Inferior Oblique Research Articles

Anatomical Study of the Inferior Oblique Muscle and Its Innervation: Morphometric Characteristics, Anatomical Variations, and Histological Evaluation of the Nerve to the Inferior Oblique Muscle.

This report aims to supplement the existing knowledge on the inferior oblique muscle. In particular, this study presents detailed anatomical and histological data concerning the muscle's entry point (or entry zone) of the nerve to the inferior oblique muscle. Particular attention was paid to the topographical relationships of the nerve to the inferior oblique muscle (NTIO), including the location of its entry point to the muscle's belly and its anatomical variations. Sixty orbits from cadaveric hemi-heads fixed in 10% formalin were studied. The course of the NTIO was traced along the lateral border of the inferior rectus muscle as far as its entry point to the inferior oblique muscle. Particular attention was paid to the various ways in which the NTIO's muscular sub-branches penetrated between the fibers of the inferior oblique muscle. Three types of NTIO entries to the inferior oblique muscle's belly were distinguished. In the most common type (48.3%), the nerve entered the muscle's inferior (orbital) surface. In the next most common type (36.7%), terminal muscular sub-branches of the NTIO joined the superior (also referred to as ocular or global) surface of the inferior oblique muscle. In the remaining four cases (15%), the terminal sub-branches of the NTIO were divided into two main groups (superior and inferior) that joined both the superior and inferior surfaces of the muscle. Histological examination confirmed that the distal part of the NTIO shows a characteristic arcuate course (angulation) just before reaching the muscle's belly. The process for splitting and forming separate muscular sub-branches of the NTIO was observed for all the examined histological specimens at the level of the nerve's angulation. The presented findings enhance the understanding of the anatomical variations and precise distribution of motor sub-branches reaching the inferior oblique muscle, which may deepen anatomical knowledge and potentially enhance the management of ocular motor disorders.

Anteriorization of the inferior oblique muscle versus anteriorization and resection for asymmetrical dissociated vertical deviation

ABSTRACT Purpose To compare the efficacy of two methods: first, bilateral symmetric anteriorization of the inferior oblique muscle and second: combined resection and anteriorization of the inferior oblique (IO) muscle for asymmetric dissociated vertical deviation (DVD). Design Prospective randomized clinical trial. Methods This study included fifty-four patients presenting with bilateral asymmetric DVD and inferior oblique overaction (IOOA). Two equal groups were randomly allocated by odd and even number distribution. Twenty-seven patients underwent bilateral symmetric anteriorization of the IO muscle and twenty-seven patients underwent anteriorization of the IO of one eye and anteriorization with IO resection in the eye with the larger deviation. According to the difference in measured DVD between the two eyes whether less or more than 5 PD; a 3 or 5 mm resection was done, respectively. Results The mean post-operative reduction of DVD in the anteriorization group was 9.19 ± 3.40 PD in the right eye and 8.78 ± 4.17 PD in the left eye, which were highly significant. (p-value .0002). The resection group had a mean post-operative DVD reduction of 11.7 ± 2.74 PD in resected eyes and 7.3 ± 3.72 PD in non-resected eyes. These reductions were also highly significant (p-value 0.0001). Reduction of inter-ocular difference between both groups failed to show a statistical difference (p-value 0.285). The IOOA was significantly reduced in both groups. Improvement in the average post-operative DVD between the two groups and the post-operative improvement in IOOA failed to show a statistically significant difference (p-value 0.265 and 0.804 respectively) which showed that both procedures are effective. Conclusion Both surgical modalities are effective in managing asymmetric dissociated vertical deviation associated with IOOA.

Exploration of Choroidal Thinning Located Temporal to the Fovea: A Pilot Study.

