Abstract
Purpose: :
High-penetration optical coherence tomography (HP-OCT) with long-wavelength light source (1060nm) can visualize the microstructure beneath the retinal pigment epithelium and deep choroid. We observed the choroidal microstructure focusing on vascular pattern and choroidal thickness in polypoidal choroidal vasculopathy (PCV) with HP-OCT.
Methods: :
A custom-built HP-OCT (Swept source, 50,000 A-scan/s, 1060 nm wavelength) was used to image a total of 11 eyes of 11 patients with treatment-naïve PCV diagnosed fluorescein angiography and indocyanine green angiography. The scan protocol was 6 x 6 mm square containing 512 x 256 A-scans.
Results: :
Full thickness choroid was visualized in all eyes, and choroidal middle to large vessels as well as chorio-scleral interface were identifiable. Hyper-reflective lesions, presumably fibrin, abnormal vessels, or polyp lesion, were observed inside pigment epithelial detachment (PED) in all eyes (100%). In 9 eyes (82%), thin hyper-reflective line, seemingly Bruch’s membrane, was clearly observed at the bottom of PED. Localized thinning of choriocapillaris was observed in 6 (55%), choroidal thinning in 5 (45%), and choroidal large vessel dilatation in 8 (73%), all of which were rare findings in normal eyes.
Conclusions: :
HP-OCT provides a clear image of deep choroid beneath PED that was quite inaccessible using conventional 840nm-OCT. These findings must be useful for understanding the pathology of PCV.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • retina • age-related macular degeneration