Deteriorating Patient
 

Pupils

 
 
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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
Last updated on April 15th, 2020
 
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