturation (OR 1.30 per 1%-point increment, p=0.017) and decrement in AV oxygen saturation difference (OR 0.72 per 1%-point increment, p=0.016) at 3M independently predicted progression of PDR.ConclusionDevelopment of higher retinal venular and lower AV global oxygen saturation independently predicts progression of PDR despite standard PRP and might be a potential non-invasive marker of angiogenic disease activity.

scholarly journals Automation improves repeatability of retinal oximetry measurements

2021 ◽  
Author(s):  
Robert Arnar Karlsson ◽  
Olof Birna Olafsdottir ◽  
Soumaya Belhadj ◽  
Vedis Helgadottir ◽  
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

AbstractPurposeRetinal 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.MethodsUntil 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.ResultsFor manual 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 manual 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.ConclusionAutomated measurements of retinal oximetry values are more repeatable compared to measurements where vessels are selected manually.

scholarly journals Retinal arteriolar oxygen saturation predicts the need for intravitreal aflibercept in patients with diabetic macular oedema

2020 ◽  
Vol 5 (1) ◽  
pp. e000382
Author(s):  
Søren Leer Blindbæk ◽  
Tunde Peto ◽  
Jakob Grauslund
Keyword(s):  
Oxygen Saturation ◽  
Macular Oedema ◽  
Diabetic Macular Oedema ◽  
First Year ◽  
Intravitreal Aflibercept ◽  
Registration Number ◽  
Treatment Plans ◽  
The Difference ◽  
Retinal Arteriolar ◽  
Retinal Oximetry

ObjectiveGiven the increasing burden of repetitive intravitreal injections in diabetic macular oedema (DMO) treatment, non-invasive markers of treatment outcome are needed. Hence, we aimed to examine retinal oximetry parameters as markers of need for intravitreal aflibercept in patients with DMO.MethodsThis study was based on data from a 12-month clinical trial including 35 eyes of 25 patients with centre involving DMO. Retinal oximetry, visual acuity (VA) and central retinal thickness (CRT) were performed at baseline (BL). Patients then received 3 monthly injections of aflibercept followed by focal/grid laser photocoagulation. From month 4 (M4) through 12 (M12), patients were followed monthly and additional injections were given pro re nata if criteria of retreatment were met. We evaluated the difference in need for intravitreal aflibercept in groups of eyes with the highest and lowest retinal arteriolar and venular oxygen saturations, respectively.ResultsFrom BL-M12, overall VA letter score improved by 8.7 (7.2–10.2). Likewise CRT reduced by 100.7 (68.2–133.3) µm and the mean number of injections was 4.3 (3.8–4.8). Overall retinal arteriolar and venular oxygen saturations were 95.7 (93.0–98.4)% and 62.7 (59.4–65.9)% at BL. Eyes with the highest retinal arteriolar oxygen saturations had significantly more injections between BL and M12 compared with eyes with the lowest retinal arteriolar oxygen saturations (5.0 (4.2–5.8) vs 3.6 (3.1–4.0), p=0.002).ConclusionHigher retinal arteriolar oxygen saturation independently predicted the need for more intravitreal aflibercept during the first year of DMO treatment and may serve as a valuable adjunctive to established procedures for retinal imaging in terms of individualised treatment plans.Trial registration numberNCT02554747

scholarly journals Influencing Factors of Daytime Sleepiness in Patients with Obstructive Sleep Apnea Hypopnea Syndrome and Its Correlation with Pulse Oxygen Decline Rate

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Fengying Zhang ◽  
Xijiang Wu ◽  
Wenping Duan ◽  
Fangfang Wang ◽  
Tingting Huang ◽  
...  
Keyword(s):  
Oxygen Saturation ◽  
Influencing Factors ◽  
Daytime Sleepiness ◽  
Severe Hypoxia ◽  
Moderate Hypoxia ◽  
Hypoxia Group ◽  
Significant Difference ◽  
Decline Rate ◽  
Simple Snoring ◽  
Mild Hypoxia

Objective. To explore the influencing factors of daytime sleepiness in patients with obstructive sleep apnea hypopnea syndrome (OSAHS) and the correlation between daytime sleepiness and pulse oxygen decline rate in patients with severe OSAHS. Methods. From January 2018 to April 2021, 246 consecutive patients with OSAHS diagnosed by polysomnography (PSG) in our hospital were selected. All patients were grouped according to the minimum nocturnal oxygen saturation and apnea hypopnea index (AHI). There were 33 cases in the no sleep hypoxia group, 34 cases in the mild hypoxia group, 119 cases in the moderate hypoxia group, and 60 cases in the severe hypoxia group. There were 30 cases in the simple snoring group, 55 cases in the mild OSAHS group, 48 cases in the moderate OSAHS group, and 113 cases in the severe OSAHS group. The Epworth Sleepiness Scale (ESS) scores of each group were compared. All patients were grouped according to ESS score. Those with score ≥9 were included in the lethargy group (n = 118), and those with score ≤10 were included in the no lethargy group (n = 128). Univariate and multivariate logistic regression analyses were used to explore the influencing factors of daytime sleepiness in OSAHS patients. Pearson correlation analysis showed the correlation between ESS score and pulse oxygen decline rate in patients with severe OSAHS. Results. The ESS score of the severe hypoxia group > the moderate hypoxia group > the mild hypoxia group > the no sleep hypoxia group. There was significant difference among the groups (F = 19.700, P < 0.0001 ). There were significant differences between the severe hypoxia group and other groups and between the moderate hypoxia group and the no sleep hypoxia group and the mild hypoxia group ( P < 0.05 ). The ESS score of the severe OSAHS group > the moderate OSAHS group > the mild OSAHS group > the simple snoring group. There was significant difference among the groups (F = 19.000, P < 0.0001 ). There were significant differences between the severe OSAHS group and other groups and between the moderate OSAHS group and the simple snoring group ( P < 0.05 ). Univariate analysis showed that BMI, neck circumference, snoring degree, total apnea hypopnea time, AHI, micro arousal index (MAI), oxygen saturation (CT90%), lowest oxygen saturation (LSaO2), and mean oxygen saturation (MSaO2) were the influencing factors of daytime sleepiness in OSAHS patients ( P < 0.05 ). Multiple logistic regression analysis showed that AHI and CT90% were independent risk factors for daytime sleepiness in OSAHS patients ( P < 0.05 ). Pearson correlation analysis showed that there was a positive correlation between ESS score and pulse oxygen decline rate in patients with severe OSAHS (r = 0.765, P < 0.0001 ). Conclusion. OSAHS patients may be accompanied by daytime sleepiness in varying degrees, which may be independently related to AHI and CT90%. The degree of daytime sleepiness in patients with severe OSAHS may be closely related to the decline rate of pulse oxygen, which should be paid great attention in clinic.

