Differences in changes in ocular blood flow in African and European descent patients with open-angle glaucoma over a 5-year period

Abstract

Purpose: To examine ocular blood flow in patients with open-angle glaucoma (OAG) of African (AD) and European Descent (ED) over a 5-year period.

Methods: 110 OAG patients (AD 28, ED 82) were assessed for retrobulbar blood flow in the ophthalmic (OA) and central retinal (CRA) arteries as measured by color Doppler imaging and for retinal capillary blood flow as measured by Heidelberg retinal flowmetry at baseline. 30 patients (AD 7, ED 23) were assessed at 5-year follow-up. Mixed-model ANCOVA was used to test for significant change from baseline to 5-year follow-up separately by race.

Results: In OAG patients of AD, the number of Inferior Zero Pixels significantly increased from 0.175 (95% CI; 0.157, 0.195) at baseline to 0.231 (0.195, 0.278) at 5 years with a change of 0.042 (0.013, 0.066; p=0.0059). In patients of ED, the number of Inferior Zero Pixels significantly was 0.186 (95% CI; 0.174, 0.199) at baseline and 0.195 (0.175, 0.216) at 5 years for a non-significant change of 0.008 (-0.012, 0.027; p=0.4121), resulting in a significant difference between groups for the change from baseline (p=0.0436). There was no significant difference in the changes in OA and CRA Peak Systolic Velocities, OA and CRA End Diastolic Velocities, or OA and CRA Resistivity Indices between OAG of AD and ED (p>0.25).

Conclusions: The amount of area with no retinal capillary blood flow increased over a 5-year period in patients of AD, but not in patients of ED. These findings suggest that retinal capillary dropout over time may play a larger role in the disease progression in patients of AD.