Related Experiment Video
Updated: Jun 7, 2026
06:49
The Rodent Model of Nonarteritic Anterior Ischemic Optic Neuropathy (rNAION)
Published on: November 20, 2016
Two presentations of nonarteritic ischemic optic neuropathy
Kiersten Nelson1, Gurjit Singh, Stephen Boyer
1Veterans Affairs Illiana Health Care System, Danville, Illinois, USA.
Optometry (St. Louis, Mo.)
|November 2, 2010
Summary
Nonarteritic anterior ischemic optic neuropathy (NAION) is a common cause of vision loss in older adults. Predisposing factors include sleep apnea and diabetes, with vision loss being irreversible.
Area of Science:
- Ophthalmology
- Neurology
Background:
- Nonarteritic anterior ischemic optic neuropathy (NAION) is the most frequent acute optic neuropathy in individuals over 50.
- NAION causes sudden, painless vision loss in one eye, often upon waking, with a 15-20% risk of affecting the fellow eye within 5 years.
- Vision loss stems from ischemia in the short posterior ciliary arteries, leading to optic nerve pallor and visual field defects.
Observation:
- Two case studies of NAION are presented: a 57-year-old woman with a 10-year history of symptoms and a 66-year-old man presenting within a week.
- Both patients exhibited predisposing systemic risk factors, decreased visual acuity, and resultant visual field loss.
Findings:
- Key predisposing factors for NAION include small cup-to-disc ratios, obstructive sleep apnea, nocturnal hypotension, diabetes, and other vascular diseases.
- The visual impairment resulting from NAION is permanent.
Implications:
- Early identification of risk factors is crucial for managing patients at risk of NAION.
- Current understanding indicates no effective treatments to prevent optic nerve atrophy or recurrent NAION episodes.
Related Concept Videos
01:25Glaucoma: Overview
Glaucoma is an eye condition characterized by increased intraocular pressure that damages the retina and optic nerve, leading to irreversible blindness if left untreated. The human eye has various components, including the cornea, iris, pupil, lens, and optic nerve. Aqueous humor is secreted by the epithelium of the ciliary body in the posterior chamber and flows through the trabecular meshwork and canal of Schlemm, maintaining normal intraocular pressure. The trabecular meshwork and the canal...
01:27Open Angle Glaucoma: Treatment
In open-angle glaucoma, the iridocorneal angle remains open, but the trabecular meshwork becomes stiff, slowing down the outflow of aqueous humor. This causes a buildup of aqueous humor in the anterior chamber, leading to a sudden increase in intraocular pressure. The treatment for open-angle glaucoma focuses on reducing the elevated intraocular pressure by either decreasing the secretion of aqueous humor or increasing its outflow.
Drugs such as carbonic anhydrase inhibitors, α2- and...
Drugs such as carbonic anhydrase inhibitors, α2- and...
01:21Peripheral Arterial Disease II: Clinical Manifestations and Diagnostic Evaluation
Clinical manifestationsPeripheral Arterial Disease (PAD) manifests through a range of symptoms, from the characteristic intermittent claudication to atypical presentations and severe complications in advanced stages. Intermittent claudication, a hallmark symptom of PAD, presents as exercise-induced muscle pain that typically resolves within minutes of rest. This pain is reproducible and stems from inadequate blood flow, leading to the accumulation of lactic acid produced during anaerobic...
01:28Angle Closure Glaucoma: Treatment
Angle-closure glaucoma, or closed-angle glaucoma, is an eye condition where the iris bulges out and blocks the iridocorneal angle, resulting in a buildup of aqueous humor and increased intraocular pressure. Immediate medical attention is necessary due to the sudden onset of symptoms. The treatment for angle-closure glaucoma includes short-term and long-term approaches. Short-term treatment involves using eye drops like pilocarpine to lower intraocular pressure by increasing aqueous humor...
01:21Aneurysm II: Clinical Manifestations and Diagnostic Studies
Thoracic, aortic arch and abdominal aneurysms are significant vascular conditions that can present with various clinical manifestations and lead to serious complications. Understanding these manifestations and the appropriate diagnostic studies is essential for effective management and treatment.Thoracic Aortic AneurysmsThoracic aortic aneurysms often remain asymptomatic until they reach a size that impinges on adjacent structures. They typically cause deep, diffuse chest pain that radiates to...