title: Increased Risk of Stroke in Patients With Nonarteritic Anterior Ischemic Optic Neuropathy: A Nationwide Retrospective Cohort Study.
abstract: OBJECTIVE
  To investigate the incidence and prevalence of nonarteritic anterior ischemic optic neuropathy (NAION), and to extrapolate the risk of cerebrovascular events following NAION.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  We identified NAION patients first, and then looked for the diagnosis of stroke after the diagnosis of NAION.
  
  
  METHODS
  The study group was composed of patients diagnosed with NAION seeking ambulatory care from 2000 to 2011. The control group was extracted from a database by randomly selecting 2 patients for every NAION patient, matched by age and sex.
  
  
  METHODS
  Cox proportional hazards regression analysis was performed to calculate adjusted hazard ratio (aHR) of stroke for the 2 groups. Subgroup analysis of subjects with or without comorbidities was also investigated.
  
  
  RESULTS
  Four hundred and fourteen patients were included in the study group and 789 in the control group. The mean follow-up period was 5.9 years. The incidence of NAION was 3.72/100 000 person-years in Taiwan, and the prevalence of NAION was 48.18/100 000 persons. The study group was more likely to have ischemic stroke (aHR = 2.03, P = .003), but not hemorrhagic stroke (aHR = 1.24, P = .696), than the control group. Among the subgroup with comorbidities, the risk of ischemic stroke among the subjects with NAION was 3.35 times higher than those without NAION (95% confidence interval: 1.67, 6.70).
  
  
  CONCLUSIONS
  Patients with NAION have an increased risk of ischemic stroke. Physicians should refer all patients with NAION for systemic survey of vasculopathy and control of modifiable risk factors to prevent irreversible neurological sequelae.
authors: Department of Ophthalmology, Buddhist Tzu Chi General Hospital, Hualien, Taiwan.
authors: Yueh-Chang
authors: YC
authors: Lee
authors: Department of Medical Research, Buddhist Tzu Chi General Hospital, Hualien, Taiwan; Department of Health Administration, Tzu Chi College of Technology, Hualien, Taiwan.
authors: Jen-Hung
authors: JH
authors: Wang
authors: Department of Ophthalmology, Far Eastern Memorial Hospital, Banciao District, New Taipei City, Taiwan; Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan.
authors: Tzu-Lun
authors: TL
authors: Huang
authors: Institute of Eye Research, Buddhist Tzu Chi General Hospital, Hualien, Taiwan; Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan. Electronic address: tsai.rk@gmail.com.
authors: Rong-Kung
authors: RK
authors: Tsai
mesh_terms: D000328:Adult; D000368:Aged; D001167:Arteritis / Q000453:epidemiology; D002340:Carotid Artery Diseases / Q000453:epidemiology; D015331:Cohort Studies; D048909:Diabetes Complications / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000453:epidemiology; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D015994:Incidence; D008297:Male; D008875:Middle Aged; D018917:Optic Neuropathy, Ischemic / Q000453:epidemiology*; D015995:Prevalence; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D020521:Stroke / Q000453:epidemiology*; D013624:Taiwan / Q000453:epidemiology