AION
Anterior Ischemic Optic Neuropathy
Plain-language definition
Sudden vision loss from reduced blood flow to the front of the optic nerve. Divided into arteritic (from GCA, emergency) and non-arteritic (NAION, more common) types.
Where this term comes up
“Glaucoma, AION,”
Symptom · Visual Field Deficits
“Anterior (AION) shows disc edema”
Finding · Optic Disc Edema (Swelling)
“Both anterior (AION) and posterior”
- Category
- Test or diagnostic term
- Also written as
- No alternate forms listed.
Diagnostic terms describe tests, measurements, imaging, or exam techniques used to understand eye and neuro-ophthalmic problems.
Related glossary terms
A note on medical context
A glossary definition can explain a word, but it cannot tell you whether a symptom or test result is serious. If this term came from an article, use the full article and your clinician's guidance for context.