Photoacoustic imaging and its preclinical application in ophthalmology

Abstract

SummaryPhotoacoustic imaging is an emerging optical imaging technique featuring optical illumination and acoustic detection. Short laser pulses deposit their energy in optical absorbers where light energy is converted to acoustic energy. Therefore photoacoustic imaging is a direct way of absorption mapping in 3D. Since absorbers, or chromophores, have unique absorption spectra, spectrascopic photoacoustic imaging can distinguish different absorbers by wavelength unmixing. In preclinical and clinical settings, photoacoustic microscopy, one major modality in photoacoustic imaging, can be used for ophthalmic imaging. Without the use of contrast agents, two absorbers can be distinguished: melanin and hemoglobin. Even though the application of photoacoustic microscopy in ophthalmic imaging is relatively new and still in its primitive phase, here we can see how photoacoustic microscopy can reveal the details of blood vessels and melanin in the eye. We will also discuss the potentials of photoacoustic imaging for ophthalmology.