Outcomes of three different vertical rectus muscle transposition procedures for complete abducens 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.

Three-muscle surgery for large-angle esotropia in chronic sixth nerve palsy: comparison of two approaches

AIMS

To report the effect of two three-muscle surgeries, inferior rectus belly transposition plus augmented superior rectus transposition plus medial rectus recession (ISM) and modified vertical rectus belly transposition plus medial rectus recession (VM), in the management of large-angle esotropia in Chinese patients with chronic sixth nerve palsy.

METHODS

Twenty-eight consecutive patients with large-angle esotropia ≥50Δ were prospectively enrolled and underwent either ISM or VM. Main outcomes included preoperative and postoperative deviation in primary position, abduction limitation and complications. Follow-up was at least 6 months.

RESULTS

Of the included patients, 13 underwent ISM and 15 underwent VM. Preoperatively, ISM group displayed larger esotropia and more severe abduction limitation. 27 patients completed the follow-up. The postoperative horizontal deviation and abduction limitation were similar in both groups. At the last follow-up, ISM group demonstrated greater improvement of abduction limitation than VM group in both grading (group difference -2.1, p<0.001) and quantitation (group difference 2.6 mm, p=0.001). However, eight (30%) patients revealed an induced adduction limitation ≤-1. Of the 22 patients with unilateral palsy, more esotropia of 14.8Δ was corrected in ISM group, compared with VM group (p=0.003). Three patients (14%) developed vertical diplopia and three (14%) developed torsional diplopia. Unexpectedly, keratitis was observed in 4 of 27 (15%) patients, all with concurrent fifth and/or seventh nerve palsy. Three patients aggravated to corneal ulceration.

CONCLUSIONS

Two three-muscle surgeries, ISM and VM were both effective for large-angle esotropia in Chinese patients with chronic sixth nerve palsy. However, attention should be paid to potential complications.

Preliminary Results of New Modification of Vertical Muscle Transposition to Enhance Abducting Force in Sixth Nerve Palsy

Introduction

Since 1907, multiple transposition procedures have been established for the treatment of abducens paralysis. The purpose of the study was to determine where the transposed muscle should be reattached in order to increase the tangential force necessary to improve abduction.

Methods

Retrospective case review of 12 consecutive patients with abducens paralysis who underwent transposition procedures between 2016 and 2019 was conducted. Vertical rectus muscles are transposed to the insertion of lateral rectus muscle; the temporal parts are joined and sutured to the sclera on top of the lateral rectus muscle in the middle of the insertion. The nasal parts are sutured to the sclera following the spiral of Tillaux. The muscle junction suture is placed 8 mm from the insertion, with the temporal parts of the vertical muscles bellies joined and sutured to the lateral rectus muscle. A full-tendon transposition was performed on 11 patients, a half-tendon transposition procedure on 1 patient. The minimum follow-up was 3 months.

Results

The mean preoperative deviation was ET of 37° (range: ET 24° to ET 51°). The mean preoperative abduction limitation was 5 mm from midline (range: 7 to 1 mm). The postoperative mean deviation was ET of 2° (range: 0° to ET 5°). The postoperative mean abduction improvement was 5 mm past midline (range: 2-6 mm). There were no complications or signs of anterior segment ischemia.

Conclusion

To achieve the maximal abductive force from the transposed muscles, we suggest that the vertical muscles be reattached as close as possible to the middle of the lateral rectus insertion.

A comparative multicentric long-term study of un-augmented modified Nishida procedure vs augmentation in unilateral sixth nerve palsy

PURPOSE

To compare the effectiveness of three procedures: modified Nishida procedure alone vs modified Nishida procedure combined with medial rectus recession (MRc) vs modified Nishida procedure combined with MRc and botulinum toxin (BT) for severe unilateral sixth nerve palsy.

DESIGN

Consecutive, interventional case series.

METHODS

The medical records of a consecutive series of patients with severe unilateral sixth nerve palsy who underwent modified Nishida procedure in multiple centres were reviewed. Surgical technique was decided preoperatively at the surgeon's discretion. The preoperative and postoperative findings were compared.

RESULTS

Of the 43 patients with abducens palsy that received the procedure, 32 were included (mean age 38.6 ± 19.8 years). Mean preoperative deviation was 63.0 ± 27.3 prism dioptres (PD) and mean limitation of abduction -4.5 ± 1.2. Five patients underwent a modified Nishida procedure alone, 24 patients had an additional MRc and 3 patients were also injected with BT. Overall, the average correction of modified Nishida technique by itself was 29.4 ± 6.6 PD (range 20-36) and adding a MRc corrected 62.6 ± 23.8 PD (range 24-120). Modified Nishida procedure, MRc and BT altogether corrected 95.0 ± 18.0 PD (range 75-110). No postoperative complications were observed in any of the patients.

