In vivo three-dimensional imaging of neovascular age-related macular degeneration using optical frequency domain imaging at 1050 nm

PURPOSE. To assess the application of optical frequency domain imaging (OFDI) at 1050 nm for the detection of choroidal neovascularization (CNV) in age-related macular degeneration (AMD) and its response to treatment. Three patients presenting with blurred vision and exudative AMD were imaged before and after anti-VEGF treatment with ranibizumab. METHODS. The patients were imaged with OFDI, a swept-source-based, high-speed optical coherence tomography (OCT) system developed at the Wellman Center for Photomedicine. A center wavelength of 1050 nm was used that has been demonstrated to provide better imaging of the deeper structures of the retina below the RPE, such as the choroidal vasculature. Three-dimensional data sets were acquired in 2 to 4 seconds. RESULTS. En face images were compiled from cross-sectional OFDI data and correlated with color fundus photography (CF) and fluorescein angiograms (FAs). Cross-sectional images were coregistered with CF and FA to obtain depth-resolved information about CNV, CNV volume, retinal thickness, subretinal fluid volume and height of neurosensory detachment before and after treatment with ranibizumab. A band of reduced reflectivity below the RPE was identified in all three subjects that corresponded to areas of confirmed and suspected occult CNV on FA. After treatment, this band was reduced in volume in all patients. CONCLUSIONS. High-speed 3-D OFDI at 1050 nm is a promising technology for imaging the retina and choroid in neovascular AMD. The developed system at 1050 nm provides good contrast for occult (type 1) CNV and may have advantages compared with time domain and current state of the art spectral domain OCT systems (SD-OCT) at 850 nm.