What is the appropriate management for a patient presenting with diplopia?

Management of Diplopia

Patients presenting with diplopia require prompt referral to ophthalmology, specifically to specialists in neuro-ophthalmology or strabismus, for comprehensive evaluation and management. 1, 2

Initial Evaluation

Diagnostic Assessment

1. Determine if diplopia is monocular or binocular

   • Monocular diplopia (persists with one eye covered) → refer to ophthalmology for ocular causes
   • Binocular diplopia (resolves with one eye covered) → neurological evaluation needed

2. Key diagnostic tests:

   • Visual acuity and refraction
   • Pupillary examination (critical for 3rd nerve palsy)
   • Ocular motility assessment
   • Cover/uncover and alternate cover testing
   • Forced duction testing when indicated 2

3. Neuroimaging based on suspected etiology:

   • 3rd nerve palsy with pupil involvement → immediate CT angiography to rule out aneurysm 2, 3
   • 6th nerve palsy → MRI brain with contrast (unless patient >50 with vascular risk factors) 3
   • 4th nerve palsy with hyperdeviation worsening in downgaze → MRI with contrast 3
   • Multiple cranial nerve palsies → urgent imaging with focus on cavernous sinus 3
   • Suspected orbital pathology → contrast-enhanced CT of orbits 4

Management Algorithm

Immediate Management

1. Temporary measures while awaiting diagnosis:
   • Occlusion of one eye (patch)
   • Prism glasses for small deviations
   • Botulinum toxin for persistent diplopia 2

Etiology-Specific Management

Cranial Nerve Palsies

• 3rd nerve palsy:

  • Pupil-involving → immediate neuroimaging to rule out aneurysm
  • Pupil-sparing with vascular risk factors → likely microvascular; observe for 3-6 months 1, 3

• 6th nerve palsy:

  • If persistent beyond 6 months → consider surgical options:
    • Medial rectus recession and lateral rectus resection for mild cases
    • Vertical rectus transposition procedures for severe cases with no abducting force 1

• 4th nerve palsy:

  • Prism therapy for small deviations
  • Surgical correction if persistent 1

Neuromuscular Junction Disorders

• Myasthenia gravis:
  • Test with acetylcholine receptor and MuSK antibodies
  • Treat with acetylcholinesterase inhibitors, immunosuppression 2, 5

Retinal Causes

• Binocular central diplopia/foveal misregistration:
  • Fogging techniques (Bangerter foils preferred over surgical tape)
  • Small amount of prism may provide additional relief
  • Surgical peeling of epiretinal membrane may help in some cases but can worsen diplopia in others 1

Surgical Management

• Consider surgery if diplopia persists >6 months 2
• Surgical options:
  • Recession/resection procedures
  • Transposition procedures for severe cases
  • Caution: Risk of anterior segment ischemia when operating on multiple muscles, especially in older patients with vascular risk factors 1

Special Considerations

Elderly Patients

• For patients >60 years with recent diplopia:
  • Check ESR and CRP to rule out giant cell arteritis 2, 4
  • Higher risk of anterior segment ischemia with strabismus surgery 1

Surgical Complications to Discuss

• Common minor complications: foreign body sensation, subconjunctival hemorrhage
• Serious complications (rare): globe perforation (0.08-5.1%), endophthalmitis (1 in 30,000), anterior segment ischemia 1

Patient Counseling

• Explain that the goal of treatment is to eliminate diplopia in primary position
• Advise that diplopia may persist in extreme gaze positions despite treatment
• Discuss that some conditions may not improve spontaneously and may require long-term management 1

Follow-up

• Regular monitoring for resolution of diplopia
• Adjustment of prisms or surgical planning if diplopia persists
• Continued evaluation for underlying conditions

Remember that while some causes of diplopia are benign, others require immediate recognition and treatment to prevent vision and life-threatening outcomes 6.