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

Abstract

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. 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. 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. OAG patients of AD may have a stronger vascular component to their glaucoma pathophysiology than patients of ED.