Study of The Effect of Cigarette Smoking on Tear film, Conjunctiva and Lacrimal System

Background: The tear film covers the ocular surface, consisting of the conjunctival and corneal epithelia, and functions as the interface between the external environment and these epithelia. Aim: This study aimed to examine the impact of cigarette smoking on the tear film, conjunctiva, and lacrimal system and the correlation between dry eye severity level and cigarette smoking, aiming to improve quality of life and reduce morbidities arising from smoking. Patients and methods: This case-control comparative research was performed on 100 eyes of cases attending Ismailia Outpatient Clinics. They have been classified into 2 groups: Group A: Smoker cases and Group B: Non-smoker cases (neither active nor passive smoker) in the Outpatient Clinic, Ophthalmology Department, Suez Canal University Hospital, Ismailia, Egypt, in 2020. Results: A statistically significant variance was discovered among both groups regarding the Schirmer test, as it was greater in group A (p-value = 0.003). A statistically significant variance was discovered among both groups regarding the Tear Break Up Time Test (TBUT) (p value = 0.372). Conclusion: Cigarette smoking negatively impacts tear film and ocular surface by decreasing tear secretion quantity, potentially leading to meibomian gland dysfunction and a risk factor for dry eye syndrome. Chronic smoking can cause ocular surface disorders, making it crucial to avoid smoking in cases of dry eye syndrome and ocular surface conditions, regardless of the severity of symptoms.