Graves’ ophthalmopathy is associated with a reduced blinking frequency, eyelid retraction, proptosis, incomplete eyelid closure. Smoking significantly increases the incidence and severity of GO in patients with Graves’ disease Objective: To assess the influence of smoking on the development of dry eyes in patients with Graves’ ophthalmopathy (GO) and to determine the properties of tear secretion and ocular surface in these patients. 

Methods: A cross-sectional study was conducted at the outpatient department of the Eye Diseases Clinic of the Lithuanian University of Health Sciences. The study included 52 patients with a mean age of 47.3 (17.4–69.6) years. The study included 25 smokers and 27 non-smokers with Graves’ ophthalmopathy (a total of 52 patients). Their mean age was 47.3 (17.4–69.6) years. 

Patients underwent ophthalmological examination, ocular surface disease index (OSDI) assessment, Schirmer test without local anesthesia (<5 mm was abnormal), slit-lamp biomicroscopy (tear break-up time (TBUT) under blue light illumination). 

Statistical analysis was performed using SPSS for Windows software (SPSS Inc., Chicago, IL, USA). Statistical significance was determined at p < 0.05. Results: The mean OSDI score in smoking GO patients was significantly higher (28.79 ± 15.29) compared to non-smoking patients (10.58 ± 7.41), (p < 0.05). 

The mean Schirmer test value in smoking GO patients was significantly lower (4.21 ± 3.07 mm) compared to non-smoking patients (11.74 ± 6.24 mm). The difference was statistically significant (p < 0.04), indicating insufficient tear production. The mean tear film breakup time (TBUT) was lower in smoking GO patients (7.04 ± 2.25 s) compared with nonsmoking patients (10.93 ± 3.12 s), ( p < 0.04), indicating an unstable tear film. 

Conclusion: The study found statistically significantly increased OSDI scores, shorter Schirmer scale and tear film breakup time measurements in smokers with GO. These data may indicate a predisposition to dry eye syndrome in smokers.