Acute Effects of Cigarette Smoking on Corneal Tomographic and Biometric Parameters: A Prospective Controlled Study.

Abstract

Objective: To evaluate the acute effects of cigarette smoking on corneal tomography and ocular biometry.

Methods: This prospective, controlled study included 92 healthy volunteers (46 smokers and 46 non-smokers); only the right eye was analyzed. Baseline ophthalmological examination, corneal tomography and biometry were performed. Participants remained outdoors for 10 minutes under standardized conditions; smokers smoked one cigarette, whereas controls did not. Measurements were then repeated, and within-group changes and between-group differences in change (Δ) were analyzed.

Results: Baseline demographic, tomographic, and biometric measurements were similar between groups (all p>0.05). Within the smoking group, significant reductions were observed in corneal thickness at the pupil center, corneal vertex, and thinnest point (p=0.011, p=0.012, and p=0.017, respectively). Within the smoking group, anterior chamber depth also decreased from 3.08±0.44 mm to 2.98±0.52 mm (p=0.034); however, the between-group difference in Δ values was not statistically significant (p=0.068). In contrast, no significant changes were observed in anterior chamber volume, keratometric values, axial length, or emmetropia-targeted intraocular lens power calculated using the Barrett Universal II formula (p>0.05 for all). No significant changes were observed in any of the parameters examined in the control group. In the between-group comparison of Δ values, changes in pupil-center pachymetry and thinnest corneal thickness were significantly different (p=0.002 and p=0.004). Anterior 0-2 mm densitometry decreased in smokers, with a significant between-group difference in Δ (p=0.029).

Conclusions: Acute cigarette smoking was associated with measurable alterations in corneal thickness, anterior chamber depth and several corneal densitometry parameters. However, these changes did not significantly affect keratometric values, axial length, or intraocular lens power calculations. Recent cigarette smoking may affect anterior segment measurements, and recent cigarette smoking should be considered when interpreting measurements, especially in situations requiring sensitive corneal assessment.