Objective:
To determine if moderate- or low-dose corticosteroid therapy can reduce the diplopia and frequency of deterioration to generalized disease in ocular myasthenia gravis.
Design:
Retrospective record review.
Setting:
Two university-based neuro-ophthalmology services.
Patients:
All 32 patients with ocular myasthenia gravis, treated with prednisone, followed up for a minimum of 2 years were included. Patients were treated with 1 or more courses of daily prednisone (highest initial dose, 40-80 mg) gradually withdrawn over 4 to 6 weeks. Subsequently, in 6 patients, 2.5 to 20 mg of prednisone was given on alternate day.
Outcome Measures:
Diplopia in the primary position or downgaze diplopia and generalized myasthenia gravis after 2 years of follow-up.
Results:
Diplopia, which was initially found in the primary position in 29 patients and in the downgaze position in 26 patients, was absent in 21 patients at 2 years. Generalized myasthenia gravis occurred in 3 patients at 2 years. Elevated serum acetylcholine receptor antibody levels and abnormal electromyography findings were not predictive of worsening. No patient experienced a major steroid complication.
Conclusions:
Moderate-dose daily prednisone for 4 to 6 weeks, followed by low-dose alternate-day therapy as needed, can control the diplopia in patients with ocular myasthenia gravis. The frequency of deterioration to generalized myasthenia gravis at 2 years may be reduced; 9.4% in this study compared with more than 40% previously reported frequency. Corticosteroids may be useful even when ocular motor dysfunction is not normalized.