- Email: [email protected]
Lateral rectus muscle resection following maximal recession of the medial rectus muscle in thyroid eye disease
Accepted Manuscript Lateral rectus muscle resection following maximal recession of the medial rectus muscle in thyroid eye disease Eric Weldy, BS, Natalie C. Kerr, MD PII:
S1091-8531(16)30561-4
DOI:
10.1016/j.jaapos.2017.05.027
Reference:
YMPA 2647
To appear in:
Journal of AAPOS
Received Date: 26 October 2016 Revised Date:
9 April 2017
Accepted Date: 10 May 2017
Please cite this article as: Weldy E, Kerr NC, Lateral rectus muscle resection following maximal recession of the medial rectus muscle in thyroid eye disease, Journal of AAPOS (2017), doi: 10.1016/ j.jaapos.2017.05.027. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT
Lateral rectus muscle resection following maximal recession of the medial rectus muscle in thyroid eye disease Eric Weldy, BS, and Natalie C. Kerr, MD
RI PT
Author affiliations: University of Tennessee Hamilton Eye Institute, Memphis Submitted October 25, 2016. Revision accepted May 8, 2017.
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Correspondence: Natalie Kerr, MD, 930 Madison Ave #200, Memphis, TN 38103 (email: [email protected]).
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Word count: 2,293 Abstract only: 214
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Abstract Background Rectus muscle restriction is a common finding in thyroid eye disease (TED). Typically, restricted
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muscles are recessed to address strabismus and diplopia. However, some patients have residual strabismus following maximal recession of a restricted muscle. The purpose of this study was to
medial rectus muscle in patients with TED. Methods
SC
report outcomes following resection of the lateral rectus muscle after maximal recession of the
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The medical records of patients with TED who underwent lateral rectus resection between 1998 and 2015 were reviewed retrospectively. Information regarding thyroid disease history and surgical treatment, including history of orbital decompressions, rectus muscle recessions, rectus muscle resections, and pre- and postoperative alignment was collected. Adjustable suture was
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used in all cases. Success was defined as a postoperative orthotropia with ≤2∆ of phoria at distance and a phoria at near. Results
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A total of 11 patients were included. Of these, 10 (91%) required postoperative adjustment. A successful outcome was achieved in 10 cases (91%).
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Conclusions
Lateral rectus muscle resection to address residual esotropia and diplopia was effective at reducing residual esotropia following medial rectus recession in our study cohort.
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Strabismus occurs in 15% of all patients with thyroid eye disease (TED).1 The most common cause is extraocular muscle restriction resulting from inflammation and scarring, which produces inelastic, fibrotic muscles.2 Typically, strabismus secondary to restricted muscles is surgically
RI PT
treated with recessions of the restricted muscles, which has been shown to safely restore
binocular single vision in 76%-82% of diplopic TED patients.3-4 Resection is often avoided out of concern for further limiting eye movements.5
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Medial rectus recession is commonly used to address esotropia secondary to restricted medial rectus muscles in TED; however, following maximal or supramaximal medial rectus
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recessions, some patients have residual esotropia. Further recession of the medial rectus muscles may result in exodeviations at near, which create asthenopia and reading difficulties. After maximal medial recession, lateral rectus muscle resection may be a viable surgical option.6-9 The purpose of this case series was to report outcomes of lateral rectus muscle resection following
of TED. Subjects and Methods
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maximal recession of the medial rectus to alleviate residual strabismus and diplopia in the setting
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This study was approved by the University of Tennessee Institutional Review Board and complied with the US Health Information Portability and Accountability Act of 1996. Surgical
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logs were reviewed to identify patients undergoing lateral rectus resection in the setting of TED: cases from 1998 to 2003 were identified from a comprehensive database of all TED patients surgically treated by the senior author (NCK); cases from 2004 to 2015, by review of surgical logs. Inclusion criteria, in addition to a diagnosis of TED and lateral rectus resection, were as follows: all patients had to have undergone a full orthoptic and ophthalmic examination; had to be in the fibrotic phase of their disease process, as indicated by a euthyroid state, lack of
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orbital/anterior ocular inflammation, and stable ocular motility measurements; and all orbital surgery or treatment for hyperthyroidism had to have been concluded more than 6 months prior to any muscle surgery.
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The following data was collected from the medical record: thyroid disease history,
including duration of TED and diplopia; systemic thyroid disease treatment (ie, radioactive
iodine, corticosteroids, medications); history of orbital decompression; and smoking history.
