Association Between Tobacco Smoking and the Development of Diabetic Macular Edema.

To explore the effect of cigarette smoking on the risk for developing diabetic macular edema (DME) among patients with diabetes. This retrospective exactly-matched cohort study used claims data for patients from all 50 states in the United States from 2010 through 2020. Patients with an initial diagnosis of diabetes were stratified into 3 cohorts as follows: active smokers, never smokers, and former smokers. After exact matching based on demographics and comorbidities, Kaplan-Meier survival functions for the 3 cohorts were compared using pairwise log-rank tests. After matching, there were 42 298 patients in each cohort. Over 6 years of follow-up, the cumulative risk for DME was significantly higher among never smokers (1.18%) than among active smokers (0.88%) and former smokers (0.90%) (both  < .001). Among patients with diabetes, smoking may decrease the risk for developing DME. Although the harms of smoking far outweigh any potential protective benefits, further investigation into the mechanisms behind these findings has potential to uncover new therapeutic targets.