Retinal arteriolar narrowing and hypertension

Narrowing of the retinal arterioles is a common but characteristic clinical sign in patients with hypertension. Traditionally, physicians have diagnosed this sign using the direct ophthalmoscope, a technique that has been found to have questionable reliability.1 Partly as a result of the inability to define retinal arteriolar narrowing, our understanding of its clinical and research significance has been limited. Improvements in retinal photography and imaging technology now allow us to determine more precisely the presence of retinal arteriolar narrowing. One method, based on measuring retinal vessel diameters from photographs and first reported in the Atherosclerosis Risk In Communities (ARIC) study,2 has been used in several recent populations to examine the relationship of retinal arteriolar narrowing to hypertension and cardiovascular disease. These recent studies show that retinal arteriolar narrowing is not only associated with concurrent blood pressure (BP), but also with historic BP measured 6 to 8 years earlier.3,4 The studies also demonstrate that the presence of retinal arteriolar narrowing predicts the subsequent development of overt hypertension in individuals initially classified as normotensives,5,6 as well as a variety of clinically important cardiovascular outcomes, such as stroke, independent of traditional risk factors.7 These recent data therefore raise the possibility that an accurate documentation of the presence and severity of retinal arteriolar narrowing from photographs may provide useful information for hypertension prediction and vascular risk stratification.