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Updated: Jul 16, 2026
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The Rodent Model of Nonarteritic Anterior Ischemic Optic Neuropathy (rNAION)
Published on: November 20, 2016
Incipient nonarteritic anterior ischemic optic neuropathy
Sohan Singh Hayreh1, M Bridget Zimmerman
1Department of Ophthalmology and Visual Sciences, College of Medicine, University of Iowa, Iowa City, Iowa 52242-1091, USA. sohan-hayreh@uiowa.edu <sohan-
Ophthalmology
|March 30, 2007
Summary
Incipient nonarteritic anterior ischemic optic neuropathy (NAION) is a distinct condition presenting with optic disc edema but no vision loss. Recognizing it early aids in managing NAION risk, especially in diabetics.
Area of Science:
- Ophthalmology
- Neurology
- Vascular Medicine
Background:
- Nonarteritic anterior ischemic optic neuropathy (NAION) is a common cause of sudden, painless vision loss.
- Understanding the early stages of NAION is crucial for timely diagnosis and management.
- Incipient NAION represents an early, asymptomatic phase of the disease.
Observation:
- This cohort study analyzed 60 eyes of 54 patients with incipient NAION.
- Patients presented with optic disc edema (ODE) but no visual impairment attributable to NAION.
- Key clinical features and progression patterns were documented over a median follow-up of 6.3 years.
Findings:
- Incipient NAION is a distinct clinical entity characterized by asymptomatic optic disc edema.
- Progression to classic NAION occurred in 25% of cases, with visual field worsening in 31% of those progressing.
- Patients with incipient NAION showed a higher prevalence of diabetes mellitus and lower prevalence of ischemic heart disease compared to classic NAION.
Implications:
- Early identification of incipient NAION is vital, particularly in patients with a history of NAION in the fellow eye or those with diabetes.
- Recognizing this distinct entity can prevent unnecessary diagnostic investigations.
- This knowledge aids in risk stratification and potentially proactive management strategies for NAION.
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