Is the association between smoking and the retinal venular diameter reversible following smoking cessation?

Wider retinal venular caliber is shown to be associated with an increased risk of stroke, and smoking is associated with a wider retinal venular caliber. However, the impact of smoking cessation on the retinal vessels has not been previously reported. We examined this issue in an adult cohort of atomic bomb survivors.

In the Adult Health Study of Japanese atomic bomb survivors, 1664 subjects had retinal photographs taken from 2006 to 2008. The central retinal artery and vein equivalents (CRAE and CRVE) were calculated using a semiautomated software program. Multiple surveys have assessed the effects of smoking since 1963. The associations between smoking, the time since cessation, and the retinal vessel caliber were determined using linear mixed effects models.

The CRVE was associated with an increased number of cigarettes smoked per day among women after adjusting for potential confounding factors (age, sex, blood pressure, hypertensive medications, white blood cell count, diabetes, body mass index, lipids, and radiation dose). Females who smoked 10 cigarettes per day had a 6.9-μm wider mean CRVE (P = 0.001) than nonsmokers. Females who had stopped smoking for 10 or more years had a mean CRVE similar to those who had never smoked (191.8 vs. 194.4 μm; P = 0.23). These associations were not observed in males or for CRAE.

Wider retinal venular caliber is associated with smoking in Japanese females; however, this association becomes nonsignificant after 10 or more years of smoking cessation, suggesting that the impact of smoking on retinal venular dilation is reversible following long-term smoking cessation.