Background/Objectives: Posterior staphyloma (PS) is a hallmark of pathological myopia, corresponding to a circumscribed outpouching of the eyeball with choroidal thinning and inward scleral deformation at its edges. Its pathogenesis is still unclear, thus constituting a research priority as the prevalence of myopia is increasing worldwide. Recently, it has been suggested that the optic nerve sheaths or oblique muscles are potential promoters of PS through the traction or compression effect that they apply to the eye wall. The inferior oblique muscle (IOM) inserts 1-2 mm from the macula. The projection of its insertion is accessible using Optical Coherence Tomography (OCT). Before launching prospective studies, we sought to detect any choroidal thinning (ChT) in the temporal vicinity of the macula and to measure the distance between it and the fovea (FT-distance). Methods: This retrospective cross-sectional pilot study included 120 eyes. Using Spectralis®-OCT, the area centered by the Bruch's membrane opening-fovea axis was analyzed for ChT and FT-distance. Results: Of the 112 defined eyes, 70% (78 eyes) had ChT. Pachymetry was significantly thinner (p = 0.018) in eyes with than without ChT. The mean FT-distance was 3601.9 ± 93.6 µm. Conclusions: The location of ChT coincided with the insertion distance of the IOM, suggesting a link between them. The association between the presence of ChT and a thinner pachymetry suggests a reduced scleral resistance, as a thinner pachymetry is related to a thinner sclera. Our results suggest a link between ocular deformation and the IOM, which may be relevant for the pathogenesis of PS, warranting further investigation.

Clinical outcomes of inferior oblique myectomy in age categorized patients with unilateral superior oblique palsy

BackgroundUnilateral superior oblique palsy (SOP) is the most common isolated cranial nerve palsy. This report looks at the results and safety of inferior oblique (IO) myectomy for SOP. MethodsA retrospective chart review of patients with fusional ability who underwent IO myectomy for unilateral SOP over a 15-year period, at one of our university-associated health care centers. Primary outcomes were: distance hypertropia and excyclotropia in primary position, inferior oblique overaction (IOOA) and the correlation between the age at surgery and the residual distance hypertropia. ResultsA total of 73 patients with unilateral SOP who underwent IO myectomy were included in the analysis. Mean pre-operative values were: distance hypertropia: 15.41 ± 6.8 Prism Diopters (range 4–30 PD), IOOA: +2.2 ± 0.7 (range 0–3.5) and excyclotropia: +5.34 ± 3.6° (range 0–12°). Mean post-operative values were: distance hypertropia: 3.7 ± 3.4PD [0-14PD], IOOA: −0.1 ± 0.8 [(-2)-2] and excyclotropia: +1.1 ± 2.3°[(-5)-10]. The younger age group (0–20 years old) had a trend toward smaller preoperative distance hypertropia (P = 0.051), and a significantly smaller distance hypertropia post-operatively (p = 0.007). There was no case of ocular complication. ConclusionsOn average, IO myectomy results in a 11.7PD reduction of the distance hypertropia, and 4° reduction of excyclotropia, with an effective reduction of IOOA. While these results are comparable to other surgical methods reported in the literature, they underline an efficacy without the risks of complications such as anti-elevation syndrome and possible scleral perforation. The younger age group had a trend toward smaller preoperative deviation, and better outcomes compared to the older age group.

Laterality Targeting in Graded Inferior Rectus Tenotomy Corrects Lateral Incomitance of Hypertropia in Sagging Eye Syndrome

