Acute Ischemic Optic Neuropathy (AION)

Optic Nerve Disease

• Compressive Optic Neuropathy
• Optic Neuritis
• Acute Ischemic Optic Neuropathy
• Temportal Arteritis

What is AION ?

AION is damage to the nerve that results from not enough blood flow.

A	Anterior = sudden/rapid
I	Ischemic = not enough blood supply
O	Optic Neuropathy = damage to the nerve that controls sight. anterior = the optic nerve appears swollen when your doctor looks behind your eye.
N	Neuropathy

There are two types of AION: arteritic and non-arteritic. Non-arteritic is more common (90-95%). Although less common, the arteritic type is asscociated with (giant cell) temporal arteritis, an inflammatory condition of the large blood vessels, especially the temporal artery which runs along the side of the face and temple.

Please advise your doctor if you have any of the following symptoms:

1. New or altered headaches
   
2. Pain or tenderness along the area adjacent to your hairline = temporal artery region
   
3. Eye pain
   
4. Pain with chewing
   
5. Ear pain
   
6. Abdominal pain
   
7. Fatigue, loss of appetite or weight
   
8. Muscle ache

How do I know if I have AION?

Patients with AION typically wake up with painless loss of vision. This form of visual loss has been described in patients who have taken Viagra the night before.

The most common visual loss is altitudinal – you can’t see either below, or less commonly above the center of vision. Red looks more brown or orange. When your doctor looks at your optic nerve in the back of your eye, a quadrant or half of the nerve is swollen with some hemorrhages. Visual field testing will often reveal a loss of the inferior (lower) visual field, but any pattern of loss is possible.

Normal Retina

AION

Who gets AION?

Patients with AION tend to be in their 50s or 60s; women and men are affected equally. Risk factors include a history of high blood pressure, diabetes, elevated cholesterol and a small optic nerve cup/disc ratio.

How is AION treated?

There is no known effective treatment for AION. If the visual loss is severe or the second eye has been effective intravenous steroids and blood thinners have been tried, but there is no medical evidence to support any intervention.

What should I expect if I am diagnosed with AION ?

Once the visual loss has occurred, one third of patients notice some improvement in visual field loss, one-third remain stable and one-third worsen.

If your vision is dramatically decreased (less than 20/200) and you are older than 50 years old, giant cell arteritis should be suspected. Blood work (CBC, ESR, CRP) and a biopsy of your temporal artery is indicated.

Temporal Arteritis

If your visual dysfunction progresses or you have any other neurologic symptoms, an imaging study of your optic nerve and brain should be performed (MRI to exclude a tumor or other process).

Compressive optic neuropathy