Transcript Ocular Myasthenia Gravis

Eye Findings in Myasthenia Gravis:
Diagnosis, Evaluation, and Treatment
Sophia M. Chung, M.D.
Depts of Ophthalmology &
Neurology and Psychiatry
Saint Louis University School of Medicine
Ocular Myasthenia Gravis
• >90% patients w/MG have eye finding
• Ptosis (droopy lid)
• Diplopia (double vision)
• 50% patients’ initial presentation of
MG
– Most convert to generalized MG
– Within 2 years
Ocular Myasthenia Gravis
• Pure ocular disease occurs in 20% MG
– Later age
– Men > women
Generalized Myasthenia
(Grob et al. ‘81)
women
men
140
120
n=868
100
80
60
40
20
0
1st
2nd
3rd
4th
5th
6th
7th
8th
Ocular Myasthenia (Grob et al. ‘81)
women
men
35
30
n=168
25
20
15
10
5
0
1st
2nd
3rd
4th
5th
6th
7th
8th
Ocular Myasthenia Gravis
• 24 yo man complains of droopiness of
left upper lid-variable throughout the
day
Ocular Myasthenia Gravis
• Ptosis
– Isolation
– Company of double vision
– Variable
– Often asymmetric
– Fatigable
– Worsens later in the day
Ocular Myasthenia Gravis
Ocular Myasthenia Gravis
• Patient photos
Ocular Myasthenia Gravis
• Ptosis (droopy eyelid)
– Cogan’s lid twitch
– Patient asked to look up after
looking down
– Eyelid briefly over-elevated and
appears to be waving
Ocular Myasthenia Gravis
• Video ptosis from MG
Myasthenia Gravis
• Double vision
– Variable
– May involve:
• One eye muscle
• Multiple eye muscles
• All eye muscles
Ocular Myasthenia Gravis
• Patient photos
Ocular Myasthenia Gravis
• Diagnosis
– Sleep test
– Ice test
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Ocular Myasthenia Gravis
• Before ice test
• After ice test
Ocular Myasthenia Gravis
• Weakness of eyelid muscles
– Nearly always present
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Ocular Myasthenia Gravis
• Diagnosis: anti-acetylcholine receptor
Ab
– Present in 80-90% generalized MG
– Present in 50% ocular MG
– Level has no correlation with disease
activity
Ocular Myasthenia Gravis
• Thyroid function tests
• 20% MG patients has concurrent
thyroid disease
• Anti-nuclear antibody
• Erythrocyte sedimentation rate
Ocular Myasthenia Gravis
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Tensilon test
Test dose
Bolus
Response within 30 sec
Duration 2-5 minutes
Look for change
Ocular Myasthenia Gravis
• Patient photos
Ocular Myasthenia Gravis
• Repetitive stimulation test
– Positive 20-30% ocular MG
• Single fiber EMG
– Eyelid muscles or forehead
– 85-100% sensitivity
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Ocular Myasthenia Gravis
• Chest CT
– Thymomas present in 15% all MG
patients
– Considered rare-uncommon in ocular
MG
– Presence warrants surgery
Myasthenia Gravis
• CT chest
• Thymoma 10-15% of MG
– (of thymomas, 50% have MG)
– >age 30, males
• Thymus hyperplasia 60-80%
– younger age, females
• Anti-Ach Rec Ab +95-100% of the time
w/thymoma
Ocular Myasthenia Gravis
• No randomized clinical trials for pure
ocular MG
• Treatment based on clinical
experience, retrospective trials
Ocular Myasthenia Gravis
• Treatment
– Withdraw medications that might
exacerbate MG
– Long list: cardiac drugs, antibiotics,
anti-epileptics, psychiatric drugs
– Most common: aminoglycosides
and beta-blockers
Ocular Myasthenia Gravis
• Pyridostigmine (Mestinon)
– Less effective in pure ocular MG
– 50% patients respond
– Ptosis responds better than diplopia
– Side effects: gastrointestinal
– Contraindications: bradycardia, reactive
airway disease, BPH
Ocular Myasthenia Gravis
• Corticosteroids
– Start low (5-10mg) and increase slowly
until symptoms improve
– Maintain resolution
– Slow taper
– Recurrence common despite slow taper
– Improvement of ptosis & diplopia 7296% patients
Ocular Myasthenia Gravis
• Corticosteroids
• Side effects
– Mood swings
– Sleep disorders
– Hyperglycemia
– Weight gain
-Cataract
-GERD
-Osteoporosis
-Hypertension
Ocular Myasthenia Gravis
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Azathioprine
Mycophenolate mofetil
Cyclosporine A
Tacrolimus
Cyclophosphamide
Rituximab
Etanercept
Myasthenia Gravis
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Plasmapharesis (respiratory failure)
Human Immunoglobulin
Thymectomy
Referral to Neurologist
Ocular Myasthenia Gravis
• Patient photos
Myasthenia Gravis:
Thymectomy
• Data for generalized MG helpful early in
disease
• Promotes long term clinical improvement
under the age of 50
• Unclear role with pure ocular MG
• Always indicated with the presence of
thymoma
– 50% chance of malignancy
• Patient photos
Ocular Myasthenia Gravis
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Conclusions
>90% patients w/MG have eye finding
Ptosis and diplopia
50% patients’ initial presentation of
MG
– Most convert to generalized MG
Ocular Myasthenia Gravis
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Conclusions
20% MG is purely ocular
Diagnosis often more challenging
Treatment usually requires 2 or more
drugs