Augmented superior rectus transposition procedure in Duane retraction syndrome compared with sixth nerve palsy

Outcomes of "a new modification of Jensen technique combined with medial rectus recession" in patients with complete sixth cranial nerve palsy

BACKGROUND

To report the outcomes of "our modified Jensen technique" for treating esotropia in cases with complete sixth cranial nerve (CN VI) palsy.

METHODS

This study is a 30-year case series of isolated complete CN VI palsy who underwent combined medial rectus recession and our modified Jensen operation. We modified the original technique by anchoring the muscle-unifying sutures to the sclera near the equator using a non-absorbable suture. Major outcomes such as postoperative diplopia, face turn, horizontal and vertical eye deviations, and abduction limitation were assessed. Successful surgery was defined as orthotropia or esotropia equal to or less than 8 prism diopters (PD) and the absence of any vertical deviation.

RESULTS

Fifty-three cases with a mean age of 28 years old were included in this study. The male-to-female ratio was 3 to 1. Forty-five cases (85%) presented with unilateral palsy, whereas 8 patients (15%) had bilateral palsy. Trauma was the most common etiology (85%). Diplopia or face turn, presented in 42 patients before the operation, remained in seven cases after the operation. Primary position esotropia, which was the main complaint in all patients, decreased from 49 PD to 4 PD in unilateral palsy and from 101 PD to 10 PD in bilateral palsy. The mean reduction of abduction deficit was 1.78 in unilateral and 1.75 in bilateral palsy. The success rate was 76% in unilateral and 62% in bilateral palsy.

CONCLUSION

Our modified Jensen operation was effective in treating patients with complete CN VI palsy, producing no significant permanent complications.

No-split, no-tenotomy transposition of only the superior rectus muscle combined with medial rectus recession in patients with complete abducens nerve palsy

PURPOSE

To evaluate the outcomes of no-split, no-tenotomy transposition of only the superior rectus muscle combined with medial rectus recession in patients with complete abducens nerve palsy.

METHODS

In this procedure, the temporal margin of the superior rectus muscle, 10 mm posterior to the insertion, was secured with a nonabsorbable suture and sutured to the sclera at a distance of 12 mm from the limbus in the superotemporal quadrant, halfway between the superior rectus and lateral rectus. Success was defined as distance and near alignment of ≤8^Δ and no diplopia in primary position 6 months after surgery.

RESULTS

A total of 8 patients with abducens nerve palsy underwent the procedure. At the last follow-up, the mean postoperative change in primary position deviation was 42.6^Δ ± 8.1^Δ (range, 34^Δ-57^Δ) for distance and 42.1^Δ ± 7.5^Δ (35^Δ -57^Δ) for near, a significant reduction (P = 0.012). Abduction deficit also improved significantly (P = 0.010). Postoperatively, no vertical deviation or torsional diplopia was induced. At the 6 months' follow-up, compared with the first postoperative visit, an esodrift at near developed in 1 patient. Of the 8 cases, 6 fulfilled the criteria for success.

CONCLUSIONS

In our small study cohort, no-split, no-tenotomy superior rectus transposition and medial rectus recession improved esotropia and abduction limitation without inducing significant vertical deviations or torsional diplopia.

Superior Rectus Transposition in the Management of Duane Retraction Syndrome: Current Insights

Various surgical approaches have been described for the management of Duane retraction syndrome (DRS), a type of congenital cranial dysinnervation disorder (CCDD), the goals of which include correcting the primary position deviation and abnormal head posture (AHP), minimizing globe retraction and overshoots and improving the ocular rotations. Vertical rectus transposition (VRT) is one such technique, found more effective in improving abduction and thereby expanding the field of binocular vision, as compared to horizontal muscle surgery. VRT, however, is associated with the risk of inducing vertical deviations and also poses a risk for development of anterior segment ischemia. To overcome these concerns, transposition of only the superior rectus to the lateral rectus was proposed and evaluated to reveal improvement in alignment, AHP and motility comparable to VRT but with lesser surgical time and fewer post-operative complications. With promising results in the management of DRS, superior rectus transposition (SRT) has been extensively studied and has evolved over the last decade with several modifications to further increase the efficiency and reduce the risk of post-operative complications. This article focusses on the pre-operative considerations while planning SRT in DRS, various approaches and surgical techniques described, and the outcomes and complications of SRT in DRS. The role of SRT in the management of other CCDDs may be explored with further studies.