scholarly journals Current Use of Automatic Retinal Oximetry – a Review

2020 ◽  
Vol 76 (1) ◽  
pp. 3-11
Author(s):  
Petra Hübnerová ◽  
Petr Mlčák ◽  
Irena Šínová ◽  
Marta Karhanová ◽  
Martin Šín
Keyword(s):  
Oxygen Saturation ◽  
Retinal Vein Occlusion ◽  
Interdisciplinary Cooperation ◽  
Eye Diseases ◽  
Systemic Diseases ◽  
High Reproducibility ◽  
Non Invasive ◽  
Vein Occlusion ◽  
Pathological Mechanism ◽  
Retinal Oximetry

Purpose: To inform about possible use of the automatic retinal oximetry for the retinal oxygen saturation measurement in the eye and systemic diseases. Methods: We performed a literature review dealing with issues of retinal oxygen saturation monitoring by dual non-invasive retinal oximetry Oxymap T1 (Oxymap ehf. Reykjavík, Iceland). Results: We have found two main strains writing our paper on retinal oxygen saturation eye diseases. The first section concerns diseases created by having hypoxia as its main pathological factor - for example diabetes mellitus and retinal vein occlusion. The second group deals with atrophy as the main pathological mechanism which is typical for decreasing retinal oxygen consumption – for example glaucoma or retinitis pigmentosa (the second one named is not included in our work). Oximetry in systemic diseases creates a relatively new chapter of this branch with a very big potential of interdisciplinary cooperation for the future. It is possible the cooperation will not only include diabetologists but also neurologists (for example, in diseases like sclerosis multiplex or Devic‘s, Alzheimer‘s and Parkinson‘s disease) and haematologists (retinal oxygen saturation changes in patients with different rheological attributes of blood). Conclusion: Retinal oxygen saturation measuring by automatic retinal oximetry is a relatively new method with scientifically confirmed high reproducibility of results. Currently it is the only experimental method with vast potentials not only in the realm of the possibility of observing eye diseases (diabetic retinopathy, retinal vein occlusion or glaucoma) but also in developing interdisciplinary cooperation with diabetologists, neurologists and haematologists.

scholarly journals Optic disc centered imaging versus quadrant imaging in retinal oximetry

2018 ◽  
Author(s):  
Ashwin Mohan ◽  
Rohit Shetty ◽  
Padmamalini Mahendradas ◽  
Carroll AB Webers ◽  
Tos TJM Berendschot
Keyword(s):  
Oxygen Saturation ◽  
Optic Disc ◽  
Negative Correlation ◽  
Healthy Subjects ◽  
Retinal Vessel ◽  
Positive Correlation ◽  
Retinal Oximetry

AbstractWe aimed to compare intra eye quadrant variation in retinal vessel oxygen saturation in optic disc centered versus quadrant imaging. Forty two consecutive healthy subjects were included in the study. Fifty degree optic disc centered images and images of 4 quadrants (supero-temporal - ST, supero-nasal - SN, infero-nasal - IN and infero-temporal - IT) were taken. The thickest arteriole and venule were chosen in each quadrant in the optic disc centered images. For quadrant images averaged values of 3 segments of thickest arterioles and venules, each above 100µm were chosen. The intra-eye variation between quadrants for arteriolar and venous saturation (%) was compared between optic disc centered and quadrant images. Smaller vessels (70 – 100 µm) in the quadrant images were selected to study the effect of vessel calibre on oxygen saturation. Optic disc centered images gave average arteriolar saturation (%) of 90, 94, 93 and 89 and venous saturation of 58, 60, 60 and 52 in the ST, SN, IN and IT respectively. For quadrant images the average arteriolar saturation was 94, 95, 94 and 91 and the venous saturation was 62, 60, 61 and 60 in the ST, SN, IN and IT respectively. Temporally, the saturation values were significantly different (p<0.001) between optic disc centered and quadrant images. We found no differences nasally. The average intra eye range for arterioles was 11.9 in optic disc centered versus 7.1 in quadrant images (p<0.001) and for venules was 11.6 in optic disc centered versus 7.5 in quadrant images (p<0.001). We found a positive correlation of r=0.18 between saturation and vessel calibre for arteries (p=0.001) and a negative correlation of r=-0.52 for venes (p<0.001). Quadrant imaging significantly reduced intra eye variation between quadrant measurements indicating that maybe the larger variation observed in optic disc centered images are artefactual. Differences in saturation between optic disc centered and quadrant imaging were only seen temporally. We also see physiologically reducing saturation from large arterioles to small arterioles to small venules to large venules.

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