Background/aims To investigate the effect of smoking on choroidal thickness using Fourier domain optical coherence tomography.

Methods 17 otherwise healthy smokers (study group) and 17 non-smokers (control group) were enrolled. In the study group, all participants underwent optical coherence tomography scanning at baseline, and 1 and 3 h following smoking one standard cigarette. Also the participants of the control group underwent optical coherence tomography scanning in the morning which was followed by two further examinations at the first and third hours, respectively. Choroidal thickness measurements were performed.

Results The mean choroidal thickness at the fovea prior to smoking was 301.1±63.1 μm, which decreased to 284.2±56.7 μm at 1 h and 270.8±80.0 μm at 3 h following smoking (p=0.001). The mean choroidal thickness was significantly decreased following smoking at all five extrafoveal points. The difference in choroidal thickness was not statistically significant at 1 and 3 h of smoking at all six points. In the control group, the mean baseline choroidal thickness at the fovea was 270.6±57.9 μm, which was 272.5±52.4 μm at 1 h and 273.8±57.4 μm at 3 h (p=0.816).

Conclusions Cigarette smoking causes a significant decrease in choroidal thickness following smoking. Fourier domain optical coherence tomography can effectively demonstrate choroidal thickness.