Choroidal Vascularity Index Using Swept-Source and Spectral-Domain Optical Coherence Tomography: A Comparative Study

BACKGROUND AND OBJECTIVE: Choroidal vascularity index (CVI) is a noninvasive tool to assess choroidal structure. The objective of the current study was to compare the CVI measurements on swept-source optical coherence tomography (SS-OCT) and spectral-domain OCT (SD-OCT) scans using the same image binarization protocol. PATIENTS AND METHODS: This prospective study was conducted from July 2016 through January 2017 and involved 54 healthy volunteers at a tertiary referral eye care institute in Southern India. Choroidal scans were obtained using both SS- and SD-OCT machines. An automated binarization algorithm was used to compute CVI. RESULTS: The mean CVI with SS-OCT scans was 53.88% ± 12.54% (range: 20.46% to 73.93%), whereas the mean CVI with SD-OCT scans was 51.11% ± 7.97% (range: 29.90% to 67.72%)(P < .001). The unadjusted (95% confidence interval [CI], 0.554–0.851) and adjusted (95% CI, 0.607–0.871) intraclass correlation (ICC) estimates were quite similar and indicate moderate-to-good reliability of measurements by two machines. The interval estimate for a conversion factor between SD-OCT and SS-OCT can be calculated as follows: SD = [0.383*SS+19.467, 0.586*SS+30.661]. CONCLUSION: CVI is a noninvasive, robust, and reliable measurement of choroidal vascularity and CVI measurements obtained using both SS-OCT and SD-OCT concur with each other. [ Ophthalmic Surg Lasers Imaging Retina. 2019;50:e26–e32.]