The aim of this study is to compare the effect of smoking in corneal endothelial cell number and morphology by specular microscopy on a non-smoker population.

Our cross-sectional study was performed on 150 participants from a non-smoker population. Noncontact specular microscopy (Tomey Corporation Inc., Nagoya, Japan) was performed in the center of the cornea of all subjects. The cell density (CD), average cell size (AVG), percent of hexagonality (HEX %), and central corneal thickness (CCT) were calculated and compared in both groups.

Totally, 76 eyes of 76 smokers and 74 eyes of 74 non-smokers were enrolled in the study from 2015 until 2016. The mean age of smokers and non-smokers were 48.61±17.04 and 46.39±13.02, respectively. The mean number of pack/year among the smokers was 17.36±14.68. Also, the mean values of AVG and CD were significantly different for these two groups (P=0.011 and P=0.039, respectively). Other corneal endothelial variables did not show a significant difference between smokers and non-smokers (P˃0.05). However, smokers with severe nicotine dependency had significantly greater AVG and lower CD in comparison with the nonsmokers (P=0.004 and P=0.013, respectively).

Our study showed that smoking can cause significant changes in some of the corneal endothelial variables, but not all of them.