Mini Review Volume 2 Issue 5 - April 2017 DOI: 10.19080/JOJO.2017.02.555598 JOJ Ophthal Copyright © All rights are reserved by Joobin Khadamy Optical Coherence Tomography Angiography (OCTA) in Ophthalmology; Technology, Pros, Cons and Commercial Prototypes Joobin Khadamy * Iran University of Medical Sciences (IUMS), Iran Submission: February 21, 2017; Published: April 19, 2017 *Corresponding author: Joobin Khadamy, MD, Eye Research Center, Rassoul Akram hospital, Iran University of Medical Sciences (IUMS), Sattarkhan- Niayesh Street, Tehran 14456-13131, Iran, Tel: , Fax: +982166509162; Email: Introduction Optical Coherence Tomography Angiography (OCTA) is a novel imaging technology which has considerable advantages over older angiograms token by Fluorescein Angiography (FA) or Indocyanine Green Angiogarphy (ICGA). On top of them, one may list advantages like being non-invasive; no needs for dye; high resolution simultaneous visualization of the both retinal and choroidal vasculatures; simultaneous 3 dimensional (3D) visualization of retinal and choroidal structure; and possibility of segmentation of retinal layers and capillary plexuses in 3 layers including Superficial (SCP), Middle (MCP) and Deep (DCP) [1]. One of the promising features of this technology is that beside qualitative data, it provides quantitative data regarding retinal and choroidal structural and vascular indices like Vascular Density (VD), Foveal Avascular Zone (FAZ), etc. Feasible Quantitative data provided by OCTA; may revolutionize current ophthalmic practice in regards of predicting [2,3], grading [4,5], following up treatment in patients with important vascular diseases like diabetic retinopathy, retinal vein obstruction, choroidal neovascularization, etc. [6-10]. However, currently the quantitative data are mostly used for researches, But it seems that in the future when some cut off points are available by large scale studies. Then, these data could be used for everyday clinical practices. For an instance, quantitative assessment of Foveal Avascular Zone (FAZ) could be useful in optimal selection of therapy in patients with Diabetic Macular Edema (DME) [11] or even grading the severity of Diabetic Retinopathy (DR) [5,12]. It has also shown that FAZ metrics could change in response to treatment [6] so it could be used in following up patients. But a recent study has challenged these changes [13]. It should be emphasized that FA could also provide data regarding FAZ, but OCTA is more reliable, precise and also much more feasible. In FA, frequently dye leakage or DCP and SCP overlaps may influence the FAZ measurement [14]. Hereby, the OCTA technology, advantages, disadvantages and some commercial prototypes are discussed. Optical Coherence Tomography Angiography Technology The principal of this imaging system is detecting motion contrasts. This device record and compare multiple fast B-Scans of each vascular layer of retina. It simply presumes that the only motion inside retina is related to red blood cells (RBC) within vasculatures. These decorrelation signals are mapped in an OCT angiogram. Lastly, OCT B-Scan and OCT angiogram join together JOJ Ophthal 2(5): JOJO.MS.ID.555598 (2017) 001 Abstract The OCTA is a novel evolving imaging technology which utilizes motion contrast to visualize retinal and choroidal vessels. It showed promises to be used in predicting, grading, guiding and following treatment of important ocular vascular diseases. The main advantages of the OCTA are being non-invasive; being blue light and dye free and providing high quality images in a relatively short time. It has alleviated important limitations of Fluorescein Angiography (FA), but still it is not considered as a complete substitute of FA, by experts. The Combined FA/ICGA and OCTA imaging systems are introduced to the market. It may have the advantages of the both systems, while having the least limitations. Resolution of images, field of view, depth of images and scan speed are important factors when choosing a device. But one should also take into account that higher image quality needs more time to be acquisitioned. It could be challenging in busy clinics. In this article we compared FA and OCTA and also compared widely available commercial prototype of OCTA devices.