title: Amiodarone-Associated Optic Neuropathy: A Nationwide Study.
abstract: OBJECTIVE
  To investigate whether amiodarone use is associated with an increased risk of optic neuropathy.
  
  
  METHODS
  Retrospective population-based cohort study.
  
  
  METHODS
  Patients newly treated with amiodarone between 2005 and 2009 were identified from the Taiwan National Health Insurance Research Database. For each case patient, the study also included 4 age- and gender-matched control subjects who did not receive amiodarone treatment.
  
  
  METHODS
  Cox multivariate regression analysis was used to assess the association between amiodarone and the occurrence of optic neuropathy.
  
  
  METHODS
  Hazard ratios (HRs) and 95% confidence intervals (CIs).
  
  
  RESULTS
  The analysis included 6175 amiodarone-treated patients and 24 700 controls. The mean age was 66.7 years and 55.3% of subjects were male. The mean follow-up was 688 days. During the observational period, optic neuropathy developed in 17 amiodarone-treated patients (0.3%) and 30 control patients (0.1%; P = 0.006). Multivariate Cox regression analysis showed that amiodarone-treated patients had a 2-fold increased risk of optic neuropathy (HR, 2.09; 95% CI, 1.13-3.85; P = 0.02). After stratification by gender, amiodarone use remained a significant factor for optic neuropathy development among male subjects (HR, 3.05; 95% CI, 1.42-6.55; P = 0.004), but not among female subjects (HR, 1.15; 95% CI, 0.38-3.47; P = 0.81). Among amiodarone-treated patients, male gender was associated with a nearly 3-fold increased risk of optic neuropathy development compared with female gender (HR, 2.91; 95% CI, 0.94-9.01; P = 0.06). We also detected a trend of increased cumulative incidence of optic neuropathy with longer treatment duration (>41 vs. ≤41 days; HR, 3.46; 95% CI, 0.99-12.07; P = 0.05). However, higher daily dose did not increase the risk of optic neuropathy (HR, 0.96; 95% CI, 0.91-1.00; P = 0.07).
  
  
  CONCLUSIONS
  These results demonstrated a higher risk of optic neuropathy in patients treated with amiodarone, especially in males and possibly in patients with longer duration of treatment.
authors.affiliation: Department of Ophthalmology, Taipei Veterans General Hospital, Taipei, Taiwan; Department of Ophthalmology, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Hui-Chen
authors.initials: HC
authors.lastname: Cheng
authors.affiliation: Department of Physical Medicine and Rehabilitation, Taoyuan General Hospital, Ministry of Health and Welfare, Taoyuan, Taiwan; Institute of Public Health, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Huan-Jui
authors.initials: HJ
authors.lastname: Yeh
authors.affiliation: Institute of Hospital and Health Care Administration, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Nicole
authors.initials: N
authors.lastname: Huang
authors.affiliation: Institute of Public Health, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Yiing-Jenq
authors.initials: YJ
authors.lastname: Chou
authors.affiliation: Department of Ophthalmology, Taipei Veterans General Hospital, Taipei, Taiwan; Department of Ophthalmology, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: May-Yung
authors.initials: MY
authors.lastname: Yen
authors.affiliation: Department of Ophthalmology, Taipei Veterans General Hospital, Taipei, Taiwan; Department of Ophthalmology, School of Medicine, National Yang-Ming University, Taipei, Taiwan. Electronic address: agwang@vghtpe.gov.tw.
authors.forename: An-Guor
authors.initials: AG
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000638:Amiodarone / Q000009:adverse effects*; D000889:Anti-Arrhythmia Agents / Q000009:adverse effects*; D016208:Databases, Factual; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009313:National Health Programs / Q000706:statistics & numerical data; D009901:Optic Nerve Diseases / Q000139:chemically induced* / Q000453:epidemiology; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors; D013624:Taiwan / Q000453:epidemiology; D055815:Young Adult
chemical_list: D000889:Anti-Arrhythmia Agents; D000638:Amiodarone