Medium and long-term effect of chronic smoking on retinal nerve fiber layer.

Objective: The study aims to investigate the medium and long-term effects of smoking on the retinal nerve fiber layer (RNFL). Methods: The study was conducted with 66 non-smoking patients (Group 1), 76 patients (Group 2) with smoking duration between 10-20 years and 74 patients with smoking duration >20 years (Group 3), who admitted the ophthalmology clinic for various reasons between January 2018 and May 2019. Intraocular pressure (IOP), central corneal thickness (CCT), average and regional (superior, inferior, nasal and temporal quadrants) RNFL thicknesses of all participants were measured with OCT and recorded for comparison among 3 groups. ANOVA test was applied in group comparisons. Bonferroni correction was performed in the comparisons between the groups. The Pearson correlation analysis test was used for the correlation analysis of different variables. Results: There was no statistically significant difference between the groups in terms of gender, age, IOP and CCT values (p>0.05). There were a statistically significant difference between the groups in the average RNFL and superior quadrant RNFL values (p=0.013, p= 0.032, respectively, ANOVA). Also, there was no statistically significant differences between the groups in the average RNFL values of the nasal, inferior and temporal quadrants (p=O.23O, p=0.153, p=0.581, respectively, ANOVA). There was a significant negative correlation between smoking duration and average RNFL, superior RNFL and temporal RNFL(r=-0.325, p<0.05, r=-0.366, p<0.05, r=- 0.308, p<0.05, respectively). Conclusion: A significant relationship was found between chronic smoking and average, and superior quadrant RNFL thicknesses. [ABSTRACT FROM AUTHOR]