Prospective Study Phase: Retinal Oxygen Saturation, Blood Flow, Vascular Function and High Resolution Morphometric Imaging in the Living Human Eye

Overview

Canadians fear loss of vision more than any other disability. Vision loss has an enormous impact on quality-of-life and is extremely costly from a societal and economic perspective. In 2001, more than 600,000 Canadians were estimated to have severe vision loss, accounting for 17% of total disability in Canada. One in 9 individuals experience severe vision loss by 65 years of age; however, this increases to 1 in 4 individuals by 75 years. The financial cost of vision loss in Canada is $15.8 billion per year. There is a general perception that vision loss is "normal with aging" but 75% of vision loss is estimated to be preventable. The major causes of severe vision loss are age-related macular degeneration (ARMD), glaucoma, particularly primary open-angle glaucoma (POAG), and diabetic retinopathy (DR). Canada is headed for an epidemic of age-related eye disease and, unless something is done to prepare for this, severe vision loss will have significant consequences in terms of societal and economic costs. Through this proposed Research Program, and in conjunction with the investigators international academic and private sector partners, the investigators will build and develop unique quantitative imaging technologies to permit non-invasive assessment of visual changes, structural changes in the thickness of the retina at the back of the eye and also changes in the amount of blood flowing through the blood vessels that feed the retina with oxygen. This research will add to the investigators basic knowledge in predicting the development of sight-threatening change in patients with the three diseases, and facilitate earlier detection of the problem to help us discover earlier treatments for people with these conditions. The reliability of each imaging technology will be assessed by determining its ability to differentiate between diseased and healthy eyes. Cross-sectional analyses at yearly intervals, as well as change over time analyses, will be undertaken.

This research will add to our basic knowledge in predicting the development of sight-threatening change in patient with the ARMD, diabetic retinopathy and primary open glaucoma, and facilitate earlier detection of the problem to help us discover earlier treatments for people with these conditions. The reliability of each imaging technology will be assessed by determining its ability to differentiate between diseased and healthy eyes. Through this proposed Research Program, and in conjunction with our international academic and private sector partners, we will build and develop unique quantitative imaging technologies to: * Comprehensively assess the blood supply to, and vascular regulation characteristics of the posterior segment of the eye, a diagnostic capability that is currently severely limited. * Assess oxygen saturation disturbances in the retina and ON that occur prior to clinically detectable changes, diagnostic capability that currently does not exist * Using the retinal blood supply and oxygen saturation parameters, we will derive net oxygen delivery to the retina and optic nerve head (ONH), a diagnostic capability that does not exist.