Hagag Ahmed M, Pechauer Alex D, Liu Liang, Wang Jie, Zhang Miao, Jia Yali, Huang David
Casey Eye Institute, Oregon Health & Science University, Portland, Oregon.
Ophthalmol Retina. 2018 Apr;2(4):329-336. doi: 10.1016/j.oret.2017.07.022. Epub 2017 Oct 16.
Use projection-resolved OCT angiography to investigate the autoregulatory response in the 3 parafoveal retinal plexuses under hyperoxia.
Prospective cohort study.
Nine eyes from 9 healthy participants.
One eye from each participant was scanned using a commercial spectral-domain OCT system. Two repeated macular scans (3 × 3 mm) were acquired at baseline and during oxygen breathing. The split-spectrum amplitude-decorrelation algorithm was used to detect blood flow. The projection-resolved algorithm was used to suppress projection artifacts and resolve blood flow in 3 distinct parafoveal plexuses. The Wilcoxon signed-rank test was used to compare baseline and hyperoxic parameters. The coefficient of variation, intraclass correlation coefficient, and pooled standard deviation were used to assess the reliability of OCT angiography measurements.
Flow index and vessel density were calculated from the en face angiograms of each of the 3 plexuses, as well as from the all-plexus inner retinal slab.
Hyperoxia induced significant reduction in the flow index (-11%) and vessel density (-7.8%) of only the deep capillary plexus ( < 0.001) and in the flow index of the all-plexus slab ( = 0.015). The flow index also decreased in the intermediate capillary plexus and the superficial vascular complex, but these changes were small and not statistically significant. The projection-resolved OCT angiography showed good within-session baseline repeatability (coefficient of variation, 0.8%-5.2%; intraclass correlation coefficient, 0.93-0.98) in all parameters. Relatively large between-day response reproducibility was observed (pooled standard deviation, 1.7%-9.4%).
Projection-resolved OCT angiography was able to show that the retinal autoregulatory response to hyperoxia affects only the deep capillary plexus, but not the intermediate capillary plexus or superficial vascular complex.
使用投影分辨光学相干断层扫描血管造影术研究高氧状态下3个黄斑旁视网膜神经丛的自动调节反应。
前瞻性队列研究。
9名健康参与者的9只眼睛。
使用商用光谱域光学相干断层扫描系统对每位参与者的一只眼睛进行扫描。在基线和吸氧期间获取两次重复的黄斑扫描图像（3×3毫米）。采用分裂谱幅度去相关算法检测血流。使用投影分辨算法抑制投影伪影并分辨3个不同黄斑旁神经丛中的血流。采用Wilcoxon符号秩检验比较基线和高氧参数。变异系数、组内相关系数和合并标准差用于评估光学相干断层扫描血管造影测量的可靠性。
从3个神经丛以及全神经丛内层视网膜平板的正面血管造影图计算血流指数和血管密度。
高氧仅导致深层毛细血管丛的血流指数（-11%）和血管密度（-7.8%）显著降低（P<0.001），以及全神经丛平板的血流指数降低（P=0.015）。中间毛细血管丛和浅层血管复合体的血流指数也有所下降，但这些变化较小且无统计学意义。投影分辨光学相干断层扫描血管造影在所有参数中均显示出良好的日内基线重复性（变异系数，0.8%-5.2%；组内相关系数，0.93-0.98）。观察到相对较大的日间反应再现性（合并标准差，1.7%-9.4%）。
投影分辨光学相干断层扫描血管造影能够显示视网膜对高氧的自动调节反应仅影响深层毛细血管丛，而不影响中间毛细血管丛或浅层血管复合体。
