Purpose: The aim of this study is to determine if oral fluoroquinolone exposure is associated with an increased hazard for having a retinal tear or detachment.
Methods: A retrospective cohort study was performed using individuals who met inclusion criteria from The Health Improvement Network database. Cohorts were created for individuals who had a prescription written for either an oral fluoroquinolone or an oral β-lactam antibiotic (comparison group). Subjects were excluded if they had a previous diagnosis of a retinal tear or detachment (hereafter retinal break (RB)), or a procedure code to treat an RB, where in the practice for less than 365 days, had a previous prescription for either antibiotic within 365 days of the index date or had intraocular surgery or a diagnosis of endophthalmitis within 90 days prior to the antibiotic prescription. Covariates of interest were age, gender, diabetes, and year of index. The primary outcome measure of interest was the hazard ratio (HR) of undergoing a procedure to treat an RB within 7, 30, 90, or 365 days after exposure to an oral fluoroquinolone prescription versus an oral β-lactam prescription.
Results: After exclusions, 6,604,423 prescriptions (290,393 fluoroquinolone; 6,314,030 β-lactam) from 3,413,498 patients (247,073 fluoroquinolone; 3,303,641 β-lactam) and 2685 RB procedures were eligible for analysis (661 retinal tears and 2024 retinal detachments). For fluoroquinolones, 0, 1, 5, and 23 RBs occurred at the 7-, 30-, 90-, and 365-day time points, respectively. For β-lactam prescriptions, 7, 28, 87, and 373 RBs occurred at the 7-, 30-, 90-, and 365-day time points, respectively. Because of zero events occurring in the fluoroquinolone cohort during the 7-day observation period, an unadjusted or an adjusted HR (and subsequent p-value or confidence intervals) was unable to be calculated. Univariate and multivariate analyses demonstrated that fluoroquinolones were not significantly associated with RB in the 30-, 90-, or 365-day observation periods (30-day HR = 0.78, p = 0.80, 95%CI: 0.11, 5.71; 90-day HR = 1.25, p = 0.63, 95%CI: 0.51, 3.08; and 365-day HR = 1.35, p = 0.16, 95%CI: 0.89, 2.06).
Conclusions: Our results do not support an association between oral fluoroquinolone use and subsequent procedures to treat an RB.
Keywords: Cox regression; cohort; fluoroquinolones; pharmacoepidemiology; retinal break; retinal detachment; retinal tear.
Copyright © 2014 John Wiley & Sons, Ltd.