16 - overview of approach to diplopia

What are the important causes of double vision?

1. ocular motor nerve disease → CN palsies

2. orbital disease

3. neuromuscular junction disease

4. supra or internuclear disease

what are case history questions to ask about diplopia?

1. is it monocular or binocular

2. side by side or up and down

3. any change with gaze direction

4. when did it start

5. is it getting worse

6. is it different at different times of day

7. ocular → change in vision, eye pain

8. neurological → headache, numbness, tingling, weakness, trouble walking or talking

9. medical → Hx of cancer, smoke, CV risk factors, GCA symptoms

What extra testing should you do for a diplopia exam?

1. eye movements

2. lids → check for ptosis, retraction, orbit

3. CN → corneal + facial sensation, orbicularis + facial muscle strength

4. BP

what extra eye movement tests should you do for a diplopia exam?

1. consider vergences

2. CT in all gazes

3. doll's eye reflex (VOR)

4. saccades/pursuits

5. convergence

what do you do if patient does not have binocular diplopia?

investigate potential causes of monocular diplopia

what do you do if patient does have binocular diplopia?

workup for orbital disease or myasthenia gravis

what do you do if patient has binocular diplopia but rule out orbital disease and myasthenia gravis?

workup for ischemic or congenital ocular motor nerve palsy

what do you do if patient has binocular diplopia but rule out orbital disease, myasthenia gravis and ischemic or congenital ocular motor nerve palsy?

urgent workup for other potential causes

What causes of diplopia can you make a safe clinical diagnosis for?

ischemic CN III, IV, or VI palsy

congenital CN IV palsy

Myasthenia Gravis

orbital disease → TED

*however an CN III palsy still needs urgent MRI/MRA to check for aneurysm

can you diagnose acquired strabismus by looking at it?

NO → many diseases that cause motility disturbances can present with same clinical picture

If no safe clinical diagnosis can be made for acute onset diplopia complaint, what do you do?

urgent referral for:

1. ocular motility assessment

2. examination including, pupils, lids, corneal/facial sensation, optic disc evaluation and perimetry

3. MRIs of orbits/brain

what are advanced assessments tailored to patient's case?

orthoptic testing of pt's sensory status and fusional abilities

full systemic clinical Hx and neurological exam

blood tests → ESR, CRP, ACE, ANA

chest x-ray or CT or PET scan

lumbar puncture