Choriocapillaris hypoperfusion artifact in OCT angiography

BACKGROUND AND OBJECTIVE: To illustrate how optical coherence tomography (OCT) angiography (OCTA) can be misinterpreted if not evaluated along with structural en face OCT to analyze the signal intensity. PATIENTS AND METHODS: Patients with different macular diseases associated with suspicious flow impairment in the choriocapillaris were recruited to be imaged on the RTVue XR Avanti device (Optovue, Fremont, CA) with the Angio Retina mode. En face OCT angiograms, structural en face OCT, and corresponding OCT B-scans with flow signal overlaid were compared to evaluate the correspondence of signal strength to areas of flow reduction in the choriocapillaris. RESULTS: Six eyes from six patients were enrolled. Macular lesions evaluated in this study included acute central serous chorioretinopathy, paracentral acute middle maculopathy, age-related macular degeneration, adult-onset foveomacular vitelliform dystrophy, and branch retinal vein occlusion. In all cases, areas of suspicious flow decrement in the choriocapillaris corresponded to hyporeflective areas in the intensity en face OCT. Thus, a precise confirmation of choriocapillaris flow impairment was not possible. CONCLUSION: It is essential to be aware of the importance of analyzing the structural image alongside with the flow image to interpret flow impairment. This is more important in subretinal pigment epithelial structures such as choriocapillaris and choroid.