Real-time retinal blood flow imaging with Fourier Domain Optical Coherence Tomography

Optical Coherence Tomography (OCT) is a non-invasive micrometer-resolution depth resolved medical imaging tool for diagnostic visualization of the retinal structures in vivo. In this thesis, we first describe the capability of OCT for providing structural information by quantitative retinal thickness measurements in animal models of diseases causing vision loss. In the rest of the work described in this thesis, we focus on the development of an extension of OCT called speckle variance (sv) OCT, which provides functional information such as detecting capillaries within in the retina. Retinal capillary networks are critically linked to retinal neuronal health and disease. The ability to perform accurate in vivo examination of human retinal capillary networks is therefore valuable for studying mechanisms that govern retinal homeostasis and retinal vascular diseases. A real-time implementation of the svOCT provided by the GPU acceleration was described to provide visualization of en-face vasculature networks during acquisition. A qualitative comparison study was described in this thesis by comparing the retinal vasculature images acquired from svOCT and Florescence Angiography (FA) for both healthy and diseased patients. The capability of svOCT with respect to quantifying capillary network information has been also validated in this thesis. The results of these studies suggest that this GPU accelerated svOCT has the potential to non-invasively provide useful quantitative information about human retinal capillary networks, and may have clinical and research applications for the management of retinal microvascular diseases, a major cause of vision loss worldwide. To further adapt the svOCT to be more clinical friendly, preliminary work on enhancing the real-time visualization of vascular information from distinct retinal capillary beds during acquisition was proposed and implemented in this thesis.