Visual and Systemic Outcomes in Pediatric Ocular
Myasthenia Gravis
STACY L. PINELES, ROBERT A. AVERY, HEATHER E. MOSS, RICHARD FINKEL, THANE BLINMAN,
LARRY KAISER, AND GRANT T. LIU
●
PURPOSE: To evaluate visual and systemic outcomes in
pediatric patients with purely ocular myasthenia gravis
(OMG) treated at the Children’s Hospital of Philadel-
phia.
●
DESIGN: Retrospective chart review.
●
METHODS: Pediatric patients with OMG seen at a single
institution over a 16-year period with a minimum follow-up
of 1 year were reviewed. Associations of demographic and
clinical characteristics with disease resolution, amblyopia,
and development of generalized symptoms of myasthenia
gravis were analyzed.
●
RESULTS: Thirty-nine patients were identified, with a
mean age of 5.4 4.8 years and mean follow-up of 4.8
4.3 years. Fifteen patients were treated with pyridostigmine
only, 19 (49%) also received steroids, and 15 (38%)
underwent thymectomy. Four patients (10%) received ste-
roid-sparing immunosuppressive therapy. Resolution oc-
curred in 10 patients, and generalized symptoms eventually
occurred in 9 patients. Although 10 patients were treated
for amblyopia, only 1 had amblyopia at the final visit. There
was no correlation between sex or age with amblyopia or
development of generalized symptoms. Thymectomy, when
performed before the onset of generalized symptoms,
showed a trend toward protection from the development of
generalized symptoms (P .07).
●
CONCLUSIONS: In our series, 24% of patients had
disease resolution and 23% had generalized symptoms.
Our larger cohort confirms previous findings that treated
and untreated pediatric patients with OMG have a
relatively low risk of developing generalized symptoms
and that related amblyopia is readily reversible. Although
our treatments were more aggressive than those previ-
ously reported, our rates of amblyopia and development
of generalized symptoms are comparable. (Am J Oph-
thalmol 2010;150:453– 459. © 2010 by Elsevier Inc.
All rights reserved.)
M
YASTHENIA GRAVIS IS AN ACQUIRED AUTOIM-
mune disorder in which acetylcholine receptors
(AChRs) within the neuromuscular junction of
skeletal muscle are targeted by autoantibodies. This results
in disrupted neuromuscular transmission and symptoms of
fluctuating and fatigable weakness.
1
Myasthenia gravis is
relatively uncommon in the pediatric population, with chil-
dren accounting for approximately 10% to 15% of cases
annually.
2
Approximately 90% of children with myasthenia
gravis will have ophthalmic features, such as ptosis or
ophthalmoplegia, in isolation, or in association with other
systemic weakness.
1
In 10% to 15% of children, weakness
is strictly limited to the extraocular muscles, resulting in a
diagnosis of ocular myasthenia gravis (OMG).
1
One group
has suggested that in 50% of pediatric patients with OMG,
systemic or bulbar symptoms will develop within 2 years.
3
Data regarding the treatment and prognosis of children
with OMG at initial presentation is limited. There are a
few case series, of fewer than 25 patients, that specifically
describe the characteristics and outcomes of relatively
small cohorts of pediatric patients with OMG.
3–6
Because
we have seen a relatively larger number of children with
OMG at the Children’s Hospital of Philadelphia and many
of our patients have undergone more aggressive treatment
regimens than those published by previous groups, we
sought to compare our outcomes with those previously
reported. Finally, we set out to evaluate risk factors for the
development of undesirable outcomes, such as amblyopia
and development of generalized symptoms.
METHODS
RECORDS WERE REVIEWED FOR ALL PATIENTS 1 TO 18 YEARS
of age with at least 1 year of follow-up and a diagnosis of
OMG who were seen by one of the coauthors (G.T.L.)
from July 1993 through September 2009 at the Children’s
Hospital of Philadelphia. Pediatric OMG is also often
referred to as juvenile OMG to differentiate it from
congenital myasthenic syndromes and neonatal myasthe-
nia. To meet inclusion into the study, patients had to
Supplemental Material available at AJO.com.
Accepted for publication May 5, 2010.
From the Neuro-ophthalmology Service, Children’s Hospital of Phil-
adelphia, and the Division of Neuro-ophthalmology, Departments of
Neurology and Ophthalmology, University of Pennsylvania School of
Medicine, Philadelphia, Pennsylvania (S.L.P., R.A.A., H.E.M., G.T.L.);
Division of Neurology, Children’s Hospital of Philadelphia, and Depart-
ments of Neurology and Pediatrics, University of Pennsylvania School of
Medicine, Philadelphia, Pennsylvania (R.F.); the Department of Surgery,
Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania (T.B.);
and the Department of Surgery, University of Pennsylvania School of
Medicine, Philadelphia, Pennsylvania (L.K.). Dr Kaiser’s current affilia-
tion is the University of Texas Health Science Center at Houston, and
the Department of Cardiothoracic and Vascular Surgery, University of
Texas Medical School at Houston, Houston, Texas.
Inquiries to Grant T. Liu, Division of Neuro-Ophthalmology, Hospital
of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA
19104; e-mail: gliu@mail.med.upenn.edu
© 2010 BY ELSEVIER INC.ALL RIGHTS RESERVED. 0002-9394/$36.00 453
doi:10.1016/j.ajo.2010.05.002