Table 1. Technical characteristics of five different OCTA systems.
| System | AngioVue™ | AngioPlex™ | Spectralis® OCTA | AngioScan™ | SS OCT Angio™ | |
| Manufactory | OptoVue, Fremont Inc., Calif., USA | Carl Zeiss Meditec Inc., Dublin, Calif., USA | Heidelberg Engineering, Heidelberg, Germany | Nidek, Aichi, Japan | Topcon Corporation, Tokyo, Japan | |
| Algorithm | SSADA | OMAG | Full-spectrum probabilistic approach | Complex Difference | OCTARA | |
| OCT device | RTVue XR AVANTI Widefield; SD-OCT | CIRRUS HD-OCT 5000; SD-OCT | Spectralis OCT2; SD-OCT | RS-3000 Advance; SD-OCT | DRI Triton; SS-OCT | |
| Optical source (nm) | Centered on 840 with a bandwidth of 50 | Centered on 840 with a bandwidth of 90 | Centered on 870 with a bandwidth of 50 | Centered on 880 (infrared, invisible) | Tunable laser centered on 1050 (invisible) | |
| Scan speed (A-scan/s) | 70000 | 68000 | 85000 | 53000 | 100000 | |
| Resolution (µm) | Axial | 5 | 5 | 5 | 7 | 8 |
| Transverse | 15 | 15 | 6 | 20 | 20 | |
| Imaging depth (mm) | 2.0-3.0 | 2 | 2 | 2.1 | 2.6 | |
| Scan area (H×V, mm2) | Macula: 3×3, 6×6, 8×8; optic disc: 3×3, 4.5×4.5 | 3×3, 6×6 | 3×3 | 3×3 to 9×9 (in 0.3 mm increment) | 3×3, 4.5×4.5, 6×6 | |
| Scan range (H×V) | 45°×45° | 67°×45° | 30°×30° | 40°×30° | 45°×45° | |
| A-scan count (H×V) | 304×304, 400×400(for 6×6 HD mode) | 245×245 (for 3×3), 350×350 (for 6×6) | 256×256, 512×512 | 256×256 | 256×256, 320×320 | |
| Repeated B-scan count | 2 | 2 (6×6), 4 (3×3) | 7 | 2, 4 or 8 | 4 | |
| Acquisition count (for each complete image) | 1 in X and 1 in Y | 1 in X | 1 in X | 1 in Y (AngioScan2 and 4), 2 in Y (AngioScan8) | 1 in X | |
| Theoretical acquisition time | 2.7s×2, 4.6s×2(HD mode) | 3.6s | 5.4s (256×256), 21.6s (512×512) | 2.5s (AngioScan2),5.0s (AngioScan4) | 2.7s (256×256), 4.1s (320×320) | |
| Default layer segmentationa (inner boundary to outer boundary) | Macula: SRL: ILM -3 µm to IPL -15 µmb; DRL: IPL -15 µm to IPL -70 µm; ORL: IPL -70 µm to RPE ref -30 µm; CC: RPE ref -30 µm to RPE ref -60 µm; Optic disk: vitreous: above ILM -50 µm; ONH: ILM to ILM -150 µm; RPC: ILM to NFL; choroid: below RPE +75 µmc | VRI: ILM +300 µm to ILM; SRL: ILM to IPL (ILM -70% TILM-OPL); DRL: IPL to OPL (RPE fit +110 µm); avascular slab: OPL to RPE fit +70 µm; CC: RPE -29 µm to RPE -49 µm; choroid: RPE -64 µm to RPE -115 µm | SRL: ILM to IPL; DRL: IPL to OPL; Avascular layer: OPL to BM | Macula: SRL: ILM to IPL -8 µm; DRL: IPL -13 µm to IPL -88 µm; ORL: IPL -92 µm to RPE; choroid: RPE -4 µm to RPE -63 µm; optic disk: RPCP: ILM to ILM -105 µm; ORL: IPL -109 µm to RPE; choroid: RPE -4 µm to RPE -126 µm; lamina cribrosa: ILM -63 µm to ILM -378 µm | SRL: ILM -2.6 µm to IPL -15.6 µm; DRL: IPL -15.6 µm to IPL -70.2 µm; ORL: IPL -70.2 µm to BM; CC: BM to BM -10.4 µm | |
| Eye-tracking technology | DualTrac™ | FastTrac™ | SMARTTrack™ | Real-time SLO Eye HD Tracer | TruTrack™ Active Eye Tracking | |
| Software version | AngioVue (2016.2) | AngioPlex v.9.0 | HEYEX V6.4a | Navis-EX 1.5.5 | FastMap10.11 | |
| Other highlighted features | MCT™; Angio Analytics; Blood flow signal overlay on structural OCT; follow-up settings; color composite layers | Blood flow signal overlay on structural OCT; superficial projection elimination technology; ganglion cell OU analysis; color composite slab | ART; multimodal imaging system; angiography overlay on multicolor or IR image; follow-up settings | Multimodal imaging system; automate mosaic panorama | Multimodal imaging system with fundus photography | |
aIn layer segmentation, ILM, IPL, OPL, RPE and BM refer to the loci of their outer boundary respectively; bInferior to; cSuperior to. ART: Automated real-time mode; BM: Bruch's membrane; CC: Choriocapillaris; DRL: Deep retinal layer; H×V: Horizontal×vertical; HD: High definition; ILM: Inner limiting membrane; IPL: Inner plexiform layer; IR: Infrared; MCT: Motion correction technology; NFL: Nerve fiber layer; N/A: Not applicable; OCT: Optical coherence tomography; OCTA: OCT angiography; OCTARA: OCTA ratio analysis; OMAG: Optic micro-angiography; ONH: Optic nerve head; OPL: Outer plexiform layer; RPC: Radial peripapillary capillary; RPCP: RPC plexus; RPE: Retinal pigment epithelium; SD-OCT: Spectral domain OCT; ORL: Outer retinal layer; SRL: Superficial retinal layer; SSADA: Split-spectrum amplitude-decorrelation angiography; SS-OCT: Swept source OCT; TILM-OPL: Thickness between ILM and OPL; VRI: Vitreoretinal interface.