CONCLUSIONS

Excellent outcomes with fewer complications are obtained with modified Nishida procedure alone. The need for additional procedures such as MRc and BT which increase the effect in primary position can be determined depending on passive duction and preoperative horizontal deviation.

Supramaximal Horizontal Rectus Recession-Resection Surgery for Complete Unilateral Abducens Nerve Palsy

Purpose

To review the surgical procedures and outcomes of supramaximal horizontal rectus recession–resection surgery for abduction deficiency and esotropia resulting from complete unilateral abducens nerve palsy.

Methods

A total of 36 consecutive cases diagnosed as complete abducens nerve palsy, receiving supramaximal medial rectus recession (8.5 ± 1.4 mm, range: 6–10) combined with a supramaximal lateral rectus resection (11.1 ± 1.7 mm, range: 8–14) as performed over the period from 2017 to 2020, were reviewed retrospectively. All surgeries were performed by a single surgeon. Pre- and post-operative ocular motility, ocular alignment, forced duction test, binocular vision, abnormal head posture, and surgical complications were assessed.

Results

Of these 36 cases, 23 (63.8%) were followed up for greater than 2 months (Mean ± SD = 8.4 ± 6.0, range: 2–24) after surgery and the collected data was presented. Mean ± SD age of these patients was 41.7 ± 14.4 (range: 12–67) years with 73.9% being female. Trauma (52.2%, 12/23) and cerebral lesions (21.7%, 5/23) were the primary etiologies for this condition. Esodeviation in primary position improved from 55.5 ± 27.2 prism diopters (PD) (range: +25 to +123) to 0.04 ± 7.3 PD (range: −18 to +12) as assessed on their last visit. Pre-operative abduction deficits of −5.6 ± 1.0 (range: −8 to −4) reduced to −2.4 ± 1.4 (range: −4 to 0) post-operatively. The mean dose-effect coefficient of 2.80 ± 1.20 PD/mm (range: 1.07–6.05) was positively correlated with pre-operative esodeviation. Rates of overcorrection and ortho were 69.6 and 26.1%, respectively, on the first day after surgery, while on their last visit the respective levels were 4.3 and 82.6%.

Conclusion

Supramaximal horizontal rectus recession–resection surgery is an effective treatment method for complete abduction deficiency. The dose-effect was positively correlated with pre-operative esodeviation. Overcorrection on the first day post-operatively is required for a long-term satisfactory surgical outcome.

Outcomes of half-width vertical rectus transposition augmented with posterior fixation sutures for sixth cranial nerve palsy

AIM

To describe the experience with half-width vertical muscles transposition (VRT) augmented with posterior fixation sutures.

METHODS

The clinical charts of all patients, who underwent half-width VRT augmented with posterior fixation sutures for sixth cranial nerve palsy from January 2003 to December 2018, were retrospectively reviewed. For each patient, pre- and post-operatively, the largest measured angle was used for the calculations, usually resulting with the angle for distance, except in young infants, where measurements were made at near fixation using the Krimsky test.

RESULTS

Fifteen patients met the inclusion criteria for the study, of them 9 (60.0%) had also medial rectus muscle recession at the time of surgery. Mean follow-up period was 21.4±23.2mo (range 1.5-82mo). Preoperative mean esotropia was 51.3±19.7 prism diopter (PD; range 20-90 PD). Postoperative mean deviation on final follow-up was 7.7±20.2 PD (range -40 to 35 PD; P=0.018). In all patients with preoperative abnormal head position, improvement was noted. Ten (66.7%) patients had improvement in abduction and 10 (66.7%) patients reported improvement in their diplopia, by final follow-up. The addition of medial rectus recession was correlated with a larger change in postoperative horizontal deviation compared to baseline (P=0.026). Two (13.3%) patients developed a vertical deviation in the immediate postoperative period which had resolved in one of them.

CONCLUSION

Half-width VRT augmented with posterior fixation suture, with or without medial rectus muscle recession, is an effective and safe procedure for esotropia associated with sixth cranial nerve palsy. A major improvement in the angle of deviation is expected. Most patients will have improvement in their abnormal head position and diplopia.

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.

[Nishida Extraocular Muscle Transposition Surgery for Abducens Nerve Palsy]

BACKGROUND

Surgical treatment of abducens nerve palsy depends on the remaining function of the lateral rectus muscle. Vertical rectus transposition surgery is indicated if the attempted maximal abduction effort does not rotate the eye beyond the midline. After the first description more than 100 years ago, a variety of muscle transposition modifications have been suggested. Nishida's minimally-invasive adaptation has attracted a great deal of attention in recent years.

