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

Purpose:Since 1907, multiple transposition procedures have been established for the treatment of abducens paralysis. In this study, we try 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. All patients underwent the transposition procedure between 2016 and 2019.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: The temporal parts of the vertical muscles bellies are joined and sutured to the lateral rectus muscle. A full tendon transposition was performed on 11 patients, a half tendon transposition procedure on one 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 -1mm). The postoperative mean deviation was ET of 2° PD (range: 0 to ET 5°). The postoperative mean abduction improvement was 5mm past midline (range: +2 to +6mm). There were no complications, or signs of anterior segment ischemia. Conclusions: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.

Worldwide outcomes of nasal transposition of the split lateral rectus muscle for strabismus associated with 3rd-nerve palsy

Background/aimsTo determine success rate and complications associated with nasal transposition of the split lateral rectus muscle (NTSLR) for treating strabismus from 3rd-nerve palsy.MethodsAn international, multicentre, registry of patients with unilateral 3rd-nerve palsy treated with NTSLR was created. Patients with concurrent surgery on the contralateral eye were excluded. Primary outcome was horizontal alignment within 15 prism dioptres (PD) of orthotropia. Incidence of technical difficulties and vision-threatening complications by 6 months post-procedure were reported.ResultsNinety-eight patients met inclusion criteria. Median age was 33.5 years (IQR 10.75–46). Aetiologies included congenital (31%), neoplastic (16%) and traumatic (15%). Twenty-five per cent of patients had prior ipsilateral strabismus surgery. Median exotropia decreased from 70PD preoperatively (IQR 50–90) to 1PD postoperatively (IQR 0–15.5), with a success rate of 69%. Performing concurrent superior oblique muscle tenotomy (SOT) was independently associated with success (p=0.001). Technical challenges occurred in 30% of cases, independently associated with a history of ipsilateral strabismus surgery (p=0.01). Eleven per cent of patients had vision-threatening complications, independently associated with more posterior placement of the split lateral rectus (LR) muscle (p<0.001), and most commonly transient serous choroidal effusion. Surgical placement of the split LR muscle within 4.25 mm of the medial rectus (MR) muscle insertion reduced this risk.ConclusionNTSLR significantly improved primary position alignment altered by 3rd-nerve palsy. Concurrent SOT and placement of the split LR muscle ≤4.25 mm posterior to the MR muscle insertion optimised outcomes. NTSLR proved technically challenging when prior ipsilateral strabismus surgery had been performed.

Correlation between Thyroid-stimulating Antibody Level Change and Extraocular Muscle Thickness Change in Thyroid Eye Disease

Purpose: To investigate the changes in extraocular muscle thicknesses by variations in the thyroid stimulating antibody (TSAb) level in patients with thyroid eye disease (TED).Methods: A total of 67 TED patients were enrolled. They were divided into two groups: an experimental group with clinically significant elevated TSAb levels (≥140 IU/L) and a control group (TSAb <140 IU/L). All of the lateral, medial, superior, and inferior rectus muscle thicknesses were measured with the aid of anterior segment optical coherence tomography (OCT). The average thicknesses for both eyes were recorded for each patient based on the values measured at the ends of the muscles (which become vertically thinner from the points of tendon attachment). We measured changes in TSAb levels and extraocular muscle thicknesses after two follow-up periods and sought correlations among these parameters.Results: At the initial visits, the inferior rectus muscle thickness was positively correlated with the TSAb level in the experimental group (p = 0.045, r = 0.478). None of the medial, superior, or lateral rectus muscle thicknesses were so correlated. On follow-up, the variation in TSAb level correlated negatively with changes in lateral rectus muscle thickness (p = 0.038, r = -0.357). The superior rectus muscle thickness tended to be negatively correlated with the TSAb level, but statistical significance was not attained (p = 0.146, r = -0.669). The thicknesses of the inferior and superior rectus muscles did not change over time.Conclusions: In TED patients, TSAb variations seem to reflect the extent of periorbital tissue edema, thus correlating negatively with especially lateral rectus muscle thickness changes.

Orbital pseudotumor masquerading orbital cellulitis

Here with presenting a case of pseudotumor orbit initially diagnosed as orbital cellulitis which responded to steroids. A 44 year old male presented with complaints of swelling, redness, watering and inability to open the right eye for 1 day. He had no h/o trauma or insect bite. On examination, visual acuity in both eyes was 6/6. The right eye was proptosed with gross restriction of the extra ocular movements, conjunctival congestion and chemosis. The intra ocular pressure was 52 mm Hg. The left eye was normal. CT orbit showed enlargement of right lateral rectus muscle and lacrimal gland, with fat stranding and soft tissue thickening of periorbital, pre septal and perinasal regions diagnostic of pseudotumor tumour. He was started on high dose oral steroids with which he improved dramatically.