Medial rectus disinsertion for management of chronic complete sixth nerve palsy

PURPOSE

To report the outcomes of the medial rectus (MR) disinsertion procedure for the management of refractory esotropia (ET) with or without Abnormal head posture (AHP) in chronic complete sixth nerve palsy.

METHODS

This is a retrospective case series of patients with sixth nerve palsy who suffered from residual ET and diplopia following the conventional strabismus surgeries and underwent MR disinsertion procedure between April 2017 and February 2020. This procedure was offered to the patients who declined to use prism and did not wish to perform surgery on the fellow eye. The demographic and clinical data, including sex, age, visual acuity, pre and postoperative angle of strabismus, duction limitations, results of forced duction and force generation tests, details of prior strabismus surgeries, orbital CT scan findings, and follow up duration were collected from the medical records.

RESULTS

Six patients were enrolled in this study. Mean age was 35.0  ±  14.0 years, and mean follow-up was 15.3  ±  5.9 months. The ET at the Primary position (PP) was 35.0  ±  18.4 prism dioptre (PD) before MR disinsertion, which decreased to 14.2  ±  17.4 PD after MR disinsertion procedure. Four cases needed additional complementary surgeries to improve residual ET in PP. No case developed overcorrection. Abduction deficiency was -5.0  ±  1.3 before MR disinsertion, which improved to - 2.8  ±  0.5 units at last follow-up. The mean of induced adduction deficiency was - 2.9  ±  0.4 at last follow-up.

CONCLUSIONS

MR disinsertion can be considered in patients with chronic complete sixth nerve palsy and refractory diplopia when the conventional methods have failed.

A Review of Transposition Techniques for Treatment of Complete Abducens Nerve Palsy

Purpose:

To review various types of extraocular muscle transposition procedures for management of strabismus in sixth cranial nerve palsy with little lateral rectus (LR) muscle function, along with their pros and cons.

Methods:

We performed a comprehensive review of transposition procedures in sixth cranial nerve palsy, based on literature published anytime up to March 2021. A thorough search through PubMed and Cochrane databases was performed. All types of clinical studies on different transposition procedures in LR palsy, were included.

Results:

Eighty-six original articles in English, with full text or abstracts available, were included in the review, among which 16 are prospective studies, 48 retrospective, 3 review articles, 1 randomized clinical trial, 17 case reports, and 1 letter. Vertical rectus transposition has demonstrated promising results, especially in abduction improvement and expansion of binocular diplopia-free visual field, albeit the possible adverse effects such as anterior segment ischemia, especially in the presence of medial rectus contracture, and induced vertical deviation may become troublesome. Partial muscle transposition, single muscle transposition, and also transposition without tenotomy have all been introduced to reduce the risk of multiple muscle manipulation and ischemia. On the other hand, different adjustable transpositions are being utilized to manage concomitant or induced vertical deviations.

Conclusion:

Transposition procedures are highly effective in the treatment of esotropia caused by complete LR palsy. Various techniques for vertical muscle transposition have been proposed, with each of them having certain advantages and disadvantages.

