Assessment of the Tear Evaporation Rate in Chronic Smokers Using Delfin VapoMeter

Background: Smoking cigarettes is associated with many chronic illnesses such as cancer, heart diseases, and cataract. In addition, smokers are more likely to develop dry eye symptoms compared with nonsmokers. Purpose: To assess the tear evaporation rate in chronic smokers using a VapoMeter. Materials and Method: This observational, case-control and non-randomized study included one hundred and twenty male smokers that ranged in age from 18 to 43 years (mean ± SD = 25.4±5.8 years). An age (18-43 years) matching control group (120 male subjects), with a mean age of 26.1±5.2 years participated in the study. Each participant completed the ocular surface disease index dry eye questionnaire, then a VapoMeter was used to determine the tear evaporation rate. Result: Significant (Kolmogorov-Smirnov test; p<0.05) differences were found between the average scores collected from the ocular surface disease index and the tear evaporation rate measurements within the smokers and nonsmokers groups. The average tear evaporation rate was significantly (p<0.05) higher in the study group [median (interquartile range; IQR) = 37.7 (59.3) g/m2h] compared with that obtained in control group [15.4 (13.1) g/m2h]. Moreover, the average score from the ocular surface disease index in smokers was significantly (p<0.05) higher [15.4 (13.1)] compared with that obtained in the control group [5.4 (5.5)]. Conclusion: Smokers have significant higher tear evaporation rates compared with nonsmokers and normal eye subjects. Clearly, VapoMeter can be used as a reliable tool to assess the eye dryness due to excessive evaporation of tears. Smoking is a risk factor for cancer, heart diseases, and cataract. In addition, smoking is a risk factor for eye dryness and contributes to evaporative dry eye disease, more likely due to the disturbance in the non-polar lipid layer within the tear film. Lipid-rich eye drops could be used to manage dry eye symptoms in smoker subjects. Moreover, smoking cessation remains the single most effective prophylactic measure to avoid dry eye symptoms.