Abstract
Purpose :
To investigate the relationships between choroidal thickness (CT), age, hemodynamic and structural parameters measured by optical coherence tomography angiography (OCTA) in open-angle glaucoma (OAG) patients and healthy controls.
Methods :
In a prospective cross-sectional analysis, 48 eyes (13 OAG and 35 healthy) underwent OCTA (Optovue) assessment of: subfoveal CT, retinal nerve fiber layer (RNFL) thickness, cup-to-disc vertical ratio (C/D), average ganglion cell complex (GCC) thickness, and radial peripapillary capillary (RPC) vessel density percentages (VD%). Using enhanced depth imaging (EDI) and a defined anatomical landmark protocol, CT was assessed perpendicularly from the outer edge of the hyper-reflective retinal pigment epithelium to the inner sclera at the fovea. Intra-operator repeatability and inter-operator agreement were evaluated using intraclass correlation coefficients (ICC) and Bland-Altman plots. Associations were calculated across all patients, as well as by presence or absence of OAG, using Pearson’s correlation coefficient and two-tailed, two-sample T-tests assuming unequal variances, repeated before and after adjustment for age.
Results :
Mean age was significantly higher in OAG group compared to control group (65.5+/-16.6 years vs. 40.3+/-17.9, p<0.001). In all subjects, after adjusting for age, CT was positively correlated with average RNFL thickness (r=0.39, p=0.040), GCC thickness (r=0.36, p=0.046), and peripapillary RPC VD% (r=0.38, p=0.0035), and negatively correlated to vertical C/D (r=-0.47, p=0.013). CT also had a strong positive correlation with peripapillary RPC VD% (r=0.90, p=0.010) only in OAG patients. Mean CT was significantly lower in OAG eyes only prior to age adjustment (166.6+/-80.4 μm vs. 266.6+/-85.9 μm, p=0.001; after adjustment p=0.077). The inter-operator agreement of three independent operators was 0.90.
Conclusions :
CT was positively correlated with RNFL thickness, GCC thickness, and peripapillary RPC VD%, and negatively correlated with vertical C/D. CT also had a strong positive correlation with retinal peripapillary capillary density in OAG subjects. After adjusting for differences in age, average mean CT was not statistically significantly different between OAG patients and controls.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.