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Deteriorating Patient
Deteriorating Patient


February 15th, 2021

Inspection of Pupils

  • Look For

  • The size of the pupils (dilated, normal, constricted) and equality of size bilaterally.
    • Normal Pupillary Size

    • In the dark - 4-8mm
    • Under bright light - 2-4mm
  • Causes of Abnormal Pupils

  • Bilateral Pupillary Dilation

  • Cerebral lesion - herniation, encephalitis, visual cortex infarct, tumour, trauma, MS
  • Drugs - anticholinergics, SSRIs / SNaRIs, stimulants, barbiturates, methanol
  • Brain stem death
  • Bilateral Pupillary Constriction

  • Drugs - opiates, antipsychotics, acetylcholine, clonidine
  • Intracranial haemorrhage
  • Horner's syndrome (bilateral) - autonomic failure, amyloidosis, diabetes
  • Unequal Pupils (Anisocoria)

  • Physiological (20% of the population - compare with an old photo)
  • Migraine
  • Post-ictal
  • Horner's syndrome (unilateral)
  • Drugs applied to one eye - pilocarpine, tropicamide, cocaine
  • Intraocular conditions - glaucoma, retinal detachment
  • Optic (II) or oculomotor (III) nerve lesion - trauma, compression, optic neuritis, Guillain barré
  • CNS lesion - trauma, tumour, haemorrhage, infarct, MS

Pupillary Light Reflexes

  • How to Perform

  • Shine a light into each pupil. Watch to see that both the ipsilateral (direct response) and contralateral (consensual response) pupils constrict as a result of the stimulus.
  • Causes of Absent Pupillary Reflexes

  • Intraocular conditions - glaucoma, retinal detachment
  • Optic (II) nerve lesion - trauma, compression, optic neuritis
  • Midbrain lesion - encephalitis, tumour, trauma, haemorrhage, MS, midbrain infarct
  • Oculomotor (III) nerve lesion - trauma, compression, small vessel ischaemia, Guillain barré
  • Medications - sympathomimetic, parasympatholytic (anticholinergics), barbiturates
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