Comparative Study of Recession with Y- splitting Vs Recession Only of Lateral Rectus Muscle Surgery for up/down Shoot in Duane Retraction Syndrome

Purpose: To evaluate and compare the effectiveness of lateral rectus muscle recession with Y-splitting versus recession only in the surgical treatment of up/down shoot in Duane retraction syndrome patients. Material and Methods: In this prospective study, 42 patients of Duane retraction syndrome with up/down shoot underwent surgery over a period of seven years, were divided into two groups of twenty one each. In group A, Y-splitting of lateral rectus with recession and in group B, only lateral rectus recession was performed. In all the patients width of lateral rectus muscle at its insertion was measured. Postoperative results were compared and analyzed in terms of up/down shoot on adduction. Data analysis was performed using R Core Team (2020) R., and the P value <0.05 was taken as significant. Results: The Mean age at the time of surgery was 12.5 ± 4.5 years in group A, and 11.5 ± 3.9 years in group B (range, 5 to 22 years). Correction of up/down shoot was 100% in group A and 81% in group B. Five patients in group B showed no improvement of up/down shoot in whom the width of lateral rectus was 7mm or less and the surgery was recession of lateral rectus only. In these 5 patients, Y-splitting of lateral rectus was done in second sitting with good result Mean follow up was 12 months (range, 3 weeks to 3 years). Conclusions: Recession of lateral rectus muscle with Y-splitting is more effective (100%) when compared to recession only, in correcting significant up/down shoot in Duane retraction syndrome. Lateral rectus muscle Y- splitting is not necessary in these patients with upshoot / down shoot if the width of the muscle at insertion is within normal limits (8.3 -12.5 mm). In these cases simple recession is enough. Lateral rectus muscle Y splitting is essential when the width of lateral rectus muscle at insertion is 7mm or less.

Lateral rectus muscle differentiation potential in paralytic esotropia patients

Purpose and background Recently, we found that maximal medial rectus recession and lateral rectus resection in patients with complete lateral rectus paralysis resulted in a partial restoration of abduction. In an attempt to understand some of the mechanisms involved with this effect we examined gene expression profiles of lateral recti from these patients, with our focus being directed to genes related to myogenesis. Materials and methods Lateral recti resected from patients with complete lateral rectus paralysis and those from concomitant esotropia (controls) were collected. Differences in gene expression profiles between these two groups were examined using microarray analysis and quantitative Reverse-transcription PCR (qRT-PCR). Results A total of 3056 differentially expressed genes (DEGs) were identified between these two groups. Within the paralytic esotropia group, 2081 genes were up-regulated and 975 down-regulated. The results of RT-PCR revealed that PAX7, MYOG, PITX1, SIX1 and SIX4 showed higher levels of expression, while that of MYOD a lower level of expression within the paralytic esotropia group as compared with that in the control group (p < 0.05). Conclusion The decreased expression of MYOD in the paralytic esotropia group suggested that extraocular muscle satellite cell (EOMSCs) differentiation processes were inhibited. Whereas the high expression levels of PAX7, SIX1/4 and MYOG, suggested that the EOMSCs were showing an effective potential for differentiation. The stimulation resulting from muscle surgery may induce EOMSCs to differentiate and thus restore abduction function.

Augmented Lateral Rectus Muscle Recession for treatment of Infantile Exotropia

Background: For the majority of the patients, surgical treatment of primary infantile exotropia (PIE) with large exodeviation angels of more than 50 prism diopters (PD) is not satisfactory. We evaluate the effectiveness of augmented lateral rectus (LR) muscle recession in treatment of congenital exotropia with large deviation angles. Methods: A retrospective analysis was performed for 25 patients with congenital exotropia who had at least 60 prism diopters (PD). Augmented LR recession was performed using a hemi hang-back technique. The ocular alignment, ocular motility and binocular vision were evaluated pre- and postoperatively. Results: There were 14 male and 11 female affected individuals with congenital exotropia included in this study, with a mean age of (3.92±2.02) years (range, 1 - 7 years). The average exodeviation angle was (68.0±8.78) PD (range, 60 - 80 PD) preoperatively. All patients underwent bilateral LR recession, of whom 3 patients underwent bilateral inferior oblique muscle transposition in the same operation. The mean surgical dosage was (11.08±1.19) mm for each lateral rectus muclse. All patients did not have abduction deficiency after a large amount of lateral rectus recession. 21 of 25 patients (84.0%) acquired orthophoria at the primary gaze position at the final visit. 13 patients obtained binocular vision. Conclusions: Augmented bilateral LR recession is an effective and safe surgical procedure for treatment of congenital exotropia with large deviation angles.