不同影像学检查在湿性老年性黄斑变性诊断、分型中的特点比较

Multimodal imaging examination for diagnosis of wet age-related macular degeneration and its classification

目的对比观察湿性老年性黄斑变性(w AMD)患者的脉络膜新生血管(CNV)在眼底荧光血管造影(FFA)、频域光学相干断层成像技术(SD-OCT)和光学相干断层扫描血管造影(OCTA)下的成像特点,寻找它们之间的相关性,同时在OCTA下定性观察CNV血管网的形态特征及周边脉络膜血流情况。方法收集wAMD患者40例40眼,所有患者均行眼底照相、FFA、SD-OCT和OCTA检查。对比观察w AMD患者的CNV在FFA、SD-OCT和OCTA下检查图像特征,同时在OCTA下定性观察CNV血管网的形态特征及周边脉络膜血流情况。结果在FFA上表现为典型性CNV,SD-OCT以Ⅱ型CNV为主;OCTA下显示的血流信号位于视网膜色素上皮层之上,在外网膜层可见黄斑区边界清楚的、团状的高反射信号,CNV血管周围均可见形态不规则的低信号影。在FFA上表现为隐匿性CNV,SD-OCT以Ⅰ型及混合型CNV为主;而OCTA下显示的血流信号位于视网膜色素上皮和布鲁赫膜之间,CNV周围常伴有低密度晕,并呈现出不同的形态,且CNV形态在OCTA上比FFA显示得更清晰。在OCTA下根据CNV血管结构及成分,将Ⅰ型w AMD患者的CNV分为5种类型:纤维状血管团型(41.0%)、毛细血管团型(13.6%)、枯树型(13.6%)、局部血管扩张型(13.6%)及不明分型(18.2%)。而Ⅱ型CNV的血管网表现较为一致,均由细小微血管组成,未见较粗大的主干血管。结论 OCTA能清晰地显示CNV血管形态,OCTA作为实时无创的血管观测技术,将成为传统眼底血管造影的一项补充甚至替代的检查方式,有助于提高对眼底血管性疾病的认识。

Objective To compare multimodal imaging examination in detecting choroidal neovascularization(CNV) in wet age-related macular degeneration(wAMD). Methods 40 patients(40 eyes) with CNV secondary to w AMD were retrospectively reviewed. All patients underwent color fundus photographs, fundus fluorescein angiography( FFA), spectral domain optical coherence tomography( SD-OCT), fundus and optical coherence tomography angiography( OCTA) for CNV. The morphological characteristics detected by different imaging techniques were compared. At the same time, the morphological characteristics of CNV and peripheral choroidal blood flow were observed qualitatively under OCTA. Results Most of the typical CNV showed by FFA was type Ⅱ CNV on SD-OCT. The blood flow signal was above the retinal pigment epithelium(RPE) on OCTA, and CNV presented the well defined and cluster-type hyperreflected signal in macular region on the outer retina layer. The irregular low-signal shadows were observed around CNV vessel;the similar site and range of lesions in the early-phase of FFA or ICGA. Most of the occult CNV showed by FFA was also located at sub-RPE(type Ⅰ or mixed type) on SD-OCT, while the blood flow signal between RPE and Bruch membrane on OCTA was observed. On OCTA the CNV presents different vascular morphology, simultaneously an irregular peripheral low-signal halo ring was observed around CNV. The CNV morphology showed on OCTA was more clearly than FFA or ICGA. According to the structure and the vascular component,type Ⅰ CNV was divided into five types: fibrous vessel mass type(41.0%), capillary mass type(13.6%), dead tree type(13.6%), local vasodilation type(13.6%) and unknown type(18.2%). However, the vascular network of type Ⅱ CNV was more consistent, composed of tiny capillaries and there was no thicker blood vessel. Conclusion OCTA can show the vascular morphology of CNV clearly and can offer noninvasive monitoring of the CNV, which would be a supplement or even a substitute for the traditional fundus angiography.