Impact of Chronic Smoking on Meibomian Gland Dysfunction

PURPOSE The aim of this study was to explore the relationship between chronic cigarette smoking and meibomian gland dysfunction (MGD). METHODS This study enrolled 322 smokers with MGD and 2067 non-smokers with MGD. All enrolled subjects were tested in the following sequence: Ocular Surface Disease Index (OSDI), tear film breakup time (TBUT), corneal fluorescein staining (CFS), Schirmer I test (SIT)and finally slit-lamp microscope examination of lid margin abnormalities, meibomian gland expression as well as meibum. RESULTS Compared with the MGD patients without smoking, the MGD patients with smoking had significantly increased scores of lid margin abnormality and meibum (P<0.01 for each comparison). No significant difference was noted in OSDI, TBUT, CFS, SIT or the score of Meibomian gland expressibility between the smokers and non-smokers (P>0.05 for each comparison). In the smokers, the smoking index was significantly correlated with the scores of lid margin abnormality (Both sexes, R = 0.19, P<0.01; Male, R = 0.18, P<0.01) and meibum (Both sexes, R = 0.29, P<0.01; Male, R = 0.20, P<0.01), whereas it was not significantly correlated with OSDI, TBUT, CFS, SIT or score of Meibomian gland expressibility (P>0.05 for each comparison). CONCLUSION The findings of this study suggest chronic smoking might be associated with MGD.