Retinal oxygen saturation in Chinese adolescents.

PURPOSE

To study the retinal oxygen saturation in normal eyes of Chinese adolescents.

METHODS

Performing retinal oximetry with the Oxymap T1 Retinal Oximeter in healthy children and adolescents (aged 5-18 years old), we measured the arterial (SaO ) and venular (SvO ) oxygen saturation and the arteriovenous difference in oxygen saturation (Sa-vO ).

RESULTS

The study included 122 individuals with a mean age of 13.0 ± 2.9 years (range: 5-18 years) and a mean refractive error of -3.25 ± 2.49 dioptres (range:-8.88 to +3.13 dioptres). Mean SaO , SvO and Sa-vO was 85.5 ± 7.1%, 48.2 ± 5.5% and 37.3 ± 6.5%, respectively. Mean SaO was significantly (p < 0.001) the lowest in the inferotemporal quadrant (79.1 ± 9.0%), followed by the superotemporal quadrant (83.4 ± 9.7%), the inferonasal quadrant (90.4 ± 10.6%) and the superonasal quadrant (93.4 ± 10.8%). In a similar manner, the values of the SvO were the lowest (p < 0.001) in the inferotemporal quadrant (42.1 ± 8.3%), followed by the superotemporal quadrant (47.8 ± 7.2%), the inferonasal quadrant (52.3 ± 8.4%) and the superonasal quadrant (55.1 ± 7.6%). Arteriovenous difference in oxygen saturation (Sa-vO ) did not differ significantly (all p > 0.05) between the fundus quadrants. In multiple linear regression analysis, SaO increased (regression coefficient r = 0.28) with older age (standardized regression coefficient β: 0.23; p = 0.01) and more myopic refractive error (β: -0.39; p < 0.001). Higher SvO was significantly correlated with more myopic refractive error (β: -0.46; p < 0.001; r = 0.20), while Sa-vO increased significantly only with older age in the multivariate analysis (β: 0.26; p = 0.01; r = 0.07).

CONCLUSIONS

Our study provides normative data for Chinese children and adolescents who showed lower values than adults for SaO and SvO . SaO increased with older age and higher myopic refractive error, SvO increased with higher myopic refractive error, and Sa-vO increased with older age.