Table 1 Comparison of currently available OCTA systems for imaging the anterior segment of the eye
From: Optical coherence tomography angiography for the anterior segment
| Â | AngioVue RTVue XR Avanti | Angioscan RS-3000 Advance | Triton Prototype DRI-OCT (swept source) | PLEX Elite 9000 Swept source OCT |
|---|---|---|---|---|
Imaging company | Optovue, Fremont, California, USA | Nidek, Gamagori, Aichi, Japan | Topcon Corporation, Tokyo, Japan | Carl Zeiss Meditec, Dublin, California, USA |
Algorithm | Split-spectrum amplitude-decorrelation angiography (SSADA) | Complex difference (full spectrum amplitude) | OCTA-Ratio Analysis (full spectrum amplitude) | Complex optical microangiography (OMAGc) |
Type of algorithm | Amplitude | Amplitude + Phase | Amplitude | Amplitude + Phase |
Light source | 840 nm | 880 nm | 1050 nm | 1050 nm |
Scanning speed | 70,000 scans/sec | 53,000 scans/sec | 100,000 scans/sec | 200,000 scans/sec |
Scanning volume | 304 × 304 A scans | 256 × 256 A scans | 320 × 320, 512 × 512 A scans | 300 × 300 A scans (3 × 3 mm), 500 × 500 A scans (6 × 6 mm, 9 × 9 mm, 12 × 12 mm) |
Scan area (macula) | 3 × 3, 6 × 6, 8 × 8 mm | 3 × 3 to 9 × 9 mm (12 × 9 panorama) | 3 × 3, 4.5 × 4.5 mm 6 × 6, 9 × 9 mm | 3 × 3 mm, 6 × 6 mm, 9 × 9 mm, 12 × 12 mm (15 × 9 mm panorama) |
Optical Resolution (Axial) | 5 μm | 7 μm | 8 μm | 6.3 μm |
Optical Resolution (Lateral) | 15 μm | 20 μm | 20 μm | 20 μm |
Scan duration | 3–4 s | 5–6 s | 4–5 s | Variable (scanning stops when motion is detected) |
Axial imaging depth | 2–3 mm | 2.1 mm | 2.6 mm | 6.0 mm |
Cross-sectional OCTA | Yes | No | Yes | Yes |
Motion correction | Yes | No | No | Yes |
Projection artefact removal | Yes | Yes | Yes | NA (no projection artefacts hence no need to remove) |
Anterior segment function | Yes | No | No | No |
Quantitative analysis | Yes | Yes | Yes | Yes |
Comparative follow-up | Yes | No | Yes | Yes |