Risk of torsion in superior rectus transposition surgery augmented with posterior scleral fixation sutures

It has been reported that superior rectus transposition combined with medial rectus recession can provide as good results as transposition of both vertical rectus muscles, with no adverse effects on torsion or postoperative vertical misalignment. Further augmentation of transposition surgery can be achieved through the use of posterior fixation sutures, myopexy and botulinum toxin into the medial rectus. We report a patient with complete bilateral traumatic sixth cranial nerve palsies who underwent sequential superior rectus transposition surgery combined with medial rectus recession. The surgery was augmented with a myopexy (posterior suture joining superior and lateral recti with no scleral fixation) in the first eye and with a posterior fixation suture (with scleral fixation) in the second eye. After the second procedure, despite a significant improvement in horizontal alignment, the patient developed 15 degrees of incyclotorsion which was attributed to the scleral fixation suture. The patient underwent removal of the scleral suture and 3 months postoperatively had a significant reduction in incyclotorsion to 8 degrees; however this continued to be a barrier to fusion. Vertical rectus transposition of superior and inferior recti augmented with posterior scleral fixation sutures is one type of conventional surgery for complete lateral rectus palsy. In more recent times, it has become common to transpose the superior rectus alone along with recession of the contracted medial rectus. This procedure can also be augmented with a posterior fixation suture which may or may not be attached to the sclera. Whilst this surgery has gained popularity it is not without risk as demonstrated by our case in which transposition of the superior rectus was associated with postoperative incyclotorsion. In this case a possible explanation may be the use of a the posterior scleral fixation suture as it did not occur when no scleral fixation was used. Furthermore, removal of the posterior scleral fixation suture did reduce the torsion significantly although it did not eliminate it.

Superior Rectus Transposition and Medial Rectus Recession for Treatment of Duane Retraction Syndrome and Sixth Nerve Palsy

Purpose: To evaluate the outcome of augmented superior rectus transposition (SRT) with medial rectus (MR) recession in patients with Duane Retraction Syndrome (DRS) and sixth nerve palsy.Methods: Twenty four patients (16 DRS and 8 sixth nerve palsy) that underwent the procedure were included. The superior rectus muscle was secured, detached, and re-attached to the sclera along the spiral of Tilaux, adjacent to lateral rectus insertion. A non-absorbable augmentation suture was passed through the sclera, 8 mm posterior to the insertion of the lateral rectus.Results: At the last follow-up, the effect of surgery in decreasing esotropia in both groups was significant (P = .001 for DRS group, P = .002 for sixth nerve palsy). In both groups, abduction deficit improved significantly (P < .001 for DRS and P = .008 for sixth nerve palsy). After the surgery, small, asymptomatic vertical deviation in primary position was induced in five patients (20.8%). Post-operatively, none of the patients complained of torsional diplopia. In the 6-month follow-up, compared with the first postoperative visit, an eso-drift at distance or near developed in 11 patients (45.8%). Of the 11 patients with eso-drift, overcorrection (exotropia of 3-14 PD) was present at the first post-operative visit in 5 cases. Four cases showed an exo-drift (2-5 PD) at distance or near over time.Conclusion: SRT with medial rectus recession improves esotropia and abduction limitation without inducing significant vertical deviations and torsional diplopia. Some of the cases that underwent SRT with MR recession may show an eso-drift. The eso-drift can correct initial exotropia in some cases.

Augmented superior rectus muscle transposition in management of defective ocular abduction

Background

Superior rectus muscle transposition (SRT) is one of the proposed transposition techniques in the management of defective ocular abduction secondary to chronic sixth nerve palsy and esotropic Duane retraction syndrome (Eso-DRS). The aim of the current study is to report the outcomes of augmented SRT in treatment of Eso-DRS and chronic sixth nerve palsy.

Methods

a retrospective review of medical records of patients with Eso-DRS and complete chronic sixth nerve palsy who were treated by augmented full tendon SRT combined with medial rectus recession (MRc) when intraoperative forced duction test yielded a significant contracture. Effect on primary position esotropia (ET), abnormal head posture (AHP), limitation of ocular ductions as well as complications were reported and analyzed.

