Outcomes of Early Surgery in Children under Four Years Old with Large Angle Intermittent Exotropia

Purpose: To find out the significance of early surgery in children of 4 years old and under with large angle intermittent exotropia of 35 prism diopters (PD) and more by examining the results of bilateral lateral rectus recession surgery and factors influencing the surgical outcome.Methods: It was a retrospective study of patients who underwent bilateral lateral rectus muscle recession surgery between 2006 to 2016 with intermittent exotropia greater than or equal to 35 PD and who were able to follow-up for at least 2 years after surgery were divided into two groups based on age of 4 years old. The surgical motor success was defined as exodeviation less than 10 PD, esodeviation less than 8 PD. The angle of deviation, binocular function, best corrected visual acuity, and amount of corrected PD per lateral recession (PD/mm) were compared at each observation point after surgery.Results: The motor success of bilateral rectus muscle recession surgery was 85% in children of age 4 years and under, 65.5% in age over 4 years. Success rate of early surgery was 1.3 times higher in younger age group, but there was no statistical meaning. The complication of surgery after 2 years of follow up was less in younger group-the rate of recurrent exotropia was 15% in younger group, 31.3% in older group and the rate of consecutive esotropia was 0% and 3.1%, respectively. Stereoacuity after 2 years of surgery was not fall behind in younger group compared to older group.Conclusions: It is possible to obtain good surgical results by performing early surgery rather than hesitating to operate due to the younger age in patients younger than 4 years old with large angle exotropia of 35 PD and more for long-term follow up and efficient patient management.

Changes in Hypertropia in Patients with Asymmetric Inferior Oblique Overaction after Symmetric Inferior Oblique Myectomy

Purpose: This study assessed the effects of bilateral inferior oblique myectomy for hypertropia on the preoperative vertical deviation angle in patients with asymmetric primary inferior oblique overaction (IOOA).Methods: This study included patients who underwent bilateral inferior oblique myectomy and lateral rectus recession due to asymmetric primary IOOA and intermittent exotropia, and were followed up for at least 6 months postoperatively. Pre- and post-operative vertical deviation angles were compared. The correlation between the extent of correction of vertical deviation after surgery and residual hypertropia, according to the preoperative degree of vertical deviation and difference between bilateral IOOA, was evaluated.Results: This study included 178 eyes from 89 patients. The angle of hypertropia in the primary position was reduced from 3.2 ± 2.2 prism diopters (PD) preoperatively to 0.5 ± 2.5 PD postoperatively (Wilcoxon signed-rank test, p < 0.001). No significant correlation was observed between the preoperative interocular difference in IOOA and postoperative extent of correction of the vertical deviation (r = 0.044, p = 0.684), or between the preoperative difference in bilateral IOOA and residual hypertropia (Spearman's rank-order correlation, r = -0.084, p = 0.432). Increased preoperative hypertropia correlated with a greater extent of surgical correction of the vertical deviation (r = 0.733, p < 0.001). Preoperative hypertropia had no significant correlation with residual hypertropia (Spearman's rank-order correlation, r = 0.182, p = 0.087).Conclusions: In symmetric bilateral inferior oblique myectomy with bilateral lateral rectus recession for asymmetric bilateral primary IOOA with V-type intermittent exotropia, a positive correlation between the degree of preoperative vertical deviation and extent of correction of the vertical deviation was observed. Additionally, IOOA and hypertropia were significantly improved postoperatively.

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.

Effect of Applying Binocular Visual Training after Slanted Lateral Rectus Recession on Orthophoric Rate and Binocular Visual Function Recovery on Patients with Convergence Insufficiency-Type Intermittent Exotropia

Objective. To explore the effect of applying binocular visual training after slanted lateral rectus recession on orthophoric rate and binocular visual function recovery on patients with convergence insufficiency-type intermittent exotropia (CI-IXT). Methods. A total of 76 CI-IXT child patients treated at the Strabismus and Pediatric Ophthalmology Department of our hospital from June 2019 to June 2020 were selected as the research objects, and those who met the inclusion criteria were equally divided into group A (63 eyes) and group B (61 eyes) according to the sealed envelope randomization. All child patients accepted the slanted lateral rectus recession, and after that, those in group A accepted the binocular visual training and those in group B accepted the conventional visual function rehabilitation training, so as to compare their position of eye, the best corrected visual acuity, etc., after training for statistical analysis. Results. Compared with group B after one month of surgery, group A had significantly less patients with grade I binocular vision function ( P < 0.001) and more patients with grade II and III vision function ( P < 0.05); between group A and group B, after 3 months and 6 months of treatment, the number of eyes with normal stereoscopic vision was significantly higher in group A ( P < 0.05); at 15 days, 1 month, 3 months, and 6 months of treatment, the visual strain scores of group A were significantly lower ( P < 0.001); after treatment, the number of orthophoria eyes was significantly higher in group A ( P < 0.001), while the numbers of overcorrected eyes and undercorrected eyes were significantly higher in group B ( P < 0.001); and the total incidence rate of adverse reactions was significantly lower in group A ( P < 0.05). Conclusion. Applying binocular visual training to child patients with CI-IXT after slanted lateral rectus recession can promote the recovery of binocular vision and ensure higher safety, and further study will help to establish a better solution for the affected children.

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.

