Anterior segment optical coherence tomography: its application in clinical practice and experimental models of disease

Abstract

Optical coherence tomography (OCT) provides non-invasive, high-resolution in vivo imaging of the ocular surface and anterior segment. Over the years, it has become an essential tool for evaluating the anterior segment of the eye to monitor ocular development and ocular pathologies in both the clinical and research fields of ophthalmology and optometry. In this review, the clinical applications relating to the use of anterior segment OCT for imaging and quantifying normal and pathological features of the ocular surface, cornea, anterior chamber, and aqueous outflow system are summarised in a range of human ocular diseases. Applications of anterior segment OCT technology that have improved imaging and quantitation of ocular inflammation in experimental animal models of ocular diseases, such as anterior uveitis, microbial keratitis and glaucoma, are also described. The capacity to longitudinally evaluate anterior segment anatomical changes during development, and inflammation facilitates the understanding of the dynamics of tissue responses, and further enhances the intra-operative in vivo imaging during procedures, such as corneal transplantation and drug delivery. Future developments including in vivo ultrahigh-resolution anterior segment OCT, automated analyses of anterior segment OCT images and functional extensions of the technique, may revolutionise the clinical evaluation of anterior segment, corneal and ocular surface diseases.

Intradevice Repeatability and Interdevice Agreement of Ocular Biometric Measurements: A Comparison of Two Swept-Source Anterior Segment OCT Devices

“…However, while the CASIA SS-1000 has been used extensively for scientific research, it never received US Food and Drug Administration (FDA) approval for clinical use. [1][2][3] The latest swept-source AS-OCT device is the Heidelberg ANTERION (Heidelberg Engineering). While the ANTERION also uses a 1300-nm wavelength laser, it supports image averaging and greater range of imaging depth than the CASIA SS-1000.…”

“…4,5 When anatomical landmarks, such as the scleral spur, are marked, quantitative measurements of biometric parameters describing the position or configuration of anatomic structures can be obtained, including the width of the anterior chamber angle. [1][2][3] The importance of these measurements is threefold. First, biometric parameters of anatomical structures, such as the lens and iris, are risk factors for gonioscopic angle closure and PACD.…”

Comparison of Different Types of Corneal Foreign Bodies Using Anterior Segment Optical Coherence Tomography: A Prospective Observational Study

“…FBs show high or low signals on AS-OCT images. High signals followed by a shadowing effect were reported in previous literature [5,14,18]. However, these studies ignored the phenomenon that the low signals could also be followed by a shadowing effect, which we named a marginal zone shadowing effect.…”

Phacoemulsification in bilateral anterior lenticonus in Alport syndrome

“…AS-OCT has been used in exploring the anterior segment parameters, mainly the cornea and anterior chamber characteristics (depth, angle, and volume), but some of them are able to evaluate other structures of the anterior segment, such as iris characteristics and features of the crystalline lens. [8,9] Comparing the depth measurement range from front corneal surface to posterior lens surface and anterior portion of the vitreous body of different AS-OCTs including Visante (Carl Zeiss Meditec, Inc., Dublin, CA), RTVue (Optovue, Inc., Fremont, California), Cirrus 5000 HD (Carl Zeiss Meditec, Inc., Dublin, CA), Casia SS-1000 (Tomey Corporation, Nagoya, Japan), Casia2 (Tomey Corporation, Nagoya, Japan) indicates that the CASIA2 as a Swept-source OCT provides the highest depth rage (approximately 13 mm) which allows for visualization of the entire lens and a better overview analysis of lens shape, position and orientation. [10,11] Therefore, this feature enables the device to evaluate the localized curvature changes in the shape of both lens surfaces, such as lenticonus.…”