SC
Preoperative data recorded for this study included date of birth, history of previous strabismus surgeries, and preoperative measurement of ocular deviation. Deviations were measured using
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the prism and alternate cover test in primary position at distance with best refractive correction to determine the primary deviation. The following surgical data was collected: muscle and amount recessed, use of adjustable suture, and postoperative ocular alignment following recession. All patients had undergone recession (and, in some cases, re-recession for residual
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strabismus) until maximal recession was achieved. Maximal recession was considered to be 6–7 mm of medial rectus recession. Any recession >7 mm was considered supramaximal. Surgical data regarding resection included the muscle and amount resected, the use of adjustable suture,
EP
and postoperative alignment measurements at day 1 and at 2 months’ follow-up. All patients had a limbal peritomy and muscle resection following placement of the muscle on a resection clamp
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near the insertion and amount of resection measured from the cut end of the muscle. An adjustable suture technique was utilized. The muscle was attached using a hang-back technique and a noose was fashioned out of polyglactin 910 suture. The senior author (NCK) used a nomogram of 1∆-2∆ of correction per millimeter of lateral rectus resection to create the surgical plan. Surgical success was defined as orthotropia with ≤2∆ of horizontal phoria at distance and
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a fusible horizontal deviation or phoria at near at 2 months’ follow-up. Other studies have used ≤8∆ tropia as the definition for surgical success.9-11 We chose strict motor criteria for success, because divergence amplitudes at distance are usually small and more than a few prism diopters
RI PT
of undercorrection would likely result in diplopia and/or the need for prism glasses. We did not use sensory criteria for judging the success of the surgery because some patients had known preexisting vertical deviations that precluded fusion postoperatively and had to be addressed with
SC
further vertical muscle surgery. The motor criteria we utilized for defining a successful outcome allows us to assess the efficacy of the lateral rectus resection for alleviating residual esotropia,
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and although the final goal for our patients is fusion and freedom from diplopia, alleviating esotropia is an important step toward achieving the sensory goals for these complex cases. Results
A total of 11 cases (5 males) met inclusion criteria. Lateral rectus muscle resection was
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performed in 14 muscles. The mean patient age, with standard deviation, at resection was 59.4 ± 11.8 years (range, 49-81 years). Of the 11 patients, 8 were white; 3 were African American. The median duration of Grave’s disease at resection was 4 years (range, 1-35 years). TED
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preceded diplopia in all cases, with a median duration of diplopia of 3 years (range, 1-17 years). Nine patients (82%) had a history of radioactive iodine therapy, and 4 patients (36%) had a
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history of prednisone use. Six patients (55%) had a history of smoking. All 11 patients had a history of orbital decompression, and all 11 had diplopia before orbital decompression. On initial examination, 1 patient (patient 2) had a history of prior strabismus surgery from another ophthalmologist before presenting for treatment at our institution. Using a standard 4-point scale, we considered a muscle restricted with an ocular duction of −2 to −4 in the opposite direction of gaze. On average, 3.4 ± 0.8 muscles were restricted at
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initial presentation prior to any surgery by the author. All patients had restriction of at least one muscle. All patients subsequently underwent recession of the restricted muscle creating the strabismus in primary gaze.
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Residual esotropia was treated with further recession until maximal medial rectus
recession was achieved. Average medial rectus recession prior to lateral rectus resection was 6.8 mm (range, 6.5–8 mm). The average horizontal deviation following medial rectus recession was
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17.8∆ of esotropia (range, 8∆-30∆).
Operative data on the 11 patients is summarized in Table 1. Of the 11 patients undergoing
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lateral rectus muscle resection, 3 surgical encounters were bilateral lateral rectus resections with one muscle on an adjustable suture, and 8 were unilateral lateral rectus resections on adjustable suture. Unilateral lateral rectus resections were performed on patients with a deviation ≤20∆-25∆. The total resection was calculated as the amount of resected muscle minus the amount of hang
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back (recession) left to facilitate postoperative adjustment. We were not able to determine the amount of adjustment that occurred for the 10 muscles that were adjusted postoperatively. Overall, 10 patients (91%) were successfully aligned following lateral rectus resection at
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the 2-month postoperative follow-up (mean alignment at distance, 1.1∆; range, 0∆-8∆). There were no postoperative complications.
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Discussion
Conventionally, resection is avoided in TED out of concern for further limiting ocular motility by increasing extraocular muscle tightness.5 Review of the literature confirmed that this surgical approach is not common.6-9
In a study of surgical treatment of 38 patients with Grave’s ophthalmopathy, Mourits and colleagues6 simultaneously performed lateral rectus muscle resection and extraocular muscle
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recession in 3 patients with restricted muscles: 2 of the patients had an optimal response, and none of the patients were overcorrected. Yan and colleagues7 reported combined rectus muscle recession and ipsilateral antagonist
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resection in 6 of 27 TED patients with large-angle deviation (>25∆). There were no
overcorrections following resection. The authors suggested considering antagonist muscle
resection in large-angle deviations that may not otherwise be corrected by maximal recession of
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the restricted muscle.
Yoo and colleagues8 reported rectus muscle resection in 8 Graves patients. Following
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resection, 7 patients (88%) were orthotropic in primary position. There was no increased restriction or overcorrection following resection. Although all 8 patients had TED, 3 did not have muscle restriction on ocular duction testing, with 2 having history of strabismus prior to TED onset and 1 having developed esotropia secondary to abducens nerve palsy following orbital
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decompression. Two different patients received medial rectus resection for exotropia: one developed following medial recession, and another had decompensated intermittent exotropia, given the absence of duction limitations. Similar to our study, 3 patients did receive recessions of
at last follow-up.
