Optical clearing agent enhanced multimodal photoacoustic microscopy and optical coherence tomography imaging of rabbit eyes

Multimodal imaging photoacoustic microscopy (PAM) and optical coherence tomography (OCT) can provide morphological and functional information of living organisms which reveals the physiological and pathological state of biological tissues. In this study, a dual-modal PAM and OCT system was custom-built to simultaneously image the optical absorption and scattering characteristic of rabbit eyes. Glycerol solution was used as optical clearing agent to enhance PAM and OCT imaging of New Zealand White rabbit eyes in vivo. Results showed that both OCT and PAM signals were increased by retro-bulbar injection of glycerol to New Zealand White rabbit eyes. The PAM signal amplitude increased from 0.1476 (a.u) to 0.1701 (a.u) after glycerol solution injection, which increased by 115%. And intensity of OCT signal was increased up to 150%. The optical clearing agent enhanced multimodal imaging technique provides a new method to increase the depth of optical measured depth and to improve the imaging contrast, which can be used to evaluate pathophysiological early symptoms in vivo.