Reductions in Retrobulbar and Retinal Capillary Blood Flow Strongly Correlate With Changes in Optic Nerve Head and Retinal Morphology Over 4 Years in Open-angle Glaucoma Patients of African Descent Compared With Patients of European Descent

Abstract

Purpose To investigate the relationship of changes in ocular blood flow with optic nerve head and retinal morphology in open-angle glaucoma patients of African versus European descent over four years. Materials and Methods In this study, 112 patients with open-angle glaucoma were examined at baseline, 79 (59 European descent, 20 African descent) of which were followed for four years. Retinal capillary blood flow was assessed with Heidelberg retinal flowmetry. Retrobulbar blood flow was measured by color Doppler imaging. Retinal structural changes were examined with optical coherence tomography and Heidelberg retinal tomography-III. Mixed-model analysis of covariance was used to test for the significance of change from baseline to four-year follow-up, and Pearson correlation coefficients were calculated to evaluate linear associations. Results In open-angle glaucoma patients of African descent, structural changes of the optic nerve head demonstrated a strong association with the end diastolic velocities and resistive indices of the short posterior ciliary arteries over four years. In addition, there was a significantly larger increase in the avascular area of the inferior retina in patients of African descent, and this reduction in retinal capillaries strongly correlated with a reduction in macular thickness. Conclusion Reductions in retinal capillary and retrobulbar blood flow strongly correlated with changes in the optic nerve head and macular thickness over four years in open-angle glaucoma patients of African descent compared to European descent. This data suggests that ocular vascular health may be a more influential contributing factor in the pathophysiology of open-angle glaucoma in patients of African descent compared to European descent.

Molecular Genetics of Glaucoma: Subtype and Ethnicity Considerations

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Reduced Macular Vessel Density and Capillary Perfusion in Glaucoma Detected Using OCT Angiography

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Primary open-angle glaucoma in patients of Middle Eastern descent

“…A recent review by Huck et al highlighted that among POAG patients; African decent patients have larger cup-to-disc ratios (CDR), thinner corneas, a greater proportion of systemic vascular diseases, and possibly higher IOP levels when compared to European descent patients 2 . Our group recently demonstrated that reductions in retrobulbar and retinal capillary blood flow in African decent POAG patients are strongly correlated with glaucomatous structural changes in the optic nerve head and reduced macular thickness compared to their European decent counterparts 3 …”