PATIENTS AND METHODS

Retrospective case series of four patients with abducens nerve palsy who were treated with Nishida muscle transposition surgery. Patients' characteristics with special emphasis on comparison between pre- and postoperative angle of deviation and ocular motility are reported.

RESULTS

Four patients (2 females, 2 males) were included in this study. Unilateral transposition surgery was performed in a 7-year-old girl and a 37-year-old woman with a left abducens nerve palsy. In a 56-year-old male with a left sixth nerve palsy and in an 82-year-old male with a right sixth nerve palsy the transposition maneuver was combined with a recession of the medial rectus muscle in the same eye. In all patients, ocular motility was improved and the angle of deviation was reduced.

CONCLUSIONS

Transposition of vertical rectus muscles is well established in the surgical treatment of abducens nerve palsy. Nishida's adaptation is a safe, effective and minimally-invasive treatment option. This vessel-sparing technique also allows for equilateral weakening of the medial rectus muscle.

Extraocular Muscle Injury in Zygomatic Implant Placement: A Case Report, Review of the Literature, and Simple Maneuver for Avoidance

Zygomatic implants (ZIs) are used to support dental prostheses in patients with inadequate maxillary bone volume. Although the ZI success rates have been high, cases of inadvertent orbital entry during zygoma drilling have been reported, with varying severity of clinical sequelae. We report the second case treated at our institution of inadvertent orbital entry during zygoma drilling. The patient experienced partial lateral rectus muscle transection resulting in diplopia, and ultimately underwent strabismus surgery. Postoperatively, his diplopia resolved, and only a small angle esophoria persisted. A review of the literature revealed 3 other cases of extraocular muscle injury secondary to orbital entry during zygoma drilling, all of which required strabismus surgery to restore alignment. We propose placement of a metal shoehorn in the inferior fornix during zygoma drilling to protect the globe and intraorbital structures from injury in the event of orbital entry.

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.

Nishida procedure associated with botulinum toxin in a long-standing complete bilateral sixth cranial nerve palsy

In severe cases of abducens or sixth cranial nerve palsy, transpositions of the superior rectus and inferior rectus into the paralytic lateral rectus have been demonstrated to be useful. Numerous techniques have been described over time to carry out these transpositions, such as the Hummelsheim, O'Connor, Jensen, Foster, or Nishida technique. The first 4 techniques mentioned above have an increased risk of anterior segment ischaemia. The case is presented of a long-standing bilateral sixth cranial nerve palsy secondary to a severe cranial injury. Given the risk of ischaemia of the anterior segment, the Nishida technique was chosen in order to reduce the risk of suffering from this complication. This is combined with botulinum toxin in both middle rectus to try to resolve the muscle contracture associated with the long evolution of the case, obtaining good results at 6, and 12 months after the surgical procedure.

Postoperative Correction and Drift After Vertical Rectus Muscle Transposition for Total Sixth Cranial Nerve Palsy

PURPOSE

To determine the magnitude of change between the preoperative and postoperative alignment and amount of postoperative drift for two vertical rectus muscle transpositions (VRTs).

METHODS

Retrospective review of medical records of patients with total sixth cranial nerve palsy who underwent VRT procedures. The primary outcome measure was the magnitude of esotropia in prism diopters (PD) at the preoperative and postoperative visits.

RESULTS

Twenty-seven patients were included. Sixteen had full tendon transposition with Foster augmentation (FTT+FA) and 11 had partial tendon transposition with resection and simultaneous medial rectus recession (PTT+R+MRR). A larger correction was obtained with PTT+R+MRR (mean ± standard deviation [SD]: 52 ± 19 PD; range: 27 to 87 PD) when compared to FTT+FA (mean: 40 ± 13 PD; range: 15 to 68 PD). At postoperative month 2, a greater esotropic drift was noted in the PTT+R+MRR group (16 PD) than the FTT+FA group (6 PD). Although the difference in the amount of correction was not statistically significant (P = .071), the difference in the amount of drift was statistically significant (P = .009).

CONCLUSIONS

There was a trend toward greater correction with PTT+R+MRR than FTT+ FA, but it was not statistically significant. FTT+FA had significantly less postoperative drift than PTT+R+MRR. The results suggest that a small immediate postoperative overcorrection may be desirable in some VRT procedures. [J Pediatr Ophthalmol Strabismus. 2019;56(4):238-242.].

Dual-Augmented Transposition of Vertical Recti in Chronic Abducens Palsy

PURPOSE

To report the results of dual augmentation of vertical rectus muscle transposition (VRT) in the treatment of chronic sixth nerve palsy.

DESIGN

Retrospective case series.