Results

a total of 21 patients were identified: 10 patients with 6th nerve palsy and 11 patients with Eso-DRS. In both groups, SRT was combined with ipsilateral MRc in 18 cases. ET, AHP and limited abduction were improved by means of 33.8PD, 26.5°, and 2.6 units in 6th nerve palsy group and by 31.1PD, 28.6°, and 2 units in Eso-DRS group respectively. Surgical success which was defined as within 10 PD of horizontal orthotropia and within 4 PD of vertical orthotropia was achieved in 15 cases (71.4%). Significant induced hypertropia of more than 4 PD was reported in 3 patients (30%) and in 2 patients (18%) in both groups, respectively.

Conclusion

augmented SRT with or without MRc is an effective tool for management of ET, AHP and limited abduction secondary to sixth nerve palsy and Eso-DRS. However, this form of augmented superior rectus muscle transposition could result in high rates of induced vertical deviation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-020-01779-1.

Hummelsheim procedure combined with medial rectus recession in complete sixth nerve palsy and esotropic Duane Retraction Syndrome

PURPOSE

To evaluate the effect of half tendon vertical rectus muscle transposition (HVRT) combined with medial rectus muscle recession (MRrec) in complete sixth nerve palsy (CSNP) and esotropic Duane Retraction Syndrome (eDRS).

METHODS

A retrospective study of patients with unilateral CSNP or eDRS who underwent HVRT combined with medial rectus recession over the course of 18 years. The patients with previous strabismus surgery and follow up less than 3 months were excluded. Overcorrection was defined as any amount of exotropia, and undercorrection was defined as residual esotropia of ⩾10 prism diopter (PD).

RESULTS

A total of 39 patients were enrolled including 22 CSNP and 17 eDRS patients. Esotropia improved from 45.8 ± 22 and 22.5 ± 6.4 PD to 0.8 ± 2.5 and 0.3 ± 1 PD in CSNP group and eDRS group respectively. The angle of face turn improved from 34.3 ± 8.4° and 26.5 ± 9° to 0.6 ± 2.4° and 0.8 ± 1.6° in the CSNP group and eDRS group respectively. Abduction limitation improved from -4.5 ± 0.5 and -4 ± 0 units to -2.9 ± 0.5 and -2.7 ± 0.5 units in CSNP group and eDRS group respectively. No patient developed a new vertical deviation. An overcorrection occurred in one patient of the eDRS group who improved after botulinum toxin injection in the ipsilateral lateral rectus muscle. Undercorrection was seen in two patients.

CONCLUSION

HVRT combined with MRrec is an effective procedure to improve esotropia, face turn, and abduction limitation in CSNP and eDRS.

Outcomes of symmetric bilateral medial rectus recession in large-angle esotropic Duane syndrome

PURPOSE

To evaluate the efficacy of symmetric bilateral medial rectus recession in large-angle esotropic Duane retraction syndrome (DRS) with moderate to severe globe retraction.

METHODS

In a retrospective study, medical reports of 30 patients with esotropia of equal or more than 20 prism diopters (pd) and moderate to serve globe retraction due to unilateral DRS who underwent symmetric bilateral medial rectus recession were reviewed. Age, gender, laterality, amblyopia, length of follow-up, pre- and postoperative measurements of primary position deviation, ocular ductions and severity of globe retraction and abnormal head posture were evaluated. A successful result was defined as decreasing esotropia to equal or less than 8 pd or equal or less than 8 pd of consecutive exotropia.

RESULTS

The mean age of patients at surgery was 13.7 ± 8.5 years old (range: 3-38). The mean preoperative esotropia measured 28.9 ± 9.1 pd in distance and 25.7 ± 7.2 pd in near, which decreased to 4.9 ± 6.1 pd in distance and 3.9 ± 8.8 pd in near postoperatively. The mean bilateral medial rectus recession was 4.9 ± 0.9 mm (range: 3-6 mm). The mean abnormal head posture improved from 19.1 ± 6.9 degrees (range: 10-30 degrees) to 3.3 ± 4.7 degrees (range: 0-15 degrees) postoperatively. At the last follow-up visit, 23 patients (76.7%) had a successful outcome.

