Purpose: To describe the use of optical coherence tomography angiography (OCT-A) for evaluating the spectrum of polypoidal vascular diseases.
Methods: Retrospective observational case series of seven patients with polypoidal choroidal vasculopathy (three cases) or polypoidal choroidal neovascularization (four cases). Optical coherence tomography angiography information was acquired using two different OCT-A devices (the Optovue RTVue XR Avanti SD-OCT and the Spectralis OCT angiography). Flow signals within branching vascular networks, type 1 neovascularization and polyps were evaluated. Comparisons were made between en face and cross-sectional OCT-A images. Vascular information from OCT-A was also compared with indocyanine green angiography.
Results: En face images from OCT-A provided anatomical information about branching vascular networks that were comparable to indocyanine green angiography. Polyps were poorly resolved on en face OCT-A images but were clearly defined on cross-sectional OCT-A images. Cross-sectional OCT-A revealed flow signals within focal regions of the polyps with a significant portion of the polyp lumen being devoid of flow signal. Flow signals from cross-sectional OCT-A images also showed that branching vascular networks, type 1 neovascularization, and polyps were confined to the anatomic compartment between the retinal pigment epithelium and Bruch's membrane. It was not possible to detect leakage on en face or cross-sectional OCT-A.
Conclusion: The combination of en face and cross-sectional OCT-A images provides anatomical information about polypoidal structures that is comparable to indocyanine green angiography. OCT-A may be a useful modality for the management of polypoidal diseases. However, the limitations of OCT-A identified in this study suggest that it is not a replacement for indocyanine green angiography.