PurposeTo determine if laterally selective graded vertical rectus tenotomy (GVRT) of the inferior rectus (IR) can correct the lateral incomitance of hypertropia (HT) commonly encountered in sagging eye syndrome (SES), comparing it with inferior oblique (IO) recession. DesignRetrospective comparative interventional clinical study. MethodsWe reviewed 73 consecutive patients undergoing GVRT of the IR for correction of horizontally incomitant HT due to SES from July 2012 to October 2023. Confounding diagnoses were excluded. Using topical anesthesia, GVRT was initiated from the nasal versus temporal side corresponding to greater HT, with dosing adjusted intraoperatively until cover testing in central gaze indicated orthotropia. We compared 8 cases of IO recession to 4mm posterior and 3mm lateral to the IR insertion. ResultsNasal GVRT was performed in 41 patients (standard deviation), and temporal GVRT on 32 patients. Mean nasal GVRT was 69±15% and mean temporal GVRT was 62±17%. Mean HT in central gaze was reduced by nasal GVRT from 3.9±1.7Δ to 0.3±1.4Δ, and from 4.0±1.6Δ to 0.2±1.1Δ by temporal GVRT. Nasal GVRT corresponding to the side of the tenotomy had greater effect in contralateral gaze at 3.2±2.2Δ than ipsilateral gaze at 2.1±2.0Δ (p=0.0250), whereas temporal GVRT had greater effect in ipsilateral gaze at 4.9±2.7D than contralateral gaze at 2.9±2.9D (p=0.0002). Inferior oblique recession in 8 patients reduced lateral incomitance from 13±5.0Δ to 0.5±1.4Δ (p<0.0001). ConclusionNasal GVRT corrects about 1Δ and temporal GVRT 2Δ horizontal incomitance of HT, while IO recession corrects about 12.5Δ. Selection of GVRT laterality improves outcomes without additional risk or operating time.

Effect of Electrode Montage on Frequency Tuning Properties of Air-Conducted Ocular Vestibular-Evoked Myogenic Potential.

The use of a 500 Hz tone burst over other frequencies was adopted for the clinical recording of ocular vestibular-evoked myogenic potential (oVEMP) on the basis that this stimulus frequency produces larger response amplitudes (frequency tuning) than the other frequencies. However, the possibility of reflex contamination due to a spatially displaced reference electrode from the muscle of the response origin raises questions about using an infraorbital (IO) montage. Nonetheless, the belly-tendon (BT) montage, which places both the recording electrodes over the inferior oblique muscle, increases the chances of obtaining a response with greater contribution from the inferior oblique muscle. However, whether this response continues to show the frequency tuning to 500 Hz is not known. Therefore, the present study aimed to examine the frequency tuning of oVEMP using various electrode montages. Thirty-eight young adults underwent simultaneous oVEMP recording from IO, BT, chin-referenced, and sternum-referenced electrode montages in response to 250, 500, 750, 1000, 1500, 2000, 3000, and 4000 Hz tone bursts. The frequency tuning most often coincided with a 750-Hz tone burst irrespective of the montage, with the BT montage exhibiting significantly higher response rates and larger peak to peak amplitudes than other montages (p < 0.008). Further, there was a "substantial" agreement on frequency tuning between BT and IO montages. With better response rates and response amplitudes yet similar frequency tuning to the IO montage, the BT montage can be a better option for the clinical recording of oVEMP across frequencies.

Surgical outcomes in patients with congenital superior oblique palsy: A comparison between clinical and radiological diagnosis

PurposeThe diagnosis of superior oblique (SO) palsy can be achieved by examining the radiological and clinical characteristics. Despite their usefulness, the radiological and clinical methods are not always aligned to each other. The objective of this research is to analyze the surgical results of eyes with SO palsy, based on whether the diagnosis was made radiologically or clinically. DesignA prospective study, conducted at a single tertiary hospital. MethodsFollowing the diagnosis of SO palsy, either through clinical assessment or radiological imaging, the patients were categorized into three distinct groups according to their clinical measurements and MRI findings. Group 1 exhibited consistent clinical measurements and MRI findings indicating SO palsy, whereas Group 2 displayed clinical measurements without MRI confirmation. In contrast, Group 3 presented inconclusive measurements, but MRI scans revealed signs of atrophy. Patients underwent inferior oblique (IO) myectomy with and without contralateral inferior rectus recession and ocular deviation before and after myectomy were collected. ResultsThe study included 49 patients with congenital unilateral SO palsy (average age: 30 years). Out of 35 patients who tested positive across all three stages of the test, 15 did not show notable muscle atrophy in their MRI findings. In contrast, among those who displayed muscle atrophy in their MRI scans, 58.8 % had positive outcomes in all steps of the three-step assessment. Group 1 and 3 displayed a reduced muscle volume measuring 110.988 ± 42.49 mm³ and 91.5 ± 56.8 mm³, respectively, on the affected side. Group 2 showcased a muscle volume of 184.1 ± 44.64 mm³ on the affected side. In all three groups with SO palsy eyes who underwent IO myectomy, there was a reduction in hypertropia in the primary position, with no statistically significant differences observed among the groups (P = 0.1). All five patients with SO palsy who underwent IO myectomy with contralateral inferior rectus recession were classified in group 3, and they exhibited a significant reduction in hypertropia postoperatively. ConclusionComparable results can be attained through IO surgery in patients with SO palsy, regardless of whether they are diagnosed through clinical or radiological means.

