Modified Nishida muscle transposition procedure combined with superior rectus muscle tenotomy for inferior rectus muscle aplasia.

The modified Nishida muscle transposition procedure, in which one-third of each vertical rectus muscle belly is sutured onto the sclera in the infero- and superotemporal quadrants without either tenotomy of the vertical rectus muscles or splitting of the vertical rectus muscle is an effective treatment for abducens nerve palsy. We report a case of inferior rectus muscle aplasia treated using the modified Nishida procedure to transpose both horizontal rectus muscles inferiorly combined with superior rectus tenotomy.

New Surgical Double Interlacing Technique for Correction of Sixth Cranial Nerve Palsy.

This interventional case series presents a novel surgical procedure involving double interlacing for the correction of esotropia in individuals with sixth cranial nerve palsy. The technique involves first splitting the tendons of the superior rectus, inferior rectus, and lateral rectus muscles. Subsequently, the superior half of the lateral rectus muscle is passed through the undisinserted superior rectus muscle, and the inferior half of the lateral rectus muscle is passed through the undisinserted inferior rectus muscle. Finally, the two halves of the lateral rectus muscle are sutured together and reattached at the original insertion point. The surgical outcomes demonstrate a significant improvement in alignment, abduction, and binocular vision. [J Pediatr Ophthalmol Strabismus. 2023;60(5):e58-e64.].

Case Report: Unilateral Cranial Nerve VI Palsy Secondary to Intracranial Hypotension.

SIGNIFICANCE: Intracranial hypotension is a condition that occurs from a cerebrospinal fluid leak. Various visual symptoms have been associated with this condition. Cranial nerve VI (CN VI) palsies are the most common ocular manifestation, as the abducens nerve is prone to injury because of its intracranial anatomical course. PURPOSE: This case report presents a CN VI palsy secondary to intracranial hypotension from ventriculoperitoneal shunt overfiltration. Diagnosis, treatment, and management considerations are discussed. No identifiable health information was included in this case report. CASE REPORT: A 70-year-old White man was referred to the eye clinic for evaluation of binocular horizontal diplopia. The patient had a recent history of a left ventriculoperitoneal shunt for a persistent cerebrospinal fluid leak after complex mastoid surgery. The patient was also symptomatic for positional headaches, which improved in a recumbent position. He was diagnosed with a left CN VI palsy secondary to intracranial hypotension from a ventriculoperitoneal shunt overfiltration. The patient was followed up by neurosurgery for shunt adjustments to resolve the overfiltration. Binocular horizontal diplopia was managed conservatively with Fresnel prism. CONCLUSIONS: Intracranial hypotension should be considered in patients presenting with cranial nerve palsies and positional headaches. Obtaining neuroimaging and comanaging with neurology or neurosurgery are advised to make prompt diagnosis and treatment. Careful clinical monitoring and conservative diplopia therapy are recommended as visual symptoms improve upon resolution of the cerebrospinal fluid leak.

Predictors of Surgical Outcomes in Patients with Abducens Nerve Schwannoma: A Comprehensive Systematic Review and a Case Report.

BACKGROUND: Abducens nerve (AN) schwannomas are extremely rare tumors. Clinical characteristics and factors that influence postoperative outcomes are not well defined. OBJECTIVE: To characterize clinical features of AN schwannomas and predictors of surgical outcomes. METHODS: PRISMA-guided systematic review of the literature on AN schwannomas was performed. Subsequently, univariate and multivariate regression analyses were performed to identify the predictive value of variables that influence postoperative outcomes. RESULTS: A total of 42 studies with 55 patients were evaluated. The mean age at presentation was 43.9 ± 14.6 years. The most common presenting symptom was cranial nerve VI palsy (69.1%). Cavernous sinus (49.1%) and prepontine cistern (36.3%) were the most commonly involved locations. Complete recovery after surgery was seen in 36.3% at a median follow-up of 28.4 ± 25.8 months. Preoperative AN palsy (P < 0.001), suboccipital approach (P = 0.007), and subtotal resection of tumor (P = 0.044) were significant protective factors for postoperative complications. Prepontine location and postoperative complications were poor prognostic indicators of AN recovery (odds ratio [OR], 0.10, P = 0.030 and OR, 0.10, P = 0.028, respectively). Subtotal resection was significantly correlated with higher odds of AN recovery (OR, 6.06; P = 0.040). CONCLUSIONS: AN schwannomas are rare but serious tumors that can cause significant morbidity, with only approximately one third of patients showing complete recovery after surgery. The suboccipital approach was a protective factor for postoperative complications, especially when combined with subtotal resection. Knowledge of these factors along with tumor characteristics helps optimize surgical planning and preoperative counseling.

