Normative values of retinal vessel oximetry in healthy children against adults

Abstract

Background: 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 compare the RO parameters of healthy children to those in adults. Methods: A total of 200 eyes of 104 healthy subjects were examined: 20 eyes of children aged <10 years and 62 eyes of children aged 10–19 years were compared to the eyes of adult controls from five different age groups (20–29 years:n = 24; 30–39 years:n = 32; 40–49 years:n = 15; 50–59 years:n = 20, 60–80 years:n = 27; n indicates the number of analysed eyes). The oxygen saturation was estimated with the oxygen saturation measurement tool of the Retinal Vessel Analyser (RVA; IMEDOS Systems UG, Jena, Germany). The global oxygen saturations, within 1.0–1.5 optic disc diameters from the disc margin, in the peripapillary retinal arterioles (A-SO2; %) and venules (V-SO2; %) were estimated and their difference (A-V SO2; %) was calculated. In addition, we evaluated the mean diameter in all four major retinal arterioles (D-A; μm) and venules (D-V; μm). The ratio between venular and arterial vessel diameter (D-V/A; μm) was calculated thereafter. For statistical evaluation, anova-based linear mixed-effects models were calculated with spss®. Results: Based on our results, younger children (<10 years) present a statistically significant lower A-SO2 and A-V SO2 when compared to adult subgroups. The D-A values revealed to be significantly lower in 10 + children when compared to the other groups, while the D-V values did not show significant differences. Conclusion: These data indicate that the retinal oxygen metabolism changes throughout lifetime. Therefore, normative data for different age groups are mandatory.