Current capabilities of anterior segment optical coherence tomography

Abstract

Optical coherence tomography of the anterior segment of the eye (AS-OCT) is a non-invasive method based on the principles of optical reflectometry (measurement of the degree of backscattering of light passing through transparent or translucent media). Limitations of the first devices of this type were associated with insufficient image quality of the details of the anterior chamber angle and the posterior parts of the lens, primarily due to the "working" level of the scanning wavelength (within 800 μm). Fundamentally new possibilities in the structural and functional assessment of the anterior segment of the eye are associated with the introduction into clinical practice of swept-source AS-OCT device - the CASIA2 anterior optical coherence tomograph (Tomey Corporation, Japan). Its high scanning speed (50 000 A-scans per second) with a wavelength of 1310 μm allows high-quality visualization by building a scan at a depth of 13 mm. The previous model (CASIA SS-1000, Tomey Corporation, Japan) supported scan depth of only 6 mm. This review summarizes the results of research on the clinical use of CASIA2 tomograph.