Anterior ischaemic optic neuropathy (AION) is sudden damage to the optic nerve head due to reduced blood flow. It causes abrupt, painless loss of vision in one eye.
Types and risk factors
Non-arteritic AION is linked to vascular risk factors such as hypertension, diabetes, and sleep apnoea, while arteritic AION is associated with giant cell arteritis and requires emergency treatment. Both forms can produce sectoral optic disc swelling and field loss.
- Vision loss typically occurs over hours to days
- Some patients notice altitudinal visual field defects
- The fellow eye is also at risk over time
Diagnosis and management
Assessment includes detailed history, examination, visual fields, and blood tests; suspected giant cell arteritis requires immediate high-dose steroids. Long-term care is often shared between neuro-ophthalmology, medical teams, and medical retina or general ophthalmology clinics.
