Abstract
Purpose :
To examine optic nerve head (ONH) and retinal nerve fiber layer (RNFL) structure and its relationship to optical coherence tomography angiography (OCTA) biomarkers of hemodynamics in open angle glaucoma (OAG) patients of African (AD) and European descent (ED).
Methods :
In a cross-sectional analysis, thirty one patients with OAG (13 AD, 18 ED) were assessed for visual field (VF), intraocular pressure (IOP), ONH and RNFL structure and hemodynamics via OCTA for radial peripapillary capillary vessel density (VD) of all the vessels (ALL) and small blood vessels (SV) (AngioVue Imaging System, RTVue XR Avanti, Optovue Inc., Fremont, CA, USA). Age-adjusted nonparametric tests and Spearman correlations were used to identify differences and associations between measurements, with p<0.05 considered statistically significant.
Results :
OAG patients of AD and ED demonstrated significant differences between hemodynamics and structure even with statistically similar IOP and VF biomarkers (p>0.05). Strong and positive correlations were found between average global RNFL thickness and vascular parameters in OAG patients of ED, while these correlations were weak in AD (correlations between RNFL thickness and peripapillary VD SV: ED r=0.90, AD r=0.34, p=0.019; inferior hemisphere (IH) VD SV: ED r=0.88, AD r=0.29, p=0.025; whole image VD ALL: ED r=0.85, AD r=0.25, p=0.038; peripapillary VD ALL: ED r=0.90, AD r=0.26, p=0.010; IH VD ALL: ED r=0.85, AD r=0.02, p=0.009). Moderate to strong negative correlations were found between ONH structural parameters and hemodynamic biomarkers in OAG patients of AD, with positive associations identified in ED patients (correlation between cup to disc horizontal ratio and inside disc VD ALL: AD r=-0.30, ED r=0.62, p=0.029; between cup volume and whole image VD SV: AD r=-0.63, ED r=0.27, p=0.032; IH VD SV: AD r=-0.78, ED r=0.06, p=0.020; inside disc VD ALL: AD r=-0.65, ED r=0.18, p=0.043; and IH VD ALL: AD r=-0.76, ED r=0.06, p=0.026).
Conclusions :
In this cohort, vascular biomarkers in OAG patients of AD were more strongly associated with structural damage at the level of the ONH, while in OAG patients of ED hemodynamic parameters were more strongly associated with RNFL thickness. Large well-designed longitudinal studies are required to investigate how differences in hemodynamic biomarkers may affect the risk for OAG onset and progression.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.