CONCLUSIONS

In the large-angle esotropic DRS patients with moderate to severe globe retraction, symmetric bilateral medial rectus recession, can be conducted to successfully resolve primary position deviation and abnormal head posture.

Adjustable graded augmentation of superior rectus transposition for treatment of abducens nerve palsy and Duane syndrome

PURPOSE

To report the results of adjustable graded augmentation of superior rectus transposition, a novel modification of superior rectus transposition (SRT) designed to reduce postoperative vertical or torsional diplopia.

METHODS

The medical records of patients who underwent adjustable graded augmentation of SRT with or without adjustable medial rectus recession (MRc) from February 2017 to December 2019 were reviewed retrospectively. A Mendez ring was used to monitor torsional change after transposition of the superior rectus muscle to the lateral rectus muscle and after sequential placement of 2 or 3 augmentation sutures by superior rectus-lateral rectus loop myopexy. If excessive mechanical intorsion was induced, the responsible augmentation suture was severed intraoperatively. If torsional or vertical diplopia was noted after recovery, the distal-most augmentation suture was cut. Exotropia was managed by severing the distal-most augmentation suture or by medial rectus adjustment.

RESULTS

A total of 8 patients who underwent adjustable graded augmentation of SRT were included (6 using the 3-suture technique): 3 for esotropic Duane syndrome, 2 for abducens nerve palsy, 1 for Moebius syndrome, and 2 for combined trochlear and abducens nerve palsies. Of the 8 patients, 4 had prior strabismus surgery, and 1 patient had previously undergone treatment with botulinum toxin. Severing one augmentation suture in 3 cases resolved vertical (n = 2) or torsional (n = 1) diplopia and consecutive exotropia (n = 2), resulting in excellent alignment and reduction of torticollis to ≤4° in 7 cases. The technique proved insufficient in 1 patient, who had undergone 3 prior strabismus procedures.

CONCLUSIONS

In this study cohort, adjustable graded augmentation of SRT effectively managed the risk of postoperative vertical or torsional diplopia.

Efficacy and complications of transposition surgery in Duane esotropia syndrome

OBJECTIVE

To study the long-term efficacy and the complications of several transposition techniques for the treatment of Duane syndrome. These included, full vertical rectus transposition, partial vertical rectus transposition, transposition without muscle disinsertion, and superior rectus transposition.

MATERIAL AND METHODS

A retrospective study of the patients diagnosed with Duane syndrome, and who underwent any of the different transposition techniques associated or not to the medial rectus recession with a follow-up longer than 12 months. A good result was considered a final deviation≤10 prism dioptres (pd) in primary position, anomalous head posture<10°, and an improvement of the abduction without diplopia.

RESULTS

Seven cases were included (6 women, 6 unilateral), and a mean age of 37.71 years. Pre-operative central gaze esotropia of 28±11.68pd decreased to 6±4.62pd at the final visit (P=.009). The anomalous head posture decreased in 6 patients, and the abduction improved one degree from -3.14 to -2.14 (mean). An induced vertical deviation≤8pd was observed in 4 cases. None experienced diplopia at the final visit. The percentage of reoperations was 71.42%. Only 28.57% had a favourable outcome with a single surgery, which increased to 71.42% with further surgeries at the final follow-up. Mean evolution time was 52±31.65 months.

CONCLUSIONS

Vertical rectus transpositions in Duane syndrome with moderate or severe clinical signs have only been effective in a small percentage of the cases. Most of them required further surgeries to resolve the complications or the under-corrections.

Effect of Foveal Location on Retinal Nerve Fiber Layer Thickness Profile in Superior Oblique Palsy Eyes

PRéCIS:: Superior oblique palsy (SOP) eyes show thinner inferotemporal retinal nerve fiber layer (RNFL) without adjusting for foveal position. There was a strong correlation between the degree of torsion and the difference in the RNFL thickness before and after adjusting foveal location.

