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Review Retinal Imaging Past and Present Terminology for the Retinal and Choroidal Structures in Optical Coherence Tomography Burak Turgut Fırat University, School of Medicine, Department of Ophthalmology, Elazig, Turkey S pectral domain optical coherence tomography (SD-OCT) is a non-invasive imaging method which is used in the diagnosis and follow- up of various macular diseases. SD-OCT provides detailed imaging of the retina. However, it has also been used to evaluate the choroidal layers. There are many publications on the OCT terminology, the definition and classification of retinal and choroidal structures including lines, bands and zones described in OCT. The aim of this review is to provide an overview of the literature on the past and present terminology for the retinal and choroidal structures seen in SD-OCT. To know OCT terminology will provide to be understanding better the pathogenesis of these diseases and the effects of therapeutic applications for these. Keywords Optical coherence tomography, terminology, international nomenclature Disclosure: Burak Turgut has nothing to disclose with any trade or device in relation to this article. No funding was received for the publication of this article. This study involves a review of the literature and did not involve any studies with human or animal subjects performed by any of the authors. Authorship: All named authors meet the International Committee of Medical Journal Editors (ICMJE) criteria for authorship of this manuscript, take responsibility for the integrity of the work as a whole, and have given final approval to the version to be published. Open Access: This article is published under the Creative Commons Attribution Noncommercial License, which permits any non-commercial use, distribution, adaptation and reproduction provided the original author(s) and source are given appropriate credit. Received: 20 March 2017 Accepted: 3 June 2017 Citation: European Ophthalmic Review, 2017;11(1):59–61 Corresponding Author: Burak Turgut, Associate Professor of Ophthalmology, Fırat University, Faculty of Medicine, Department of Ophthalmology, 23119, Elazig, Turkey. E: drburakturgut@gmail.com Spectral domain optical coherence tomography (SD-OCT) is a very useful non-invasive imaging method which is used in the diagnosis and follow-up of various retinal and choroidal diseases involving macular region. 1–3 In 2014, at International Nomenclature OCT (INOCT) Panel, Staurenghi et al. 4 proposed a nomenclature system for normal anatomic landmarks in SD-OCT and it has been reached a consensus regarding the most proper terminology and normal anatomic landmarks in the posterior segment SD-OCT. In addition, it has been recommended as the standardised nomenclature for use in the future publication in the panel. Currently, this terminology has been commonly used by some ophthalmologists, especially retina specialists. 4 In this review, based on the literature, it has been aimed to provide an overview of the definition and classification of the retinal and choroidal structures seen in SD-OCT, and to propose the standard nomenclature and terminology for these structures. To know the INOCT, OCT terminology and nomenclature of retinal and choroidal layers, the landmarks, zones, bands and lines described in OCT in healthy eyes will also provide to be understanding better the pathogenesis of various macular diseases and the effects of therapeutic applications for these. The anatomical/histologic landmarks in current OCT literature and INOCT In an SD-OCT scan of a normal eye, the high reflectivity signals come from the retinal nerve fibre layer (INOCT, Zone 3), outer plexiform layer (OPL) (INOCT, Zone 7), inner plexiform layer (INOCT, Zone 5), internal limiting membrane (ILM), ellipsoid zone (EZ) of photoreceptors (INOCT, Zone 11), interdigitation zone (IZ) of photoreceptors (INOCT, Zone 13) and retina pigment epithelium (RPE)-Bruch’s membrane (BM) complex (INOCT, Zone 14). The low reflectivity signals belong to the nuclear layers, ganglion cell layer, Henle’s nerve fibre layer (HFL), myoid zone (MZ) of the photoreceptors (INOCT, Zone 10), and outer segments (OSs) of the photoreceptors (INOCT, Zone 12). The vitreous gel is not visible in OCT imaging of the healthy subjects because it is optically clear and transparent, and it seems black colour in OCT scans. However, posterior cortical vitreous (INOCT, Zone 1) can seem mildly hyper-reflective in the high-resolution OCT images in some healthy subjects (Figure 1). 4–7 The external limiting membrane (ELM) (INOCT, Zone 9) is located at the boundary between the nuclei and the inner segments (ISs) of the photoreceptors and corresponds to the multiple junctional complexes between Müller cells and the photoreceptors. 4–7 The outer (dendritic) plexiform layer (OPL) (INOCT, Zone 7) is the hyper-reflective layer that corresponds with the synapses between cone pedicles and rod spherules with dendrites of horizontal and bipolar cells. 4–7 TOU CH MED ICA L MEDIA 59