Abstract
Purpose :
Ocular oximetry is an emerging imaging technique that measures oxygen saturation in ocular tissues. The Zilia imaging system is a new technology that uses diffuse reflectance spectroscopy to determine oxygen concentration at a specific point in the retina or the optic nerve. The objective of this study was to verify the repeatability of the oxygen saturation values obtained by Zilia.
Methods :
This study included 17 eyes of 17 patients (12 healthy and 5 patients diagnosed with glaucoma). Three continuous 30-second video measurements (m1, m2, m3) were taken with Zilia, asking the patient to withdraw between each of the measures in order to restart data acquisition. Software analysis was used to obtain the mean oxygen saturation (%), standard deviation, maximum and minimum values for the period of acquisition. In order to minimize possible variations in oximetry measurements, all three recordings were taken within 5 minutes of each other and 30 minutes after pupil dilation. The right eye of patients was selected for statistical analysis, which included a repeated measures ANOVA.
Results :
There was no significant difference between all three measurements of oxygen saturation within subjects, F(2, 32) = 0,129, p = .879. Post hoc analysis using the Bonferonni test indicated that the mean difference did not differ between m1 and m2 (M=0.22, SE=1.0), m1 and m3 (M=0.54, SE=1.18), m2 and m3 (M=0.32, SE=.96).
Conclusions :
Ocular oximetry could be an important tool to understand the pathophysiology of multiple optic nerve and retinal diseases. This study shows that oxygen saturation values obtained with the new Zilia device provide low variability between measurements. Specifically, our results suggest that these values are repeatable. Further studies are needed to better understand the role of oximetry, and the Zilia device, in clinical practice and research in ocular disease.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.