Surgical outcomes following strabismus surgery for abducens nerve palsy.

PURPOSE: To assess ocular alignment outcomes and their stability for patients who underwent strabismus surgery for abducens nerve palsy and to identify preoperative patient variables that predict surgical success or repeated surgeries. METHODS: We retrospectively reviewed the medical records of patients diagnosed with abducens nerve palsy and who subsequently underwent strabismus surgery. RESULTS: A total of 209 patients (386 procedures) were included. The mean number of surgeries for patients was 1.9 ± 1.4. Success was achieved after a single surgery for 112 patients (53.6%), and success was achieved for an additional 42 patients, for a total of 154 patients (73.7%), following all surgeries. Preoperative abduction deficit severity was the only variable predictive of surgical success, with mild deficits having the highest odds of both initial success (OR = 5.555; CI, 2.722-11.336) and final success (OR = 5.294; 95% CI, 1.931-14.512). When analyzing survival time until additional surgery, the median survival was 406 days; abduction deficit severity, older age, other coincidental motility abnormalities, greater magnitude esotropia, and surgical technique were predictive of repeat surgical incidence. CONCLUSIONS: In our patient cohort, preoperative abduction deficit was an important predictor of both surgical success and repeat surgical incidence for abducens nerve palsy. Older patient age, additional motility abnormalities, and greater amounts of baseline strabismus were also associated with greater likelihood of multiple surgeries.

Inferior rectus transposition as a secondary surgery in patients with acquired abducens nerve palsy.

We report the outcomes in 2 patients with acquired abducens nerve palsy with residual esotropia following superior rectus transposition and medial rectus recession who subsequently underwent inferior rectus transposition as a second procedure. Both patients showed improved abduction and reduced esotropia, with no induced cyclotorsion or vertical deviation. Inferior rectus transposition as a secondary procedure in these 2 patients with abducens nerve palsy appeared to augment the effect of prior superior rectus transposition and medial rectus recession.

A Potentially Adjustable Modification of the Nishida Procedure.

For patients with a complete, chronic abducens nerve palsy and resulting abduction deficit, a transposition procedure is often the procedure of choice. One such transposition procedure involves transposing the superior rectus (SR) and inferior rectus (IR) laterally without disinserting or splitting either muscle. While effective, this procedure - like many transposition procedures - carries with it the risk of induced torsional or vertical misalignment. Here, we describe an adjustable variation of the above transposition procedure, one which potentially would allow for post-operative correction of induced vertical or torsional deviations.

Overcorrection after vertical muscle transposition with augmentation sutures in sixth nerve palsy.

PURPOSE: To report a series of cases, who developed consecutive exodeviation after vertical muscle transposition (VRT) performed for sixth nerve palsy, describe their management and analyse their outcome. DESIGN: Retrospective case series. METHODS: This is an institutional study on patients who developed consecutive exotropia following VRT for sixth nerve palsy in two different centres. The age, gender, cause, and time to surgery were reviewed. Ductions, versions and angles of misalignment were analysed. In those who developed an exotropia >10 PD after surgery, a second surgery was performed. The time to the second surgery, intra-operative findings, surgical procedure and outcome were studied. RESULTS: A total of 164 cases of VRT for sixth nerve palsy were identified. Nine patients developed consecutive exotropia >10 PD (5.5%). There were no significant differences in the characteristics of those who developed overcorrection compared to those who did not. Five patients had full-tendon muscle transposition, three patients had Hummelsheim procedure and one patient had Jensen procedure. The average angle of consecutive exotropia was 26 ± 9 Δ (range 10-40 Δ). After the second surgery, angle of exotropia decreased to 21 ± 15 PD. Seven patients still had residual exotropia ≥10Δ and the exotropia was corrected in the remaining two patients. The time to second surgery in those two patients was much shorter than the other seven patients. CONCLUSIONS: Patients who undergo VRT should be followed up in the early post-operative period and revisiting the transposition should be done immediately in case of consecutive exotropia to avoid permanent overcorrection.

