Agrawal Rupesh, Seen Sophia, Vaishnavi Shiva, Vupparaboina Kiran Kumar, Goud Abhilash, Rasheed Mohammed Abdul, Chhablani Jay
Ophthalmic Surg Lasers Imaging Retina. 2019 Feb 1;50(2):e26-e32. doi: 10.3928/23258160-20190129-15.
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.
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.
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 = [0.383SS+19.467, 0.586SS+30.661].
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.].
脉络膜血管指数（CVI）是一种评估脉络膜结构的非侵入性工具。本研究的目的是使用相同的图像二值化方案，比较扫频源光学相干断层扫描（SS-OCT）和谱域光学相干断层扫描（SD-OCT）扫描获得的CVI测量值。
本前瞻性研究于2016年7月至2017年1月进行，纳入了印度南部一家三级转诊眼科护理机构的54名健康志愿者。使用SS-OCT和SD-OCT机器进行脉络膜扫描。采用自动二值化算法计算CVI。
SS-OCT扫描的平均CVI为53.88%±12.54%（范围：20.46%至73.93%），而SD-OCT扫描的平均CVI为51.11%±7.97%（范围：29.90%至67.72%）（P<.001）。未调整的组内相关系数（ICC）估计值（95%置信区间[CI]，0.554 - 0.851）和调整后的估计值（95%CI，0.607 - 0.871）非常相似，表明两台机器测量的可靠性为中度至良好。SD-OCT和SS-OCT之间转换因子的区间估计可按以下方式计算：SD = [0.383SS + 19.467, 0.586SS + 30.661]。
CVI是一种非侵入性、稳健且可靠的脉络膜血管测量方法，使用SS-OCT和SD-OCT获得的CVI测量值相互一致。[《眼科手术、激光与视网膜成像》。2019；50：e26 - e32。]
