Association of Antibiotic Use and New-Onset ICD Coding of Geographic Atrophy

Purpose: To determine whether exposure to antibiotics is associated with new-onset International Classification of Diseases (ICD) coding of geographic atrophy (GA). Methods: This case-control study of patients ages sixty and older used health insurance claims data from the Merative MarketScan Research Databases. A total of 3254 cases with new-onset ICD coding of GA between 2019 and 2021 were matched by year to 3249 controls without GA using propensity scores estimated by age, hypertension, U.S. Census Bureau region, and Charlson Comorbidity Index. For cases, we analyzed prescription drug claims of antibiotics in the two years before GA diagnosis. For controls, we analyzed claims in the two years before a randomly selected eye examination. We calculated the odds of new-onset ICD coding of GA controlling for age-related macular degeneration risk factors. Results: Exposure to any antibiotics (OR = 1.25; 95% confidence interval [CI], 1.11-1.41; P < 0.001), tetracyclines (OR = 1.18; 95% CI, 1.03-1.36; P = 0.021), quinolones (OR = 1.16; 95% CI, 1.03-1.31; P = 0.017), or broad-spectrum antibiotics (OR = 1.20; 95% CI, 1.07-1.34; P = 0.003) was associated with increased odds of new-onset ICD coding of GA. Greater cumulative day supply was associated with increasing odds, suggesting a dose-dependent relationship. Conclusions: Exposure to antibiotics is associated with increased odds of new-onset ICD coding of GA. This association may be dose dependent. These findings suggest that antibiotic exposure could be a novel modifiable risk factor for GA, although this conclusion is tempered by potential confounding by health status or misclassification of GA and by multiple comparisons. Further investigation will be needed to validate these findings.