SPECTRAL DOMAIN OCT DOPPLER ASSESSES AQUEOUS OUTFLOW

Glaucoma is the second leading cause of blindness worldwide, affecting approximately 67 million people and costing the US healthcare system an estimated $2.5 billion annually. The greatest risk factor for the diagnosis and progression of glaucoma is high eye pressure. All glaucoma medications and procedures are designed to reduce eye pressure, slowing disease progression and preserving vision. The eye’s aqueous humor nourishes avascular tissues in the anterior segment. It also maintains the eye’s geometry by pressurizing the globe, facilitating its ability to focus light on the retina. The balance between aqueous humor production and uptake is responsible for the pressure within the eye. Most glaucoma medications are designed to reduce pressure by increasing aqueous humor outflow, and surgeries are designed to enhance or bypass exiting outflow pathways. But, the effects of medications and procedures on a patient by patient basis on outflow remain speculative. Here, techniques for the non-invasive direct mapping and measurement of aqueous humor outflow in the living human eye are proposed. Mapping provides morphometric insights and measurements of the components of the outflow system, while the flow technique is the first to provide direct measurements of outflow, free of the assumptions plaguing other modalities. “Virtual casting” of the outflow system yields 3D maps from which terminal branches are identified. Doppler measurements quantify velocity within those branches. Total aqueous humor outflow is determined by integrating calculated flow across all identified terminal branches. These technologies can be adapted to existing FDA approved OCT clinical scanners. Clinical application of these technologies may improve the management of glaucoma by reducing the time needed to determine and implement optimal therapeutic strategies, thereby preserving vision in glaucoma patients