- Binocular diplopia is usually sinister (monocular not so)
- Beware: new headache or ocular pain, unilateral pupil dilation, neurological features or fatigability, ptosis, facial trauma, papilloedema.
- Advise all patients with diplopia to stop driving
- Monocular—diplopia persists when one eye is covered.
- Monocular generally = eye abnormality (cornea/ant chamber/lens/post chamber/retina) or non-organic.
- Binocular—Diplopia disappears when one eye is covered
- Vertical diplopia = abnormal elevation/depression of eye
- Fourth nerve palsy
- Squint, T4 eye disease
- Horizontal diplopia = abnormal ab/adduction of eyes
- 6th nerve palsy
- Intermittent or fatigue diplopia - myasthenia gravis (±ptosis)
- Check worse direction / triggering movement
- Trauma - blow out # with entrapment
- Sudden onset - acute aetiology e.g. ischaemia/vascular
- Headache/eye pain - ischaemia, arterirtis, infection, ↑ICP, aneurysm
- May indicate ischaemia, inflammation, infection, raised intracranial pressure, or aneurysm
- Jaw claudication, temporal tenderness, myalgia suggest temporal arteritis
- Check Hx for coagulopathy risks
- Lamotrigine, topiramate, gabapentin, fluroquinolones, and citalopram are associated with diplopia
- Eyelids - ptosis = 3rd N palsy or myaesthenia, retraction = T4 disease
- Check for strabismus in all directions (please see below)
- Proptosis = orbital disease (cellulitis, tumour, AVM) or T4
- Record visual acuity
- New poor vision = neurological or orbital
- Unilateral mydriasis, headache and diplopia (3rd N) = aneurysm
- Meiosis (±ptosis) = Horner's (cavernous sinus or neck pathology)
- Fundoscopy (papilloedema)
- Cranial and peripheral nerve examination
- New onset of headache or ocular pain
- Unilateral mydriasis
- Associated neurological features or fatigability
- Facial trauma (with ANY) eye signs
Painful 3rd N palsy with ipsilateral dilated pupil or 6th nerve palsy with papilloedema
- Discuss with your senior re imaging or refer neurology
Suspected giant cell arteritis
- Request ESR/CRP. Start high dose treatment and refer medical.
Trauma associated diplopia
- Refer maxillofacial or ophthalmology
Long-standing or spectacle related diplopia or painless monocular diplopia
New isolated fourth and sixth cranial nerve palsies
- Assume stroke (admit medical)
Suspected T4 eye disease
- Check TFTs (results to GP). Stop smoking. GP follow up.
Advise patients with diplopia not to drive.
Content By Dr Íomhar O' Sullivan . Last review Dr ÍOS 28/05/21.