Quantification of diabetic macular ischemia using novel three‐dimensional optical coherence tomography angiography metrics

Abstract

We applied three-dimensional (3D) analysis to optical coherence tomography angiography (OCTA) to measure macular ischemia in eyes affected by non-proliferative diabetic retinopathy (DR). A previously validated algorithm was applied to OCTA data in order to obtain 3D visualization of the retinal vasculature. Successively, a global thresholding algorithm was applied and two novel quantitative metrics were introduced: 3D vascular volume and 3D perfusion density. Two-dimensional (2D) OCTA metrics were also obtained with different binarization thresholds for comparison. Of the 30 patients included, 15 were diagnosed with DR and 15 were controls. The 3D vascular volume and 3D perfusion density were reduced in DR eyes (P < .0001). The 2D variables also significantly differ between groups. The 3D perfusion density had the highest area under the receiver operating characteristic curve (0.964) among tested variables. Assessing quantitative perfusion using 3D analysis is reliable and promising, and with an elevated diagnostic efficacy in identifying DR eyes.

Spatial distribution of diabetic capillary non‐perfusion

“…Recently, a 3D algorithm was proposed for visualization of the retinal vasculature. 28 Future studies using this approach may show 3D relationship of the retina ischemia in inner retinal plexuses.…”

Guidelines on Optical Coherence Tomography Angiography Imaging: 2020 Focused Update

“…As discussed above, while OCTA data are mainly displayed using 2D en face images, recent evidence suggests that a 3D analysis may permit a reliable visualization and quantification of the retinal vessels (Figs. 2 and 3) [39][40][41][42][43].…”

“…Conversely, a 3D illustration does not require flattening of flow data and it is independent of data segmentation [41,42]. More importantly, we recently introduced two novel 3D OCTA metrics to quantify macular perfusion (3D vascular volume and 3D perfusion density) [43]. In this previous publication, 15 patients with diabetes and 15 healthy subjects were retrospectively enrolled and their OCTA data were processed for generating 2D and 3D OCTA metrics.…”

“…Our group recently proposed a quantification of the 3D retinal vasculature in healthy subjects and patients with diabetes [43]. We adopted a standardized methodology to obtain 3D visualization of the retinal circulation in the macular region and we also introduced two novel 3D quantitative metrics to measure macular perfusion in diabetic retinopathy and healthy eyes: (i) 3D vascular volume and (ii) 3D perfusion density [43]. In the latter study, we demonstrated that this approach may be effective to provide quantitative data from the macular microvascular networks.…”

Volume rendered 3D OCTA assessment of macular ischemia in patients with type 1 diabetes and without diabetic retinopathy

“…A new approach to OCTA, known as volume rendered three-dimensional (3D) OCTA 14 – 18 , has been shown to reliably quantify the macular perfusion in healthy and diabetic eyes 18 . Measurements of diabetic macular ischemia using volume rendered OCTA were obtained with two novel 3D OCTA metrics: (i) 3D perfusion density, and (ii) 3D vascular volume 18 . Three-dimensional measurements of diabetic macular ischemia gave excellent intra-session repeatability 19 .…”