Department of Bioengineering, University of Washington, Seattle, Washington, United States.
Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States.
Invest Ophthalmol Vis Sci. 2018 Jan 1;59(1):203-211. doi: 10.1167/iovs.17-22953.
To achieve reproducible imaging of the choriocapillaris and associated flow voids using swept-source OCT angiography (SS-OCTA).
Subjects were enrolled and SS-OCTA was performed using the 3 × 3 mm scan pattern. Blood flow was identified using the complex optical microangiography (OMAG) algorithm. The choriocapillaris was defined as a slab from the outer boundary of Bruch's membrane (BM) to approximately 20 μm below BM. Compensation for the shadowing effect caused by the RPE and BM complex on the choriocapillaris angiogram was achieved by using the structural information from the same slab. A thresholding method to calculate the percentage of flow voids from a region was developed based on a normal database.
Twenty normal subjects and 12 subjects with drusen were enrolled. SS-OCTA identified the choriocapillaris in normal subjects as a lobular plexus of capillaries in the central macula and the lobular arrangement became more evident toward the periphery. In all eyes, signal compensation resulted in fewer choriocapillaris flow voids with improved repeatability of measurements. The best repeatability for the measurement was achieved by using 1 standard deviation (SD) for the thresholding strategy.
SS-OCTA can image the choriocapillaris in vivo, and the repeatability of flow void measurements is high in the presence of drusen. The ability to image the choriocapillaris and associated flow voids should prove useful in understanding disease onset, progression, and response to therapies.
利用扫频源光学相干断层扫描血管造影术（SS-OCTA）实现脉络膜毛细血管及其相关血流空洞的可重复性成像。
招募研究对象并使用 3×3mm 扫描模式进行 SS-OCTA 检查。使用复杂光学微血管造影术（OMAG）算法识别血流。脉络膜毛细血管定义为从 Bruch 膜（BM）的外边界到 BM 下方约 20μm 的薄片。通过使用相同薄片的结构信息，补偿 RPE 和 BM 复合物对脉络膜毛细血管造影的遮蔽效应。开发了一种基于正常数据库的阈值方法来计算血流空洞区域的百分比。
纳入 20 名正常受试者和 12 名有玻璃膜疣的受试者。SS-OCTA 在正常受试者的中央凹处识别出脉络膜毛细血管呈毛细血管小叶丛状，并且小叶排列在周边更为明显。在所有眼睛中，信号补偿导致脉络膜毛细血管血流空洞减少，测量的重复性提高。使用 1 个标准差（SD）作为阈值策略可实现最佳的测量重复性。
SS-OCTA 可以在体内成像脉络膜毛细血管，并且在有玻璃膜疣的情况下，血流空洞测量的重复性很高。成像脉络膜毛细血管及其相关血流空洞的能力应该有助于理解疾病的发生、进展和对治疗的反应。
