Diplopia

  • This is mostly an approach to isolated diplopia
  • Monocular diplopia = refraction problem
Binocular diplopia
History - Speed of onset
Examination - Eye position at rest
- Head position (head tilt may suggest congenital CN4 palsy?)
- CN3: vertical/horizontal diplopia, anisocoria, ptosis, mydriatic/dilated pupil on affected side
- CN4: vertical diplopia, worse on downgaze, head tilted away from affected side
- CN6: horizontal, binocular diplopia, worse in the distance and worse looking to the ipsilateral side
Diagnostic investigations Generally aiming to rule out cavernous sinus lesions e.g. cavernous sinus thrombosis. Other ddx: trauma; microvascular;
Bilateral CN6 palsy: check for Raised ICP
Differentials Myasthenia gravis
Thyroid eye disease e.g. Graves disease
Convergence insufficiency
Trauma e.g. Facial bone fractures - orbital floor fracture
nasopharyngeal cancers; multiple sclerosis, drug induced, botulism infection
Immediate management
Ongoing management
  • internuclear ophthalmoplegia looks like diplopia/impaired extraocular movement o/e but they don't usually complain of diplopia??
    • = lesion of medial longit fasciculus
    • yes you learned this for finals