Abstract
Purpose:
To examine the relationship between blood flow velocities in the retrobulbar and retinal circulation and volumetric blood flow in retinal vessels in open angle glaucoma (OAG) patients with and without diabetes (DM).
Methods:
137 patients with OAG (19 with DM, 118 without DM) were assessed for retrobulbar blood flow velocity in the ophthalmic (OA), central retinal (CRA) and the nasal (NPCA) and temporal (TPCA) posterior ciliary arteries using color Doppler imaging (CDI). Volumetric blood flow, arterial and venous velocities of retinal vessels were obtained using Doppler Fourier-domain optical coherence tomography (FD-OCT). Pearson correlations were used to test for associations between measurements, with p<0.05 considered statistically significant.
Results:
Blood flow (microliters/min) was positively and significantly correlated with CRA peak systolic (PSV) and end diastolic (EDV) velocities in OAG patients with DM(r=0.69-0.75; p<0.0007), leading to a significant difference between groups (p<0.0452). Blood flow was also more strongly correlated to NPCA PSV in those with DM (r=0.73; p<0.0002) than in those without DM (r=0.27, p<0.0031) resulting in a significant difference between groups (p<0.0155). Additionally, venous velocity (FD-OCT) was more strongly positively correlated with OA PSV, OA EDV, CRA PSV, CRA EDV, and NPCA PSV in patients with DM (r=0.48-0.68; p<0.0375) than in those without DM (r=-0.09-0.24; p>0.05) with a significant difference between groups (p<0.0472). Arterial velocity (FD-OCT) also showed a stronger association with CRA EDV in those with DM (r=0.67; p<0.0010) than in those without DM (r=0.26; p<0.0045); leading to a significant difference between the two groups (p<0.0375).
Conclusions:
In OAG patients with DM, Doppler FD-OCT assessed retinal vessel volumetric blood flow and arterial and venous velocities show strong correlation to the retrobulbar blood supply compared to non-diabetic OAG patients. This data suggests that OAG patients with DM may be have compromised local vascular autoregulation leading to passive blood flow dynamics from the retrobulbar blood supply to the retinal vessels.
Keywords: 436 blood supply •
498 diabetes •
552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)