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.

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.

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 ≤8Δ 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 42.6Δ ± 8.1Δ (range, 34Δ-57Δ) for distance and 42.1Δ ± 7.5Δ (35Δ -57Δ) 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.

Anterior segment ischemia following modified Nishida procedure.

Anterior segment ischemia (ASI) can occur following strabismus surgery on multiple muscles. Procedures such as modified Nishida procedure (MNP) have been developed to reduce the risk of ASI. We report the case of a 68-year-old patient presenting with traumatic bilateral abducens nerve palsies who required surgical intervention. We performed MNP with medial rectus recession. The patient presented with reduced vision, corneal edema, anterior chamber reaction, and pupillary dilation 24 hours after surgery. A diagnosis of ASI was made, and immediate reversal of the Nishida procedure was performed. Symptoms improved within 24 hours. In this case, ASI may have been caused by ligation and compression of ciliary arteries due to overstretching of the vertical rectus muscles during transposition.

Temporary 6TH cranial nerve paralysis after accidental durotomy in endoscopic disc surgery.

We present a unique case of 6th nerve palsy following accidental durotomy in endoscopic lumbar spine surgery, which has not been reported in the literature before. A 72- year-old female patient was admitted to our outpatient clinic complaining of right leg pain for 6 months. A 4/5 motor paresis was observed on her right toe with a positive Lasegue test at 45°. On her magnetic resonance imaging (MRI), a L5-S1 disc herniation was detected. The patient was planned for percutaneous endoscopic interlaminar disc surgery. The extruded disc was adherent to the dura. During removal, a dural tear was observed. She was relieved of her right leg pain immediately after surgery, but after 30 min postoperatively, she complained of double vision with left abducens nerve paralysis. On cranial MRI, no abnormality could be observed. Intravenous fluids were administered and the paralysis resolved on the postoperative 24th hour. The patient was discharged from the hospital and did not show any complaints on her follow-ups. A 6th nerve palsy can be caused due to alterations of intracranial pressure or mechanic injury. We believe that the durotomy following removing of the disc fragment caused a rapid drainage of CSF, leading to intracranial hypotension and injury of the abducens nerve. Intracranial pressure should be monitored perioperatively and brisk deteriorations has to result in immediate finishing of the surgery to avoid further secondary damage.

[Clinical observation of superior rectus transposition with/without augmented suture and vertical rectus transposition for the treatment of strabismus caused by complete abducens nerve palsy].

