Abstract
Purpose :
To evaluate the repeatability of commercial optical coherence tomography (OCT) angiography retinal vascular density measurement in eyes with retinal vascular disease and normal controls.
Methods :
This prospective study enrolled patients with retinal vascular disease or normal retina between September and October 2017 at one academic center. Both maculae were imaged using a commercial OCT angiography instrument (AngioVue, Optovue) 3 x 3-mm scan. Two separate scans were obtained on each eye at least 10 minutes apart on the same day. Signal strength and retinal vascular density measurement of the superficial and deep retinal vascular layers were recorded. Intraclass correlation coefficient (ICC) was measured to evaluate repeatability of measurement for vascular density.
Results :
A total of 36 eyes (18 patients) were included. Twenty eyes (55.5%) had retinal vascular disorders (6 retinal vein occlusion, 12 diabetic retinopathy and 2 sickle cell retinopathy) and 16 eyes had normal macula. Nine eyes (25.0%) had concurrent cystoid macular edema on OCT. Mean superficial retinal vascular density was 37.62+2.29 for eyes with retinal vasculopathy and 39.67+2.66 for normal eyes (P = 0.26). Mean deep retinal vascular density was 41.39+2.35 for eyes with retinal vasculopathy and 48.21+1.97 for normal eyes (P = 0<0.001). The ICC between 2 consecutive scans was 0.81 and 0.87 (P<0.001) for vessel density in the superficial and deep retinal layers, respectively. The ICC between consecutive scans for eyes with retinal vasculopathy was 0.80 and 0.89 in superficial and deep layers, respectively compared to 0.81 and 0.92 for normal eyes (P <0.001 for both groups). Mean signal strength of the scan was 5.77 + 2.11 for the first scans, which was similar to that of repeat scans (5.71 + 2.85; P=0.70). For subgroup of eyes with signal strength ≥6 for both scans (18 eyes), ICC was 0.91 and 0.93, respectively for the superficial and deep retinal layers (P<0.001 for both layers). For eyes with retinal vascular disease and signal strength > 6 (9 eyes), ICC was 0.94 and 0.93 for superficial and deep retinal layers (P<0.001 for both layers).
Conclusions :
Vascular density measurements obtained using OCT angiography have high level of repeatability in eyes with retinal vascular disease and normal eyes. The reproducibility is further improved by using scans of higher image quality.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.