RTVue XR angiovue optical coherence tomography angiography software upgrade impacts on retinal thickness and vessel density measurements

Purpose: To determine the impact of an AngioVue software upgrade on total retinal thickness (RT) and inner retinal vessel density (VD) measurements derived from optical coherence tomography angiography (OCTA). Methods: Optovue OCTA images (3 × 3 mm) from 126 individuals (105 healthy eyes and 72 eyes with retinal disease) were acquired before an upgrade of the AngioVue software, which resulted in an inward shift of the outer boundary of the inner retinal vessels and improved Bruch’s membrane segmentation. Total RT and inner retinal VD values were extracted before and after the software upgrade for comparison. Bias and limits of agreement (LA) were calculated. Results: The mean (SD) age of participants was 46 (17) years. Mean (LA) foveal RT increased by 3.0 (–11 to +17) and 3.7 (–11 to +18) μm (P < 0.001) and parafoveal RT increased by 9.7 (–3.8 to +23) and 6.4 (–2.5 to +15) μm (P < 0.001) in healthy and diseased retina, respectively. Mean (LA) foveal inner retinal VD decreased by 6.6 (2.5–11) and 7.7 (0.4–15) percentage units (P < 0.001) and parafoveal inner retinal VD decreased by 4.1 (1.2–7.0) and 4.7 (0.5–8.9) percentage units (P < 0.001) in healthy and diseased retina, respectively. Conclusions: The AngioVue software upgrade resulted in an unexpected increase in total RT and an expected reduction in inner retinal VD measurements in all regions due to altered segmentation. Translational Relevance: RT and VD measures derived from the newer AngioVue software version are not directly comparable to the reported normative data derived from the older software.