Ipsilateral recurrence of nonarteritic anterior ischemic optic neuropathy

PURPOSE: To report the prevalence of recurrence of nonarteritic anterior is chemic optic neuropathy (NA-AION) in the same eye and possible contributing risk factors. DESIGN: Cohort study. METHODS: Setting: Institutional. STUDY POPULATION: The study includes 594 consecutive patients (829 eyes) wi th a diagnosis of NA-AION and follow-up of at least two months after the on set of NA-AION, examined in the Ocular Vascular Clinic since 1973. Simple p rogression of visual loss during an episode of NA-AION was not considered a fresh episode. INTERVENTION OR OBSERVATION PROCEDURES: Every patient had ophthalmic evalua tion, including visual acuity, visual fields with a Goldmann perimeter, int raocular pressure, and slit lamp and ophthalmoscopic evaluation at initial visit and at each follow-up visit. The patients also had systemic evaluatio n; 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 presen t, 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 year ly intervals unless they had some new visual complaint. MAIN OUTCOME MEASURES: Prevalence of a fresh episode of NA-AION in the same eye, and comparison of ocular and systemic risk factors between patients w ith 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 recurrenc e 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 nocturna l arterial hypotension. Overall patients with a recurrence of NA-AION had a significantly lower mean nighttime minimum diastolic BP (P = .003) and gre ater mean percentage drop during sleep in diastolic BP (P = .011) than thos e with no recurrence of NA-AION; all other measures of nocturnal hypotensio n 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 diseased other so far unkn own risk factors may also play a role. The role of various risk factors whi ch may contribute to the recurrence of NA-AION is discussed. (C) 2001 by El sevier Science Inc. All rights reserved.