Abstract
Purpose:
To examine the relationship between change in retinal capillary blood flow and change in macular thickness in open angle glaucoma (OAG) patients of African (AD) and European descent (ED).
Methods:
77 patients with OAG (18 AD, 59 ED) were assessed for change over 4 years in retinal capillary blood flow as measured by Heidelberg retinal flowmetry (HRF) and macular thickness as measured by optical coherence tomography (OCT). Pearson correlations were used to test for associations between measurements, with p<0.05 considered statistically significant.
Results:
In patients of AD, change in the number of superior zero blood flow pixels was significantly correlated with a change in outer superior macular thickness (p=0.0059), outer inferior macular thickness (p=0.0001), outer nasal macular thickness (p=0.0097) and change in macular volume (p=0.0061). In patients of AD, change in the number of inferior zero blood flow pixels was significantly correlated with a change in outer superior macular thickness (p=0.0011), outer inferior macular thickness (p=0.0000), inner inferior macular thickness (p=0.0028), outer nasal macular thickness (p=0.0024), outer temporal macular thickness (p=0.0104) and change in macular volume (p=0.0036). Changes in inferior 10th and 25th percentile blood flow pixels were also significantly correlated with changes in various macular thickness parameters in patients of AD (p=0.0098-0.0455). In OAG patients of ED, these correlations were weak and did not reach statistical significance (p>0.05), resulting in significant differences between groups (p=0.0012-0.0489).
Conclusions:
In OAG patients of AD, change in retinal blood flow was significantly correlated with changes in macular thickness after 4 years. More specifically, retinal capillary dropout was associated with macular thinning over time in patients of AD. OAG patients of ED had weak correlations, suggesting OAG patients of AD and ED may have differences in vascular contribution to glaucomatous damage.
Keywords: 436 blood supply •
585 macula/fovea •
552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)