The diagnostic dilemma of Masticator space tumor

The masticator space is an anatomical and functional entity centered on the mandibular ramus, which divides it into medial and lateral compartments. The masticator spaces considered paired supra-hyoid cervical spaces on each side of the face that extend from the angle of the mandible to the parietal bone. The masticator space contains the mastication muscles, posterior mandible, and mandibular nerve. They are separated from the nasopharynx by the parapharyngeal spaces bilaterally. Primary malignancy of the masticator space is very uncommon.Here we report a diagnostic dilemma of primary masticator space malignancy mistaken by nasopharyngeal carcinoma as the patient 40-year old gentleman presented with left lateral rectus palsy and left nasopharynx fullness.

P30 A case of recurrent orbital myositis

Case report - Introduction An interesting case of an 11-year recurrent isolated lateral rectus myositis. Initially responsive to short courses of oral steroids; however, this has more recently become refractory and now the patient is unable to wean off steroids. The use of biologics in these patients is uncommon and there are very few case reports of this and the outcomes. We present a case of refractory orbital myositis treated with rituximab. Case report - Case description A 38-year-old female presented in 2009 with ocular pain, swelling and diplopia. After review by the ophthalmology team an MRI orbits was requested which showed swelling and enhancement of the right lateral rectus muscle, consistent with orbital myositis. She had no other symptoms of myositis elsewhere, and no other symptoms suggestive of a connective tissue disease. Her ANA, ENA and extended myositis panel were negative and therefore aetiology was uncertain. She had no past medical history, but was later diagnosed with hypothyroidism with positive TPO antibodies. Throughout the 11 years since diagnosis her thyroid disease has been well controlled, and she has had normal free T3/T4 and TSH. It was felt that thyroid eye disease was unlikely to present with a single muscle. She was initially treated with a course of 40mg oral prednisolone reducing over 6 weeks and symptoms resolved. In 2013 she had her first relapse, which was treated with prednisolone reducing over the course of 12months, and again symptoms resolved. Her third relapse in 2019 was treated with steroids, but patient was unable to wean off this, requiring 60mg of prednisolone, and at this point was referred to rheumatology for steroid sparing agents. Between 2013 and 2019 there was MRI progression with volumetric enlargement of the right lateral rectus with intra-orbital space reduction. Under the care of rheumatology, she had repeat connective tissue disorders and myositis screen. She was started on azathioprine as a steroid sparing agent. This had little effect and she was still debilitated by orbital pain and diplopia, and unable to reduce her prednisolone below 30mg daily. She trialled intra-orbital steroid injections with little benefit. She has now been started on rituximab infusions to allow us to wean steroids. Thus far she has had two doses and we await the outcome from this treatment. Case report - Discussion Orbital myositis can be a debilitating condition causing diplopia and pain, as in the case of this 38-year-old female who has been off work for the past year due to the condition. It can affect single muscles or multiple muscles and may be unilateral or bilateral. The major differential diagnosis is thyroid eye disease which would not usually cause an isolated myopathy, is usually painless and slowly progressive and as such was felt unlikely to be the underlying pathology in this case. From a literature review into idiopathic orbital inflammation, including myositis, 75% of patients are found to have a good response to corticosteroids. Second-line treatments include radiotherapy, methotrexate/azathioprine and other biologic agents. A case report in 2014 of 10 patients with orbital myositis refractory to steroids and at least one other immunosuppressant, demonstrated that rituximab was safe and effective, with 7/10 patients noting improvement of their symptoms. Out of those seven patients, four had been on steroids at induction of rituximab and all of the patients were able to reduce their steroid dose. The patients in this trial received two initial doses of rituximab and were permitted to have a further dose at 24 weeks if there were recurrence of symptoms. Four out of the seven patients required a further infusion after 24 weeks. In a review of the literature, we have noted a further two case reports of the use of rituximab in orbital myositis from 2008 and 2012 with good response. Both patients were unable to wean from corticosteroids and had tried other DMARDs such as methotrexate. Other case reports of biologics therapy include a case report of two patients in which adalimumab was used and allowed steroid reduction with good results for at least 9 months. Case report - Key learning points

Long term surgical outcomes of unilateral recession-resection versus bilateral lateral rectus recession in basic-type intermittent exotropia in children

The long-term results of surgical treatment of intermittent exotropia (X(T)) according to the type of surgery are controversial. We conducted a retrospective cohort study to compare the long-term results between unilateral recession-resection (RR) and bilateral lateral rectus recession (BLR) with an average follow-up of 9.5 years in children with basic-type X(T). Patients with basic-type X(T), who underwent RR (RR group) or BLR (BLR group) and were followed-up for more than 5 years postoperatively, were analyzed. Of the 560 patients, 363 patients received BLR and 197 patients underwent RR. There was no significant difference in the success rates between the two groups until postoperative 3 years. At an average of 9.5 ± 2.6 years after surgery, the success rate of the RR group was significantly higher than that of the BLR group starting from the fourth post-operative year until the last follow-up examination (64.5% vs 43.3%, P < 0.001). By multivariate analysis, preoperative hyperopia of more than + 2.00 diopters, younger age of onset, younger age at surgery, larger exodeviation at near than at distance of > 5 prism diopters, and the type of surgery (BLR) were risk factors of recurrence. In conclusion, RR was more successful than BLR with a lower recurrence rate in the long-term follow-up of patients with basic-type X(T).