Associations of Retinal Oximetry in Healthy Young Adults

PURPOSE. To assess factors associated with retinal oximetry values in healthy young adults. METHODS. Retinal oximetry readings were assessed using the oximetry module of the Vesselmap System in 100 eyes of 50 healthy subjects aged 18 to 58 years. Generalized estimating equation models were used to estimate the associations of candidate variables (age, sex, retinal capillary flow, HbA1c, triglyceride, total cholesterol, ocular perfusion pressure, and finger oxygen saturation [SO2]) with retinal oximetry measures (arteriolar SO2, venular SO2, and the arterio-venous [A-V] difference). RESULTS. Of the candidate factors assessed, only age and finger SO2 were found to be significantly associated with one or more measures of retinal oximetry in unadjusted analyses. After adjusting for age, sex, and significant factors from unadjusted analyses, age and finger SO2 values remained significant. Age was associated with retinal arteriolar and venular SO2 values (per year increase in age, beta = 0.31, 95% confidence interval [CI]: 0.15-0.48 and beta = 0.26, 95% CI: 0.08-0.43, respectively), but not associated with the A-V difference. Finger SO2 values were associated with retinal arteriolar SO2 and A-V difference (per percentage change in finger SO2, beta = 1.34, 95% CI: 0.40-2.28 and beta = 0.74, 95% CI: 0.36-1.11, respectively), but not with venular SO2. CONCLUSIONS. In healthy young adults, age was positively associated with the retinal arteriolar and venular SO2 values, whereas finger SO2 was positively correlated with greater arteriolar SO2 and A-V difference. Our findings serve as a basis for future studies assessing retinal oximetry values in young adults under normal and pathophysiological conditions.