Abstract
Purpose :
Non-arteritic anterior ischemic optic neuropathy (NAION) is the most common acute optic neuropathy in patients over age 50, and there is a 15-25% risk of a sequential (sNAION) event in the fellow eye. The Ischemic Optic Nerve Decompression Trial reported 326 patients with NAION (mean follow-up: 5.1 years) with a 14.7% incidence of sNAION; median time between study enrollment and sNAION was 1.2 years.
Methods :
Retrospective query of the electronic health record (EHR) at a specialty eye hospital for encounters with ICD-10 code for “ischemic optic neuropathy” (right, left, bilateral, or unspecified), text phrase “NAION”, or “ischemic optic neuropathy”. With manual chart review, 451 patients with other diagnoses were excluded (search methodology evaluated in companion abstract) and date of vision loss, rather than ICD-10 code association, was recorded.
Results :
A total of 672 patients were identified with at least unilateral involvement. Kaplan–Meier survival analysis (12 month censure) revealed that 31% of patients had sNAION. Mean age at first NAION episode was 59.5 ±12.7 years. Median time between sNAION episodes was 19.5 months. The probability of remaining event-free at 12 months was 57% (95% CI: 50%-65%), with a cumulative incidence of the sequential NAION of 43% at 12 months. Age at first NAION episode (p<0.0001), hyperlipidemia (p=0.0076), systemic hypertension(p=0.0013), and cardiovascular risk (p=0.021) were each associated with shorter time between NAION episodes.
Conclusions :
This study assessed risks of sNAION derived from the largest cohort of patients with sNAION ever reported. The risk of sNAION is higher than previously reported. And, this study is the first to document that specific systemic factors influenced the timing between events.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.