Objective: To evaluate the efficacy and safety of superior rectus transposition (SRT) with/without augmented suture and vertical rectus transposition (VRT) for the treatment of strabismus caused by complete abducens nerve palsy. Methods: This was a retrospective cohort study. Forty-two patients (42 eyes) with complete abducens nerve palsy underwent strabismic surgeries from January 2015 to November 2020 in Tianjin Eye Hospital. According to the different procedures, the patients were divided into three groups: SRT group (16 cases, SRT with medial rectus recession), superior rectus transposition with augmented suture (SRTA) group (13 cases, SRT with Buckley suture and medial rectus recession) and VRT group (13 cases). The preoperative and postoperative (1, 6 and 12 months) data including deviations, ocular motility, binocular vision and surgical complications among three groups were analyzed and compared. χ2 test was used for comparison of count data among three groups. The measurement data were compared among three groups by the repeated measures ANOVA. LSD-t test was used for within-group comparison and between-group comparison. Results: There was no difference in sex ratio, age and course of disease among the groups (all P>0.05). The horizontal deviations of the three groups at 1, 6 and 12 months after surgeries was lower than that before surgeries, and the difference was statistically significant (all P<0.001). The horizontal deviations of the SRT group, SRTA group and VRT group at 12 months after surgeries were (+0.8±5.8), (+0.8±4.5), (+1.2±2.5) prism diopters (PD), respectively, lower than that of the preoperative (+82.8±17.2), (+77.7±26.1), (+71.5±18.6) PD. However, there was no significant difference among different postoperative follow-up timepoints (all P>0.05). There was no difference in horizontal deviations before surgeries and at 1, 6 and 12 months after surgeries among three groups (P>0.05). There were significant differences in the scales of abduction motility among preoperative, postoperative 1, 6 and 12 months measurements for three group (all P<0.001). The scales of abduction before surgeries in the SRT group, SRTA group, and VRT group were (-4.4±0.5), (-4.4±0.5), (-4.5±0.5) scale and at 12 months after surgeries were (-2.3±0.7), (-2.2±0.5), (-2.1±0.6) scale respectively. But there was no change among different postoperative follow-up timepoints (all P>0.05). Preoperative and postoperative 1-, 6-and 12-month abduction motility was similar among three groups (P>0.05). There were significant differences in the scales of adduction limitation among preoperative, postoperative 1-, 6-and 12-months measurements for three group (all P<0.05). But there was no change among different postoperative follow-up timepoints (all P>0.05). There were significant differences between the SRT group [(-0.9±0.6), (-0.8±0.6) scale] and the SRTA groups [(-1.5±0.5), (-1.4±0.5) scale] (t=-2.62, -2.52) and between the SRTA group and the VRT group [(-0.8±0.8), (-0.6±0.7) scale] (t=2.62, 3.01) at 6 and 12 months after surgeries (all P<0.05). The outcomes of binocular vision at postoperative 12 months were similar among three groups (P>0.05). No patient had torsional diplopia and anterior segment ischemia. Only 2 patients from the SRTA group had hypotropia of 4 to 5 PD in the primary position associated with supraduction limitation. Conclusions: SRT with/without augmented suture and VRT are effective and safe procedures for the treatment of strabismus caused by complete abducens nerve palsy. They could correct deviations, improve abduction motility and restore binocular vision, with stable outcomes and a small risk of vertical and torsional diplopia.

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.

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.

Increased MIB-1 Labeling Index Is Associated with Abducens Nerve Morbidity in Primary Sporadic Petroclival Meningioma Surgery: Beyond Location and Approach.

Abducens nerve palsy is a severe dysfunction after petroclival meningioma (PC MNG) surgery. The objective of this investigation was to analyze abducens nerve outcomes in patients who underwent the retrosigmoid approach in relation to the MIB-1 index. Thirty-two patients with primary sporadic PC MNG were retrospectively analyzed. Mean follow-up was 28.0 months. Analysis of the MIB-1 index was performed to evaluate the abducens nerve outcome. An optimal MIB-1 index cut-off value (<4/≥4) in the association with postoperative CN VI palsy was determined by ROC analysis (AUC: 0.74, 95% CI: 0.57−0.92). A new-onset CN VI palsy was present in 7 cases (21.88%) and was significantly associated with an increased MIB-1 index (≥4%, p = 0.025) and a peritumoral edema in the brachium pontis (p = 0.047) which might be caused by the increased growth rate. Tumor volume, cavernous sinus infiltration, auditory canal invasion, and Simpson grading were not associated with new CN VI deficits. Six (85.7%) of the 7 patients with both an increased MIB-1 index (≥4%) and new abducens nerve palsy still had a CN VI deficit at the 12-month follow-up. A peritumoral edema caused by a highly proliferative PC MNG with an elevated MIB-1 index (≥4%) is associated with postoperative abducens nerve deficits.

Abscess of the cavernous sinus in a child: a case report.

BACKGROUND: The cavernous sinus, which has several important structures, can be affected by various lesions, including tumor, vascular, infection, and inflammation. CASE REPORT: We reported a rare case of abscess of the cavernous sinus in a child presenting with headache and abducens paralysis. Exploratory surgery was performed via the Dolenc approach, and the patient recovered from abducens paralysis 3 months later. CONCLUSION: Abscess of the cavernous sinus is rare.  Inspection of cavernous sinus can confirm the characteristics of the lesion and decompress the cavernous sinus, which may be beneficial for nerve function recovery.