Optic nerve head morphology in glaucoma patients of African descent is strongly correlated to retinal blood flow

Background/Aims: To examine the relationship between change in optic nerve head (ONH) morphology and retinal blood flow in patients with open-angle glaucoma (OAG) of African (AD) and European descent (ED) over 3 years. Methods: 112 patients with OAG (29 AD; 83 ED) underwent assessment of ONH morphology using Heidelberg retinal tomography (HRT-III), and retinal blood flow using confocal scanning laser Doppler. Repeated-measures analysis of covariance was used to compare baseline and 3-year measurements, and Pearson correlations were calculated to evaluate the relationships. Results: In OAG patients of AD, change in superior mean retinal blood flow was strongly, negatively correlated with change in cup/disc (C/D) area ratio (r= -0.78, p=0.020) and cup area (r=-0.75, p=0.0283) and strongly, positively correlated with change in rim area (r=0.74, p=0.0328) over 3 years. In OAG patients of AD, change in inferior mean retinal blood flow was strongly, negatively correlated with changes in C/D area ratio (r=-0.88, p=0.0156) and linear C/D ratio (r= -0.86, p=0.0265) over 3 years. In OAG patients of ED, these correlations were weak and did not reach statistical significance. Discussion: OAG patients of AD may have a stronger vascular component to their glaucoma pathophysiology than patients of ED.