Feature Of The Week 2/16/14: En Face Enhanced-Depth Swept-Source Optical Coherence Tomography Features of Chronic Central Serous Chorioretinopath
We characterized en face features of the retinal pigment epithelium (RPE) and choroid in eyes with chronic central serous chorioretinopathy (CSCR) using a high-speed, enhanced tissue penetration, swept-source optical coherence tomography (SS-OCT) prototype. Fifteen eyes of 13 consecutive patients with the clinical diagnosis of CSCR were prospectively examined with SS-OCT. Three-dimensional 6x6mm macular cube raster scans were obtained with SS-OCT operating at 1050nm wavelength and 100,000 A-lines/sec with 6µm axial resolution. Segmentation of the RPE generated a reference surface; en face SS-OCT images of the RPE and choroid were extracted at varying depths every 3.5 µm (1 pixel). Abnormal features were characterized by systematic analysis of multimodal fundus imaging including color photographs, fundus autofluorescence, and fluorescein and indocyanine-green angiography (ICGA).
In all eyes, 15/15 (100%) en face SS-OCT imaging at the RPE level revealed absence of signal corresponding to RPE detachment and/or RPE loss. En face SS-OCT imaging at the choriocapillaris level showed focally enlarged vessels in 8 of 15 eyes (53%). At the level of Sattler’s layer, en face SS-OCT documented focal choroidal dilation in 8 of 15 eyes (53%) and diffuse choroidal dilation in 7 of 15 eyes (47%). At the level of Haller’s layer, these same features were observed in 3 of 15 eyes (20%) and 12 of 15 eyes (80%) respectively. In all affected eyes, these choroidal vascular abnormalities were seen just below areas of RPE abnormalities. In 2 eyes with secondary choroidal neovascularization, distinct en face SS-OCT features corresponded to the neovascular lesions.
We concluded that high-speed, enhanced-depth SS-OCT at 1050 nm wavelength enables the visualization of pathological features of the RPE and choroid in eyes with chronic CSCR not usually appreciated with standard spectral domain (SD) OCT. En face SS-OCT imaging appears to be a valuable tool in the identification of choroidal neovascularization without the use of angiography. This in vivo documentation of the RPE and choroidal vasculature at variable depths may help elucidate the pathophysiology of disease and can potentially contribute to the diagnosis and management of chronic CSCR.
For more information see recent Article. Courtesy Daniela Ferrara from the New England Eye Center at Tufts University.