En-face high-penetration optical coherence tomography imaging in polypoidal choroidal vasculopathy

To observe the choroidal microstructure in polypoidal choroidal vasculopathy (PCV) using high-penetration optical coherence tomography (HP-OCT) with a long-wavelength light source that visualises tissue beneath the retinal pigment epithelium (RPE) and deep choroid, and to compare the findings with those of indocyanine green angiography (ICGA).

In this retrospective, non-invasive, observational case series, 19 eyes (18 patients) with PCV were observed using HP-OCT (swept source, 100 000 A-scans/s, 1060 nm wavelength) and ICGA. The HP-OCT scan protocol was a 3×3-mm or 6×6-mm square containing 256×256 or 512×128 A-scans. The choroidal thickness (CT) was measured using HP-OCT.

ICGA showed 43 polypoidal lesions in 14 eyes and a vascular network in 17 eyes. HP-OCT showed 41 of the 43 polypoidal lesions visualised by ICGA as RPE rings with inner reflectivity and 15 eyes with a vascular network. Six eyes with RPE rings with inner reflectivity on HP-OCT were not visualised on ICGA images. The choroidal vascular network was dilated in 14 (33%) of 43 polypoidal lesions and 22 (47%) of 47 polypoidal lesions on ICGA and HP-OCT images, respectively. The mean CT at the fovea was 250 μm. The CT at the dilated choroidal vessels beneath the polypoidal lesions was significantly (p = 0.0095) thicker than that of the undilated choroidal vessels beneath the polypoidal lesions.

HP-OCT can visualise choroidal vascular abnormalities in eyes with PCV and should be useful for understanding the pathogenesis of these abnormalities.