Long-term outcomes of pediatric ocular myasthenia gravis

Abstract

Purpose: To review the presenting signs, therapeutic interventions, and clinical outcomes of purely ocular myasthenia gravis in a preadolescent population treated primarily with pyridostigmine bromide.

Design: Retrospective case series.

Participants: Twenty-one consecutive patients younger than 12 years with purely ocular myasthenia gravis at initial presentation.

Methods: The clinical charts were reviewed retrospectively.

Main outcome measures: Time to generalization, stabilization, or resolution; prism cover test results; and visual acuity.

Results: Median age at onset was 26 months. The mean duration of follow-up was 6.5 years (range, 2-15). Presenting signs included ptosis (95%), strabismus (76%), limitation of ductions (17%), and Cogan's lid twitch (76%). The most common form of strabismus was exotropia. Pyridostigmine monotherapy was the initial treatment for all patients. Corticosteroids were added to the therapy for 6 patients. Generalization to systemic disease occurred in 3 patients. Two of those required intravenous immunoglobulin and thymectomy. Complete resolution off of medical therapy occurred in 4 patients. All patients had stabilization of the ocular motor deficits regardless of treatment. Eleven patients were treated for amblyopia; 2 had residual amblyopia.

Conclusions: Ocular myasthenia in preadolescent children generally presents before age 5 and is clinically distinguished from the disease as it affects adults. Although the presenting signs of strabismus, ptosis, and Cogan's lid twitch are common in children or adults, the response to treatment and eventual outcomes differ. Most children can be safely treated with pyridostigmine alone. Generalization to systemic disease occurs at a much lower rate than in adults. Ocular manifestations stabilize in all children and completely resolve in some.