1UPMC Eye Center, Eye and Ear Institute, Ophthalmology and Visual Science Research Center, Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, United States, 2Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong, 3Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA, United States, 4Department of Radiology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States, 5Center for Neuroscience Imaging Research, Institute for Basic Science, Suwon, Korea, Republic of