Abstract
Purpose:
To examine the relationship between retinal capillary blood flow in open angle glaucoma (OAG) patients of African descent (AD) and European descent (ED) over four years.
Methods:
111 patients with OAG (28 AD, 83 ED) were assessed for retinal capillary blood flow at baseline as measured by Heidelberg retinal flowmetry (HRF). 79 patients (20 AD, 59 ED) were assessed at 4-year follow-up. Mixed-model ANCOVA was used to test for significance of changes from baseline to 4-year follow-up with p<0.05 considered statistically significant.
Results:
In patients of AD, the number of inferior zero blood flow pixels significantly increased from 0.172 (CI 95%; 0.153, 0.193) at baseline to 0.228 (0.197, 0.263) at 4 years with a change of 0.042 (0.019, 0.062; p=0.0011). In patients of ED, the number of inferior zero blood flow pixels increased slightly from 0.189 (0.174, 0.206) at baseline to 0.204 (0.184, 0.225) at 4 years with a change of 0.013 (-0.005, 0.030; p=0.1433), thus a significantly larger increase for AD than ED (p=0.0344). In patients of AD, the number of superior zero blood flow pixels increased, but not significantly, over the 4 years (p=0.21). In patients of ED, the number of superior zero blood flow pixels significantly increased from 0.199 (0.183, 0.216) to 0.224 (0.202, 0.250) with a change of 0.023 (0.005, 0.039; p=0.0124), however there was no significant difference between the two groups (p=0.86). There was no significant change in IOP (p>0.05).
Conclusions:
In this cohort of patients with OAG, the amount of area in the retina showing no capillary blood flow significantly increased more in patients of AD over a 4-year period than in OAG patients of ED. This data suggests that OAG patients of AD may experience retinal capillary loss over time which contributes to their glaucomatous damage.
Keywords: 436 blood supply •
688 retina •
572 ischemia