Strabismus after Deep Lateral Wall Orbital
Decompression in Thyroid-Related
Orbitopathy Patients Using
Automated Hess Screen
Guy J. Ben Simon, MD, Ahmad M. Syed, MD, Seongmu Lee, BS, Debbie Y. Wang, BS,
Robert M. Schwarcz, MD, John D. McCann, MD, PhD, Robert A. Goldberg, MD
strabismus in thyroid-related orbitopathy (TRO) patients using automated Hess screen (AHS).
Prospective nonrandomized clinical study.
Eleven TRO patients (19 surgeries) operated on at the Jules Stein Eye Institute from January,
2004, through December, 2004.
Automated Hess screen testing was performed in all patients before surgery and 3 months after
surgery; all patients received surgery in the nonactive phase of the disease.
Main Outcome Measures:
Amplitude of horizontal and vertical deviations (prism diopters) in all standard
positions of gaze.
Eleven TRO patients (7 females; mean age, 47 years) were included in the study; 8 patients
underwent bilateral surgery. After surgery, exophthalmos decreased an average (?standard deviation) of 2.7 mm
(?2.5 mm; P ? 0.003). Before surgery, 7 patients (63%) reported primary gaze diplopia, whereas only 2 patients
(18%) showed diplopia in primary gaze after surgery (P ? 0.03, chi-square analysis). Orbital decompression had
no statistically significant effect on horizontal and vertical ocular deviations measured by AHS. Mean amplitude
of deviation in primary gaze was 1.2 prism diopters (PD) esotropia and 0.07 PD hypotropia before surgery, and
2.5 PD exotropia with 0.6 PD hypertropia after surgery (? ? 3.7 PD for horizontal deviation and ?0.7 for vertical
deviation; P ? 0.051, paired samples t test for horizontal difference and P not significant for vertical difference).
Nonsignificant P values were obtained in all 9 positions of gaze. Most patients had periocular numbness that
resolved spontaneously 2 to 6 months after surgery.
Deep lateral wall orbital decompression with intraconal fat debulking had no statistically
significant effect on horizontal and vertical deviations measured by the AHS. Patients may demonstrate small
angle exotropia shift, but this finding was not clinically significant. Ophthalmology 2006;113:1050–1055 © 2006
by the American Academy of Ophthalmology.
To evaluate the effect of deep lateral wall orbital decompression with intraconal fat debulking on
Orbital decompression is an important cornerstone in the
surgical rehabilitation of thyroid-related orbitopathy (TRO)
patients. It is performed to treat disfiguring proptosis,1along
with corneal exposure and optic neuropathy.2,3
Several surgical options are considered in orbital decom-
pressions, including removing the medial, inferior, or deep
lateral orbital wall, with or without intraconal fat debulk-
ing.4–8Surgery is tailored to each patient, and often patients
with more severe proptosis will require additional and ex-
tensive tissue removal, with removal of bone, intraconal
fat, or both. Surgery is performed only during the non-
active phase of the disease, initially with orbital decom-
pression, followed by eye muscle surgery and some type
of eyelid retraction procedures with or without upper eyelid
One of the more common complications associated with
orbital decompression is development or worsening of dip-
lopia, with primary or downgaze diplopia being most cum-
bersome.8,11–14Medial wall and floor decompression surger-
ies are associated with up to 30% of new-onset strabismus,4
whereas deep lateral wall decompression may be associated
with a much lower rate of new-onset diplopia (2%–
15%).6,15–17Recently, we published results that showed a
new-onset primary gaze diplopia rate of only 2.6% in pa-
tients with mild to moderate TRO undergoing deep lateral
wall decompression with intraconal fat debulking.15
To understand the biomechanics of this surgical tech-
nique and to analyze its influence on ocular deviations, we
Originally received: July 5, 2005.
Accepted: February 13, 2006.
From the Jules Stein Eye Institute and Department of Ophthalmology,
David Geffen School of Medicine at the University of California Los
Angeles, Los Angeles, California.
Correspondence to Guy J. Ben Simon, MD, Goldschleger Eye Institute,
Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel 52621. E-mail:
Manuscript no. 2005-600.
© 2006 by the American Academy of Ophthalmology
Published by Elsevier Inc.
ISSN 0161-6420/06/$–see front matter
surgery associated with Graves’ orbitopathy. Am J Ophthalmol
12. Goldberg RA, Perry JD, Hortaleza V, Tong JT. Strabismus
after balanced medial plus lateral wall versus lateral wall only
orbital decompression for dysthyroid orbitopathy. Ophthal
Plast Reconstr Surg 2000;16:271–7.
13. Graham SM, Brown CL, Carter KD, et al. Medial and lateral
orbital wall surgery for balanced decompression in thyroid eye
disease. Laryngoscope 2003;113:1206–9.
14. Grenzebach UH, Schnorbus U, Buchner T, et al. Development
of ocular motility following modified 3-wall decompression of
the orbita in endocrine orbitopathy for functional and rehabil-
itative indication [in German]. Klin Monatsbl Augenheilkd
15. Ben Simon GJ, Wang L, McCann JD, Goldberg RA. Primary-
gaze diplopia in patients with thyroid-related orbitopathy un-
dergoing deep lateral orbital decompression with intraconal fat
debulking: a retrospective analysis of treatment outcome. Thy-
16. Unal M, Ileri F, Konuk O, Hasanreisoglu B. Balanced or-
bital decompression combined with fat removal in Graves
ophthalmopathy: do we really need to remove the third wall?
Ophthal Plast Reconstr Surg 2003;19:112–8.
17. Shepard KG, Levin PS, Terris DJ. Balanced orbital decom-
pression for Graves’ ophthalmopathy. Laryngoscope 1998;
18. Thomson W, Desai N, Russell-Eggitt I. A new system for the
measurement of ocular motility using a personal computer.
Ophthalmic Physiol Opt 1990;10:137–43.
19. Abramoff MD, Kalmann R, de Graaf ME, et al. Rectus ex-
traocular muscle paths and decompression surgery for Graves
orbitopathy: mechanism of motility disturbances. Invest Oph-
thalmol Vis Sci 2002;43:300–7.
20. Bailey K, Tower RN, Dailey RA. Customized, single-incision,
three-wall orbital decompression. Ophthal Plast Reconstr Surg
21. Russo V, Querques G, Primavera V, Delle Noci N. Incidence
and treatment of diplopia after three-wall orbital decompres-
sion in Graves’ ophthalmopathy. J Pediatr Ophthalmol Stra-
22. Michel O, Oberlander N, Neugebauer P, et al. Follow-up of
transnasal orbital decompression in severe Graves’ ophthal-
mopathy. Ophthalmology 2001;108:400–4.
Ben Simon et al ? Strabismus after Deep Lateral Wall Orbital Decompression