Swept-Source Optical Coherence Tomography Angio™ (Topcon Corp, Japan): Technology Review

Abstract

Optical coherence tomography (OCT) angiography (OCTA) is a novel, noninvasive, three-dimensional imaging technique that allows for the visualization of intravascular flow in the microvasculature. Swept-source OCT technology utilizes longer-wavelength infrared light than conventional spectral-domain OCT. This enables improved penetration into tissue and imaging through optical opacities and is invisible to the subject. Topcon has recently developed an innovative OCTA algorithm, OCTARA (OCTA Ratio Analysis), which benefits from being paired with swept-source OCT. OCTARA aims to provide improved detection sensitivity of low blood flow and reduced motion artifacts without compromising axial resolution. In this chapter, we describe the implementation of OCTARA with swept-source OCT technology, the technical specifications of acquisition (e.g. the number of scans, area of examination field, etc.) along with the algorithm's function and principles for analysis of B-scan data to achieve angiographic visualization. Examples of OCTA scans performed using the OCTARA algorithm and a comparison of these scans with images obtained using other technologies are also presented.

Repeatability, interocular correlation and agreement of quantitative swept-source optical coherence tomography angiography macular metrics in healthy subjects

“…There are three articles19–21 that compared FAZ area and one article22 that compared FAZ diameter between the left and the right eyes, and all of them found no statistically significant difference. Our results are consistent with these literature reports.…”

OCT Angiography–Based Detection and Quantification of the Neovascular Network in Exudative AMD

“…38 Ratio-based analysis of sequential OCT B-scans for generation of OCT-A data is employed by the Topcon (Topcon Corporation, Tokyo, Japan) devices. 39 The impact of different OCT-A generation methods has recently been investigated in single individuals. 40 Future studies on larger cohorts will elucidate the advantages of the different algorithms and devices used in clinical routine.…”

Optical Coherence Tomography Angiography in Glaucoma: A Review

“…Four types of OCT algorithms were used in the selected studies: the split-spectrum amplitude decorrelation angiography (SSADA) algorithm described in detail by Jia et al [12], the OCT-based microangiography (OMAG) described in detail by Zhang and Wang [13], the OCTA ratio analysis (OCTARA) described by Stanga et al [14], and the speckle variance OCTA described in detail by Xu et al [15]. …”