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Choroidal vascularity index: a step towards software as a medical device
  1. Bjorn Kaijun Betzler1,
  2. Jianbin Ding2,
  3. Xin Wei3,
  4. Jia Min Lee3,
  5. Dilraj S Grewal4,
  6. Sharon Fekrat4,
  7. Srinivas R Sadda4,
  8. Marco A Zarbin5,
  9. Aniruddha Agarwal6,
  10. Vishali Gupta6,
  11. Leopold Schmetterer7,8,9,
  12. Rupesh Agrawal1,2,3,7,8
  1. 1Yong Loo Lin School of Medicine, National University of Singapore, Singapore
  2. 2Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
  3. 3National Healthcare Group Eye Institute, Tan Tock Seng Hospital, Singapore
  4. 4Department of Ophthalmology, Duke University School of Medicine, Durham, North Carolina, USA
  5. 5Rutgers-New Jersey Medical School, Rutgers University, Newark, New Jersey, USA
  6. 6Department of Ophthalmology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
  7. 7Singapore Eye Research Institute, Singapore National Eye Center, Singapore
  8. 8Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore
  9. 9SERI-NTU Advanced Ocular Engineering (STANCE), Singapore
  1. Correspondence to Dr Rupesh Agrawal, Department of Ophthalmology, Tan Tock Seng Hospital, Singapore 308433, Singapore; rupeshttsh{at}


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.

  • choroid
  • imaging

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  • Contributors BKB, VG, LS and RA conceived the idea for the article. BKB and RA performed the literature search. BKB and JD wrote the manuscript with critical feedback from all authors. All authors discussed the results and contributed to the final manuscript. RA conceived the study and was in charge of overall direction and planning. RA is the guarantor of this manuscript.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests None declared.

  • Patient consent for publication Not required.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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