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Case Report
A Diagnostic Tool Used as Therapeutic Weapon in
the Management of Congenital Brown’s Syndrome
Dr. Parag K Shah, Dr. V Narendran, Dr. S. Kalpana, Aravind Eye Hospital, Coimbatore
Introduction
An eleven year old female child presented with
complaint of diplopia in up gaze since one
month. She noticed it suddenly after sleep in
the morning. Past history was not suggestive of
similar complaints, pain, inflammation, trauma
or fever. On examination her anterior segment
and posterior segment were normal. Visual
acquity was 6/6 in both eyes, Stereopsis was 60
degrees with TNO test (Baliwalla & Homi PVT,
Ltd., Mumbai). Ocular examination revealed no
deviation in primary gaze, on adduction right was
hypotropic, diminished elevation in right eye more
in adduction than abduction, upgaze revealed “V”
pattern deviation (Fig-1).
Computerized tomogram scan of brain and
orbits (coronal sections,1mm slices) suggestive
of normal study with no demonstrable lesion in
right trochlear region. The patient was diagnosed
as with moderate congenital Brown’s syndrome²
in right eye. The patient was given a dose of
oral steroids with tapering dose. Patient on first
follow up after one year had same symptoms with
no relief since then. Ocular examination, hess
and diplopia charting revealed same findings as
before suggestive of moderate congenital Brown’s
syndrome. Guyton’s exaggerated traction test¹
revealed restriction for superior oblique tendon.
Technique
Guyton’s exaggerated traction test performed with
one hand, securely grasp episclera nasally with 0.5
mm toothed forceps to feel the muscle tightness.
The eye is fully retroplaced and rotated nasally. To
test the superior oblique muscle the globe is rotated
superonasally, a bump (as it were a guitar string) is
felt as the globe is rotated superotemporally over
the taut superior oblique tendon.
In our case Guyton’s exaggerated traction
test performed under local anaesthesia showed
tightness on the initial stroke, as it was repeated for
confirmation, the tightness slowly gave away and
Fig: 1
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no further tightness was felt on repeated testing.
Similar testing was done on the fellow eye for
comparison and was found normal.
Hess and diplopia charts plotted after Guyton’s
exaggerated traction test were suggestive of full
range normal ocular movements in all gazes and
patient became free of diplopia (Fig-2). Patient
was asked for 6 months review without any
medication. On second follow up after 6 months
ocular motility was normal and patient was
asymptomatic.
Discussion
Aetiology of congenital Brown’s syndrome remains
obscure. Although initially described as a sheath
syndrome, the finding that stripping tendon failed
to alleviate the restriction prompted a search for an
alternative explanation². Historical study of this
area has revealed that the superior oblique tendon
is separated from the trochlea by a fluid filled
bursa³. It has been suggested that distension of this
bursa could restrict the movement of tendon in the
trochlea and that this is the underlying mechanism
in at least some cases of Brown’s syndrome.
Embryological study of the trochlea provides
an alternative explanation4. This work reveals
that fine trabeculae exist between the superior
oblique tendon and the trochlea and that these
can persist into adulthood. It has been postulated
AECS Illumination
that persistence of these fine trabeculae may
be responsible for the restricted ocular motility
observed in congenital Browns’s syndrome. Other
rare causes of congenital Brown’s syndrome include
a thickening in the reflected portion of the superior
oblique tendon5 and anomalous fibrous bands
between the tendon and globe6.
The indications for surgery in Brown’s
syndrome are the presence of hypotropia in
primary position and/or an anomalous head
posture. The aim of surgery is therefore to improve
the field of binocular single vision². Surgical
aggressiveness should be tempered by the fact that
surgery can result in deterioration of binocular
single vision field and fusional status7. Aetiology
of many cases of Brown’s syndrome appears to lie
within trochlea-tendon complex. We felt none
of the existing surgical treatment options were
appropriate in managing our patient who had
no abnormal head posture, was fully binocular in
primary position.
Initially Guyton’s exaggerated traction test
was described as a diagnostic test for confirming
the presence of oblique muscle tightness before
surgery. This is a case of congenital moderate
Brown’s syndrome in which Guyton’s exaggerated
traction test was used as a diagnostic and
therapeutic modality. The test might have broken
the inflammatory adhesions between the trochlear
Fig:2
Vol. XIV, No.3, July - Sep 2014
tendon complex leading to normalisation of
patient’s versions without compromising ocular
alignment in the primary position. Jampolsky
argued in 1995 that there was no uniformly
satisfactory procedure for true Brown’s syndrome7.
There was a report of congenital Brown’s syndrome
in an adult male who got sustained relief with
Guyton’s exaggerated traction test alone 9. As
demonstrated in this case, none of the attendant
risks observed in surgery on the tendon itself was
present in this procedure. We suggest that it is
worth performing Guyton’s exaggerated traction
test in every case of mild to moderate Brown’s
syndrome (congenital or acquired). It may give
sustained relief subjectively and objectively and
improvement in ocular motility.
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The spectacularly successful outcome in
our case highlights the different aetiologies that
produce the spectrum of abnormalities that we
recognise in Brown’s syndrome. Clinical experience
indicates that many patients with deviation
in primary position who undergo surgery for
Brown’s syndrome will not benefit from Guyton’s
exaggerated traction test but require tendon
lengthening procedure. However we propose
that Guyton’s exaggerated traction test could be
beneficial to certain groups of mild to moderate
Brown’s syndrome patients. We believe that at a
minimum, this test should be offered to all patients
with psychologically or functionally symptomatic
congenital or acquired Brown’s syndrome in which
there is mild to moderate restriction.
References
1. Guyton DL. Exaggerated traction test for the oblique muscles. Ophthalmology 1981;88:1035-40.
2. Wilson ME, Eustice HS, Parks MM.Brown’s syndrome.Major review. Surv Ophthlmol 1989;34:153-72.
3. Helveston EM, Merriam WW, Ellis FD, Shellhamer RH,Gosling CG. The trochlea. A study of the
anatomy and physiology. Ophthalmology 1982;89:124-32.
4. Sevel D. Brown’s syndrome, a possible aetiology explained embryologically. J Pediatr Ophthalmol
Strabismus 1981;18:26-31.
5. Mafee MF, Folk ER, Langer BG, Miller MT, Lagouros P, Mittleman D, Computer tomography in the
evaluation of Brown syndrome of the superior oblique tendon. Radiology 1985;154:691-5.
6. Raab EL, Superior oblique tendon sheath syndrome: An unusual case. Ann Ophthalmol 1976;8:345-7.
7. Jampolsky A, Discusion of: Wlson ME, Sinatra RB, Saunders RA. Downgaze restriction after placement
of superior oblique tendon spacer for Brown’s syndrome. J Pediatr Ophthalmol Strabismus 199;32:29-36.
8. Sato M, Magnetic resonance imaging and tendon anomaly associated with congenital superior oblique
palsy. Am J Ophthalmol 1999;127:379-87
9. Squirrell D. Congenital Brown’s syndrome treated with Exaggerated traction testing alone. J AAPOS
2005;9: 398-99.