Incidence of symptomatic vertical and torsional diplopia after superior rectus transposition for esotropic Duane syndrome and abducens nerve palsy

A simple marking system for accurate intraoperative monitoring and adjustment of cyclotorsion strabismus surgery

Ocular cyclotorsion is treatable only with surgery. The surgical procedure must be tailored individually to the specific etiologies causing the horizontal and vertical strabismus and its torsional components. An adjustable surgical approach is often used for postoperative or intraoperative adjustments. However, the methods currently used have some limitations. In this study, we propose a simple intraoperative marking system for all cyclotorsion correction surgery. The proposed marking system used three sets of surface markers: external horizontal markings, ocular horizontal markings, and surgical torsion markings, drawn in sequence. We retrospectively analyzed the surgical results using this novel marking system in this single-center, single-surgeon study. Fifteen patients with cyclotorsion who underwent treatment using the proposed marking system as an intraoperative aid between August 2019 and August 2021 were included. The medical charts were thoroughly reviewed, and the pre-and postoperative subjective and objective cyclotorsion were analyzed. Among the study subjects (10 males, 5 females; age range: 6-89 years), 13 had excyclotorsion and 2 incyclotorsion. Preoperative mean net subjective cyclotorsion measured by the double Maddox rod (DMR) test was 6.0° (standard deviation: 10.8°) and mean net disc-to-fovea angle (DFA) was 20.23° (13.21°). The postoperative net DMR and DFA were 0.2° (2.1°) and 14.09° (5.97°), respectively. The mean absolute net DMR and DFA being treated were 9.8° (4.8°) and 9.76° (4.61°). Overall, the proposed intraoperative marking system is a simple and quantitative method to assess, monitor, and adjust the torsional aspect for all strabismus surgeries.

Outcomes of a Simple Lateral Rectus Belly Transposition Procedure Combined With Ipsilateral Antagonist Recession for Vertical Rectus Palsy

PURPOSE

To report the surgical effects of a combination treatment comprising the lateral rectus belly transposition (LRBT) procedure, without muscle splitting or disinsertion, and ipsilateral antagonist recession for vertical rectus palsy.

METHODS

The medical records of consecutive patients who underwent the LRBT procedure between 2017 and 2020 were reviewed. Preoperative and postoperative deviation in primary position, preoperative and postoperative scale of duction of the palsied muscle, any induced horizontal or torsional deviation, and other complications were collected.

RESULTS

Thirteen patients were identified: 10 with inferior rectus palsy and 3 with superior rectus palsy. The mean postoperative follow-up time was 20.4 ± 8.0 months. Eleven patients (84.6%) underwent simultaneous recession of the ipsilateral antagonist muscle of the palsied vertical rectus. After surgery, the mean vertical deviation improved from 31.4 ± 16.4 to 1.9 ± 3.6 prism diopters (PD) (P < .001). The mean vertical duction limitation of the palsied muscle improved from -2.7 ± 0.6 to -0.6 ± 0.5 (P = .001). In one patient, the scleral fixation suture was removed due to continuous reverse vertical diplopia. The total success rate was 76.9%. No induced horizontal deviation was noted. Anterior segment ischemia or other severe surgical complications did not occur.

CONCLUSIONS

The LRBT procedure can be effective, safe, and reversible in patients with vertical rectus palsy. It allows for the option of simultaneous ipsilateral antagonist recession, and it is especially valuable in patients whose vertical duction deficiency is worse in abduction but mild in adduction. [J Pediatr Ophthalmol Strabismus. 2022;59(6):396-404.].

Augmented inferior rectus transposition with medial rectus recession in treatment of chronic unilateral sixth nerve palsy

BACKGROUND

to report the results of augmented inferior rectus muscle transposition (IRT) in management of chronic sixth nerve palsy.

METHODS

a retrospective review of medical records of patients with chronic complete sixth nerve palsy who were treated by augmented full thickness IRT to the lateral border of the paralyzed lateral rectus muscle. Patients were selected for IRT if there was more limitation of abduction in inferior gaze associated with V- pattern esotropia. Medial rectus recession (MRRc) was performed in case of positive intraoperative forced duction. Effect on primary position esotropia, face turn, amount of V-pattern and limitation of ocular ductions were reported and analyzed.

RESULTS

the review revealed 11 patients (7 males) with chronic unilateral sixth nerve palsy who were treated by simultaneous augmented IRT and MRRc. Causes of sixth nerve palsy were trauma (6 cases), vascular (3 cases), inflammation and congenital (one case each). Mean age of the patients at the time of surgery was 35.6 years (range; 11-63) and mean follow up was 8.6 months (range; 6-13). Postoperatively, average correction of esotropia, V-pattern, face turn and limited abduction were 35.9 PD, 11.4 PD, 25.9° and 2.2 unit, respectively (p < .00). Postoperative complications in the form anterior segment ischemia, symptomatic induced vertical deviations were not found.

CONCLUSIONS

In cases of chronic unilateral sixth nerve palsy associated with more limitation of abduction in downgaze and V-pattern esotropia, augmented IRT could be considered as an effective and safe modality.

Effect of Modified Vertical Rectus Belly Transposition vs Augmented Superior Rectus Transposition Plus Medial Rectus Recession for Chronic Sixth Nerve Palsy: A Randomized Clinical Trial

Importance

Both vertical rectus belly transposition (VRBT) and superior rectus transposition (SRT) can be performed simultaneously with ipsilateral medial rectus recession (MRc) and have been shown to be effective for chronic sixth nerve palsy. However, it is unclear whether VRBT is superior to SRT in correcting esotropia.

Objective

To compare the effectiveness of modified VRBT plus MRc (mVRBT-MRc) vs augmented SRT plus MRc (aSRT-MRc) in Chinese patients with chronic sixth nerve palsy.

Design, Setting, and Participants

This parallel-design, double-masked, single-center, randomized clinical trial was conducted from January 15, 2018, to May 24, 2021. The follow-up visits were scheduled at 1 month and 6 months. Eligible Chinese participants with unilateral chronic sixth nerve palsy were randomly assigned to receive either mVRBT-MRc (VRBT group) or aSRT-MRc (SRT group).

Interventions

mVRBT-MRc or aSRT-MRc.

Main Outcomes and Measures

Change of horizontal deviation in primary position from baseline to 6 months.

Results

Of the total 25 eligible participants, the mean (SD) age was 45.4 (12.6) years, with 10 male participants (40%) and 15 female participants (60%). Thirteen participants (52%) were randomly assigned to the VRBT group, and 12 (48%) were randomly assigned to the SRT group. At baseline, the mean (SD) horizontal deviation was 65.7 (10.8) prism diopters (Δ) in the VRBT group and 60.5Δ(14.1Δ) in the SRT group. Similar amounts of MRc were performed in both groups. At 6 months, the horizontal deviation changed from baseline by 66.3Δ in the VRBT group and by 51.5Δ in the SRT group. The adjusted group difference was 10.9Δ (95% CI, 5.3Δ-16.6Δ), favoring the VRBT group (P = .001). Four times as many participants corrected more than 60Δ with mVRBT-MRc compared with aSRT-MRc. The group difference of the improvement of abduction limitation was -0.2 (95% CI, -0.8 to 0.5; P = .64). Although there was a higher proportion of undercorrection in the SRT group (difference, 45%; 95% CI, 16%-75%; P = .01), no differences were identified for other suboptimal outcomes between groups.

Conclusions and Relevance

Compared with aSRT-MRc, mVRBT-MRc showed better effect in correcting esotropia with no differences detected for other suboptimal outcomes. mVRBT-MRc may be a promising alternative surgical procedure for chronic sixth nerve palsy, particularly for large esotropia of more than 60Δ, if these results are confirmed in larger, diverse cohorts with longer follow-up.

Trial Registration

ChiCTR Identifier: ChiCTR-INR-17013705.

Impact of Adding Augmented Superior Rectus Transpositions to Medial Rectus Muscle Recessions When Treating Esotropic Moebius Syndrome

PURPOSE

To describe outcomes after treatment of Moebius syndrome (MBS) esotropia by adjustable bilateral medial rectus recession (BMR) with and without augmented superior rectus transposition (SRT).

DESIGN

Retrospective case series.

METHODS

Patients meeting 2014 diagnostic criteria for MBS and treated at Boston Children's Hospital between 2003 and 2019 were identified via billing records and chart review. Visual acuity, sensorimotor evaluations, strabismus procedures, and other clinical features were recorded. Surgical outcomes for patients treated with strabismus surgery (excluding those with prior surgery elsewhere) were evaluated. The primary outcome measure was postoperative alignment comparing treatment by adjustable BMR vs adjustable BMR+SRT.

RESULTS

A total of 20 patients had MBS, and 12 of these (60%) were male. Fifteen patients (75%) had primary position esotropia, and all had bilateral abduction deficit. Eight of 20 patients met inclusion criteria for primary strabismus surgery outcome. Five had undergone adjustable BMR ranging from 4.5 to 6.5 mm. Three had undergone adjustable BMR+SRT, all with 4-mm medial rectus muscle recessions. Mean preoperative esotropia before treatment by BMR was 39.5 PD (± 15 PD) with mean postoperative esotropia 9 PD (± 7.9 PD) at 6 months. Mean preoperative esotropia before treatment by BMR+SRT was 70.8 PD (± 5.9 PD) with mean postoperative esotropia 2.5 PD (± 3.5 PD) at 6 months. Significantly greater reduction in esotropia resulted from BMR+SRT than from BMR (P = .036).

CONCLUSIONS

BMR proved sufficient to treat esotropia <50 PD and BMR+SRT for greater esotropia in patients with MBS-associated abduction limitation.

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.

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.

Single horizontal rectus muscle vertical augmented transposition with posterior fixation suture in management of monocular elevation deficiency

We describe successful management of three cases of acquired monocular elevation deficiency (MED) with superior transposition of the lateral rectus augmented with a posterior fixation suture with or without simultaneous inferior rectus muscle weakening. In each case, the lateral rectus muscle was transposed superiorly to the superior rectus muscle along the spiral of Tillaux, with maintained distance between the original lateral rectus muscle poles and the limbus. Augmentation was achieved with a posterior fixation suture 8 mm posterior to the muscles' insertion. At the time of lateral rectus transposition, simultaneous inferior rectus recession by 5.5 mm was performed in case 1 whereas simultaneous botulinum toxin injection was performed in case 3. With regards to all three cases, the mean age was 32 years [10-46 years] and the mean follow-up period was 10 months. The mean hypotropia was reduced from 35 prism diopters (PD) (range: 20 to 60 PD) to 4.67 PD (range: 0 to 14 PD) with a mean correction of 32.57 ± 9.34 PD after 9 months. In our experience, full-tendon-width transposition of the lateral rectus to the superior rectus with posterior fixation suture corrects primary position hypotropia in MED and does not always require simultaneous inferior rectus recession. When transposing the lateral rectus muscle along the spiral of Tillaux, the measured distance of the original muscle insertion point to the limbus must be maintained in order to prevent recession of the muscle.