Choroidal vascularity index: a step towards software as a medical device

• Published in: British journal of ophthalmology Vol. 106; no. 2; pp. 149 - 155
• Main Authors: Betzler, Bjorn Kaijun, Ding, Jianbin, Wei, Xin, Lee, Jia Min, Grewal, Dilraj S, Fekrat, Sharon, Sadda, Srinivas R, Zarbin, Marco A, Agarwal, Aniruddha, Gupta, Vishali, Schmetterer, Leopold, Agrawal, Rupesh
• Format: Journal Article
• Language: English
• Published: BMA House, Tavistock Square, London, WC1H 9JR BMJ Publishing Group Ltd 01.02.2022; BMJ Publishing Group LTD
• Subjects: Algorithms; Automation; Biomarkers; choroid; Choroid - blood supply; Choroid - diagnostic imaging; Diabetic retinopathy; Humans; imaging; Macular degeneration; Medical imaging; Reproducibility; Retina; Review; Software; Tomography; Tomography, Optical Coherence - methods; Singapore; choroid; imaging
• ISSN: 0007-1161; 1468-2079
• DOI: 10.1136/bjophthalmol-2021-318782

The choroidal vascularity index (CVI) is a relatively new parameter, calculated off optical coherence tomography (OCT) images, for the quantitative evaluation of choroid vascularity. It is defined as the ratio of vascular area to the total choroidal area, presented as a percentage. The choroid is an important vascular bed, often implicated in ocular and systemic conditions. Since the introduction of CVI, multiple studies have evaluated its efficacy as a tool for disease prognostication and monitoring progression, with promising results. The CVI was born out of the need for more robust and accurate evaluations of choroidal vasculature, as prior parameters such as choroidal thickness and choroidal vessel diameter had their limitations. In this review, we summarise current literature on the CVI, explain how the CVI is derived and explore its potential integration into future research and translation into clinical care. This includes the application of CVI in various disease states, and ongoing attempts to produce an automated algorithm which can calculate CVI from OCT images.