Vitreous, Retina, Macula Consultants of New York, New York.
JAMA Ophthalmol. 2015 Jan;133(1):45-50. doi: 10.1001/jamaophthalmol.2014.3616.
The retinal vasculature is involved in many ocular diseases that cause visual loss. Although fluorescein angiography is the criterion standard for evaluating the retina vasculature, it has risks of adverse effects and known defects in imaging all the layers of the retinal vasculature. Optical coherence tomography (OCT) angiography can image vessels based on flow characteristics and may provide improved information.
To investigate the ability of OCT angiography to image the vascular layers within the retina compared with conventional fluorescein angiography.
DESIGN, SETTING, AND PARTICIPANTS: In this study, performed from March 14, 2014, through June 24, 2014, a total of 5 consecutive, overlapping B-scan OCT angiography images composed of 216 A-scans were obtained at 216 discrete positions within a region of interest, typically a 2 × 2-mm area of the retina. The flow imaging was based on split-spectrum amplitude decorrelation angiography (SSADA), which can dissect layers of vessels in the retina. These distinct layers were compared with the fluorescein angiograms in 12 healthy eyes from patients at a private practice retina clinic to evaluate the ability to visualize the radial peripapillary capillary network. The proportion of the inner vs outer retinal vascular layers was estimated by 3 masked readers and compared with conventional fluorescein angiograms of the same eyes.
Outcome measures were visualization of the radial peripapillary capillary network in the fluorescein and SSADA scans and the proportion of the inner retinal vascular plexus vs the outer retinal capillary plexus as seen in SSADA scans that would match the fluorescein angiogram.
In none of the 12 eyes could the radial peripapillary capillary network be visualized completely around the nerve head by fluorescein angiography, whereas the network was readily visualized in the SSADA scans. The fluorescein angiograms were matched, with a mean proportion of the inner vascular plexus being 95.3% (95% CI, 92.2%-97.8%) vs 4.7% (95% CI, 2.6%-5.7%) for the outer capillary plexus from the SSADA scans.
Fluorescein angiography does not image the radial peripapillary or the deep capillary networks well. However, OCT angiography can image all layers of the retinal vasculature without dye injection. Therefore, OCT angiography, and the findings generated, have the potential to affect clinical evaluation of the retina in healthy patients and patients with disease.
视网膜血管参与许多导致视力丧失的眼部疾病。虽然荧光素血管造影是评估视网膜血管的标准，但它具有不良反应的风险，并且在成像视网膜血管的所有层方面存在已知缺陷。光学相干断层扫描（OCT）血管造影可以根据血流特征对血管进行成像，并且可能提供更好的信息。
研究 OCT 血管造影与传统荧光素血管造影相比，在成像视网膜血管层方面的能力。
设计、地点和参与者：本研究于 2014 年 3 月 14 日至 6 月 24 日进行，共获得 5 个连续的、重叠的 B 扫描 OCT 血管造影图像，由 216 个离散位置的 216 个 A 扫描组成，通常是视网膜的 2×2mm 区域。血流成像基于分段谱幅度去相关血管造影术（SSADA），它可以分离视网膜中的血管层。这些不同的层与来自私人执业视网膜诊所的患者的 12 只健康眼睛的荧光素血管造影图进行比较，以评估可视化放射状视盘毛细血管网络的能力。通过 3 位盲法读者评估内层和外层视网膜血管层的比例，并与相同眼睛的常规荧光素血管造影图进行比较。
主要结局是在荧光素和 SSADA 扫描中观察到放射状视盘毛细血管网络，以及在 SSADA 扫描中看到的与荧光素血管造影图匹配的内层视网膜血管丛与外层毛细血管丛的比例。
在 12 只眼中，没有一只眼的荧光素血管造影能完全显示视盘周围的放射状毛细血管网，而 SSADA 扫描则很容易显示。荧光素血管造影图与 SSADA 扫描的内层血管丛的平均比例为 95.3%（95%置信区间，92.2%-97.8%）匹配，而外层毛细血管丛的比例为 4.7%（95%置信区间，2.6%-5.7%）。
荧光素血管造影术不能很好地成像放射状视盘或深层毛细血管网络。然而，OCT 血管造影术可以在不注射染料的情况下成像视网膜血管的所有层。因此，OCT 血管造影术及其产生的结果有可能影响健康患者和疾病患者的视网膜临床评估。
