Papilloedema describes optic disc swelling that is caused by increased intracranial pressure. It is almost always bilateral.

Causes:

• space-occupying lesion: neoplastic, vascular
• malignant hypertension
• idiopathic intracranial hypertension
• hydrocephalus
• hypercapnia

Rare causes include

• hypoparathyroidism and hypocalcaemia
• vitamin A toxicity

The following features may be observed during fundoscopy:

• venous engorgement: usually the first sign
• loss of venous pulsation: although many normal patients do not have normal pulsation
• blurring of the optic disc margin
• elevation of optic disc
• loss of the optic cup
• Paton's lines: concentric/radial retinal lines cascading from the optic disc