Abstract
Purpose :
To analyze foveal avascular zone (FAZ) and retinal vascular density (RVD) at the fovea in normal eyes using optical coherence tomography angiography (OCTA).
Methods :
One hundred sixty-seven eyes of 151 cases (mean age 60 year-old) without any fundus abnormalities were examined using OCTA (RTVue XR Avanti, Optovue, USA). OCTA volume scan was obtained by central 3 x 3 mm area. All images of superficial layer and the deep layer were analyzed by an open source image processing software “ImageJ.” FAZ dimension was measured by polygon selection tool. RVD was calculated by evaluation of foveal capillary binarization within central 2 x 2 mm area. Systemic background such as hypertension and diabetes was also checked by medical chart.
Results :
Mean FAZ dimension was 0.313 mm2. FAZ dimension reached the significant correlation with age (r=0.65, p<0.01), however there was no difference in FAZ dimension between with and without systemic background. Mean RVD was 32.5% in the superficial layer and 33.5% in the deep layer. There was a negative correlation between RVD and age (r=-0.59 in superficial layer and r=-0.25 in deep layer, p<0.01, respectively). RVD in the superficial layer was significantly lower in cases with diabetes than in case without diabetes (p=0.03).
Conclusions :
OCTA can detect the subclinical abnormalities at the fovea especially in cases with diabetes. It is important for understanding the pathological condition in variety of diseases to examine the foveal capillary structure using OCTA.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.