Surgical Planning for Pattern Strabismus in Patients with Intermittent Exotropia: Evaluating Techniques and Outcomes

&amp;lt;i&amp;gt;Background or purpose&amp;lt;/i&amp;gt;: Intermittent exotropia is the most common cause of divergent deviation. Pattern strabismus may coexist with horizontal deviations in up 35% of cases. Managing pattern strabismus concomitantly with the correction of horizontal strabismus poses a challenge due to imbalances in force vectors. This study aims to evaluate the effects of planning an intermittent exotropia surgery considering the presence of pattern strabismus and its surgical resolution. &amp;lt;i&amp;gt;Methods&amp;lt;/i&amp;gt;: Observational retrospective study of patients with intermittent exotropia who underwent surgical correction at center between 2017 and 2022. Patients were categorized by the presence of pattern strabismus and furthermore by surgical technique for the correction of said incomitance (weakening of inferior oblique muscles or vertical transposition of lateral rectus muscles). Outcomes of post-surgical horizontal deviation and presence of postoperative pattern strabismus were statistical analyzed between groups using SPSS software v28.0. A p-value &amp;lt;0,05 was considered significant. &amp;lt;i&amp;gt;Results&amp;lt;/i&amp;gt;: A total of 169 patients had surgical correction for intermittent exotropia. Pattern strabismus was observed in 35,5% of patients, primarily V-pattern (88,3%). Most were male (58, 35%) with mean age of 15,13±16,38 years. 41,7% patients with pattern strabismus underwent correction of the incomitance. All techniques showed significant reduction of horizontal near (p&amp;lt;0,001) and distance (p&amp;lt;0,001) deviation. However, incomitance correction favored strongly not only the collapsing of pattern strabismus (p=0,027) but also achieved better results in postoperative distance (p=0,002) and near (p=0,031) horizontal deviation. The two techniques for resolution of pattern strabismus showed comparable results in postoperative horizontal near deviation values and resolution of pattern strabismus, favoring vertical transposition in horizontal distance deviation values (p=0,015). &amp;lt;i&amp;gt;Conclusions&amp;lt;/i&amp;gt;: The presence of pattern deviations should be actively persecuted in pre-operatively appointments to plan the surgery appropriately, as benefits in correcting the vertical incomitance are supported by this study findings. Both vertical transposition of lateral rectus muscles and weakening of inferior oblique muscles are effective techniques to correct vertical incomitances.

Surgical treatment of unilateral acquired superior oblique muscle palsy in adults by inferior oblique belly transposition: a retrospective analysis.

Evaluate and analyze the efficacy of inferior oblique belly transposition (IOBT) in treating adult patients with diplopia and small-angle hypertropia caused by mild to moderate inferior oblique overaction (IOOA) secondary to acquired superior oblique palsy (SOP). Nine adult patients with diplopia and small-angle hypertropia associated with mild to moderate IOOA secondary to unilateral acquired SOP were included in the current retrospective study. All patients received the IOBT procedure between February 2019 and May 2023 at The Second People's Hospital of Jinan and were followed up for more than 6months after the surgery. During the procedure, the belly of the inferior oblique muscle was fixed to the sclera at 5mm posterior to the temporal insertion of the inferior rectus muscle. The following indicators were reviewed pre- and post-surgery: the vertical deviation (VD) in the primary position and in the Bielschowsky test, the fovea disc angle (FDA) of the affected eye, changes in IOOA, and diplopia. After IOBT, the VD in the primary position decreased from 7.22△ ± 1.72△ (range 4△-10△) to 1.22△ ± 1.30△ (range 0△-3△). The VD in the Bielschowsky test decreased from 13.00△ ± 1.80△ to 3.22△ ± 1.09△. The FDA decreased from 10.02° ± 3.34° to 6.26° ± 1.91°. The grade of IOOA was reduced from 2.00 (1.00, 2.00) to 0.00 (0.00, 1.00). All changes were statistically significant (P < 0.001 or P = 0.006). Diplopia was resolved completely for all patients. IOBT can effectively treat adults with diplopia and small-angle hypertropia caused by mild to moderate IOOA secondary to acquired SOP.

