Optic disc abnormality DDx


The important optic disc abnormalities are: papilloedema, papillitis and optic atrophy

  • Papilloedema – swelling of the optic disc with blurring of the disc margins, hyperaemia and loss of physiologic cupping. Flame-shaped hemorrhages and yellow exudates appear near the disc margins as edema progresses. There is loss of spontaneous venous pulsations (but this is absent in 20% of people anyway).
  • Papillitis – characterised blurred disc margins, that is usually unilateral, associated with decreased visual acuity and red desaturation, a central scotoma and relative afferent pupillary defect and pain on eye movements.
  • Optic atrophy – pale insipid optic disc (loss of the normal yellowish colour), with absence of normal physiological cupping.




  • space-occupying lesions (e.g. neoplasms, trauma, infection, and vascular causes)
  • benign intracranial hypertension (trauma, drugs, idiopathic, Addisons, sinus thrombosis)
  • central venous sinus thrombosis
  • meningoencephalitis


  • hydrocephalus – obstructive, communicating (production vs. absorption of CSF)
  • high CSF protein — e.g. Guillain-Barre Syndrome


  • central retinal vein occlusion (CRVO)
  • retro-orbital mass
  • hypertension (grade IV)

Pseudopapilledema mimics papilloedema and may result from the presence of optic disc drusen or a congenitally anomalous disc.


  • multiple sclerosis
  • familial
  • idiopathic
  • inflammation
    • viral — e.g. infectious mononucleosis, herpes zoster, viral encephalitis
    • childhood infections or vaccinations — e.g. measles, mumps, chickenpox
    • Granulomatous inflammations — e.g. tuberculosis, syphilis, sarcoidosis, cryptococcus
    • Contiguous inflammation of the meninges, orbit, or sinuses.

The differential includes optic neuropathies such as:

  • toxic optic neuropathy — e.g ethambutol, chloroquine, nicotine, alcohol
  • metabolic optic neuropathy — vitamin B12 deficiency
  • ischemic optic neuropathy — diabetes mellitus, giant cell arteritis, atherosclerosis
  • compressive optic neuropathy — e.g. orbital tumour, intracranial mass

Optic atrophy

Optic atrophy may be the end stage of:

  • chronic papiloedema
  • chronic optic neuritis
  • glaucoma
  • optic neuropathies (e.g. toxic, metabolic, ischemic and compressive)
  • familial, e.g. retinitis pigmentosa


Journal Articles and Textbooks

  • Ehlers JP, Shah CP, Fenton GL, and Hoskins EN. The Wills Eye Manual: Office and Emergency Room Diagnosis and Treatment of Eye Disease (5th edition), Lippincott Williams & Wilkins 2008.

CCC Differential Diagnosis Series


Anosmia, Ataxia, Blepharospasm, Bulbar and Pseudobulbar palsy, Central Pontine Myelinosis, Cerebellar Disease, Chorea, Cranial nerve lesions, Dementia, Dystonia, Exophthalmos, Eye trauma, Facial twitches, Fixed dilated pupil, Horner syndrome, Loss of vision, Meningism, Movement disorders, Optic disc abnormality, Parkinsonism, Peripheral neuropathy, Radiculopathy, Red eye, Retinal Haemorrhage, Seizures, Sudden severe headache, Tremor, Tunnel vision


Bronchial breath sounds, Bronchiectasis, High airway pressures, Massive haemoptysis, Sore throat, Tracheal displacement


Atrial Fibrillation, Bradycardia, Cardiac Failure, Chest Pain, Murmurs, Post-resuscitation syndrome, Pulseless Electrical Activity (PEA), Pulsus Paradoxus, Shock, Supraventricular tachycardia (SVT), Tachycardia, VT and VF, SVC Obstruction


Abdominal distension, Abdominal mass, Abdominal pain, Asterixis, Dysphagia, Hepatomegaly, Hepatosplenomegaly, Large bowel obstruction, Liver palpation abnormalities, Lower GI haemorrhage, Malabsorption, Medical causes of abdominal pain, Rectal mass, Small bowel obstruction, Upper GI Haemorrhage


Genital ulcers, Groin lump, Scrotal mass, Urine colour, Urine Odour, Urine transparency


Arthritis, Shoulder pain, Wasting of the small muscles of the hand


Palmar erythema, Serious skin signs in sick patients, Thickened Tethered Skin, Leg ulcers, Skin Tumour, Acanthosis Nigricans


Diabetes Insipidus, Diffuse Goitre, Gynaecomastia, Hirsutism, Hypoglycaemia, SIADH, Weight Loss




Floppy infant 


Anaphylaxis, Autoimmune associated diseases, Clubbing, Parotid Swelling, Splinter haemorrhages, Toxic agents and abnormal vitals, Toxicological causes of cardiac arrest


CHEST: Atelectasis, Hilar adenopathy, Hilar enlargement on CXR, Honeycomb lung, Increased interstitial markings, Mediastinal widening on mobile CXR, Pulmonary fibrosis, Pseudoinfiltrates on CXR, Pulmonary opacities on CXR,
Gas on abdominal X-ray, Kidney mass,
Intracranial calcification, Intracranial structures with contrastVentriculomegaly,
OTHER: Pseudofracture on X-Ray


LOW: Anaemia, Hypocalcaemia, hypochloraemia, Hypomagnesaemia

HIGH: Bilirubin and Jaundice, HyperammonaemiaHypercalcaemia, Hyperchloraemia, Hyperkalaemia, Hypermagnesaemia

ACID BASE: Acid base disorders, Resp. acidosis, Resp. alkalosis,

Creatinine, CRP, Dipstick Urinalysis, Laboratory Urinalysis, Liver function tests (LFTs), Pleural fluid analysis, Urea, Urea Creatinine Ratio, Uric acid, Urinalysis, Urine Electrolytes


CCC 700 6

Critical Care


Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.

After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.

He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE.  He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.

His one great achievement is being the father of three amazing children.

On Twitter, he is @precordialthump.

| INTENSIVE | RAGE | Resuscitology | SMACC

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