Wider Retinal Venular Caliber Research Articles

Risk Prediction of Coronary Heart Disease Based on Retinal Vascular Caliber (from the Atherosclerosis Risk In Communities [ARIC] Study)

Recent studies showed that such retinal vascular signs as quantitative retinal vascular caliber were associated with increased risk of incident coronary heart disease (CHD), but whether these retinal vascular signs add to the prediction of CHD over and above traditional CHD risk factors was not addressed. Whether these signs add to the prediction of CHD over and above the Framingham risk score in people (n = 9,155) without diabetes selected from the ARIC Study was investigated. Incident CHD was ascertained using standardized methods, and retinal vascular caliber and other retinal signs were measured from retinal photographs. After a mean of 8.8 years of follow-up, there were 700 incident CHD events. Women with wider retinal venular caliber (hazard ratio 1.27/1-SD increase, 95% confidence interval 1.08 to 1.50) and narrower retinal arteriolar caliber (hazard ratio 1.31/1-SD decrease, 95% confidence interval 1.10 to 1.56) had a higher risk of incident CHD after adjusting for Framingham risk score variables. Area under the receiver operator characteristic curve increased from 0.695 to 0.706 (1.7% increase) with the addition of retinal vascular caliber to the Framingham risk model. Risk prediction models with and without retinal vascular caliber both fitted the data and were well calibrated for women. In men, retinal vascular caliber was not associated with CHD risk after adjustment. Other retinal vascular signs were not associated with 10-year incident CHD in men or women. In conclusion, although retinal vascular caliber independently predicted CHD risk in women, the incremental predictive ability over that of the Framingham model was modest and unlikely to translate meaningfully into clinical practice.

Arterial compliance and retinal vascular caliber in cerebrovascular disease

Arterial stiffness is a newly recognized risk factor for stroke. Whether this is mediated by small- or large-artery disease is unknown. In this study, we examined the relationship between arterial stiffness and retinal vascular caliber. A cross-sectional, population-based study of 5,731 participants (aged 45-84 years) who were free of clinical cardiovascular disease (the Multi-Ethnic Study of Atherosclerosis). Retinal arteriolar and venular calibers were measured from retinal photographs according to standardized protocols. Small- and large-artery compliance was determined from pulse contour analysis. After adjusting for age, sex, blood pressure, diabetes, smoking, lipid profile, and other risk factors, reduced large-artery compliance was associated with smaller retinal arteriolar caliber; each standard deviation decrease in large-artery compliance was associated with a 0.70 microm (p = 0.002) decrease in retinal arteriolar caliber. After adjusting for the same set of risk factors, reduced small-artery compliance was associated with wider retinal venular caliber; each standard deviation decrease in small artery compliance was associated with a 1.43 microm (p = 0.001) increase in retinal venular caliber. These associations remained significant after further adjustments for large-vessel atherosclerosis (carotid intima-media thickness, coronary artery calcium, and ankle-arm index). Reduced arterial wall compliance in large arterial beds is associated with retinal arteriolar narrowing, whereas reduced arterial wall compliance in small arterial beds is associated with retinal venular widening. These data may provide further insights into the effects of altered arterial stiffness on the cerebral microcirculation.

Long-term Effects of Smoking on Retinal Microvascular Caliber

Although cigarette smoking is a major cardiovascular risk factor, its microcirculatory effects are not well understood. The authors investigated cross-sectional and longitudinal relations between smoking and retinal microvascular caliber in an older Australian population. Retinal vessel calibers were measured from digitized retinal photographs at baseline (1992-1994; n = 3,006) and at 5-year follow-up examinations (1997-1999; n = 1,850) in the population-based Blue Mountains Eye Study. Smoking status and quantity and pack-years of smoking were defined from standardized questionnaires administered at both examinations. After adjustment for other factors, current and past smoking were associated with wider retinal venular caliber at baseline (p < 0.01). These cross-sectional findings were virtually identical at the 5-year follow-up examination (p < 0.001). Heavy smokers were more likely to have relatively large changes in venular caliber in either direction over the 5-year period (widening or narrowing more than 1 standard deviation greater than the mean change) than were nonsmokers (for continuous trend by pack-years or current amount smoked, p < 0.05). Weaker and less consistent associations between smoking and arteriolar caliber were observed. These results suggest long-term effects of smoking on venular caliber that may contribute to associations between smoking and cardiovascular disease.