diplopia (double vision)

Etiology

• horizontal diplopia:
  • images side by side
  • cranial nerve 3 or cranial nerve 6 dysfunction
• vertical diplopia
  • images on top of another
  • cranial nerve 3 or cranial nerve 4 dysfunction
• diplopia in one eye with the other eye closed
  • suggests problem in the cornea or lens (aberrant refraction)
  • uncommonly, severe retinal pathology can cause monocular diplopia
• binocular
  • extraocular muscle paralysis or weakness (cranial nerve 3, cranial nerve 4, cranial nerve 6)
    • diabetes
    • posterior communicating artery aneurysm
    • myasthenia gravis
  • difficulty moving the eyes within the orbit
    • tumor
    • Graves' disease
    • fracture
  • pharmaceuticals
    • carbamazepine
    • phenytoin
    • vincristine
• binocular diplopia suggests more serious etiology than monocular diplopia

Management

• isolated cranial nerve 6 palsy can be observed for a few weeks looking for improvement
• with cranial nerve 3 palsies, absence of pupillary involvement suggests a benign process that may be observed over a couple of weeks
• most cranial nerve 4 palsies are traumatic or idiopathic postpone neuroradiology testing until 2 months have passed
• if more than one cranial nerve is involved, referral to a neurologist or ophthalmologist is indicated
• eye patch over affected eye can be useful if cause is benign

More general terms

• eye disease (ophthalmopathy)
• sign/symptom