Reproducibility of retinal oximetry measurements in healthy and diseased retinas

Abstract

AbstractPurpose Retinal oximetry (RO) has been established as a non‐invasive method to analyse oxygen saturation in retinal vessels. The aim of our study was to determine the reproducibility of RO images in healthy and in diseased retinas.Methods A total of 46 right eyes (184 oximetry images) in 46 subjects (21♂, 25 ♀) were examined: 16 controls, 10 glaucoma patients and 20 patients with inherited retinal diseases. Four test‐retest RO images were obtained in each subject. Oxygen saturation was measured with the oxygen saturation measurement tool of the Retinal Vessel Analyser (RVA, IMEDOS Systems UG, Jena, Germany). The test‐retest standard deviation within the subject (±SDw) of the mean vessel oxygen saturation in retinal veins and in arteries, its coefficient of variation (CoV) and the interclass correlation coefficients (ICC) were analysed.Results The average test re‐test SDw in veins was ± 2.52% (CoV=4.30%) and in arteries ±1.62% (CoV=1.72%). Among controls, glaucoma eyes and eyes with inherited retinal diseases, the test re‐test SDw in veins were: ±2.17% (CoV=4.11%), ±2.81% (CoV=4.64%) and ±2.66% (CoV=4.28%) (p=0.361; one‐way ANOVA) respectively. The test‐retest SDw in arteries were: ±1.53% (CoV=1.65%), ±1.44% (CoV= 1.05%) and ± 1.83% (CoV=1.91%), respectively (p=0.633). The ICCs in veins were 0.77 in controls, 0.76 in glaucoma patients and 0.83 in patients with inherited retinal disease. The ICCs in arteries were respectively: 0.92, 0.77, and 0.93.Conclusion Reproducibility of retinal oxygen saturation in healthy, as well as in diseased retinas is excellent. Measurements in arteries seem more reliable when compared to veins.