METHODS

This is a retrospective review of medical records of patients with chronic sixth nerve palsy who underwent dual augmented VRT with or without medial rectus (MR) recession from 2013 to 2016. Data collection included sex, age, laterality, and duration of postoperative follow-up. Pre- and postoperative limitation of abduction and adduction were recorded using a 6-point scale. Improvement of esotropia in prism diopter (PD), head turn in degrees, and limitation of abduction and adduction were reported and analyzed.

RESULTS

Fourteen cases were identified. Mean patients' age at the time of surgery was 22.5 years. Postoperatively, esotropia and head turn were corrected by a mean of 31.3 PD and 18.2 degrees, respectively. Limited abduction was improved from -4.3 to -1.6, while in cases that underwent MR recession, adduction declined from 0.4 to -0.3. Postoperative induced small-amplitude hypertropia was reported in 3 cases.

CONCLUSION

Dual augmented VRT was effective in controlling esotropia, head turn, and limited abduction associated with chronic sixth nerve palsy with low rate of induced vertical deviation. Combined MR recession carries a risk of induced limitation of adduction.

Comparison of the efficiency of various muscle transposition procedures using a novel three-dimensional model

AIM

To investigate the performance of a newly developed three-dimensional (3D) biomechanical model in various transposition procedures for correction of complete sixth nerve palsy with educational purpose.

METHODS

A 3D biomechanical eye model was created using Hyperworks software based on geometry data and the biochemical properties of the eyeball and extraocular muscles. A complete sixth nerve palsy model was achieved via modification of lateral rectus muscle strength. Four different muscle transposition procedures (the Hummelsheim, Jensen, Foster, and muscle union procedures) were set up, and the objective surgical effect of each procedure was calculated using 3D model simulation.

RESULTS

In the 3D simulation, sixth nerve palsy was modeled by rotating the eye 34.16 degrees in the medial direction, consistent with 70 prism diopter (PD) esotropia. In surgical model simulation, the Hummelsheim procedure resulted in a 28 PD reduction of total deviation, the Jensen procedure achieved a 34 PD reduction, the Foster procedure led to a 57 PD reduction, the muscle union procedure yielded a 57 PD reduction in esotropia in sixth nerve palsy.

CONCLUSION

The 3D simulation provided a consistent model of sixth nerve palsy and objective data excluding the potential for variation of surgical skill. It could also help predict surgical outcomes.

No split, no tenotomy transposition procedure for complete abducens palsy

Abducens palsy is one of the commonly encountered cranial nerve palsies in strabismus clinic. For large-angle esotropia, due to complete abducens palsies, various vertical recti transposition (VRT) procedures have been described. Hummelsheim and Jensen's procedure are especially popular among them. Risk of anterior segment ischemia and induced vertical deviation postVRT prompt to search for better procedures to correct the esotropia and also improve the abduction. Modified Nishida's procedure (no split, no tenotomy transposition) is one of the newly described procedure in this direction. We describe three cases of complete abducens nerve palsy treated by this procedure.

Double Augmented Vertical Rectus Transposition for Large-Angle Esotropia Due to Sixth Nerve Palsy

PURPOSE

To study the binocular alignment and ocular motility in patients with large-angle esotropia due to sixth nerve palsy treated with double augmented vertical recti transposition.

METHODS

This was a prospective interventional study. Fifteen patients with non-resolving sixth nerve palsy who underwent surgical correction were included in the study. Fourteen patients also underwent an additional medial rectus recession. Two patients with an associated small vertical deviation had a selective augmentation of one vertical rectus muscle. Binocular alignment, ocular motility, duction limitation, improvement in head posture, induced vertical deviations, and field of diplopia-free binocular single vision (when possible) were analyzed. Successful outcome was defined as a residual horizontal deviation of 10 prism diopters (PD) or less with no vertical deviation at final follow-up (6 months).

RESULTS

The double augmented Hummelsheim procedure improved esotropia from 58.3 ± 10.8 PD preoperatively to 7.2 ± 5.1 PD postoperatively (P = .001). Three (20%) patients had residual deviation of greater than 10 PD, of which 1 patient had diplopia and was treated with prisms. Postoperative binocular field of vision was performed in 6 patients, the mean of which was 20° for abduction and 45° for adduction. Three of 6 patients had elimination of face turn and the rest had residual head posture of less than 5°. Two patients had an induced vertical deviation of less than 4 PD. In patients who had selective augmentation, the vertical deviation was completely corrected.

CONCLUSIONS

The patients operated on with double augmentation of the Hummelsheim procedure combined with medial rectus recession had reduced mean primary esotropia and improved diplopia-free field of vision postoperatively. [J Pediatr Ophthalmol Strabismus. 2016;53(6):369-374.].