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restricted muscles before subsequent resection of the antagonist. All 3 patients were orthotropic
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Kim and colleagues9 performed bilateral lateral rectus resection using nonadjustable
sutures on 9 TED patients with residual esotropia after initial bimedial rectus recession. Unlike the surgical technique used in our study, initial rectus recession involved a modified matched restrictions technique that was “less than maximal” in most cases. Additionally, muscle resection was accomplished using fixed suture. Of the 9 patients, 7 had successful outcome with fusion in primary and reading gaze without prism; 2 remained undercorrected and with unresolved
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diplopia, which the authors attributed to large preoperative horizontal deficits (>60∆). There were no exodeviations following resection. All 11 patients in our study had developed diplopia following onset of TED (ie, no
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preexisting, non-TED-related strabismus, constituting 38% of the patients in Yoo and
colleagues8’). All 11 had received orbital decompression prior to receiving maximal or
supramaximal medial rectus recessions. All maintained residual esotropia following maximal
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recession. To our knowledge, this is the largest collection of muscle resections reported in TED patients who had strabismus from TED and not abducens nerve palsies or preexisting childhood
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strabismus.
Overall, 10 of 11 (91%) surgical encounters achieved successful outcomes. Patient 6 had significant clinical improvement but maintained residual deviation of 8∆ of esotropia with diplopia. At the time of left lateral rectus resection, this patient was a candidate for bilateral
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rectus resection, given a deviation of 25∆ of esotropia. However, because of vertical deviation the patient required concurrent right superior rectus recession; therefore, maximal left lateral rectus muscle resection was performed instead of bilateral lateral rectus resections. The patient had
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undergone bilateral inferior and medial rectus recessions 6 months prior and was felt to be at risk for anterior ischemic syndrome if all 4 rectus muscles on the right eye were operated within 7
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months. To correct the postoperative deviation and diplopia of 8∆ following left lateral rectus resection, the patient later underwent right rectus muscle resection with a successful outcome and no anterior ischemia. Three patients (nos. 2, 7, 11) had persistent diplopia following alleviation of horizontal deviation at distance secondary to residual vertical deviations. All had concomitant surgery for vertical deviation at the time of the lateral rectus resection. Theoretically, the postoperative vertical deviation could have been exacerbated by the resection, although
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examination of our results on a case-by-case basis suggests that the major determinant of the postoperative vertical deviation was the preoperative vertical deviation in the setting of TED. Additionally, the resected lateral rectus muscles were not transposed vertically, further reducing
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the likelihood that the resultant vertical deviation was exacerbated by the resection.
The pathophysiology of TED includes extraocular muscle fibrosis, which alters the
muscle elasticity in a dynamic way, which may limit the application of standard dose–response
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nomograms. Our data confirms a large variation in the dose–response for lateral rectus resections (mean for lateral rectus resection, 2.1∆/mm, range 1.4–3.3∆/mm). One suggested solution to this
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unpredictability in TED is a relaxed muscle positioning technique, where muscles are recessed in a centrally placed eye until they are no longer tight. This nomogram-independent method relies on the degree of restriction to determine amount of recession rather than preoperative deviation, achieving a successful outcome in 88% of cases.12 In our study, we relied on the use of
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adjustable sutures, which have been shown to accommodate the inherent variation of strabismus surgery in TED and achieve “good” or “excellent” outcomes in 73% of recessions in TED.13 All of our surgical encounters used adjustable suture. Ten of 11 (91%) surgical encounters required
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adjustment postoperatively. Despite use of adjustable sutures, postoperative shifts are still to be expected more commonly in TED than in euthyroid patients (23% vs 16%, resp.).14-15
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Our case series is limited by the relatively small sample size and the inability to
determine the final amount of adjustment in the 10 cases adjusted postoperatively. Our analysis is also limited to study of horizontal rectus muscle resection. Using strict criteria, we found that resection achieved successful outcomes in a select
group of TED patients, specifically those with quiescent disease who remain undercorrected following previous maximal medial rectus recession. These findings are in agreement with those
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reported in the literature previously by Yoo and colleauges8 and Kim and colleagues.9 Lateral rectus muscle resection is an effective surgical treatment for correcting residual esotropia following medial rectus recession in TED.
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Literature Search
The authors searched PubMed on April 1, 2017, for English-language results using the following terms: thyroid eye disease, graves ophthalmopathy, strabismus, rectus muscle resection, residual
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esotropia, and adjustable suture.
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References 1.
Skov CM, Mazow ML. Managing strabismus in endocrine eye disease. Can J Ophthalmol 1984;19:269-74. Fells P, Kousouloides L, Pappa A, Munro P, Lawson J. Extraocular muscle problems in
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2.
thyroid eye disease. Eye (Lond) 1994;8:497-505. 3.
Schittkowski M, Fichter N, Guthoff R. Strabismus surgery in Grave’s disease—dose–
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effect relationships and functional results [in German]. Klin Monbl Augenheilkd 2004;221:941-7.
M. Flanders, M. Hastings. Diagnosis and surgical management of strabismus associated
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4.
with thyroid-related orbitopathy. J Pediatr Ophthalmol Strabismus 1997;34:333-40. 5.
Metz HS. Strabismus related to Graves ophthalmopathy. In: Rosenbaum AL, Santiago AP eds: Clinical Strabismus Management. Philadelphia, PA: W.B. Saunder Co;
6.
