Abstract
Purpose: :
Macular disorders such as age-related macular degeneration (ARMD), polypoidal choroidal vasculopathy (PCV), central serous chorioretinopathy (CSC), and myopic choroidal neovascularization (mCNV) originate from the choroid, and interest is shifting to the choroidal microstructures. Optical coherence tomography (OCT) is useful; however, conventional OCT with the 830-nm wavelength has high reflectivity at the retinal pigment epithelium (RPE), and the choroid is poorly visualized. High-penetration OCT (HP-OCT) with a longer wavelength at 1060 nm enables visualization of more details of the choroidal architecture.
Methods: :
A custom-built HP-OCT (swept source, 50,000 A-scan/s) was used to image 26 eyes with various disorders (ARMD 7 eyes, PCV 6 eyes, CSC 7 eyes, and mCNV 6 eyes). The scan length was 6 x 6 mm square (512 x 256 A-scans). The micropathologies were evaluated using HP-OCT.
Results: :
The choroidal vasculature was visualized more clearly in all eyes. The full thickness of the choroid could be seen and the scleral interface was traceable completely in 15 eyes (58%) and partially in 3 (12%); not traceable in 8 (30%). Subretinal fluid and pigment epithelial detachments (PED) were clearly identified in 15 (58%) and 17 (65%) eyes, respectively. A PED was observed in all eyes with PCV, and the region of hyper-reflectivity inside the PED, which was most likely fibrin formation, was detected in all eyes (Figure).
Conclusions: :
High-speed HP-OCT allows visualization of the high-contrast microstructures beneath the RPE and is useful for clinical application.
Keywords: age-related macular degeneration • chorioretinitis • myopia