In vivo optical frequency domain imaging of human retina and choroid

Optical frequency domain imaging (OFDI) using swept laser sources is an emerging second-generation method for optical coherence tomography (OCT). Despite the widespread use of conventional OCT for retinal disease diagnostics, until now imaging the posterior eye segment with OFDI has not been possible. Here we report the development of a highperformance swept laser at 1050 nm and an ophthalmic OFDI system that offers an A-line rate of 18.8 kHz, sensitivity of >92 dB over a depth range of 2.4 mm with an optical exposure level of 550 muW, and deep penetration into the choroid. Using these new technologies, we demonstrate comprehensive human retina, optic disc, and choroid imaging in vivo. This advance enables us to view choroidal vasculature in vivo without intravenous injection of fluorescent dyes and may provide a useful tool for evaluating choroidal as well as retinal diseases.