In reply
My colleagues and I would like to thank de Abreu Silva for raising important issues regarding our article from the Cardiovascular Health Study.1 We agree that in the study, participants with larger venular caliber were more likely African Americans and had higher levels of cardiovascular risk factors (eg, current smokers and higher glucose and cholesterol levels). Similarly, participants with narrower arteriolar caliber were older and more likely hypertensive. However, in our analysis, we controlled for age, sex, race, systolic and diastolic blood pressure, diabetes, glucose level, cigarette smoking, pack-years of smoking, and high-density lipoprotein and low-density lipoprotein cholesterol levels. Thus, the significant associations of larger retinal venular caliber with incident coronary heart disease and stroke and of narrower arteriolar caliber with incident coronary artery disease were independent of these potential confounders.