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1999:285-94.
Ph Mourits M, Koorneef L, van Mourik-Noordenbos AM, et al. Extraocular muscle surgery for Graves’ ophthalmopathy: does prior treatment influence surgical outcome? Br
7.
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J Ophthalmol 1990;74:481-3.
Yan J, Zhang H. The surgical management of strabismus with large angle in patients with
8.
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Graves’ ophthalmopathy. Int Ophthalmol 2008;28:75-82.
Yoo SH, Pineles SL, Goldberg RA, Velez FG. Rectus muscle resection in Graves’ ophthalmopathy. J AAPOS 2013;17:9-15.
9.
Kim EY, Roper-Hall G, Cruz OA. Effectiveness of bilateral lateral rectus resection for
residual esotropia in dysthyroid ophthalmopathy. Am J Ophthalmol 2016;171:84-7. 10.
Cruz OA, Davitt BV. Bilateral inferior rectus muscle recession for correction of
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hypotropia in dysthyroid ophthalmopathy. J AAPOS 1999;3:157-9. 11.
Zhang MS, Hutchinson AK, Drack AV, Cleveland J, Lambert SR. Improved ocular
surgery. Ophthalmology 2012;119:396-402. 12.
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alignment with adjustable sutures in adults undergoing strabismus
Dal Canto AJ, Crowe S, Perry JD, Traboulsi EI. Intraoperative relaxed muscle
positioning technique for strabismus repair in thyroid eye disease. Ophthalmology
13.
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2006;113:2324-30.
Lueder GT, Scott WE, Kutschke PJ, Keech RV. Long-term results of adjustable suture
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surgery for strabismus secondary to thyroid ophthalmopathy. Ophthalmology 1992;99:993-7. 14.
Peragallo JH, Velez FG, Demer JL, Pineles SL. Postoperative drift in patients with thyroid ophthalmopathy undergoing unilateral inferior rectus muscle
Kerr NC. The role of thyroid eye disease and other factors in the overcorrection of hypotropia following unilateral adjustable suture recession of the inferior rectus. Trans
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Am Ophthalmol Soc 2011;109:168-200.
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15.
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recession. Strabismus 2013;21:23-8.
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Table 1. Preoperative, surgical, and postoperative data of patients with thyroid eye disease undergoing lateral rectus muscle resection
5 6 7
8 9
10 11
RMR adj 7 LMR adj 7 LMR adj 7 RMR 7 LMR 7 RMR 9 LMR 6 RMR adj 7 re-LMR adj 3 re-RMR 3 RMR 6.5 LMR adj 6.5 RMR 6.5 LMR adj 6.5 RMR adj 6.5 LMR adj 6.5 LMR adj 6.5 RMR 6.5
RIR adj 10 LIR 10 LIR adj 8 RIR adj 6
LIR adj 7.5 RIR adjd LSR 7 RIR 7 LIR adj 10 LIR adj 10 RIR adj 10 LIR adj 10 RIR 10
8 ET
R adj 4
Yes
35 ET
R adj 12 L 12
Yes
14 ET
R adj 7
Yes
12 ET
L adj 6
25 ET
L adj 12
10 ET
L adj 8
12 ET 15 ET
20 ET 20 ET
Postoperative alignment, PD Distance Near
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RIR adj 10 LIR 8 RSR rs adj 10 LIR adj 10 RIR 10 LIR adj 7
Yes
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4
LIR adj 10
L adj 12a
30 ET
Diplopia Distance
Near
0
0
0
10 XT
0
0
No
No
LSR rs adj 9
0
2E
No
No
Yes
RIR adj 10
1E
0
No
No
Yes
RSR adj 6
8 ET
8 E(T)
Yes
No
Yes
RSR adj 3
0
20 X
Intermittent Intermittent
RIR adj 8
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3
Vertical LIR adj 4
LR Postoperative Concurrent resection, adjustment surgery, mm mm
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2
Horizontal LMR adj 8 RMR 4 RMR 7 LMR adj 7 LMR adj 6.5 RMR adj 6.5
Preoperative alignment at distance, PD
No b
Yes
No c
Yes
c
Yes
LSR adj 8
0
0
No
No
R adj 8
No
LIR adj 10
1E
0
No
No
2X
0
No
No
0
0
Yes
L adj 8 R8 L adj 6 R6
Yes Yes
re LIR 5
c
c
R adj 6
EP
1
Prior muscle surgery
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Patient
c
Yes
c
Adj, adjustable suture; E, esophoria; ET, esotropia; E(T), intermittent esotropia; IR, inferior rectus muscle; L, left; LR, lateral rectus muscle; MR, medial rectus muscle; PD, prism diopter; R, right; Rs, resection; SR, superior rectus muscle; X, exophoria; XT, exotropia. a
Unilateral resection surgery was performed out of need for local anesthesia. ∆ Patient 2 has a fusible angle but could not fuse secondary to a vertical deviation of 12 of left hypotropia. c Diplopia secondary to vertical deviations; patients 7 had intermittent diplopia secondary to vertical deviation. d Amount unknown. b
S1091-8531(16)30561-4
DOI:
10.1016/j.jaapos.2017.05.027
Reference:
YMPA 2647
To appear in:
Journal of AAPOS
Received Date: 26 October 2016 Revised Date:
9 April 2017
Accepted Date: 10 May 2017
Please cite this article as: Weldy E, Kerr NC, Lateral rectus muscle resection following maximal recession of the medial rectus muscle in thyroid eye disease, Journal of AAPOS (2017), doi: 10.1016/ j.jaapos.2017.05.027. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT
Lateral rectus muscle resection following maximal recession of the medial rectus muscle in thyroid eye disease Eric Weldy, BS, and Natalie C. Kerr, MD
RI PT
Author affiliations: University of Tennessee Hamilton Eye Institute, Memphis Submitted October 25, 2016. Revision accepted May 8, 2017.
