The proposed research aims to design and optimize a novel optical retinal imaging technology that can achieve the desired functional imaging capabilities by naturally fusing a photoacoustic ophthalmoscopy, optical coherence tomography, confocal scanning laser ophthalmoscopy and autofluorescence imaging into a single multimodal system. This multimodal system can comprehensively characterize the optical absorption, optical scattering, and autofluorescence properties, which can be correlated to hemoglobin oxygen saturation, blood flow, pigment content, and metabolic rate in the retina. Then, by applying this novel imaging technology, a hemodynamic threshold will be detected, optimized, and verified in an ischemic retinopathy rat model to fill the gap of early detection of DR. And finally, the content of the two key pigments in the retinal pigmented epithelium (RPE), melanin and lipofuscin, and their content ratio in single RPE cells will be measured to be used as a risk factor of RPE dysfunction, which leads to AMD. At the end of the project, the project team will have developed a one-of-a-kind multimodal retinal imaging technology, identified the earliest functional onset of DR, and acquired the baseline pigment ratio for further evaluation of RPE dysfunction.
