Swept-source OCT angiography of the retinal vasculature using intensity differentiation-based optical microangiography algorithms

BACKGROUND AND OBJECTIVE: To demonstrate the feasibility of using a 1,050-nm swept-source optical coherence tomography (SS-OCT) system to achieve noninvasive retinal vasculature imaging in human eyes. MATERIALS AND METHODS: Volumetric data sets were acquired using a 1-μm SS-OCT prototype that operated at a 100-kHz A-line rate. A scanning protocol designed to allow for motion contrast processing, referred to as OCT angiography or optical microangiography (OMAG), was used to scan an approximately 3 x 3-mm area in the central macular region of the retina within approximately 4.5 seconds. An intensity differentiation-based OMAG algorithm was used to extract three-dimensional retinal functional microvasculature information. RESULTS: Intensity signal differentiation generated capillary-level resolution en face OMAG images of the retina. The parafoveal capillaries were clearly visible, thereby allowing visualization of the foveal avascular zone in healthy subjects. CONCLUSION: The capability of OMAG to produce retinal vascular images was demonstrated using the 1-μm SS-OCT prototype. This technique has potential clinical value for studying retinal vasculature abnormalities.