Quantification of blood flow based on OCT-angiography

Vascular risk factors play a role in a wide variety of blinding eye diseases such as diabetic retinopathy, glaucoma, age-related macular degeneration and vascular occlusive disease. The introduction of optical coherence tomography (OCT), a medical imaging technique has revolutionized the diagnosis and clinical care of eye diseases. Standard OCT is, however, not clinically optimized to visualize the anatomy of blood vessels or quantify blood flow, making it essentially challenging to identify the onset/progression of ischemia/hypoxia, which is a major underlying factor for retinal vascular diseases and glaucoma. In the present grant, our central hypothesis is that it is possible to better quantify retinal and optic nerve head microvascular blood flow using swept source (SS) OCT angiography. To achieve this aim, we propose a collaborative approach that will harness the expertise of biomedical engineers, computer engineers, pre-clinical scientists as well as clinicians. Specifically, we aim to establish a state of the art imaging prototype SS-OCT system based on an akinetic light source that will allow the measurement of blood flow in the neurosensory retina and optic nerve non-invasively. Mathematical modeling will allow the quantification of perfusion rate at tissue level. Validation of the technology will be done against histology as well as invasive gold standard technology for measuring blood flow in non-human primates. A small pilot study in patients with glaucoma is finally scheduled as a proof of concept of the clinical applicability of this approach. Early detection of ischemia/hypoxia is crucial for identifying those who are at risk from visual debilitating eye diseases such as diabetic retinopathy, age-related macular degeneration and glaucoma and for allowing optimized treatment monitoring. Quantification of blood flow using SS-OCT angiography will be thus a major advancement in the management of patients in the future and will help reduce the burden of blindness from these diseases.