| Purpose:To describe the morphological characteristics,activity and efficacy of optical coherence tomography angiography(OCTA)in detecting choroidal neovascularization(CNV)in wet age-related macular degeneration(wAMD).Simultaneously to study whether the characteristic of CNV in wAMD patients on OCTA was related to the FFA?Methods:We retrospectively reviewed 53 patients(86 eyes)with suspected CNV secondary to wet AMD.All the patients underwent a multimodal assessment for CNV,including color fundus photographs,spectraldomain optical coherence tomography(SD-OCT),fluorescein angiography(FA)imaging,and OCTA.Two independent readers calculated the sensitivity and specificity of OCTA in detecting CNV compared with FA.A qualitative analysis of OCTA was also performed to describe the morphological appearance of CNV.Results:Among 86 eyes of 53 patients,52 eyes were diagnosed as having CNV based on the FA imaging analysis.FFA as the diagnostic gold standard,the specificity of OCTA for the detection of CNV was 67.6%,with sensitivity of 86.5%and positive and negative predictive values of 80.4%and 76.7%,respectively.The sensitivity of OCTA for the detection of CNV in the new-onset CNV secondary to AMD and type II CNV were 100%.Most of the typical CNV showed with FFA was type II CNV,We can see blood flow signal above the RPE on OCTA,CNV showed the well defined and cluster-type hyperreflected signal in macular region on the outer retina layer.Simultaneously the irregular low-signal shadows could be seen around CNV vessel.It can showed the similar site and range of lesions in the early-phase of FFA or ICGA.Most of the occult CNV showed with FFA was also located at sub-RPE(I or mixed type)in OCT,while the blood flow signal between RPE and Bruch membrane on OCTA can also be obtained.On OCTA CNV presents different vascular morphology such as medusa,scalloped and irregular,simultaneously an irregular peripheral low-signal halo ring could also be seen around CNV.The CNV morphology showed on OCTA is more clearly than FFA or ICGA.For 12 eyes of PCV patients,abnormal branch vessel network(BNV)shared similar findings in ICGA and OCTA;PCV patients with polyps showed highlight spot in OCTA.OCTA can visualize BNV and polyps of choroidal apillary.Patients previously treated with repeated intravitreal anti-VEGF injections,the vascular networks shared similar characteristics,with large main trunk vessels;vascular stiffness;increased vascular length and rarely peripheral vascular anastomosis.According to the structure and the vascular component,type I CNV were divided into five types:fibrous nidus(41%)?ill-defined group of capillaries(13.6%)?dead tree type(13.60%)?local vasodilation(13.6%)and unknown type(18.2%).Howere the vascular network of type II CNV is more consistent,composed of tiny capillaries and there is no thicker blood vessel.OCTA can be used to assess the activity of the CNV in five aspects:shape,branch,the presence of anastomoses and loops,morphology of the vessel termini,and presence of a perilesional hypointense halo.Conclusions:OCT A can show the blood flow and vascular morphology of CNV clearly and can offer noninvasive monitoring of the CNV,aiding for each treatment decision during the follow-up,will be a supplement or even a substitute for the traditional fundus angiography. |
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