Quantitative Analysis of Retinal Blood Flow in Normal and Glaucoma by Doppler Fourier-Domain Optical Coherence Tomography

Abstract

Purpose: To compare the total retinal blood flow (TRBF) in Normals, pre-perimetric glaucoma (PPG) and perimetric glaucoma (PG) eyes using Doppler Fourier-domain optical coherence tomography (FD-OCT) scans.

Methods: Fifty one eyes of 51 normal participants, sixty two eyes of 62 PPG participants and fifty one eyes of 51 PG patients from the 3 clinical centers of the Advanced Imaging Glaucoma Study were enrolled in this IRB-approved prospective study. Participants were scanned using Doppler FD-OCT imaging using a standardized, circumpapillary double circular scan protocol. The circular scans transected all major blood vessels entering/exiting the optic nerve head. The scans were graded using a semi-automated software at the Doheny Doppler OCT Reading Center. TRBF and other parameters were measured from branch retinal veins.

Results: The mean TRBF was 45.4 ± 9.8, 41.3 ± 11.8 and 38.1 ± 9.4µl/min in Normals, PPG and PG respectively. There was a significant difference (P= 0.003, ANOVA) in TRBF between the three groups. Compared to Normals, TRBF was significantly lower in PPG (P= 0.047, unpaired t-test) and PG (P <0.0001). Total venous area and average venous velocity were not significantly different between the groups.

Conclusions: As a group, a reduction in TRBF could be detected in suspected glaucoma subjects even in the pre-perimetric stage. Doppler OCT blood flow measurements may be of value in the evaluation of patients with glaucoma and warrant further investigation.