Although assessment of hypertensive retinopathy signs has been recommended for determining end-organ damage and stratifying vascular risk in persons with hypertension, its value remains unclear. A group of researchers at the National University of Singapore have examined whether hypertensive retinopathy predicts the long-term risk of stroke in people with hypertension (Ong et al. Hypertension; 2013: Aug 12) Worldwide, high blood pressure is the single most important risk factor for stroke. However, it’s still not possible to predict which high blood pressure patients are most likely to develop a stroke. “The retina provides information on the status of blood vessels in the brain,” said Mohammad Kamran Ikram, M.D., Ph.D., lead author of the study and assistant professor in the Singapore Eye Research Institute, the Department of Ophthalmology and Memory Aging & Cognition Centre, at the National University of Singapore. 
“Retinal imaging is a non-invasive and cheap way of examining the blood vessels of the retina.” Researchers tracked stroke occurrence for an average 13 years in 2,907 patients with high blood pressure who had not previously experienced a stroke. At baseline, each had photographs taken of the retina. Damage to the retinal blood vessels attributed to hypertension evident on the photographs was scored as none, mild or moderate/severe. During the follow-up, 146 participants experienced a stroke caused by a blood clot and 15 by bleeding in the brain. Researchers adjusted for several stroke risk factors such as age, sex, race, cholesterol levels, blood sugar, body mass index, smoking and blood pressure readings. They found the risk of stroke was 35 percent higher in those with mild hypertensive retinopathy and 137 percent higher in those with moderate or severe hypertensive retinopathy. Even in patients on medication and achieving good blood pressure control, the risk of a blood clot was 96 percent higher in those with mild hypertensive retinopathy and 198 percent higher in those with moderate or severe hypertensive retinopathy.
