Abstract
Purpose :
To examine the relationship between baseline retrobulbar blood flow and changes in macular structure in open-angle glaucoma (OAG) patients of African (AD) and European descent (ED) after four years
Methods :
84 patients with OAG (20 AD, 64 ED) were assessed for resistivity index (RI) in the ophthalmic artery (OA) and nasal posterior ciliary artery, and for end diastolic velocity (EDV) in the nasal and temporal posterior ciliary arteries (NPCA and TPCA) by color Doppler imaging. Macular thickness was assessed by optical coherence tomography every six months for a four-year period. Pearson correlations were used to test for associations between measurements, with p<0.05 considered statistically significant.
Results :
Baseline OA RIs were 0.76 (95% CI: 0.73, 0.78) and 0.75 (0.73, 0.77), baseline NPCA RIs were 0.68 (0.65, 0.71) and 0.66 (0.64, 0.68) in patients of AD and ED, respectively. In patients of AD, baseline OA RI positively correlated with changes in macular volume (r=0.52, p=0.017), macular thickness outer inferior (r=0.53, p=0.015), inner inferior (r=0.55, p=0.011), inner nasal (r=0.57, p=0.008), and outer temporal (r=0.58, p=0.007). Baseline NPCA RI positively correlated with macular thickness inner nasal (r=0.51, p=0.020). These correlations were weak and/or not significant in patients of ED, leading to a significant difference between ED and AD groups (all p<0.05). Additionally, baseline NPCA EDV was 2.3 (2.1, 2.6) and 2.4 (2.2, 2.6), and TPCA EDV was 2.3 (2.1, 2.6) and 2.4 (2.2, 2.6) in AD and ED patients, respectively. In OAG patients of AD, baseline NPCA EDV negatively correlated with inner nasal macular thickness (r=-0.44, p=0.0495). NPCA EDV (r=-0.56, p=0.0088) and TPCA EDV (r=-0.54, p=0.0122) negatively correlated with outer inferior macular thickness. These correlations were weak and/or not significant in patients of ED, leading to a significant difference between groups (all p<0.05).
Conclusions :
In OAG patients of AD, baseline retrobulbar blood flow parameters were more strongly associated with changes in macular thickness after four years, compared to ED patients. These findings suggest that retrobulbar blood flow may have a more prominent role in macular structural changes in OAG patients of AD.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.