Retinal and choroidal imaging using integrated photoacoustic microscopy and optical coherence tomography.

Most reported photoacoustic ocular imaging work to date uses small animals, such as mice and rats, the eyes of which are small and less than one-third the size of a human eye, which poses a challenge for clinical translation. Here we achieved chorioretinal imaging of larger animals, i.e. rabbits, using a dual-modality photoacoustic microscopy (PAM) and optical coherence tomography (OCT) system. Preliminary experimental results in living rabbits demonstrate that the PAM can noninvasively visualize depth-resolved retinal and choroidal vessels using a safe laser exposure dose; and the OCT can finely distinguish different retinal layers, the choroid, and the sclera. This reported work might be a major step forward in clinical translation of photoacoustic microscopy.