Photoacoustic Imaging of the Eye

Photoacoustic imaging (PAI) is a novel, hybrid, non-ionizing, and non-invasive imaging technology with high-resolution, high sensitivity, high-contrast, and high depth of penetration. Hence, it has particularly useful applications in eye investiga-tions. It can provide both anatomic and functional ocular characterizations. Many eye diseases, including macular degeneration and diabetic retinopathy, involve abnormalities in the vasculature, and thus the ability of PAI to affectively visualize the vasculature can be incredibly helpful to evaluate normal and disease states of the eye. In future research, PAI of the eye can be dramatically improved in terms of its resolution, use of contrast agents for molecular imaging, safety evaluations to develop a clinically approved system, and integration with existing fundus imaging modalities. Multimodality ocular imaging platforms have also been successfully developed by a combination of photoacoustic microscopy (PAM) with other optical imaging such as optical coherence tomography (OCT), scanning laser ophthalmoscopy (SLO), and fluorescence microscopy (FM). The multimodal images can accurately be acquired from a single imaging system and co-registered on the same image plane, enabling improved evaluation of eye disease states. In this book chapter, the potential application of photoacoustic imaging of the eye in both research and clinical diagnosis are comprehensively discussed as a powerful medical screening technique for visualization of various ocular diseases.