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Correspondence: Natalie Kerr, MD, 930 Madison Ave #200, Memphis, TN 38103 (email: [email protected]).
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Word count: 2,293 Abstract only: 214
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Abstract Background Rectus muscle restriction is a common finding in thyroid eye disease (TED). Typically, restricted
RI PT
muscles are recessed to address strabismus and diplopia. However, some patients have residual strabismus following maximal recession of a restricted muscle. The purpose of this study was to
medial rectus muscle in patients with TED. Methods
SC
report outcomes following resection of the lateral rectus muscle after maximal recession of the
M AN U
The medical records of patients with TED who underwent lateral rectus resection between 1998 and 2015 were reviewed retrospectively. Information regarding thyroid disease history and surgical treatment, including history of orbital decompressions, rectus muscle recessions, rectus muscle resections, and pre- and postoperative alignment was collected. Adjustable suture was
TE D
used in all cases. Success was defined as a postoperative orthotropia with ≤2∆ of phoria at distance and a phoria at near. Results
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A total of 11 patients were included. Of these, 10 (91%) required postoperative adjustment. A successful outcome was achieved in 10 cases (91%).
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Conclusions
Lateral rectus muscle resection to address residual esotropia and diplopia was effective at reducing residual esotropia following medial rectus recession in our study cohort.
ACCEPTED MANUSCRIPT
Strabismus occurs in 15% of all patients with thyroid eye disease (TED).1 The most common cause is extraocular muscle restriction resulting from inflammation and scarring, which produces inelastic, fibrotic muscles.2 Typically, strabismus secondary to restricted muscles is surgically
RI PT
treated with recessions of the restricted muscles, which has been shown to safely restore
binocular single vision in 76%-82% of diplopic TED patients.3-4 Resection is often avoided out of concern for further limiting eye movements.5
SC
Medial rectus recession is commonly used to address esotropia secondary to restricted medial rectus muscles in TED; however, following maximal or supramaximal medial rectus
M AN U
recessions, some patients have residual esotropia. Further recession of the medial rectus muscles may result in exodeviations at near, which create asthenopia and reading difficulties. After maximal medial recession, lateral rectus muscle resection may be a viable surgical option.6-9 The purpose of this case series was to report outcomes of lateral rectus muscle resection following
of TED. Subjects and Methods
TE D
maximal recession of the medial rectus to alleviate residual strabismus and diplopia in the setting
EP
This study was approved by the University of Tennessee Institutional Review Board and complied with the US Health Information Portability and Accountability Act of 1996. Surgical
AC C
logs were reviewed to identify patients undergoing lateral rectus resection in the setting of TED: cases from 1998 to 2003 were identified from a comprehensive database of all TED patients surgically treated by the senior author (NCK); cases from 2004 to 2015, by review of surgical logs. Inclusion criteria, in addition to a diagnosis of TED and lateral rectus resection, were as follows: all patients had to have undergone a full orthoptic and ophthalmic examination; had to be in the fibrotic phase of their disease process, as indicated by a euthyroid state, lack of
ACCEPTED MANUSCRIPT
orbital/anterior ocular inflammation, and stable ocular motility measurements; and all orbital surgery or treatment for hyperthyroidism had to have been concluded more than 6 months prior to any muscle surgery.
RI PT
The following data was collected from the medical record: thyroid disease history,
including duration of TED and diplopia; systemic thyroid disease treatment (ie, radioactive
iodine, corticosteroids, medications); history of orbital decompression; and smoking history.