The Experience in Lower Eyelid Blepharoplasty: Improvement of Surgical Procedures Based on Anatomical Basis.

This study characterizes the appearance changes associated with aging of the human lower eyelid, grounded in its anatomical basis. Tailored approaches to lower eyelid bag are performed by these anatomical manifestations. From January 2017 to January 2023, lower eyelid blepharoplasty was performed on 137 patients, aged 20 to 60 years. These patients were divided into 3 groups according to the periorbital aging appearance, primarily characterized by the presence and location of the "bag" bulge of the lower eyelid. We analyzed the corresponding changes in anatomical structures for each type, which included a weakened fibrous orbital support system, reduced muscle tone, and increased orbital fat. Patients were treated with tailored blepharoplasty techniques according to their classification. All patients in this study ranged in follow-up from 1 to 12 months. With patients' permit, photographs and clinical information were taken to evaluate the preoperative and postoperative outcome. Our study identified 3 morphologies of the lower eyelid. Type 1 presents a "bubble bag" in the medial and inferior aspect of the lower eyelid. Type 2 features a double convexity contour, with separate fat pad herniations demarcated by fibrous connective tissue. Type 3 exhibits a single convexity with a uniform herniation of fat pads across the entire lower eyelid. We have delineated the anatomical changes associated with each morphology type. With an approach grounded in "remodeling" and "recovery," the surgical treatment targets the fibrous support tissue to improve the outcomes of lower eyelid rejuvenation. No complications occurred. All postoperative results reached both surgeon's and patient's expectations. Surgeons must recognize the pivotal role of fibrous connective tissues-including the arcuate expansion, fascia of the inferior oblique muscle, and the orbicularis retaining ligament-and endeavor to preserve or reinforce these structures during surgical procedures. An anatomically based surgical approach would more effectively and safely to resist the facial aging process.

Outcomes of inferior oblique muscle myectomy with tucking into Tenon’s capsule, cohort prospective study

ABSTRACT Background: Inferior oblique muscle overaction (IOOA) is a prevalent ocular muscle motility disorder. This study aimed to investigate the outcomes and impact of IO muscle myectomy with and without tucking the proximal end of the muscle into Tenon’s capsule in two surgical groups as a treatment for IOOA. Methods: Randomized cohort study that involves two surgical groups. A total of 33 patients (55 eyes). Patients were randomly divided into two groups: first group underwent myectomy without tucking the proximal end of the muscle, whereas the second group underwent myectomy with tucking of the proximal end of the muscle. Each patient had four visits. During each visit, each patient had a comprehensive ophthalmic examination. Surgical success was defined as IOOA grade range of 0 to + 1 and correction of hypertropia in primary gaze. Results: The median age was 6 years. Sixteen (48.5%) patients underwent IO muscle myectomy with tucking, while 17 (51.5%) had an IO myectomy without tucking. Both the tucking and without tucking groups showed reductions in the angles of deviations, but there was no significant difference between the groups at baseline or postoperatively at 6 months. The success rate was 92.85% for the tucking group and 92.59% for the without tucking group. Conclusion: The study suggests that both surgical techniques are effective in correcting IOOA and associated HT, without any clear benefits of the addition of tucking. Ultimately, the two surgical techniques are equally effective, and the choice of surgical technique remains a personal preference of the surgeon.

