Research Article: Impact of smoking exposure on meibomian gland morphology and tear film stability: a cross-sectional study
Abstract:
To investigate the effects of smoking on the structure and function of the meibomian glands.
A total of 104 chronic smokers (with a smoking history of more than 5?years) and 44 healthy non-smokers were included. Based on smoking index, participants were categorized into four groups: non-smoking, mild, moderate, and heavy smoking. Meibomian gland images were compared across groups to assess morphological features, including defect area, number, height, and width. Furthermore, eyelid margin morphology, meibum characteristics and quantity, as well as tear film breakup time (TBUT), were evaluated to further investigate the impact of smoking on the structure and function of the meibomian glands.
The gland dropout area demonstrated the strongest positive correlation with smoking index ( ? =?0.449, p <?0.001). The number, height, and width of meibomian glands were negatively correlated with smoking index ( ? =??0.258, p =?0.002; ? =??0.192, p =?0.021; ? =??1.176, p =?0.036, respectively). Furthermore, the eyelid margin morphology score and meibum secretion function worsened with increasing smoking index ( B =?0.002, OR?=?0.998, 95% CI: ?0.001 to 0.003, p <?0.001, B =??0.002, OR?=?0.998, 95% CI: ?0.001 to ?0.002, p <?0.001). Tear film stability showed negative correlations with smoking index ( ? =??0.245, p =?0.003).
Increased smoking exposure is strongly associated with deleterious structural and functional alterations of meibomian glands. Increased smoking exposure is associated with more severe meibomian gland morphological damage, worsened eyelid margin signs, reduced meibum quality and quantity, and accelerated deterioration of tear film stability. The underlying mechanisms may involve oxidative stress and chronic inflammation induced by tobacco smoke. For the management of smoking-related meibomian gland dysfunction (MGD), smoking cessation should be advised along with targeted anti-inflammatory or antioxidant treatments.
Introduction:
The Meibomian gland, situated within the tarsus, is oriented perpendicularly to the eyelid margin and features an opening at the margin through which meibum are excreted. This meibum forms the outermost layer of the tear film, contributing critically to its stability and protecting the ocular surface from pathogenic microorganisms and environmental allergens ( 1 , 2 ). A reduction in the number of Meibomian glands, along with diminished quantity and quality of lipid secretion, leads to increased tear evaporation…
Read more