Abstract
Purpose :
We have recently presented a method to measure oxygen extraction of
the human retina. This technique combines measurement of total retinal blood flow using Doppler Optical Coherence Tomography (OCT) with the measurement of oxygen saturation using spectrometric reflectometry. In the present study we investigated whether oxygen extraction is altered in patients with glaucoma.
Methods :
A total of 40 patients with primary open angle glaucoma (POAG) and 40 healthy age and sex matched subjects were included in the study. Retinal blood flow was measured by bi-directional Doppler OCT. Oxygen saturation was assessed using reflectometry. Retinal oxygen saturation was calculated based on retinal blood flow data and oxygen saturation according to a previously published model.
Results :
Total retinal blood flow was reduced in patients with POAG compared to the healthy group (p<0.05). Calculated oxygen extraction was significantly lower in patients with POAG than in healthy subjects (p<0.05). Total retinal blood flow was significantly correlated with visual field defect (r=0.43, r<0.05). Further, calculated total retinal oxygen extraction was significantly correlation with mean visual field defect (r=0.55, p<0.05).
Conclusions :
Patients with POAG show reduced total retinal blood flow compared to healthy, age-matched subjects. Further, our data indicates that calculated retinal oxygen extraction is lower in patients with POAG and that oxygen extraction is correlated with the amount of visual field defect. Whether this is a cause or a consequence of the disease is unknown and needs to be further investigated in longitudinal studies.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.