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Eyes & Vision

Papilloedema

Papilloedema is optic-disc swelling caused by raised intracranial pressure; it is a sign rather than a diagnosis and needs urgent confirmation, brain imaging with venous imaging and specialist management to prevent irreversible visual loss or neurological deterioration.

In a nutshell

Papilloedema is optic-disc swelling due to raised intracranial pressure, usually bilateral. It is a sign, not a diagnosis. Early central acuity may be preserved while the blind spot enlarges and transient visual obscurations occur. Confirm the disc swelling, urgently image the brain with venous imaging, and only then perform specialist lumbar puncture if safe. Treat the cause; in confirmed IIH use supported weight management, specialist CSF-lowering treatment and urgent surgery if vision is threatened.

Classic presentation

A patient with headache worse on waking or lying flat, transient greying of vision and pulsatile tinnitus has bilateral swollen optic discs, an enlarged blind spot and initially preserved central acuity.

Key points

  • Papilloedema specifically means disc swelling caused by raised intracranial pressure.
  • Early acuity can be normal; formal visual fields and serial disc/OCT assessment detect visual threat.
  • Image the brain and venous system before lumbar puncture.
  • A mass, hydrocephalus, venous sinus thrombosis, infection and malignant hypertension must be excluded before calling it IIH.
  • For confirmed IIH, supported weight management is disease-modifying; acetazolamide is specialist-led and surgery protects vision when fields worsen.
  • Sight-threatening papilloedema is an admission/specialist emergency, not a routine headache review.

First-line investigation

Urgent ophthalmic confirmation with acuity, pupils, formal fields, dilated discs and OCT/photographs, followed by brain imaging with CT/MR venography before any lumbar puncture.

Management

Treat as an urgent neuro-ophthalmic sign

  • Confirm visual function and escalate immediately for reduced consciousness, focal neurology, infection, rapidly worsening headache or declining visual fields; do not discharge sight-threatening papilloedema without a plan.2,3

Image brain and venous system before LP

  • Arrange urgent brain imaging plus CT/MR venography to exclude mass, hydrocephalus and cerebral venous sinus thrombosis; only perform a specialist LP after imaging is safe.1,3

Identify and treat the cause

  • Treat infection, malignant hypertension, venous thrombosis, mass/obstruction or a causative medicine through the relevant specialist pathway; diagnose IIH only after secondary causes are excluded.2,3,1

Protect vision in IIH

  • Use supported weight management and specialist CSF-lowering treatment for confirmed IIH; worsening fields or rapidly progressive swelling requires urgent CSF diversion or optic-nerve sheath surgery, with serial LP only as a bridge.1,2,5

Monitor vision separately from headache

  • Repeat acuity, pupils, formal fields, disc grading and OCT/photographs according to severity; expedite review for any visual change. Headache response does not replace visual monitoring.1,3

Exam traps

  • Papilloedema is not a synonym for any swollen optic disc; optic neuritis and drusen are different diagnoses.
  • Never perform an unplanned lumbar puncture before imaging has excluded an obstructive mass or unsafe pressure differential.
  • Normal Snellen acuity does not exclude dangerous papilloedema; field loss may come first.
  • Venous sinus thrombosis must be actively excluded with venous imaging, including in an IIH-like phenotype.
  • Headache improvement does not prove that vision is safe; follow fields and disc appearance.
  • Serial lumbar puncture is a temporary bridge in threatened vision, not definitive long-term treatment.

Illustrations

Fundoscopy of papilloedemaA fundus photograph of severe papilloedema showing optic-disc swelling with blurred margins, vascular congestion and peripapillary haemorrhage. Label it as a clinical example, not a standalone diagnosis.Jonathan Trobe, M.D, Wikimedia Commons · CC-BY-3.0

Key sources

  1. Mollan et al., Idiopathic intracranial hypertension: consensus guidelines on management (J Neurol Neurosurg Psychiatry 2018;89:1088-1100; UK interdisciplinary consensus reviewed by ABN, BASH, SBNS and RCOphth)Updated 1 Oct 2018
  2. NHS, Intracranial hypertension (NHS Health A to Z, last reviewed 28 March 2023)Updated 28 Mar 2023
  3. University Hospitals Birmingham, Raised intracranial pressure pathway (NHS pathway, last reviewed 4 February 2025)Updated 4 Feb 2025
  4. Cambridge University Hospitals, Idiopathic intracranial hypertension (Patient information, approved 20 September 2023, version 3)Updated 20 Sept 2023
  5. BNF, Acetazolamide (BNF drug monograph)

This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer.