- Email: [email protected]
Surgical outcomes of unilateral recession-resection for vertical strabismus in patients with thyroid eye disease
Accepted Manuscript Surgical outcomes of unilateral recession-resection for vertical strabismus in patients with thyroid eye disease Ju-Yeun Lee, MD, Kyung-Ah Park, MD, PhD, Kyung In Woo, MD, PhD, Yoon-Duck Kim, MD, PhD, Sei Yeul Oh, MD, PhD PII:
S1091-8531(17)30014-9
DOI:
10.1016/j.jaapos.2016.11.019
Reference:
YMPA 2551
To appear in:
Journal of AAPOS
Received Date: 11 July 2016 Revised Date:
17 November 2016
Accepted Date: 21 November 2016
Please cite this article as: Lee J-Y, Park K-A, Woo KI, Kim Y-D, Oh SY, Surgical outcomes of unilateral recession-resection for vertical strabismus in patients with thyroid eye disease, Journal of AAPOS (2017), doi: 10.1016/j.jaapos.2016.11.019. 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
Surgical outcomes of unilateral recession-resection for vertical strabismus in patients with thyroid eye disease Ju-Yeun Lee, MD, Kyung-Ah Park, MD, PhD, Kyung In Woo, MD, PhD, Yoon-Duck Kim, MD, PhD, Sei Yeul Oh, MD, PhD
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Author affiliation: Department of Ophthalmology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea Submitted July 11, 2016. Revision accepted November 21, 2016.
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Correspondence: Sei Yeul Oh, Department of Ophthalmology, Samsung Medical Center, Sungkyunkwan University School of Medicine, #81 Irwon-ro, Gangnam-gu, 06351, Seoul, Korea (email: [email protected]).
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Word count: 2,038 Abstract only: 170
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Abstract Purpose To present the surgical outcomes of vertical muscle resection in patients with thyroid eye disease
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(TED). Methods
The medical records of 6 patients who underwent unilateral vertical muscle recession-resection
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to correct vertical strabismus in TED were reviewed retrospectively for postoperative angle of vertical deviation on days 1 and 7 and at months 1, 3, 6, and 12. Surgery was considered
M AN U
successful if the vertical deviation was ≤4∆. Reoperation rates and complications were also noted. Results
The mean preoperative angle of vertical deviation was 39.2∆ ± 3.8∆, and the mean final ocular deviation at 12 months postoperatively was 3.8∆ ± 5.9∆. There was significant reduction in
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postoperative vertical deviation (paired t test, P < 0.001). Surgery was successful in 4 patients (67%). There was neither unusual postoperative inflammation nor increased restriction of the resected muscle postoperatively in any patient.
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Conclusions
Based on careful assessment and appropriate patient selection, vertical muscle resection can be
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considered an effective option that provides satisfactory surgical outcomes with regard to vertical deviation correction in TED.
ACCEPTED MANUSCRIPT
Strabismus, which occurs in 17%-51% of patients with thyroid eye disease (TED),1,2 causes severe diplopia and cosmetic problems. The deviation is often sufficient to warrant surgery. The surgical treatment of strabismus in TED typically involves recession of the restricted muscles in
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the noninflammatory phase.3-5 Recession of the affected muscles is strongly preferred to
resection because of concern regarding severe inflammation and increased restriction of muscles that are already strongly contracted.6
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Most surgeons believe that rectus muscle resection should not be performed in patients with TED. However, two prior studies found successful surgical outcomes after rectus muscle
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resection in patients with TED7,8 These studies only investigated horizontal strabismus in TED. To our knowledge, no prior studies have addressed the resection of vertical rectus muscles for vertical strabismus in patients with TED. The present study aimed to present the surgical outcomes of vertical muscle resection in patients with TED and to evaluate the effectiveness of
Subjects and Methods
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muscle resection.
The records of patients with TED who had undergone primary operations performed by a single
EP
experienced surgeon (SO) at Samsung Medical Center between January 2008 and June 2015 were reviewed retrospectively. This study was approved by the Institutional Review Board of
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Samsung Medical Center and followed the tenets of the Declaration of Helsinki. Patient records were anonymized and deidentified prior to analysis. Data from all patients who had undergone surgery for vertical strabismus in TED were
reviewed. All patients were euthyroid and had been stable for at least 6 months prior to strabismus surgery. The following preoperative data were collected: age at surgery, duration of
ACCEPTED MANUSCRIPT
thyroid-associated ophthalmopathy, duration of diplopia, history of orbital decompression, radioactive iodine or corticosteroid treatment, smoking, levels of serum TSH receptor antibodies (TRAb) and thyroid-stimulating antibodies (TSAb), preoperative angle of deviation, and
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stereoacuity.
All patients underwent complete ophthalmic examinations, including prism and alternate cover tests. These tests were conducted at distances of 6 m in the nine cardinal gaze positions
SC
and 30 cm in primary gaze. Ocular ductions were measured using a standard four-point scale. Stereoacuity at near was tested using the standard Titmus test (Stereo Optical Co Inc, Chicago,
M AN U
IL). External examinations were performed in all patients. These examinations included assessment of orbital and ocular signs of inflammation, such as corneal staining, conjunctival injection and chemosis, lid injection, eyelid swelling, and proptosis. All patients underwent computed tomography (CT) to evaluate muscle enlargement preoperatively.
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Patients who underwent unilateral recession-resection of the vertical rectus muscles, inferior rectus recession and superior rectus resection, or inferior resection and superior rectus recession were included. Vertical recession-resection surgery was determined based on the
EP
patient’s clinical features. In patients who had remarkable monocular limitation of vertical gaze (more than grade 2) with poor visual acuity in one eye (compared with the other eye), and at
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least one of two vertical muscles in this eye that showed relatively normal size on CT images, vertical recession-resection was performed. During surgery, the enlarged vertical rectus muscle was recessed and the normal-sized vertical rectus muscle was resected. Under general anesthesia, a single, experienced surgeon (SO) performed all of the
surgical procedures. An intraoperative forced duction test was performed in every patient prior to
ACCEPTED MANUSCRIPT
the surgical procedure. The amount of surgical correction was determined based on the largest angle of vertical deviation measured before surgery (Table 1). We first performed 5–7.5 mm recession of one vertical rectus muscle, using the hang-back method. To adjust the recession
RI PT
postoperatively, the muscle was resutured to the original insertion and allowed to hang back loosely in the orbit. Next, we performed 5–7 mm resection of the antagonist muscle in the same eye. After confirming that the muscle was free with the forced duction test, the resected muscle
SC
was sutured back to its original insertion. All postoperative adjustments were performed on the day of surgery. At the time of adjustable suture, ductions and alignment were measured, and the
M AN U
muscle was repositioned until the patient became orthotropic. After adjustment, preplaced conjunctival loop sutures were tied to allow closure of the wound over the muscle slipknot. Postoperative medications included topical antibiotics and steroids.
The following data were collected from the medical records: intraoperative forced
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duction test, amount of muscle recession or resection, use of adjustable sutures, postoperative angle of vertical deviation at postoperative days 1 and 7 and months 1, 3, 6, and 12, and the final examination before additional surgery. Postoperative examinations were performed in the same
EP
manner as the preoperative examinations. All postoperative deviation measurements determined after adjustment were collected in this study. Postoperative alignment was considered successful
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if the vertical deviation was ≤4∆.
Statistical analyses were performed using SAS ver. 9.4 software (SAS Institute, Cary,
NC). A comparison between preoperative and postoperative vertical deviation was analyzed by paired t test. A P value of <0.05 was considered statistically significant. Results
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A total of 60 Asian patients were enrolled based on the eligibility criteria. Fifty-four patients were excluded, including 5 for a history of previous strabismus surgery, 39 for one or two vertical rectus muscle recession, and 10 who had undergone horizontal rectus muscle surgery.
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Therefore, a total of 6 patients (4 males) were included. The mean duration of TED (with
standard deviation) was 30.8 ± 11.9 months (range, 15-41 months). The mean duration of
diplopia was 27.2 ± 5.8 months (range, 19-35 months). The mean age at surgery was 58 ± 17
SC
years (range, 39-79 years). The mean postoperative follow-up duration was 16.7 ± 6.3 months. Cases 1 and 2 had a history of treatment with radioactive iodine and corticosteroid treatment.
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Case 3 had a history of smoking and was treated with radioactive iodine. Case 4 had a history of treatment with radioactive iodine, corticosteroid, and orbital decompression prior to strabismus surgery. Patient demographics and clinical factors are presented in Table 2. The mean preoperative vertical deviation was 39.2∆ ± 3.8∆, and the mean amount of
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resection was 5.7 ± 1.9 mm. A total of 6 vertical rectus muscles were resected, involving the SR muscle in 4 patients (67%) and the inferior rectus muscle in 2 patients (33%). One patient underwent 1.0 mm adjustment after recession-resection surgery (case 1).
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All postoperative outcomes achieved after adjustment were presented. The mean reduction of vertical deviation was 33.8∆ ± 7.0∆ at day 1, 40.2∆ ± 7.8∆ at 6 months, and 42.3∆ ±
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8.0∆ at 12 months. There were significant reductions in vertical deviation postoperatively (paired t test, all P < 0.001). Longitudinal changes in the postoperative angle of vertical deviation in each patient are shown in Figure 1. Postoperatively, 4 patients (67%) had successful surgical outcomes. One patient (17%) was overcorrected (>10∆) and underwent reoperations (case 6). There was no unusual postoperative inflammation. In addition, there was no increased restriction
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of the resected muscle or an unanticipated decrease in ocular motility postoperatively. Discussion Ocular motility restriction in TED is a common consequence of inflammatory infiltration and
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fibrosis of the extraocular muscles. Correcting strabismus in TED is challenging because of the highly variable surgical outcomes and high reoperation rates. In TED the deviation is caused by restriction of the affected muscle. Therefore, most surgeons prefer to recess the involved muscle.
SC
However, in some patients with large vertical deviations, muscle recession does not alleviate the residual deviation.
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Despite the risk of unanticipated outcomes, several previous studies performed muscle resection as the initial treatment modality in TED. Yoo and colleagues8 reported successful outcomes after muscle resection in 8 patients with TED; none of the patients experienced increased restriction or overcorrection. Yan and colleagues7 reported 6 patients who underwent
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muscle resections of the antagonist muscle; all were treated successfully, with no overcorrections. However, the successful outcomes of those studies were limited to horizontal deviation. Muscle resection for vertical deviation in patients with TED has received less attention.
EP
Our results indicate a relatively high success rate in vertical recession-resection surgery. There was significant reduction in the angle of vertical deviation postoperatively in all patients.
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The comparable results of muscle resection may be due to patient selection. Based on previous reports, resection of the antagonist muscle may be recommended in patients with large deviations.6,8 In the present study, all patients had a large angle of vertical deviation (≥20), which is unlikely to improve with maximal recession of the vertical rectus muscles. In addition, all patients who underwent recession-resection surgery had marked ocular motility restriction in one
ACCEPTED MANUSCRIPT
eye. Under these conditions, unilateral recession/resection of the antagonist muscle may effectively centralize a highly rotated eye. CT images of patients in this study revealed severe enlargement of the recessed muscle,
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whereas the resected muscle was of relatively normal size on imaging. Maximal superior rectus muscle area of 20–37 mm2 and inferior rectus muscle area of 20–47 mm2 were considered
relatively normal based on the results of our previous study.9 Therefore, we recessed the affected
SC
muscles, which are usually tight and fibrotic. We only resected normal-sized muscles to avoid unpredictable inflammation and surgical outcomes. Two patients had hypertropia with downward
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limitation, which is rarely observed in TED. In these patients, remarkable superior rectus muscle enlargements were observed on CT, whereas, inferior rectus muscles had relatively normal size compared with the superior rectus muscles. Based on the clinical manifestation and CT images, we performed inferior rectus resection and superior rectus recession, with satisfactory surgical
outcomes.
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outcomes. Therefore, the condition of the resected muscle may have contributed to the successful
The surgical outcomes of vertical muscle resection in the present study are comparable to
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those of muscle recession reported by previous studies. Prendiville and colleagues10 reported a 57% success rate of vertical muscle recession in the correction of vertical strabismus and 6.4∆ of
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postoperative residual angle of vertical deviation. Other authors have reported a 64% success rate of inferior rectus and contralateral superior rectus recession.11 Cruz and colleagues12 reported a 75% success rate of bilateral inferior rectus recession in the correction of vertical strabismus. Regarding the surgical outcomes of muscle resection, Yan and colleagues7 reported a 66.7%
success rate of horizontal and vertical rectus muscle resection in Graves’ ophthalmopathy. Yoo
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and colleagues8 reported an 87.5% success rate in horizontal rectus muscle resection in Graves’ opthalmopathy. We had a 67% success rate in vertical rectus muscle resection, which is lower
calculation of the success rate of muscle resection.
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than that of Yoo and colleagues. However, they only included horizontal muscle surgery in their
This study has several limitations. First, this was a single-center retrospective study that included participants of one ethnicity. Therefore, our results may not be generalizable to other
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ethnic groups. In addition, the sample size was small. Furthermore, we did not assess torsional status of patients in this study. Well-controlled studies with a larger sample size and longer
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follow-up are required to substantiate our results.
In conclusion, unilateral vertical recession-resection surgery in TED has several advantages. The procedure is limited to one eye and effectively corrects large deviations that are unlikely to be improved by maximal recession of the vertical muscles. With careful consideration
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of ocular motility restriction (limited to one eye), and a relatively normal-sized vertical muscle on CT, the technique may provide satisfactory correction of vertical deviation in these patients. Literature Search
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PubMed was searched, without language or date restrictions, in November 2016 using the
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following terms: thyroid eye disease, rectus muscle resection, and vertical strabismus.
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References 1.
Bartley GB, Fatourechi V, Kadrmas EF, et al. Clinical features of Graves’ ophthalmopathy in an incidence cohort. Am J Ophthalmol 1996;121:284-90. Lee H, Roh HS, Yoon JS, Lee SY. Assessment of quality of life and depression in Korean
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2.
patients with Graves' ophthalmopathy. Korean J Ophthalmol 2010;24:65-72.
Ellis FD. Strabismus surgery for endocrine ophthalmopathy. Ophthalmology 1979;86:2059-63.
4.
Hudson HL, Feldon SE. Late overcorrection of hypotropia in Graves ophthalmopathy.
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Predictive factors. Ophthalmology 1992;99:356-60. 5.
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3.
Miller JE, Van Heuven W, Ward R. Surgical correction of hypotropias associated with thyroid dysfunction. Arch Ophthalmol 1965;74:509-15.
6.
Kraus DJ, Bullock JD. Treatment of thyroid ocular myopathy with adjustable and
discussion 79-84. 7.
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nonadjustable suture strabismus surgery. Trans Am Ophthalmol Soc 1993;91:67-79;
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’
9.
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ophthalmopathy. J AAPOS 2013;17:9-15. Lee JY, Bae K, Park KA, Lyu IJ, Oh SY. Correlation between extraocular muscle size measured by computed tomography and the vertical angle of deviation in thyroid eye disease. PLoS One 2016;11:e0148167. 10.
Prendiville P, Chopra M, Gauderman WJ, Feldon SE. The role of restricted motility in
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determining outcomes for vertical strabismus surgery in Graves’ ophthalmology. Ophthalmology 2000;107:545-9. 11.
Jellema HM, Saeed P, Groenveld L, Kloos R, Mourits MP. Outcome of inferior and
Cruz OA, Davitt BV. Bilateral inferior rectus muscle recession for correction of hypotropia
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in dysthyroid ophthalmopathy. J AAPOS 1999;3:157-9.
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12.
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superior rectus recession in Graves’ orbitopathy patients. Orbit 2015;34:84-91.
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Legends FIG 1. Longitudinal changes in the postoperative angle of vertical deviation in 6 patients who
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(Patient 6 underwent reoperation 22 months after initial surgery.)
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underwent unilateral recession-resection to correct vertical strabismus in thyroid eye disease.
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Table 1. Clinical summary of 6 patients who underwent unilateral vertical muscle recession-resection a
Postoperative deviation, PD Day 1 1 year Ortho Ortho 4 LHoT 6 LHT
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No. Sex Age, Eye Disease Vertical Ocular Surgery years duration, deviation, movement months PD 1 M 75 L 39 45 HT Downgaze −2 SR rec 6.5 → 5.5 mm IR res 6.5 mm 2 M 47 L 92 35 HoT Upgaze −3 IR rec 5.5 mm SR res 6.5 mm 3 M 38 R 15 45 HT Downgaze −3 SR rec 7.5 mm IR res 5.5 mm 4 F 47 L 41 40 HoT Upgaze −3 IR rec 5.5 mm SR res 7.0 mm 5 F 76 L 17 35 HoT Upgaze −2 IR rec 5.0 mm SR res 5.0 mm 6 M 67 L 41 40 HoT Upgaze −2 IR rec 5.5 mm SR res 5.5 mm
10 RHT 2 LHT Ortho
Ortho
8 LHoT Ortho
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Ortho
15 LHT → Re-op
a
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Surgery on same side as affected eye.
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HoT, hypotropia; HT, hypertropia; IR, inferior rectus; Ortho, orthotropic; PD, prism diopter; Rec, recession; Res, resection; Re-op, reoperation; SR, superior rectus.
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Mean ± SD 58 ± 17 4/2 0.12 ± 0.14 −0.39 ± 1.43 30.8 ± 11.9 27.2 ± 5.8 1 (16.7%) 4 (66.7%) 3 (50%) 1 (16.7%) 160.30 ± 54.12 3.82 ± 5.16 39.2 ± 3.8 2 (33.3%)
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BCVA, best-corrected visual acuity; TSAb, thyroidstimulating antibody; TRAb, TSH receptor antibody.
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Characteristic Age at surgery, years Sex, male/female BCVA, logMAR Refractive error, PD Disease duration, months Diplopia duration, months Previous treatment Orbital decompression Radioactive iodine Corticosteroid Smoking history Serum TSAb level Serum TRAb level Preoperative angle of deviation, PD Preoperative stereoacuity (better than 3000 arcsec)
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Table 2. Patient demographics and clinical factors
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S1091-8531(17)30014-9
DOI:
10.1016/j.jaapos.2016.11.019
Reference:
YMPA 2551
To appear in:
Journal of AAPOS
Received Date: 11 July 2016 Revised Date:
17 November 2016
Accepted Date: 21 November 2016
Please cite this article as: Lee J-Y, Park K-A, Woo KI, Kim Y-D, Oh SY, Surgical outcomes of unilateral recession-resection for vertical strabismus in patients with thyroid eye disease, Journal of AAPOS (2017), doi: 10.1016/j.jaapos.2016.11.019. 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
Surgical outcomes of unilateral recession-resection for vertical strabismus in patients with thyroid eye disease Ju-Yeun Lee, MD, Kyung-Ah Park, MD, PhD, Kyung In Woo, MD, PhD, Yoon-Duck Kim, MD, PhD, Sei Yeul Oh, MD, PhD
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Author affiliation: Department of Ophthalmology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea Submitted July 11, 2016. Revision accepted November 21, 2016.
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Correspondence: Sei Yeul Oh, Department of Ophthalmology, Samsung Medical Center, Sungkyunkwan University School of Medicine, #81 Irwon-ro, Gangnam-gu, 06351, Seoul, Korea (email: [email protected]).
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Word count: 2,038 Abstract only: 170
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Abstract Purpose To present the surgical outcomes of vertical muscle resection in patients with thyroid eye disease
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(TED). Methods
The medical records of 6 patients who underwent unilateral vertical muscle recession-resection
SC
to correct vertical strabismus in TED were reviewed retrospectively for postoperative angle of vertical deviation on days 1 and 7 and at months 1, 3, 6, and 12. Surgery was considered
M AN U
successful if the vertical deviation was ≤4∆. Reoperation rates and complications were also noted. Results
The mean preoperative angle of vertical deviation was 39.2∆ ± 3.8∆, and the mean final ocular deviation at 12 months postoperatively was 3.8∆ ± 5.9∆. There was significant reduction in
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postoperative vertical deviation (paired t test, P < 0.001). Surgery was successful in 4 patients (67%). There was neither unusual postoperative inflammation nor increased restriction of the resected muscle postoperatively in any patient.
EP
Conclusions
Based on careful assessment and appropriate patient selection, vertical muscle resection can be
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considered an effective option that provides satisfactory surgical outcomes with regard to vertical deviation correction in TED.
ACCEPTED MANUSCRIPT
Strabismus, which occurs in 17%-51% of patients with thyroid eye disease (TED),1,2 causes severe diplopia and cosmetic problems. The deviation is often sufficient to warrant surgery. The surgical treatment of strabismus in TED typically involves recession of the restricted muscles in
RI PT
the noninflammatory phase.3-5 Recession of the affected muscles is strongly preferred to
resection because of concern regarding severe inflammation and increased restriction of muscles that are already strongly contracted.6
SC
Most surgeons believe that rectus muscle resection should not be performed in patients with TED. However, two prior studies found successful surgical outcomes after rectus muscle
M AN U
resection in patients with TED7,8 These studies only investigated horizontal strabismus in TED. To our knowledge, no prior studies have addressed the resection of vertical rectus muscles for vertical strabismus in patients with TED. The present study aimed to present the surgical outcomes of vertical muscle resection in patients with TED and to evaluate the effectiveness of
Subjects and Methods
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muscle resection.
The records of patients with TED who had undergone primary operations performed by a single
EP
experienced surgeon (SO) at Samsung Medical Center between January 2008 and June 2015 were reviewed retrospectively. This study was approved by the Institutional Review Board of
AC C
Samsung Medical Center and followed the tenets of the Declaration of Helsinki. Patient records were anonymized and deidentified prior to analysis. Data from all patients who had undergone surgery for vertical strabismus in TED were
reviewed. All patients were euthyroid and had been stable for at least 6 months prior to strabismus surgery. The following preoperative data were collected: age at surgery, duration of
ACCEPTED MANUSCRIPT
thyroid-associated ophthalmopathy, duration of diplopia, history of orbital decompression, radioactive iodine or corticosteroid treatment, smoking, levels of serum TSH receptor antibodies (TRAb) and thyroid-stimulating antibodies (TSAb), preoperative angle of deviation, and
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stereoacuity.
All patients underwent complete ophthalmic examinations, including prism and alternate cover tests. These tests were conducted at distances of 6 m in the nine cardinal gaze positions
SC
and 30 cm in primary gaze. Ocular ductions were measured using a standard four-point scale. Stereoacuity at near was tested using the standard Titmus test (Stereo Optical Co Inc, Chicago,
M AN U
IL). External examinations were performed in all patients. These examinations included assessment of orbital and ocular signs of inflammation, such as corneal staining, conjunctival injection and chemosis, lid injection, eyelid swelling, and proptosis. All patients underwent computed tomography (CT) to evaluate muscle enlargement preoperatively.
TE D
Patients who underwent unilateral recession-resection of the vertical rectus muscles, inferior rectus recession and superior rectus resection, or inferior resection and superior rectus recession were included. Vertical recession-resection surgery was determined based on the
EP
patient’s clinical features. In patients who had remarkable monocular limitation of vertical gaze (more than grade 2) with poor visual acuity in one eye (compared with the other eye), and at
AC C
least one of two vertical muscles in this eye that showed relatively normal size on CT images, vertical recession-resection was performed. During surgery, the enlarged vertical rectus muscle was recessed and the normal-sized vertical rectus muscle was resected. Under general anesthesia, a single, experienced surgeon (SO) performed all of the
surgical procedures. An intraoperative forced duction test was performed in every patient prior to
ACCEPTED MANUSCRIPT
the surgical procedure. The amount of surgical correction was determined based on the largest angle of vertical deviation measured before surgery (Table 1). We first performed 5–7.5 mm recession of one vertical rectus muscle, using the hang-back method. To adjust the recession
RI PT
postoperatively, the muscle was resutured to the original insertion and allowed to hang back loosely in the orbit. Next, we performed 5–7 mm resection of the antagonist muscle in the same eye. After confirming that the muscle was free with the forced duction test, the resected muscle
SC
was sutured back to its original insertion. All postoperative adjustments were performed on the day of surgery. At the time of adjustable suture, ductions and alignment were measured, and the
M AN U
muscle was repositioned until the patient became orthotropic. After adjustment, preplaced conjunctival loop sutures were tied to allow closure of the wound over the muscle slipknot. Postoperative medications included topical antibiotics and steroids.
The following data were collected from the medical records: intraoperative forced
TE D
duction test, amount of muscle recession or resection, use of adjustable sutures, postoperative angle of vertical deviation at postoperative days 1 and 7 and months 1, 3, 6, and 12, and the final examination before additional surgery. Postoperative examinations were performed in the same
EP
manner as the preoperative examinations. All postoperative deviation measurements determined after adjustment were collected in this study. Postoperative alignment was considered successful
AC C
if the vertical deviation was ≤4∆.
Statistical analyses were performed using SAS ver. 9.4 software (SAS Institute, Cary,
NC). A comparison between preoperative and postoperative vertical deviation was analyzed by paired t test. A P value of <0.05 was considered statistically significant. Results
ACCEPTED MANUSCRIPT
A total of 60 Asian patients were enrolled based on the eligibility criteria. Fifty-four patients were excluded, including 5 for a history of previous strabismus surgery, 39 for one or two vertical rectus muscle recession, and 10 who had undergone horizontal rectus muscle surgery.
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Therefore, a total of 6 patients (4 males) were included. The mean duration of TED (with
standard deviation) was 30.8 ± 11.9 months (range, 15-41 months). The mean duration of
diplopia was 27.2 ± 5.8 months (range, 19-35 months). The mean age at surgery was 58 ± 17
SC
years (range, 39-79 years). The mean postoperative follow-up duration was 16.7 ± 6.3 months. Cases 1 and 2 had a history of treatment with radioactive iodine and corticosteroid treatment.
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Case 3 had a history of smoking and was treated with radioactive iodine. Case 4 had a history of treatment with radioactive iodine, corticosteroid, and orbital decompression prior to strabismus surgery. Patient demographics and clinical factors are presented in Table 2. The mean preoperative vertical deviation was 39.2∆ ± 3.8∆, and the mean amount of
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resection was 5.7 ± 1.9 mm. A total of 6 vertical rectus muscles were resected, involving the SR muscle in 4 patients (67%) and the inferior rectus muscle in 2 patients (33%). One patient underwent 1.0 mm adjustment after recession-resection surgery (case 1).
