Centre for Ophthalmology and Visual Science, University of Western Australia, Perth, Australia; Lions Eye Institute, Nedlands, Australia; Department of Ophthalmology, Sir Charles Gairdner Hospital, Nedlands, Australia.
Centre for Ophthalmology and Visual Science, University of Western Australia, Perth, Australia; Lions Eye Institute, Nedlands, Australia.
Am J Ophthalmol. 2018 May;189:55-64. doi: 10.1016/j.ajo.2018.02.007. Epub 2018 Feb 19.
To use the capillary-free zone along retinal arteries, a physiologic area of superficial avascularization, as an anatomic paradigm to investigate the reliability of optical coherence tomography angiography (OCTA) for visualizing the deep retinal circulation.
Validity analysis and laboratory investigation.
Five normal human donor eyes (mean age 69.8 years) were perfusion-labeled with endothelial antibodies and the capillary networks of the perifovea were visualized using confocal scanning laser microscopy. Regions of the capillary-free zone along the retinal artery were imaged using OCTA in 16 normal subjects (age range 24-51 years). Then, 3 × 3-mm scans were acquired using the RTVue XR Avanti (ver. 2016.1.0.26; Optovue, Inc, Fremont, California, USA), PLEX Elite 9000 (ver. 1.5.0.15909; Zeiss Meditec, Inc, Dublin, California, USA), Heidelberg Spectralis OCT2 (Family acquisition module 6.7.21.0; Heidelberg Engineering, Heidelberg, Germany), and DRI-OCT Triton (Ver. 1.1.1; Topcon Corp, Tokyo, Japan). Images of the superficial plexus, deep vascular plexus, and a slab containing all vascular plexuses were generated using manufacturer-recommended default settings. Comparisons between histology and OCTA were performed.
Histologic analysis revealed that the capillary-free zone along the retinal artery was confined to the plane of the superficial capillary plexus and did not include the intermediate and deep capillary plexuses. Images derived from OCTA instruments demonstrated a prominent capillary-free zone along the retinal artery in slabs of the superficial plexus, deep plexus, and all capillary plexuses. The number of deep retinal capillaries seen in the capillary-free zone was significantly greater on histology than on OCTA (P < .001).
Using the capillary-free zone as an anatomic paradigm, we show that the deep vascular beds of the retina are not completely visualized using OCTA. This may be a limitation of current OCTA techniques.
利用视网膜动脉无血管区（即浅层无血管化的生理性区域）作为解剖学范例，研究光相干断层扫描血管造影（OCTA）在显示深层视网膜循环中的可靠性。
有效性分析和实验室研究。
对 5 只正常人类供体眼（平均年龄 69.8 岁）进行内皮抗体灌注标记，并使用共聚焦扫描激光显微镜观察周边凹毛细血管网络。在 16 名正常受试者（年龄 24-51 岁）中使用 OCTA 对视网膜动脉旁的无血管区进行成像。然后，使用 RTVue XR Avanti（版本 2016.1.0.26；Optovue，Inc，弗里蒙特，加利福尼亚州，美国）、PLEX Elite 9000（版本 1.5.0.15909；蔡司 Meditec，Inc，都柏林，加利福尼亚州，美国）、Heidelberg Spectralis OCT2（家族采集模块 6.7.21.0；Heidelberg Engineering，海德堡，德国）和 DRI-OCT Triton（版本 1.1.1；Topcon Corp，东京，日本）采集 3×3mm 扫描。使用制造商推荐的默认设置生成浅层丛、深层血管丛和包含所有血管丛的切片图像。对组织学和 OCTA 之间的比较进行了分析。
组织学分析显示，视网膜动脉旁的无血管区局限于浅层毛细血管丛平面，不包括中间和深层毛细血管丛。OCTA 仪器获得的图像显示，在浅层丛、深层丛和所有毛细血管丛的切片中，视网膜动脉旁都有明显的无血管区。组织学上观察到的深层视网膜毛细血管数量明显多于 OCTA（P<0.001）。
我们利用无血管区作为解剖学范例，表明 OCTA 并不能完全显示视网膜的深层血管床。这可能是当前 OCTA 技术的一个局限性。