Effect of graded partial inferior rectus muscle tenotomy in treatment for superior oblique paralysis.

To evaluate the surgical outcomes for patients with superior oblique paralysis (SOP) who underwent the inferior oblique weakening and the graded partial inferior rectus muscle tenotomy in the contralateral eye. Medical records were retrospectively reviewed for those SOP patients who had hyperdeviation of 4△ -20△ in the primary position and 8△ -25△ in the downgaze position. Patients were subdivided into three subgroups according to their vertical deviation angle in the downgaze position. They underwent an ipsilateral inferior oblique muscle recession and a graded partial tenotomy of the contralateral inferior rectus muscle. The vertical deviation angles, abnormal head position, and fundus torsion were compared statistically before and after operations. All patients were followed up at least 1 year. Forty-seven patients were included in this study. The mean follow-up period was 17.2 months after surgery (ranging from 12 to 28 months). The vertical deviation angle was averaged preoperatively to 7.74△ ± 3.23△ in the primary position and 15.30△ ± 5.92△ in the downgaze position and reduced postoperatively to 0.85△ ± 1.15△ in the primary position and 1.53△± 1.49△ in the downgaze position (P < 0.001). All patients had an abnormal head position preoperatively and had improved significantly postoperatively. Fundus extorsion had been improved significantly postoperatively. The surgical procedure of IO weakening combined with contralateral graded partial inferior rectus muscle tenotomy is a successful intervention for the correction of small deviation in primary position of SOP.

The Outcome of Inferior Oblique Myectomy for Apparent Inferior Oblique Overaction Associated with Craniosynostosis.

Strabismus in patients with craniosynostosis is common, but surgical correction of strabismus in these patients remains challenging. We report our findings in six patients (four of whom were Korean) with craniosynostosis who underwent strabismus surgery to specifically address V-pattern horizontal strabismus with moderate-to-severe inferior oblique (IO) overaction, using IO myectomy at a single tertiary hospital between 2005 and 2016. We recorded preoperative characteristics including sex, age, type of strabismus, versions grading, refractive error, and visual acuity. The grading of cyclorotation of horizontal rectus muscles by V-pattern categorized using coronal computed tomography imaging. Of the six patients, exodeviation was found in four patients and vertical deviation in two patients in primary position. One patient had both horizontal and vertical strabismus. Available computed tomography imaging showed that V-patterns were category 1 (mild) in two patients, category 2 (moderate) in one patient, and category 3 (severe) in two patients. Complete success was defined as absence of IO overaction any more. Overall complete success rate of IO myectomy was 83.3%. IO myectomy appeared to have some benefits in V-pattern horizontal strabismus with moderate-to-severe IO overaction in patients with craniosynostosis.

Extraocular Muscle Enlargement in Thyroid Eye Disease Using Volumetric Analysis.

It is commonly taught that thyroid eye disease (TED) causes enlargement of the extraocular muscles (EOMs) in the following descending order: inferior rectus (IR), medial rectus (MR), superior rectus (SR), lateral rectus (LR), superior oblique (SO) and inferior oblique (IO). However, with recent literature challenging this notion, we aimed to compare EOMvolumes in our cohort of TED patients. Methods: We conducted a retrospective, non-randomized case-control study. Twenty-eight orbits from 28 unique patients with TED who had high-resolution CT scans were compared to 31 normal orbits, all from a single academic institution. Orbital soft tissues were manually segmented using ITK-SNAP 3.8.0 (http://itksnap.org), and soft tissue volumes of the control and TED orbits were compared using independent-sample t-tests. Of the TED orbits, 54% of SR/levator palpebrae superioris complex volumes (SRC) and 50% of IR volumes were greater than two standard deviations above the normal orbit average. Compared to controls, the mean SRC volume in TED subjects was 2.3 times enlarged, followed by the IR (2.1 times), SO (1.8 times), MR (1.7 times), LR (1.6 times), IO (1.6 times), and orbital fat (1.4 times) (p < 0.01 for all). Conclusions: Our findings suggest that contrary to previous teaching, the SRC may be the most severely affected in TED.