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All postoperative outcomes achieved after adjustment were presented. The mean reduction of vertical deviation was 33.8∆ ± 7.0∆ at day 1, 40.2∆ ± 7.8∆ at 6 months, and 42.3∆ ±
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8.0∆ at 12 months. There were significant reductions in vertical deviation postoperatively (paired t test, all P < 0.001). Longitudinal changes in the postoperative angle of vertical deviation in each patient are shown in Figure 1. Postoperatively, 4 patients (67%) had successful surgical outcomes. One patient (17%) was overcorrected (>10∆) and underwent reoperations (case 6). There was no unusual postoperative inflammation. In addition, there was no increased restriction
ACCEPTED MANUSCRIPT
of the resected muscle or an unanticipated decrease in ocular motility postoperatively. Discussion Ocular motility restriction in TED is a common consequence of inflammatory infiltration and
RI PT
fibrosis of the extraocular muscles. Correcting strabismus in TED is challenging because of the highly variable surgical outcomes and high reoperation rates. In TED the deviation is caused by restriction of the affected muscle. Therefore, most surgeons prefer to recess the involved muscle.
SC
However, in some patients with large vertical deviations, muscle recession does not alleviate the residual deviation.
M AN U
Despite the risk of unanticipated outcomes, several previous studies performed muscle resection as the initial treatment modality in TED. Yoo and colleagues8 reported successful outcomes after muscle resection in 8 patients with TED; none of the patients experienced increased restriction or overcorrection. Yan and colleagues7 reported 6 patients who underwent
TE D
muscle resections of the antagonist muscle; all were treated successfully, with no overcorrections. However, the successful outcomes of those studies were limited to horizontal deviation. Muscle resection for vertical deviation in patients with TED has received less attention.
EP
Our results indicate a relatively high success rate in vertical recession-resection surgery. There was significant reduction in the angle of vertical deviation postoperatively in all patients.
AC C
The comparable results of muscle resection may be due to patient selection. Based on previous reports, resection of the antagonist muscle may be recommended in patients with large deviations.6,8 In the present study, all patients had a large angle of vertical deviation (≥20), which is unlikely to improve with maximal recession of the vertical rectus muscles. In addition, all patients who underwent recession-resection surgery had marked ocular motility restriction in one
ACCEPTED MANUSCRIPT
eye. Under these conditions, unilateral recession/resection of the antagonist muscle may effectively centralize a highly rotated eye. CT images of patients in this study revealed severe enlargement of the recessed muscle,
RI PT
whereas the resected muscle was of relatively normal size on imaging. Maximal superior rectus muscle area of 20–37 mm2 and inferior rectus muscle area of 20–47 mm2 were considered
relatively normal based on the results of our previous study.9 Therefore, we recessed the affected
SC
muscles, which are usually tight and fibrotic. We only resected normal-sized muscles to avoid unpredictable inflammation and surgical outcomes. Two patients had hypertropia with downward
M AN U
limitation, which is rarely observed in TED. In these patients, remarkable superior rectus muscle enlargements were observed on CT, whereas, inferior rectus muscles had relatively normal size compared with the superior rectus muscles. Based on the clinical manifestation and CT images, we performed inferior rectus resection and superior rectus recession, with satisfactory surgical
outcomes.
TE D
outcomes. Therefore, the condition of the resected muscle may have contributed to the successful
The surgical outcomes of vertical muscle resection in the present study are comparable to
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those of muscle recession reported by previous studies. Prendiville and colleagues10 reported a 57% success rate of vertical muscle recession in the correction of vertical strabismus and 6.4∆ of
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postoperative residual angle of vertical deviation. Other authors have reported a 64% success rate of inferior rectus and contralateral superior rectus recession.11 Cruz and colleagues12 reported a 75% success rate of bilateral inferior rectus recession in the correction of vertical strabismus. Regarding the surgical outcomes of muscle resection, Yan and colleagues7 reported a 66.7%
success rate of horizontal and vertical rectus muscle resection in Graves’ ophthalmopathy. Yoo
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and colleagues8 reported an 87.5% success rate in horizontal rectus muscle resection in Graves’ opthalmopathy. We had a 67% success rate in vertical rectus muscle resection, which is lower
calculation of the success rate of muscle resection.
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than that of Yoo and colleagues. However, they only included horizontal muscle surgery in their
This study has several limitations. First, this was a single-center retrospective study that included participants of one ethnicity. Therefore, our results may not be generalizable to other
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ethnic groups. In addition, the sample size was small. Furthermore, we did not assess torsional status of patients in this study. Well-controlled studies with a larger sample size and longer
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follow-up are required to substantiate our results.
In conclusion, unilateral vertical recession-resection surgery in TED has several advantages. The procedure is limited to one eye and effectively corrects large deviations that are unlikely to be improved by maximal recession of the vertical muscles. With careful consideration
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of ocular motility restriction (limited to one eye), and a relatively normal-sized vertical muscle on CT, the technique may provide satisfactory correction of vertical deviation in these patients. Literature Search
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PubMed was searched, without language or date restrictions, in November 2016 using the
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following terms: thyroid eye disease, rectus muscle resection, and vertical strabismus.
