Non-contact, in-vivo, functional, and structural ophthalmic imaging using multimodal photoacoustic remote sensing (PARS) microscopy and optical coherence tomography (OCT)

Early diagnosis of ocular diseases improves the understanding of pathophysiology and helps with accurate monitoring and effective treatment. Advanced multimodal ocular imaging platforms play a crucial role in the visualization of the ocular components and provide clinicians with a valuable tool for evaluating different eye diseases. Here, for the first time, we present a non-contact, multimodal photoacoustic remote sensing (PARS) microscopy and swept-source optical coherence tomography (SS-OCT) for in-vivo functional and structural imaging of the eye. The system provides complementary imaging contrasts of optical absorption and optical scattering and is used for non-contact, in-vivo imaging of the murine eye. Results of vasculature and structural imaging as well as melanin content in the retinal pigment epithelium (RPE) layer are presented. Multiwavelength PARS microscopy using Stimulated Raman Scattering (SRS) is applied for the first time, to provide non-contact oxygen saturation estimation in the ocular tissue. The reported work may be a major step toward clinical translation of ophthalmic technologies and has the potential to advance the diagnosis and treatment of ocular diseases.