Abstract
Purpose :
Nonarteritic anterior ischemic optic neuropathy (NAION) is the most common optic neuropathy in adults over the age of 50 years. We sought to determine the population based incidence and characterize the features of NAION using the Rochester Epidemiology Project (REP).
Methods :
All patients diagnosed with an optic neuropathy from January 1, 1990 through December 31, 2016 were retrospectively reviewed to identify incident cases of NAION using the REP database, which is a record-linkage system for all patient-physician encounters among Olmsted County, Minnesota residents. A diagnosis of NAION required a new onset of unilateral vision loss and/or optic nerve-type visual field defect with optic disc edema noted at initial presentation; patients with an alternative cause for symptoms were excluded. Visual outcomes and local and systemic factors were evaluated.
Results :
One-hundred four patients were diagnosed with NAION during the study period. The overall age and sex adjusted incidence was 3.89 per 100,000 individuals (95% confidence interval (CI): 6.24–9.22).The incidence was 7.73 (CI: 6.24-9.22) in patients aged 40 years or older and 10.2 (CI: 8.14-12.22) in patients 50 years or older. Mean age at diagnosis was 65.8 years (range, 40-90 years), and 59 (57%) patients were male. The mean logMAR visual acuity at presentation was 0.71 (Snellen 20/100) with 11 patients (11%) having vision of counting fingers or worse. Of the 91 patients with follow-up of at least 3 months, the mean acuity was 0.76 (Snellen 20/125) with 8 patients (9%) having vision of counting fingers or worse. Twenty-three (25%) were noted to have final acuity at least three Snellen lines worse than at presentation, while 21 (23%) improved by at least three lines. The average mean deviation on automated visual field testing was -9.5 dB at presentation and -10.9 dB at follow-up. Twenty-two patients (21%) suffered NAION in the fellow eye; the average interval between involvement of the first and second eyes was 4.2 years. The mean duration of follow-up was 90 months. Systemic conditions present included hypertension (80%), hyperlipidemia (74%), diabetes mellitus (39%), and obstructive sleep apnea (23%).
Conclusions :
NAION is a relatively common optic neuropathy in elderly patients with vascular risk factors. Our data indicate that the incidence of NAION has remained relatively stable in the population of Olmsted County over the last four decades.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.