Comparison of Zeiss Cirrus and Optovue RTVue OCT Angiography Systems: A Quantitative and Qualitative Approach Examining the Three Capillary Networks in Diabetic Retinopathy

BACKGROUND AND OBJECTIVES: Construct a method for visualizing the middle capillary plexus (MCP) using Zeiss optical coherence tomography angiography (OCTA) and compare to established segmentation methods using the Optovue system. PATIENTS AND METHODS: Twenty eves with diabetic retinopathy were imaged. Visualization of the MCP, image artifacts, preservation of pathological changes, foveal avascular zone (FAZ) area, and vessel length density (VLD) were compared between devices. RESULTS: The authors successfully segmented the superficial (SCP), MCP, and deep (DCP) capillary plexuses on both devices. More images artifacts were detected on Optovue. Microaneurysms and telangiectatic vessels were better visualized in the MCP on the Optovue. FAZ area showed a strong correlation between the two instruments (r(2) = 0.666; P < .0001). The SCP had lower VLD compared to the MCP and DCP on both devices. CONCLUSION: The authors provide an objective and consistent method for manual segmentation using Zeiss OCTA to visualize the three retinal capillary plexuses.