Enhancement of multimodal imaging of rabbit anterior segment using glucose solution

Refractive index mismatch between different tissues will cause light scattering and thus induce light attenuation. The imaging depth of Optical Coherence Tomography (OCT) and Photoacoustic Microscopy (PAM) are limited by the light attenuation, especially in shorter wavelength regions (OCT at 800 nm and PAM at 532 nm). Over the past few decades, Optical Clearing Agents (OCAs) have been extensively explored and widely used to achieve deeper optical penetration in transparent tissues. In this study, we used a 40% glucose solution as an OCA to enhance tissue transparency and reduce light attenuation during deep tissue imaging. The transparency effects on the ex vivo anterior segment of rabbit eyes were verified using OCT. For in vivo treatment, we applied a 40% glucose solution topically to the anterior segment of rabbit eyes and subsequently performed imaging using dual-modal PAM and OCT system. The results showed that the glucose solution altered the tissue refractive index, enhancing both signal intensity and imaging depth. Therefore, this study may provide a potential method for investigating the theory of ocular accommodation by offering deeper cross-sectional structural images and detailed vascular information of the anterior segment, while also expanding the imaging applications of OCT and PAM.