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Optic Nerve


Introduction

Optic nerve damage can arise from inflammation, poor blood supply, pressure, trauma, genetics, or infection, amongst other causes.

 

In scope:          

  • Suspected Giant Cell Arteritis with ophthalmic symptoms
     
  • Anterior non-ischaemic optic neuropathy (AION)
     
  • Optic Neuritis

 

Not in scope:           

  • Suspected Giant Cell Arteritis with no ophthalmic symptoms


 

Red Flag Features

  • Systemically unwell patient
     
  • Sudden onset reduced visual acuity
     
  • Photophobia
     
  • Patient describing ‘grey veil’, ‘shadow’ or ‘dark curtain’ in their vision
     
  • Abnormal neurology or mental state, including suspected stroke
     
  • Headache with concerning features (see linked page)
     
  • Vomiting

 

This list is not exhaustive.


 

Assessment/Diagnosis

Anterior ischaemic optic neuropathy (AION)

  • Non-arteritic anterior ischaemic optic neuropathy (NAION):
    • Common cause of sudden painless loss of vision in patients >50yrs.
    • Vision may become blurred, dimmer or darker often above or below what is being looked at
    • Central vision remains normal
    • There should be no discomfort, pain or change in the appearance of the eye
    • There is no specific treatment for this condition, but managing risk factors (e.g. hypertension, smoking) can help protect the unaffected eye.

 

  • Arteritic anterior ischaemic optic neuropathy (AAION):
    • Caused by vasculitis, e.g. Giant Cell Arteritis (GCA)

 

  • Optic Neuritis
    • Unilateral aching eye exacerbated by eye movement, associated with acute rapid (but not sudden) visual loss. Patient may also experience a frontal headache
    • (Optic neuritis can in rare cases be bilateral, and these cases are often more serious)
    • Fundoscopy often normal but the disc may appear pale or swollen

 

This list is not exhaustive.


 

Advice and Guidance

Please send advice and guidance requests to Ophthalmology via eRS


 

Referral instructions

Red flag features

See list above. Consider acute medical admission/discussion with Acute GP as appropriate.

 

Emergency Referral

  • Any clinical suspicion of stroke, admit via 999 stroke pathway.
  • If fluctuating vision consider amaurosis fugax and complete a TIA clinic referral.  If there is any uncertainty consider discussion with AcuteGP or Neurologist of the day, contacted via RCHT switchboard
  • If sudden monocular visual loss in patient > 50 years old, take blood for CRP and plasma viscosity and refer to emergency eye casualty
  • If sudden binocular double vision in patient > 50 years old, take blood for CRP and plasma viscosity and refer to emergency eye casualty.  If possible please include Snellen VA in the referral

If no ophthalmic symptoms, and GCA suspected, please contact on-call rheumatology registrar or consultant via switchboard

  • Isolated symptoms of optic neuritis including eye pain with documented visual loss, for exclusion of optic neuritis refer to emergency eye casualty.

 

This list is not exhaustive

 

Routine Ophthalmology Referral

  • Any unexplained loss of vision or unexplained loss of field of vision, without emergency or urgent symptom presentation, suspected anterior eye pathology or red flag features, please include an optician report if available.

 

Supportive Information

For Professionals

 

For Patients

 

References

 

Page review information

Date reviewed         30 September 2025

Next review due      30 September 2027

Sifter name             Dr Kate Northridge

Contributor             Dr David Jones, Consultant Ophthalmologist, Royal Cornwall Hospital    

                               Dr Oliver Leach, Consultant Neurologist, Royal Cornwall Hospital