In 2012, a further advance in OCT technology was brought to market with the arrival of the first commercial available swept-source OCT (SS-OCT) device (the Topcon DRI OCT). SS-OCT technology uses a tuneable laser light source with a longer wavelength of light (typically 1040-1050 nm central wavelength) than the light sources seen in more conventional SD-OCT devices. This leads to greater tissue penetration with less backscatter from the RPE, producing images of the choroid with greater resolution with fast image acquisition speeds (100,000 A scans/s) and longer line scan lengths. The ability to take rapid scans with the only commercially available SS-OCT device (the DRI, Tocon Inc. Paramus, NY, USA) also enhances image quality by line scan averaging capability.