Retinal photography—used to detect abnormalities in blood vessels at the back of the eye—could help identify people who are at an increased risk of stroke, suggest authors of a study in this week’s issue of THE LANCET.
Damage to the small blood vessels in the retina (retinal microvascular abnormalities) arises from high blood pressure and other vascular processes. Tien Yin Wong and colleagues from the University of Wisconsin-Madison, USA, examined the relation of such abnormalities to the incidence of stroke.
More than 10 300 men and women (aged 51-72 years) living in four US communities underwent retinal photography and standard grading for retinal microvascular abnormalities. The calibres of all retinal arterioles and venules were measured after digital conversion of the photographs, and a summary arteriole-to-venule ratio (AVR) was calculated as an index of arteriolar narrowing (smaller AVR indicated a greater narrowing).
Over three and a half years, 110 patients had incident strokes. After adjustment for age, sex, race, 6-year mean arterial blood pressure, diabetes, and other stroke risk-factors, most retinal microvascular characteristics more than doubled the risk of stroke. The relative risk of stroke increased with decreasing AVR; the associations were similar for ischaemic strokes, and for strokes in individuals with high blood pressure, either with or without diabetes.
Tien Yin Wong comments: "Our findings support a microvascular role in the pathogenesis of clinical strokes, and suggest that retinal photography may be useful for cerebrovascular risk stratification in appropriate populations."
Contact: Dr Tien Yin Wong, Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison,610 North Walnut Street, 460 WARF, Madison, WI 53705-239,USA;T) 1-608-265-8923;F) 1-608-263-0279;E) wong@epi.ophth.wisc.edu
Journal
The Lancet