Associated immune disorders to be considered in children include rheumatoid arthritis, juvenile-onset diabetes mellitus, asthma, and thyroid disease; neoplasia (breast cancer, uterine cancer, carcinoma of the colon, pinealoma) is also seen.408 Thymoma rarely occurs in children although it is recognized to accompany 10% of myasthenia gravis.
Inheritance is usually sporadic. Approximately 1% to 4% of cases are familial without a clear Mendelian pattern. This familial predisposition may be due to predilection for autoimmunity in general.
Once the ophthalmologist diagnoses or strongly suspects myas-thenia, a neurologist generally directs further testing and treatment. The ophthalmologist's role remains important, however. In addition to monitoring the motility and lid dysfunction and providing symptomatic relief for these disorders, the ophthalmologist should be alert to the possibility of amblyopia. If not promptly detected and attended to, amblyopia can be extremely difficult to treat, particularly when there is sufficient ptosis to necessitate taping or a ptosis crutch for the lid during occlusion of the sound eye.
Current therapy aims to increase the amount of acetyl-choline available through the use of anticholinesterase agents or to diminish the autoimmune reaction with corticosteroids, other immunosuppressive agents, such as azathioprine, cyclosporin A, and mycophenolate mofetil,93,150 plasmapheresis, or thymectomy. Supervision of these treatments is clearly in the bailiwick of the neurologist. It is worth noting that anti-cholinesterase agents are not as effective in ameliorating ocular motility as they are for other manifestations of myasthenia149 nor are they as effective as steroids462 or other treatments directed against the autoimmune response.431 However, because of the risks and complications, the use of steroids, immuno-suppressives, plasmapheresis, and thymectomy in pure ocular myasthenia gravis remains controversial.68,365,441 In a recent pilot study, cyclosporin A was found to be effective in a series of eight patients, resulting in complete remission in seven of the eight, with a mean follow-up of 14 months; the eighth patient was noncompliant.80
Strabismus surgery has been performed on patients with stable deviations of at least 5 months, using conventional strabismus surgical techniques.115,360 The presence of systemic disease is an important consideration in deciding on the method of anesthesia, although general anesthesia is not an absolute contraindication when the disease is clinically controlled.
Was this article helpful?