PURPOSE

The impact of foveal position on RNFL thickness has been shown. In this study, we evaluate RNFL thickness profiles according to the disc-foveal angle in SOP and control eyes.

MATERIALS AND METHODS

In 44 eyes of 22 patients with unilateral congenital SOP and 42 eyes of 42 normal controls, the position of the fovea relative to the optic disc was calculated by optical coherence tomography using FoDi (fovea-to-disc) technology. After measuring RNFL thickness with FoDi alignment technology, each optical coherence tomography image was reevaluated with FoDi turned off, and the measurements were repeated to determine RNFL values according to the disc-foveal angle.

RESULTS

The average disc-foveal angle was -10.85±6.60 degrees and -10.71±6.63 degrees in the affected and fellow eyes of SOP patients; these values were significantly greater than control subjects (-5.88±4.09 degrees). There was no significant difference in RNFL sector values between SOP and control eyes with FoDi. From all RNFL sectors, the measured inferotemporal thickness was less in SOP eyes without FoDi than in SOP eyes with FoDi (129.7±20.5 µm vs. 144.6±17.8 µm, respectively, P=0.001). Differences of the RNFL thicknesses with and without FoDi in SOP eyes in the superotemporal and inferotemporal sectors were 5.40±13.42 and 14.84±15.00, respectively, which were significantly more than the same changes in control eyes with amount of 0.30±6.57 and 8.52±10.4 (P=0.02 for both sectors).

CONCLUSIONS

In SOP eyes with large amounts of torsion, a correction for the disc-foveal angle is necessary for accurate determination of the RNFL thickness profile.

Reoperation in esotropic Duane retraction syndrome: Long-term motor outcome of superior rectus transposition

AIM

The aim was to evaluate the long-term motor outcome of superior rectus transposition procedure in patients affected by unilateral esotropic Duane retraction syndrome with residual esotropia and anomalous head position.

METHODS

A retrospective analysis of medical records of patients affected by esotropic Duane retraction syndrome who underwent superior rectus transposition procedure as reoperation for residual esotropia and/or residual anomalous head position. Amount of deviation, anomalous head position, duction limitation, globe retraction, presence of upshoot/downshoot, and vertical deviation were analyzed before and after superior rectus transposition procedure.

RESULTS

Twenty patients were selected. All patients underwent unilateral medial rectus recession or bilateral medial rectus recession, for unilateral esotropic Duane retraction syndrome at least 2 years before superior rectus transposition reoperation. Mean age at surgery (superior rectus transposition) was 12 ± 6.8 years, and the follow-up period was 2.7 ± 0.6. Mean deviations at distance and near before surgery were 19.5 ± 5.7 and 15.2 ± 6.8, respectively. Two patients showed upshoot. Head turn was 11.4 ± 5.1°; abduction limitation was -2.6 ± 0.9. After superior rectus transposition, all patients showed an improvement of esotropia at distance and near (8.1 ± 5.7 and 5.1 ± 5.6, respectively; p < 0.05), anomalous head position (5.6 ± 3.9°; p < 0.05), and abduction limitation (-2.3 ± 0.8; p < 0.05). No statistically significant changes occurred in globe retraction. No adduction limitation, vertical deviation, and upshoot/downshoot were present after superior rectus transposition procedure. Results were stable during follow-up.

CONCLUSION

Superior rectus transposition procedure is an effective procedure in esotropic Duane retraction syndrome patients who previously undergone unilateral/bilateral medial rectus recession, with residual esotropia and anomalous head position. It allows improvement of esotropia, head turn, and partial recovery of abduction in a significant percentage of patients (30%) with no vertical complications.

Vertical rectus transposition procedures for lateral rectus palsy: A systematic review

Multiple transposition procedures have been described for management of lateral rectus palsy. However, relative effect and indications of each procedure are unclear. This systematic review was planned to evaluate functional and anatomical outcomes of vertical rectus transposition (VRT) surgery in patients with lateral rectus palsy. We searched databases in English language, namely, MEDLINE, PubMed Central, EMBASE, Google Scholar, Scopus, and Index Copernicus without any date restrictions in electronic searches, using the search words 'vertical rectus transposition for lateral rectus palsy," "vertical rectus transposition for abducens palsy," "superior rectus transposition," "inferior rectus transposition," and "Hummelsheim procedure." References of the selected publications were also searched to find any relevant studies. We searched for studies that provided data on single VRT and double VRT surgeries for lateral rectus palsies. Three authors independently assessed the related studies gathered from electronic and manual searches. We found 27 studies which were relevant to the review question. As there were no randomized control trials (RCTs) available related to our study question, nonrandomized studies were used to arrive at summarization of outcomes of different transposition procedures. There is a need for prospective RCTs to investigate the different types of transposition procedures for lateral rectus palsy.

Superior or inferior rectus transposition in esotropic Duane syndrome: a longitudinal analysis

PURPOSE

To evaluate the results of superior rectus transposition (SRT) or inferior rectus transposition (IRT) in esotropic Duane syndrome.

METHODS

The medical records of patients with esotropic Duane syndrome who underwent ciliary vessel-sparing SRT or IRT by a single surgeon in private practice were included. Pre- and postoperative head posture, primary position deviation, fundus torsion, collapse in pattern, and improvement in ductions were analyzed between groups.

RESULTS

A total of 21 patients were included: 7 had a V-pattern esotropia and/or larger abduction deficiency in downgaze compared to upgaze and underwent IRT; 14 underwent SRT of which 6 had A pattern and/or larger abduction deficiency in upgaze compared to downgaze. Orthotropia within 10^Δ of esotropia was achieved in 10 patients (71.4%) with SRT and 4 patients (57.1%) with IRT. Pattern was reduced and abduction improved in all patients. The improvement in abduction was slightly better in elevation after SRT compared with IRT (1.7 ± 1 vs 1.4 ± 0.7; P = 0.4) and in depression after IRT compared to SRT (2 ± 1.2 vs 1.1 ± 0.7; P = 0.05).

CONCLUSIONS

Both SRT and IRT procedures effectively correct the head posture and primary position deviation in esotropic Duane patients. SRT can be advantageous in patients with an A pattern or more limitation of abduction in elevation; IRT, in patients with a V pattern or more limitation of abduction in depression.

Transposition procedures in Duane retraction syndrome

Duane retraction syndrome, or Duane syndrome (DS), is one of several congenital cranial dysinnervation disorders. Patients present with limited horizontal eye movement(s) and globe retraction with eyelid fissure narrowing on attempted adduction due to co-contraction of the lateral and medial rectus muscles in one or both eyes. Various surgical approaches have been proposed to improve binocular alignment, reduce head turn, and minimize undesirable up- or downshoots in DS. Transposition procedures are one such approach, and a number of techniques have been described. These may involve one or both vertical rectus muscles and may or may not include full or partial disinsertion of the rectus muscle(s) from the insertion. Options involving both vertical rectus muscles include full vertical rectus transposition (VRT), partial VRT, rectus muscle union, and other modifications to be discussed. Options involving one vertical rectus muscle include superior rectus transposition (SRT) and inferior rectus transposition (IRT). The effectiveness of any transposition procedure may be enhanced with augmentation (posterior fixation) sutures, resection of the transposed muscle(s), and/or simultaneous weakening of the ipsilateral medial rectus muscle. This review discusses the indications, strengths, weaknesses, and other considerations of these approaches within the context of DS. Since the majority of DS cases are unilateral and most have the esotropic form, this will be the main focus of the review, although other forms will also be discussed.