Neuro-ophthalmology: Optic Disc Oedema

Question 1

Describe optic disc oedema?

Answer 1

• Swelling of nonmyelinated nerve fibres (at ONH) from impaired axoplasmic flow (down the nerve)
  o Myeline improves the speed of conduction down nerve
• It is evidence of acute/ evolving pathology – something is happening now to the ONH

Question 2

What is a caution to remember when you think you see a swollen disc?

Answer 2

Caution: cannot write down that disc is swollen & then not follow it up with proper management – if writing down, make sure it is properly swollen

Question 3

Describe the appearance of optic disc oedema?

Answer 3

• Elevated appearance of nerve head
• Filling of cup – compare to previous pic (if have it)
• Retinal vessels drape over disc margin – adds to raised appearance
• Blurring of margin
• RNFL oedema – greyish appearance that obscures vessels – follow vessels from centre of cup outwards and they become obscured
• Hyperaemia – increased redness
• Retinal venous dilation & tortuosity – more obvious if can compare to previous pic – vessels look wider than normal and more wiggly
• Peripapillary haemorrhages & exudates
  o Flame-shaped haemorrhages

Question 4

What are the causes of optic disc oedema?

Answer 4

• Papilloedema (acute & chronic)
• Ischaemia:
  o Anterior Ischaemic Optic Neuropathy (AION)
   Arteritic Anterior Ischaemic Optic Neuropathy (AAION)
   Non-Arteritic Anterior Ischaemic Optic Neuropathy (NAION)
  o Posterior Ischaemic optic neuropathy
• Inflammation
  o Optic neuritis – demyelinating, infection, non-infectious
  o Neuroretinitis
• Diabetic papillopathy