Materials and Methods: The retinal vascular caliber of 21 healthy subjects aged 22 to 36 years were measured before, and 10 min and 60 min after cigarette smoking. Retinal vascular caliber assessment was performed manually on images of line scan imaging mode scan by using the semi-automated program of Spectralis optical coherence tomography. Statistical analyses of differences between retinal vascular caliber were determined using repeated measures of analysis of variance and Bonferroni adjustment.

Results: The mean retinal arteriolar diameter of non-smokers and smokers before smoking was 95.45±10.95 and 99.14±11.81 μm, respectively. Mean retinal venular diameter of non-smokers and smokers before smoking was 126.58±17.32 and 128.52±8.46 μm, respectively. No significant difference was found between the retinal arteriolar and venular diameter of the smoking and non-smoking groups (p values were 0.636 and 0.658, respectively). There was a statistically significant increase in retinal venular diameter during the study period (p<0.001). Bonferroni adjustment revealed significant retinal venular vasodilation between before smoking and 10 min after smoking. There was no statistically significant change in retinal arteriolar diameter during the study period (p=0.296).

Conclusions: Smoking led to vasodilation of retinal venules that returned to baseline diameter after an hour, but did not affect retinal arteriolar caliber significantly. Keywords : Optical coherence tomography, retinal vascular caliber, smoking