Comparison of OCT angiography and indocyanine green angiographic findings with subtypes of polypoidal choroidal vasculopathy

Purpose To compare the findings of optical coherence tomography angiography (OCTA) with indocyanine green angiography (ICGA) in polypoidal choroidal vasculopathy (PCV) that was divided into two types: polypoidal choroidal neovascularisation (CNV) and typical PCV (type 2 PCV). Methods We studied a retrospective case series of 32 patients with treatment-naive PCV (24 men, eight women; mean age 65.4 years). PCV was categorised into polypoidal CNV (type 1 PCV) and type 2 PCV based on ICGA findings. OCTA was performed using the RTVue XR Avanti. Macular cubes (3x3 or 6x6 mm) were acquired. To evaluate the locations of polyps and branched vessel networks (BVNs), we used B-mode scan. Results OCTA clearly depicted only 17% of the type 1 PCV polyps and 46% of the type 2 PCV polyps which were detectable by ICGA. All type 1 PCV polyps detectable by OCTA were located just beneath the retinal pigment epithelium (RPE). On the other hand, type 2 PCV polyps were detected in various locations. All BVNs of type 1 PCV were located between the RPE and Bruch's membrane on OCTA images. However, the BVNs in type 2 PCV were located mainly under the RPE, though some were located in the choroid. Conclusions Polyps of type 1 PCV were more difficult to detect with OCTA than those of type 2 PCV. Polyps of type 1 PCV were located just beneath the RPE. The BVNs of type 1 PCV were located between the RPE and Bruch's membrane.