OCT血流成像技术的现在与未来

The Present and Future of OCT Angiography

光相干断层成像血流成像（OCT angiography，OCTA）是近年来发展起来的一项新的眼科影像检查技术，它通过特殊的运算法则对连续扫描的OCT进行计算，获取血流信号，可快速、无创地重建视网膜、脉络膜血管的三维结构。虽然这种血流成像技术目前尚无法检测眼底血管的充盈时间，也无法评价血-视网膜屏障的功能，但是它已经显示出与传统血管造影基本一致的眼底血管结构，甚至可以更好地揭示视网膜深层毛细血管的形态，发现早期脉络膜新生血管，从而提供更多的病理信息，因此该技术正广泛应用于糖尿病性视网膜病变、黄斑旁毛细血管扩张症、年龄相关性黄斑变性、中心性浆液性脉络膜视网膜病变、视网膜静脉阻塞等多种眼底血管性疾病的检查。尽管这项新技术目前还存在各种局限性，如移动性伪影、浅层血管在视网膜色素上皮层的投影等问题，但是未来随着设备和软件的不断更新，现有技术必将进一步完善，影像会更加清晰而完美，而我们对疾病的认识也会更加深入和彻底。

Optical coherence tomography angiography （OCTA） is a new imaging technology that allows the non-invasive and rapid reconstruction of the three-dimensional structure of the retinal and choroidal vascularization. Importantly, blood flow signals within the vessels can be derived from consecutive scans of the selected areas. OCTA can show vascular structure consistent with conventional angiography, although it cannot yet calculate the filling time and evaluate the function of the blood-retinal barrier. OCTA can reveal deep capillary networks better than ever and detect choroidal neovascularization much earlier, providing additional information of the underlying pathology. Thus, it is now being widely used in diabetic retinopathy, macular telangiectasia, age-related macular degeneration, central serous chorioretinopathy, retinal vein occlusion, and other fundus vascular diseases. Currently, this new technology still has some limitations such as movement artifacts and projection of superficial retinal vessels at the level of the retinal pigment epithelium. However with upgrades in the equipment and software, the current techniques will be improved, providing images more clearly. As a result, we will develop a more thorough understanding of the diseases.