N. Sommer et al., OCULAR MYASTHENIA-GRAVIS - RESPONSE TO LONG-TERM IMMUNOSUPPRESSIVE TREATMENT, Journal of Neurology, Neurosurgery and Psychiatry, 62(2), 1997, pp. 156-162
Objective-Ocular myasthenia gravis is a subtype of myasthenia gravis t
hat causes relatively mild disability, but may convert into severe gen
eralised muscle weakness. A universal management plan for ocular myast
henia gravis has not been established. This study was performed to det
ermine the outcome of ocular myasthenia gravis with the currently avai
lable therapeutic options. Methods-Retrospective analysis of 78 patien
ts with ocular myasthenia gravis with a mean disease duration of 8.3 (
range 0.5-58.3) years. Results-In 54 patients (69%) symptoms and signs
remained confined to the extraocular muscles during the observation p
eriod. The remaining 24 patients (31%) developed symptoms of generalis
ed myasthenia gravis; 50% of them within two years, 75% within four ye
ars after onset. A somewhat reduced risk of generalisation was found i
n those with mild symptoms, normal repetitive nerve stimulation test,
and low or absent antiacetylcholine receptor (AChR) antibodies at the
time of diagnosis. Patients receiving immunosuppressive treatment (cor
ticosteroids and/or azathioprine) rarely developed generalised myasthe
nia gravis (six of 50, 12%). Those without such treatment, usually due
to uncertain diagnosis and late referral, converted into generalised
myasthenia gravis significantly more often (18 of 28, 64%). Conclusion
s-The prognosis of ocular myasthenia gravis is good. A conventional sc
heme with short term corticosteroids and long term azathioprine seems
adequate to achieve remission in most patients. The proportion of pati
ents developing generalised myasthenia gravis was smaller in this popu
lation compared with previously published groups (usually 50%-70%). Ea
rly immunosuppressive treatment is at least partially responsible for
this finding. Thymectomy (performed here in 12 patients with an abnorm
al chest CT) also correlated with a good outcome, but had no apparent
advantage over medical treatment alone.