SC
Preoperative data recorded for this study included date of birth, history of previous strabismus surgeries, and preoperative measurement of ocular deviation. Deviations were measured using
M AN U
the prism and alternate cover test in primary position at distance with best refractive correction to determine the primary deviation. The following surgical data was collected: muscle and amount recessed, use of adjustable suture, and postoperative ocular alignment following recession. All patients had undergone recession (and, in some cases, re-recession for residual
TE D
strabismus) until maximal recession was achieved. Maximal recession was considered to be 6–7 mm of medial rectus recession. Any recession >7 mm was considered supramaximal. Surgical data regarding resection included the muscle and amount resected, the use of adjustable suture,
EP
and postoperative alignment measurements at day 1 and at 2 months’ follow-up. All patients had a limbal peritomy and muscle resection following placement of the muscle on a resection clamp
AC C
near the insertion and amount of resection measured from the cut end of the muscle. An adjustable suture technique was utilized. The muscle was attached using a hang-back technique and a noose was fashioned out of polyglactin 910 suture. The senior author (NCK) used a nomogram of 1∆-2∆ of correction per millimeter of lateral rectus resection to create the surgical plan. Surgical success was defined as orthotropia with ≤2∆ of horizontal phoria at distance and
ACCEPTED MANUSCRIPT
a fusible horizontal deviation or phoria at near at 2 months’ follow-up. Other studies have used ≤8∆ tropia as the definition for surgical success.9-11 We chose strict motor criteria for success, because divergence amplitudes at distance are usually small and more than a few prism diopters
RI PT
of undercorrection would likely result in diplopia and/or the need for prism glasses. We did not use sensory criteria for judging the success of the surgery because some patients had known preexisting vertical deviations that precluded fusion postoperatively and had to be addressed with
SC
further vertical muscle surgery. The motor criteria we utilized for defining a successful outcome allows us to assess the efficacy of the lateral rectus resection for alleviating residual esotropia,
M AN U
and although the final goal for our patients is fusion and freedom from diplopia, alleviating esotropia is an important step toward achieving the sensory goals for these complex cases. Results
A total of 11 cases (5 males) met inclusion criteria. Lateral rectus muscle resection was
TE D
performed in 14 muscles. The mean patient age, with standard deviation, at resection was 59.4 ± 11.8 years (range, 49-81 years). Of the 11 patients, 8 were white; 3 were African American. The median duration of Grave’s disease at resection was 4 years (range, 1-35 years). TED
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preceded diplopia in all cases, with a median duration of diplopia of 3 years (range, 1-17 years). Nine patients (82%) had a history of radioactive iodine therapy, and 4 patients (36%) had a
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history of prednisone use. Six patients (55%) had a history of smoking. All 11 patients had a history of orbital decompression, and all 11 had diplopia before orbital decompression. On initial examination, 1 patient (patient 2) had a history of prior strabismus surgery from another ophthalmologist before presenting for treatment at our institution. Using a standard 4-point scale, we considered a muscle restricted with an ocular duction of −2 to −4 in the opposite direction of gaze. On average, 3.4 ± 0.8 muscles were restricted at
ACCEPTED MANUSCRIPT
initial presentation prior to any surgery by the author. All patients had restriction of at least one muscle. All patients subsequently underwent recession of the restricted muscle creating the strabismus in primary gaze.
RI PT
Residual esotropia was treated with further recession until maximal medial rectus
recession was achieved. Average medial rectus recession prior to lateral rectus resection was 6.8 mm (range, 6.5–8 mm). The average horizontal deviation following medial rectus recession was
SC
17.8∆ of esotropia (range, 8∆-30∆).
Operative data on the 11 patients is summarized in Table 1. Of the 11 patients undergoing
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lateral rectus muscle resection, 3 surgical encounters were bilateral lateral rectus resections with one muscle on an adjustable suture, and 8 were unilateral lateral rectus resections on adjustable suture. Unilateral lateral rectus resections were performed on patients with a deviation ≤20∆-25∆. The total resection was calculated as the amount of resected muscle minus the amount of hang
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back (recession) left to facilitate postoperative adjustment. We were not able to determine the amount of adjustment that occurred for the 10 muscles that were adjusted postoperatively. Overall, 10 patients (91%) were successfully aligned following lateral rectus resection at
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the 2-month postoperative follow-up (mean alignment at distance, 1.1∆; range, 0∆-8∆). There were no postoperative complications.
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Discussion
Conventionally, resection is avoided in TED out of concern for further limiting ocular motility by increasing extraocular muscle tightness.5 Review of the literature confirmed that this surgical approach is not common.6-9
In a study of surgical treatment of 38 patients with Grave’s ophthalmopathy, Mourits and colleagues6 simultaneously performed lateral rectus muscle resection and extraocular muscle
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recession in 3 patients with restricted muscles: 2 of the patients had an optimal response, and none of the patients were overcorrected. Yan and colleagues7 reported combined rectus muscle recession and ipsilateral antagonist
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resection in 6 of 27 TED patients with large-angle deviation (>25∆). There were no
overcorrections following resection. The authors suggested considering antagonist muscle
resection in large-angle deviations that may not otherwise be corrected by maximal recession of
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the restricted muscle.
Yoo and colleagues8 reported rectus muscle resection in 8 Graves patients. Following
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resection, 7 patients (88%) were orthotropic in primary position. There was no increased restriction or overcorrection following resection. Although all 8 patients had TED, 3 did not have muscle restriction on ocular duction testing, with 2 having history of strabismus prior to TED onset and 1 having developed esotropia secondary to abducens nerve palsy following orbital
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decompression. Two different patients received medial rectus resection for exotropia: one developed following medial recession, and another had decompensated intermittent exotropia, given the absence of duction limitations. Similar to our study, 3 patients did receive recessions of
at last follow-up.
