Examination of the eye is an effective way of assessing an individual's health. Diabetes and high blood pressure and a multitude of other disease have signs that show up in an eye examination. In recent years, examination of the characteristics of blood vessels on the retina at the back of the eye has been shown to be a powerful tool in the assessment of risk of coronary heart disease, stroke, diabetes and a variety of eye disease such as glaucoma and age-related macular degeneration.
Advances in imaging and computational methods are providing opportunities to analyse retinal vessels with increasing precision. However, to date, these methods are not fully automated and rely heavily on operator involvement, especially to distinguish arteries from veins (which may change in size and shape differently in response to disease). These problems limit the use of of retinal imaging in large population studies of cardiovascular disease and other key chronic diseases in later life, particularly ocular disease (macular degeneration and glaucoma) and type 2 diabetes.
Two groups within our consortium are actively developing new methods of examining the characteristics of retinal blood vessels to assess risk of disease. One group are based at St George’s, University of London (Dr Christopher Owen, Dr Alicja Rudnicka, Professor Peter Whincup, Professor David Strachan) and Kingston University (Dr Sarah Barman). The second group have developed a system called Vampire, and are based at the Universities of Edinburgh and Dundee. Together, they aim to fully automate identification and characterisation of vessels in retinal images, including identification of arteries and veins.
Retinal images (nearly 150,000 images from over 70,000 participants) will be used to refine our existing approaches to measurement of retinal vessel size and shape (which include both measures of vessel width and tortuosity, i.e., a measure of twisting / turning), and to examine their association with risk of cardiovascular disease in later life. Middle age adults are often seen by family doctors and given a risk score for cardiovascular disease (i.e., risk of heart attack), based on a number of simple measures (e.g., age, gender, blood pressure and blood cholesterol); this often determines whether treatments (e.g., BP medications, statins) are prescribed. The work will determine the value of examining retinal vessels as a predictor of disease risk and outcome (both circulatory and ocular disease), and ensure that the value is realised by the widest possible scientific community.
