The calibre of the small veins and arteries in the eye may be a good indicator of a middle aged person's chances of dying from coronary heart disease, suggests research published ahead of print in Heart.
The researchers analysed the calibre of the vasculature of the retina in more than 3600 men and women over the age of 49.
This was done by looking at detailed photographs of the back of the eye, measuring the diameters of the small arteries (arterioles) and small veins (venules), and calculating their ratio, known as the AVR.
Arterioles and venules are small branches of main arteries and veins, and their condition reflects the general state of the smaller blood vessels in the body, or microcirculation.
During the nine years of the study, 78 women (just over 4%) and 114 men (just under 8%) died from coronary heart disease.
Among those aged 49 and up to the age of 75, although relatively uncommon, deaths from coronary heart disease doubled if the venules were wider.
Wider venules have been linked to several risk factors for coronary heart disease, including smoking, systemic inflammation, high total cholesterol and obesity.
In women in this age narrower arterioles were also associated with a 50% increased risk of dying from coronary heart disease.
The authors point out that the numbers involved are small, as fewer people die from heart disease. But signs in the small vessels of the eye appear to be independent predictors of the risk of death from coronary heart disease among those under 75, particularly in women.
Retinal photography may be a useful non-invasive method of assessing this risk, they suggest.