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restricted muscles before subsequent resection of the antagonist. All 3 patients were orthotropic
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Kim and colleagues9 performed bilateral lateral rectus resection using nonadjustable
sutures on 9 TED patients with residual esotropia after initial bimedial rectus recession. Unlike the surgical technique used in our study, initial rectus recession involved a modified matched restrictions technique that was “less than maximal” in most cases. Additionally, muscle resection was accomplished using fixed suture. Of the 9 patients, 7 had successful outcome with fusion in primary and reading gaze without prism; 2 remained undercorrected and with unresolved
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diplopia, which the authors attributed to large preoperative horizontal deficits (>60∆). There were no exodeviations following resection. All 11 patients in our study had developed diplopia following onset of TED (ie, no
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preexisting, non-TED-related strabismus, constituting 38% of the patients in Yoo and
colleagues8’). All 11 had received orbital decompression prior to receiving maximal or
supramaximal medial rectus recessions. All maintained residual esotropia following maximal
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recession. To our knowledge, this is the largest collection of muscle resections reported in TED patients who had strabismus from TED and not abducens nerve palsies or preexisting childhood
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strabismus.
Overall, 10 of 11 (91%) surgical encounters achieved successful outcomes. Patient 6 had significant clinical improvement but maintained residual deviation of 8∆ of esotropia with diplopia. At the time of left lateral rectus resection, this patient was a candidate for bilateral
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rectus resection, given a deviation of 25∆ of esotropia. However, because of vertical deviation the patient required concurrent right superior rectus recession; therefore, maximal left lateral rectus muscle resection was performed instead of bilateral lateral rectus resections. The patient had
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undergone bilateral inferior and medial rectus recessions 6 months prior and was felt to be at risk for anterior ischemic syndrome if all 4 rectus muscles on the right eye were operated within 7
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months. To correct the postoperative deviation and diplopia of 8∆ following left lateral rectus resection, the patient later underwent right rectus muscle resection with a successful outcome and no anterior ischemia. Three patients (nos. 2, 7, 11) had persistent diplopia following alleviation of horizontal deviation at distance secondary to residual vertical deviations. All had concomitant surgery for vertical deviation at the time of the lateral rectus resection. Theoretically, the postoperative vertical deviation could have been exacerbated by the resection, although
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examination of our results on a case-by-case basis suggests that the major determinant of the postoperative vertical deviation was the preoperative vertical deviation in the setting of TED. Additionally, the resected lateral rectus muscles were not transposed vertically, further reducing
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the likelihood that the resultant vertical deviation was exacerbated by the resection.
The pathophysiology of TED includes extraocular muscle fibrosis, which alters the
muscle elasticity in a dynamic way, which may limit the application of standard dose–response
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nomograms. Our data confirms a large variation in the dose–response for lateral rectus resections (mean for lateral rectus resection, 2.1∆/mm, range 1.4–3.3∆/mm). One suggested solution to this
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unpredictability in TED is a relaxed muscle positioning technique, where muscles are recessed in a centrally placed eye until they are no longer tight. This nomogram-independent method relies on the degree of restriction to determine amount of recession rather than preoperative deviation, achieving a successful outcome in 88% of cases.12 In our study, we relied on the use of
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adjustable sutures, which have been shown to accommodate the inherent variation of strabismus surgery in TED and achieve “good” or “excellent” outcomes in 73% of recessions in TED.13 All of our surgical encounters used adjustable suture. Ten of 11 (91%) surgical encounters required
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adjustment postoperatively. Despite use of adjustable sutures, postoperative shifts are still to be expected more commonly in TED than in euthyroid patients (23% vs 16%, resp.).14-15
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Our case series is limited by the relatively small sample size and the inability to
determine the final amount of adjustment in the 10 cases adjusted postoperatively. Our analysis is also limited to study of horizontal rectus muscle resection. Using strict criteria, we found that resection achieved successful outcomes in a select
group of TED patients, specifically those with quiescent disease who remain undercorrected following previous maximal medial rectus recession. These findings are in agreement with those
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reported in the literature previously by Yoo and colleauges8 and Kim and colleagues.9 Lateral rectus muscle resection is an effective surgical treatment for correcting residual esotropia following medial rectus recession in TED.
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Literature Search
The authors searched PubMed on April 1, 2017, for English-language results using the following terms: thyroid eye disease, graves ophthalmopathy, strabismus, rectus muscle resection, residual
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esotropia, and adjustable suture.
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References 1.
Skov CM, Mazow ML. Managing strabismus in endocrine eye disease. Can J Ophthalmol 1984;19:269-74. Fells P, Kousouloides L, Pappa A, Munro P, Lawson J. Extraocular muscle problems in
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2.
thyroid eye disease. Eye (Lond) 1994;8:497-505. 3.
Schittkowski M, Fichter N, Guthoff R. Strabismus surgery in Grave’s disease—dose–
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effect relationships and functional results [in German]. Klin Monbl Augenheilkd 2004;221:941-7.
M. Flanders, M. Hastings. Diagnosis and surgical management of strabismus associated
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with thyroid-related orbitopathy. J Pediatr Ophthalmol Strabismus 1997;34:333-40. 5.
Metz HS. Strabismus related to Graves ophthalmopathy. In: Rosenbaum AL, Santiago AP eds: Clinical Strabismus Management. Philadelphia, PA: W.B. Saunder Co;
6.
