Three‐dimensional high‐speed optical coherence tomography for the investigation of the cornea and anterior eye‐segments

Abstract

Abstract Purpose: Optical coherence tomography (OCT) has a history of more than a decade for posterior eye investigations. This posterior OCT has been optimized for retinal investigation and is not suitable for anterior eye examinations, although interest for the application of OCT to the anterior eye exist. Recently, anterior‐segment OCT has been introduced and its application fields are rapidly extending. However, these anterior OCT systems are based on a time‐domain OCT configuration, which has relatively slow measurement speed; hence, it is difficult to have a full three‐dimensional (3‐D) tomographic dataset. Methods: Our group recently demonstrated ultra‐high‐speed corneal & anterior eye segment OCT (CAS‐OCT). This OCT system is based on Fourier domain detection and provides 20,000 A‐lines/sec. This fast measurement speed enables a full 3‐D dataset of the anterior eye within 2 sec. This 3‐D dataset provides several useful applications : e.g. visualisation of the internal structure of the bleb of glaucoma surgery. An en‐face projection or en‐face OCT slices are available from the 3‐D dataset, which enables en‐face assessment of corneal diseases whose extension directly relates to the patient's visual acuity. Results: Using this 3‐D CAS‐OCT, we have examined 46 eyes with several types of pathologies including granular, Avellino and lattice corneal dystrophy, post LASIK corneal changes, keratoplasty, keratoconus, iris nodules, anterior synechiae, angle recession, ciliary body detachment, scleritis, and several types of glaucoma surgery; trabeculectomy, trabeculotomy, and laser iridotomy. Conclusions: In the presentation, we introduce our CAS‐OCT and show clinical outcomes form the above‐mentioned examinations.