Response of retinal blood flow to systemic hyperoxia as measured with dual‐beam bidirectional Doppler Fourier‐domain optical coherence tomography

Abstract

AbstractPurpose Much effort was directed towards the quantification of retinal blood flow in the past decades. In the recent years, optical coherence tomography (OCT) based systems were introduced to measure retinal perfusion. The current study compares a new technique, dual beam bidirectional Doppler Fourier domain OCT (FD‐OCT), with laser Doppler velocimeter (LDV), while breathing ambient air and pure oxygen.Methods 10 healthy volunteers were included into the present study and two study days were scheduled. On one study day assessment of the effect of 100% O2 breathing on retinal blood velocities was performed using FD‐OCT. LDV was used to investigate retinal blood velocities on the other study day. In addition to velocity measurements retinal vessel diameters were assessed with Dynamic Vessel Analyzer (DVA, Imedos, Germany). Baseline data as well as hyperoxia data were compared between each study day.Results Reduced vessel diameters, velocities and blood flow were found while breathing 100% O2 compared to baseline. Our findings showed a high correlation between retinal blood velocities obtained with the OCT system and the LDV during baseline and under hyperoxia (p<0.01 each). However, velocities measured with the OCT were slightly higher.Conclusion Good correlation was found between dual‐beam bidirectional Doppler FD‐OCT and LDV data. Dual‐beam bidirectional Doppler FD‐OCT is a promising approach for studying retinal blood flow in vivo.