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1999:285-94.
Ph Mourits M, Koorneef L, van Mourik-Noordenbos AM, et al. Extraocular muscle surgery for Graves’ ophthalmopathy: does prior treatment influence surgical outcome? Br
7.
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J Ophthalmol 1990;74:481-3.
Yan J, Zhang H. The surgical management of strabismus with large angle in patients with
8.
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Graves’ ophthalmopathy. Int Ophthalmol 2008;28:75-82.
Yoo SH, Pineles SL, Goldberg RA, Velez FG. Rectus muscle resection in Graves’ ophthalmopathy. J AAPOS 2013;17:9-15.
9.
Kim EY, Roper-Hall G, Cruz OA. Effectiveness of bilateral lateral rectus resection for
residual esotropia in dysthyroid ophthalmopathy. Am J Ophthalmol 2016;171:84-7. 10.
Cruz OA, Davitt BV. Bilateral inferior rectus muscle recession for correction of
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hypotropia in dysthyroid ophthalmopathy. J AAPOS 1999;3:157-9. 11.
Zhang MS, Hutchinson AK, Drack AV, Cleveland J, Lambert SR. Improved ocular
surgery. Ophthalmology 2012;119:396-402. 12.
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alignment with adjustable sutures in adults undergoing strabismus
Dal Canto AJ, Crowe S, Perry JD, Traboulsi EI. Intraoperative relaxed muscle
positioning technique for strabismus repair in thyroid eye disease. Ophthalmology
13.
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2006;113:2324-30.
Lueder GT, Scott WE, Kutschke PJ, Keech RV. Long-term results of adjustable suture
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surgery for strabismus secondary to thyroid ophthalmopathy. Ophthalmology 1992;99:993-7. 14.
Peragallo JH, Velez FG, Demer JL, Pineles SL. Postoperative drift in patients with thyroid ophthalmopathy undergoing unilateral inferior rectus muscle
Kerr NC. The role of thyroid eye disease and other factors in the overcorrection of hypotropia following unilateral adjustable suture recession of the inferior rectus. Trans
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Am Ophthalmol Soc 2011;109:168-200.
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15.
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recession. Strabismus 2013;21:23-8.
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Table 1. Preoperative, surgical, and postoperative data of patients with thyroid eye disease undergoing lateral rectus muscle resection
5 6 7
8 9
10 11
RMR adj 7 LMR adj 7 LMR adj 7 RMR 7 LMR 7 RMR 9 LMR 6 RMR adj 7 re-LMR adj 3 re-RMR 3 RMR 6.5 LMR adj 6.5 RMR 6.5 LMR adj 6.5 RMR adj 6.5 LMR adj 6.5 LMR adj 6.5 RMR 6.5
RIR adj 10 LIR 10 LIR adj 8 RIR adj 6
LIR adj 7.5 RIR adjd LSR 7 RIR 7 LIR adj 10 LIR adj 10 RIR adj 10 LIR adj 10 RIR 10
8 ET
R adj 4
Yes
35 ET
R adj 12 L 12
Yes
14 ET
R adj 7
Yes
12 ET
L adj 6
25 ET
L adj 12
10 ET
L adj 8
12 ET 15 ET
20 ET 20 ET
Postoperative alignment, PD Distance Near
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RIR adj 10 LIR 8 RSR rs adj 10 LIR adj 10 RIR 10 LIR adj 7
Yes
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4
LIR adj 10
L adj 12a
30 ET
Diplopia Distance
Near
0
0
0
10 XT
0
0
No
No
LSR rs adj 9
0
2E
No
No
Yes
RIR adj 10
1E
0
No
No
Yes
RSR adj 6
8 ET
8 E(T)
Yes
No
Yes
RSR adj 3
0
20 X
Intermittent Intermittent
RIR adj 8
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3
Vertical LIR adj 4
LR Postoperative Concurrent resection, adjustment surgery, mm mm
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2
Horizontal LMR adj 8 RMR 4 RMR 7 LMR adj 7 LMR adj 6.5 RMR adj 6.5
Preoperative alignment at distance, PD
No b
Yes
No c
Yes
c
Yes
LSR adj 8
0
0
No
No
R adj 8
No
LIR adj 10
1E
0
No
No
2X
0
No
No
0
0
Yes
L adj 8 R8 L adj 6 R6
Yes Yes
re LIR 5
c
c
R adj 6
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1
Prior muscle surgery
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Patient
c
Yes
c
Adj, adjustable suture; E, esophoria; ET, esotropia; E(T), intermittent esotropia; IR, inferior rectus muscle; L, left; LR, lateral rectus muscle; MR, medial rectus muscle; PD, prism diopter; R, right; Rs, resection; SR, superior rectus muscle; X, exophoria; XT, exotropia. a
Unilateral resection surgery was performed out of need for local anesthesia. ∆ Patient 2 has a fusible angle but could not fuse secondary to a vertical deviation of 12 of left hypotropia. c Diplopia secondary to vertical deviations; patients 7 had intermittent diplopia secondary to vertical deviation. d Amount unknown. b