Optical coherence angiography

TLDR

The technique compensates sample motion using Doppler‑based axial correction within A‑lines and a correlation‑based algorithm across images, then integrates flow volumes to produce simultaneous retinal and choroidal 2‑D vessel maps. Noninvasive optical coherence angiography successfully visualized three‑dimensional ocular vasculature in vivo, matching the patterns seen in fluorescein and indocyanine angiograms.

Abstract

Noninvasive angiography is demonstrated for the in vivo human eye. Three-dimensional flow imaging has been performed with high-speed spectral-domain optical coherence tomography. Sample motion is compensated by two algorithms. Axial motion between adjacent A-lines within one OCT image is compensated by the Doppler shift due to bulk sample motion. Axial displacements between neighboring images are compensated by a correlation-based algorithm. Three-dimensional vasculature of ocular vessels has been visualized. By integrating volume sets of flow images, two-dimensional images of blood vessels are obtained. Retinal and choroidal blood vessel images are simultaneously obtained by separating the volume set into retinal part and choroidal parts. These are corresponding to fluorescein angiogram and indocyanine angiogram.