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References 1.
Bartley GB, Fatourechi V, Kadrmas EF, et al. Clinical features of Graves’ ophthalmopathy in an incidence cohort. Am J Ophthalmol 1996;121:284-90. Lee H, Roh HS, Yoon JS, Lee SY. Assessment of quality of life and depression in Korean
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2.
patients with Graves' ophthalmopathy. Korean J Ophthalmol 2010;24:65-72.
Ellis FD. Strabismus surgery for endocrine ophthalmopathy. Ophthalmology 1979;86:2059-63.
4.
Hudson HL, Feldon SE. Late overcorrection of hypotropia in Graves ophthalmopathy.
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Predictive factors. Ophthalmology 1992;99:356-60. 5.
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3.
Miller JE, Van Heuven W, Ward R. Surgical correction of hypotropias associated with thyroid dysfunction. Arch Ophthalmol 1965;74:509-15.
6.
Kraus DJ, Bullock JD. Treatment of thyroid ocular myopathy with adjustable and
discussion 79-84. 7.
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nonadjustable suture strabismus surgery. Trans Am Ophthalmol Soc 1993;91:67-79;
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’
9.
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ophthalmopathy. J AAPOS 2013;17:9-15. Lee JY, Bae K, Park KA, Lyu IJ, Oh SY. Correlation between extraocular muscle size measured by computed tomography and the vertical angle of deviation in thyroid eye disease. PLoS One 2016;11:e0148167. 10.
Prendiville P, Chopra M, Gauderman WJ, Feldon SE. The role of restricted motility in
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determining outcomes for vertical strabismus surgery in Graves’ ophthalmology. Ophthalmology 2000;107:545-9. 11.
Jellema HM, Saeed P, Groenveld L, Kloos R, Mourits MP. Outcome of inferior and
Cruz OA, Davitt BV. Bilateral inferior rectus muscle recession for correction of hypotropia
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in dysthyroid ophthalmopathy. J AAPOS 1999;3:157-9.
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12.
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superior rectus recession in Graves’ orbitopathy patients. Orbit 2015;34:84-91.
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Legends FIG 1. Longitudinal changes in the postoperative angle of vertical deviation in 6 patients who
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(Patient 6 underwent reoperation 22 months after initial surgery.)
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underwent unilateral recession-resection to correct vertical strabismus in thyroid eye disease.
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Table 1. Clinical summary of 6 patients who underwent unilateral vertical muscle recession-resection a
Postoperative deviation, PD Day 1 1 year Ortho Ortho 4 LHoT 6 LHT
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No. Sex Age, Eye Disease Vertical Ocular Surgery years duration, deviation, movement months PD 1 M 75 L 39 45 HT Downgaze −2 SR rec 6.5 → 5.5 mm IR res 6.5 mm 2 M 47 L 92 35 HoT Upgaze −3 IR rec 5.5 mm SR res 6.5 mm 3 M 38 R 15 45 HT Downgaze −3 SR rec 7.5 mm IR res 5.5 mm 4 F 47 L 41 40 HoT Upgaze −3 IR rec 5.5 mm SR res 7.0 mm 5 F 76 L 17 35 HoT Upgaze −2 IR rec 5.0 mm SR res 5.0 mm 6 M 67 L 41 40 HoT Upgaze −2 IR rec 5.5 mm SR res 5.5 mm
10 RHT 2 LHT Ortho
Ortho
8 LHoT Ortho
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Ortho
15 LHT → Re-op
a
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Surgery on same side as affected eye.
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HoT, hypotropia; HT, hypertropia; IR, inferior rectus; Ortho, orthotropic; PD, prism diopter; Rec, recession; Res, resection; Re-op, reoperation; SR, superior rectus.
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Mean ± SD 58 ± 17 4/2 0.12 ± 0.14 −0.39 ± 1.43 30.8 ± 11.9 27.2 ± 5.8 1 (16.7%) 4 (66.7%) 3 (50%) 1 (16.7%) 160.30 ± 54.12 3.82 ± 5.16 39.2 ± 3.8 2 (33.3%)
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BCVA, best-corrected visual acuity; TSAb, thyroidstimulating antibody; TRAb, TSH receptor antibody.
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Characteristic Age at surgery, years Sex, male/female BCVA, logMAR Refractive error, PD Disease duration, months Diplopia duration, months Previous treatment Orbital decompression Radioactive iodine Corticosteroid Smoking history Serum TSAb level Serum TRAb level Preoperative angle of deviation, PD Preoperative stereoacuity (better than 3000 arcsec)
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Table 2. Patient demographics and clinical factors
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