Approach to Diplopia 2018-01-30T16:36:28+08:00

Differential diagnosis

  • Inflammatory
    • Multiple sclerosis
    • Giant cell arteritis
    • Mononeuritis multiplex
    • Miller-Fischer syndrome
  • Eye movement defects (CN III, IV or VI)
    • Orbital apex (III, IV, VI plus ipsilateral II and V1)
    • Cavernous sinus (III, IV, V1, V2, VI, sympathetic fibres to eye)
    • Base of skull (VI, IX)
    • Posterior communicating artery aneurysm (III)
    • Cerebellopontine angle (VII, VIII and VI if severe)
    • Midbrain (Weber’s syndrome – III and contralateral hemiparesis)
    • Pontine (Millard-Gubler syndrome – VI, ipsilateral VII and contralateral hemiparesis)
    • Pontine (inter-nuclear ophthalmoplegia or one-and-a-half syndrome)
    • Raised intracranial pressure (bilateral VI)
    • Leptomeningeal disease
  • Neuromuscular
    • Myasthenia gravis
    • Lambert-Eaton myasthenic syndrome
  • Orbital pathology
    • Thyroid eye disease
    • Orbital / peri-orbital cellulitis
    • Neoplastic infiltration
  • Myopathy
    • Chronic progressive external ophthalmoplegia (CPOE)
    • Kearns-Sayre syndrome (CPOE + retinitis pigmentosa + complete heart block, ± ataxia)
    • Myotonic dystrophy
  • Endocrine
    • Diabetes mellitus
    • Acromegaly
    • Graves’ disease
    • Pituitary tumour (lateral extension into cavernous sinus / hemi-field slide)
  • Progressive supranuclear palsy
  • Migraine with ophthalmoplegia
  • Trauma
  • Ocular
    • Retinal detachment
    • Diabetic retinopathy
    • Central retinal vein / artery occlusion
    • Vitreous haemorrhage
    • Cataract

Questions to ask

  • Does the double vision go away when you cover either eye?
    • Binocular diplopia: correction when either eye is covered
    • Monocular diplopia: correction when the affected eye is covered (=ocular pathology)
  • Is the double vision horizontal or vertical?
    • Horizontal diplopia: lateral / medial rectus (unilateral / bilateral VI or INO)
    • Vertical diplopia: superior / inferior rectus, superior / inferior oblique (III or IV)
  • Is the double vision worse on looking in any particular direction?
    • Diplopia is maximal in the direction of action of the paretic muscle
  • Myasthenia gravis
    • Does the severity of the double vision fluctuate?
      • Myasthenia gravis gets worse as the day goes on, and with activity, e.g. reading
    • Can be improved by resting the eye
    • Do you cough when you swallow?
    • Do you fall asleep easily in the day / have you ever fallen asleep when driving?
  • Has anyone told you that your eyes appear different or bulging?
    • Thyroid eye disease
    • Orbital tumour
    • Carotid-cavernous fistula
  • Do you have a headache?
    • Giant cell arteritis: jaw claudication, scalp tenderness
    • Migraine: hemicranial, throbbing, may have aura, nausea, hemiplegia
    • Meningitis: photophobia, neck stiffness
  • Demyelination / optic neuritis
    • Do colours appear as vibrant as usual? (optic neuritis)
    • Is there any eye pain or redness?
    • Have you noticed any weakness or numbness?
  • Symptoms of thyroid disease
    • Do you ever feel your heart is beating very quickly?
    • Have you noticed the weather being unusually hot lately?
    • Have you noticed your hands trembling?
    • Have your periods been irregular or more heavy than usual?
    • Have you been having any diarrhoea?
  • Osmotic symptoms
    • Do you wake up in the middle of the night to pass urine?
    • Do you feel you are drinking more water than usual?
    • Have you been losing weight?

Things to examine for

  • Inspection
    • Ptosis
    • Lid retraction
    • Proptosis / exophthalmos
    • Strabismus
    • Peri-orbital swelling
    • Goitre / thyroid surgery scars
    • Parkinsonism
  • Pulse – rate, regular / irregular (hyperthyroidism)
  • Eyes
    • Acuity
      • Finger-counting
      • Red desaturation
    • Pupils
      • Equal (Horner’s may produce unequal pupils)
      • Consensual reflex
      • Relative afferent pupillary defect
    • Extra-ocular movements (in which direction is the diplopia maximal)
      • Convergence if INO detected – should be normal
    • Fatigability
  • Pronator drift (brainstem syndromes)
  • Upper limb fatigability
  • Thyroid status
    • Pulse
    • Tremor
    • Goitre – smooth / diffuse / nodular
    • Displaced apex beat
    • Murmurs
    • Lung bases for pulmonary oedema
    • Legs for pre-tibial myxedema / peripheral oedema

Investigations

  • Blood tests
    • Thyroid function tests
    • Thyroid receptor antibody if Graves’ disease
    • Fasting blood glucose
    • Erythrocyte sedimentation rate (giant cell arteritis)
  • Myasthenia gravis
    • Antibodies against nicotinic acetylcholine receptors
      • If negative and high index of suspicion: muscle-specific kinase antibodies
    • Tensilon test
      • Improvement in weakness with edrophonium
    • Repetitive nerve stimulation
      • Measures neuronal response to repeated stimulation. Indicative of myasthenia if decrement in response observed.
  • Imaging (if cranial nerve palsy present)
    • Computed tomography / magnetic resonance imaging of the brain

Patient concerns

  • Will it get better?
    • Should get better with treatment of underlying cause
    • Can refer to ophthalmology colleague in the meantime to help with aids to minimize diplopia
  • Driving: should not drive until diplopia is corrected
  • Occupation
  • Inheritance

Management

  • Multidisciplinary
    • Visual aids: e.g. patches to cover either eye, prisms
    • Referral to therapists for adaptation to monocular vision while treating underlying cause
    • Referral to neuro-ophthalmologist
    • Referral to specialist in underlying condition
  • Treat underlying cause

This Is A Custom Widget

This Sliding Bar can be switched on or off in theme options, and can take any widget you throw at it or even fill it with your custom HTML Code. Its perfect for grabbing the attention of your viewers. Choose between 1, 2, 3 or 4 columns, set the background color, widget divider color, activate transparency, a top border or fully disable it on desktop and mobile.

This Is A Custom Widget

This Sliding Bar can be switched on or off in theme options, and can take any widget you throw at it or even fill it with your custom HTML Code. Its perfect for grabbing the attention of your viewers. Choose between 1, 2, 3 or 4 columns, set the background color, widget divider color, activate transparency, a top border or fully disable it on desktop and mobile.