Sydney, Australia - A new study has found that retinopathy is associated with an increased risk of coronary heart disease (CHD) regardless of whether or not the person also has diabetes [1]. Dr Gerald Liew (University of Sydney, Australia) and colleagues report their findings online August 12, 2008 in Heart.

The researchers explain that diabetes is a known risk factor for CHD and that previous studies have reported consistent association of retinopathy with increased CHD risk in people with diabetes. "But our study may be the first to report a similar association in people without diabetes," they note.

Ophthalmologist and senior author Dr Jie Jin Wang (University of Sydney) told heartwire: "Interestingly, the risk magnitude from retinopathy is similar to the risk from diabetes alone. And if a person has both diabetes and retinopathy, the risk is double compared to those with neither."

In their study, the Australian researchers looked at those participating in the Blue Mountains Eye Study, in which 2768 participants did not have diabetes and 199 did. The presence and severity of retinopathy was assessed from retinal photographs. Twelve-year cumulative CHD deaths were ascertained from Australian National Death Index records.

Over the 12 years, 353 participants (11.9%) died from incident CHD. Retinopathy was present in 28.6% of those with diabetes and in 9.7% of people without diabetes. The presence of retinopathy increased the CHD mortality rate per person-year by an amount (0.005) equivalent to diabetes itself.

After adjustment for risk factors, retinopathy remained an independent predictor of CHD death, both in people with diabetes (hazard ratio 2.21) and in those without diabetes (HR 1.33). More severe (known as moderate) retinopathy was associated with adjusted HR of 6.68 in those with diabetes and 2.29 in those without.

Wang told heartwire that the link between retinopathy and CHD is as yet unclear, but "there is increasing recognition that coronary microvascular dysfunction also plays an important role in CHD, particularly in women and in persons with diabetes."

The small-vessel condition in the retina may be used as a window to the small-vessel condition of the body.

The researchers say, "These findings suggest that the presence of retinopathy, regardless of a person's diabetes status, may indicate underlying subclinical vascular disease."

Wang says: "We speculate that retinopathy may mirror similar changes in small vessels of other organs of the body including the heart. If this is proven, the small-vessel condition in the retina may be used as a window to the small-vessel condition of the body, and assessment of retinal condition using retinal imaging may help to identify those at high risk of cardiovascular disease."

As retinopathy lesions, particularly moderate retinopathy, can readily be identified in emergency departments and doctors' clinics, the findings support a role for direct ophthalmoscopy to help identify such people, she says

They "may benefit from a thorough CV risk assessment, lifestyle changes, better management of risk factors, and closer monitoring for CHD events," she and her colleagues conclude.