title: Ipsilateral recurrence of nonarteritic anterior ischemic optic neuropathy.
abstract: OBJECTIVE
  To report the prevalence of recurrence of nonarteritic anterior ischemic optic neuropathy (NA-AION) in the same eye and possible contributing risk factors.
  
  
  METHODS
  Cohort study.
  
  
  METHODS
  
  
  
  METHODS
  Institutional.
  
  
  METHODS
  The study includes 594 consecutive patients (829 eyes) with a diagnosis of NA-AION and follow-up of at least two months after the onset of NA-AION, examined in the Ocular Vascular Clinic since 1973. Simple progression of visual loss during an episode of NA-AION was not considered a fresh episode. INTERVENTION OR OBSERVATION PROCEDURES: Every patient had ophthalmic evaluation, including visual acuity, visual fields with a Goldmann perimeter, intraocular pressure, and slit lamp and ophthalmoscopic evaluation at initial visit and at each follow-up visit. The patients also had systemic evaluation; some patients had echocardiography (166 patients) and 24-hour ambulatory blood pressure (BP) monitoring-the latter was investigated in 80 patients (17 with and 63 without recurrence of NA-AION) who consented to participate in this study which was started in 1989. While optic disk edema was present, the patients were followed every 2 to 3 weeks. Once the optic disk edema resolved, they were followed up after 3 months, 6 months, and then at yearly intervals unless they had some new visual complaint.
  
  
  METHODS
  Prevalence of a fresh episode of NA-AION in the same eye, and comparison of ocular and systemic risk factors between patients with and without recurrence of NA-AION in the same eye.
  
  
  RESULTS
  Of the 594 patients (829 eyes) in the study, recurrence of NA-AION in the same eye occurred in 45 patients (53 eyes) with a median follow-up of 3.1 years (range 2 months to 30.5 years) from the first onset of NA-AION. The Kaplan-Meier survival curve showed cumulative percentage of recurrence of NA-AION from first episode to second episode at three months 1.0%+/-0.4%(SE), at 6 months 2.7%+/-0.7%, at one year 4.1%+/-0.9%, and 2 years 5.8%+/-1.1%. There was no significant association between recurrence of NA-AION and the systemic conditions that were examined, except for nocturnal arterial hypotension. Overall patients with a recurrence of NA-AION had a significantly lower mean nighttime minimum diastolic BP (P =.003) and greater mean percentage drop during sleep in diastolic BP (P =.011) than those with no recurrence of NA-AION; all other measures of nocturnal hypotension were not significantly predictive.
  
  
  CONCLUSIONS
  Recurrence of NA-AION in the same eye is uncommon (6.4%). Our study indicates that nocturnal diastolic arterial hypotension may be a risk factor; however, since this is a multifactorial disease, other so far unknown risk factors may also play a role. The role of various risk factors which may contribute to the recurrence of NA-AION is discussed.
authors.affiliation: Department of Ophthalmology, College of Medicine, University of Iowa, Iowa City, Iowa 52242, USA. sohan-hayreh@uiowa.edu
authors.forename: S S
authors.initials: SS
authors.lastname: Hayreh
authors.forename: P A
authors.initials: PA
authors.lastname: Podhajsky
authors.forename: B
authors.initials: B
authors.lastname: Zimmerman
mesh_terms: D000328:Adult; D000368:Aged; D001167:Arteritis / Q000150:complications; D001794:Blood Pressure; D018660:Blood Pressure Monitoring, Ambulatory; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D018917:Optic Neuropathy, Ischemic / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D015995:Prevalence; D012008:Recurrence; D012307:Risk Factors; D014792:Visual Acuity; D014794:Visual Fields