Development and Standardization of Modified Simultaneous Multifrequency (SiMFy) Stimulus for Recording oVEMP And Its Interaction with the Alternate Electrode Montages.

Simultaneous Multifrequency (SiMFy) is a time-saving and reliable stimulus to determine the frequency tuning of ocular vestibular-evoked myogenic potential (oVEMP); however, the absence of 4000 Hz in SiMFy potentially makes it a less potent tool for the diagnosis of Superior semicircular canal dehiscence, a pathology with an ever-increasing prevalence. Further, SiMFy was validated using only the infra-orbital (IO) electrode montage. However, the recordings obtained using the IO montage might be susceptible to reference contamination introduced by a small separation between the recording electrodes, and also susceptible to reflex impurity due to the spatially displaced reference electrode from the inferior oblique muscle (IOM), rendering it vulnerable to picking up responses from other muscles. Nonetheless, little is known about the similarities/differences between the SiMFy-induced oVEMPs using alternate montages [belly-tendon (BT), chin-reference (CR), and sternum-reference (SR)] and the non-simultaneous multifrequency oVEMPs (NSM-oVEMPs) using the IO montage. To develop a modified SiMFy stimulus and investigate its effects on frequency tuning of oVEMP using various electrode montages. Within-subject experimental design. Thirty-three healthy adults aged 20-30 years. Tone bursts of octave and mid-octave frequencies from 250 Hz to 4000 Hz were generated and concatenated to create the modified SiMFy stimulus. All participants underwent non-simultaneous multifrequency oVEMPs and modified SiMFy oVEMPs using BT, CR, SR, and IO montages simultaneously. The response rate, peak-to-peak amplitude, and frequency tuning were compared between NSM-oVEMP and modified SiMFy oVEMP and also between the electrode montages. BT montage recorded the largest amplitude among the montages in non-simultaneous multifrequency stimulation and modified SiMFy stimulation. Although the response rates were comparable, the modified SiMFy produced significantly lower oVEMP amplitudes than the non-simultaneous multifrequency stimulation within each electrode montage (p < 0.05). A moderate-to-strong agreement on frequency tuning existed between the non-simultaneous multifrequency stimuli and modified SiMFy stimulus for all the montages, except for the SR montage. Although the modified SiMFy produces smaller amplitude oVEMPs than the non-simultaneous multifrequency stimulation for the respective montages, its use in combination with the BT montage yields higher response rates and larger peak-to-peak amplitudes than the non-simultaneous multifrequency recording using IO montage.

The effects of refractive status on the outcomes of strabismus surgery in patients with esotropia

BackgroundThe success of the strabismus surgery can hinge on several factors. One of these factors is refractive condition like hyperopia or myopia. Our study seeks to evaluate the surgical outcomes in patients with esotropia and myopia.MethodsThis case-control study encompassed all surgical cases of esotropia at Torfe and Negah Hospital between 2016 and 2021, which satisfied our specified inclusion criteria. The initial variables from electronic medical records were collected, including demographic, clinical, and surgery-related factors. At the final follow-up appointment, the level of eye deviation, both at distance and near, was recorded. We considered the operation a “success” for patients with a post-surgery distance eye deviation of 10(Pd) or less. Patients with greater deviation were classified as surgery failure. Statistical analyses were executed using SPSS software (version 16.0), and a P-value less than 0.05 was considered significant.ResultsOf the 194 patients evaluated, 112 were incorporated into the study. Surgical failure was observed in 14.29% of myopic patients, 29.79% of hyperopic patients, and 31.82% of emmetropic patients. The myopia group displayed a 0.19 odd ratio for surgical failure compared to the combined hyperopia and emmetropia groups, not statistically significant (OR: 0.19, CI 95%: 0.03–1.02). Additionally, patients diagnosed with Lateral Rectus Under-action were found to be 6.85 times more likely to experience surgery failure(OR: 6.85, CI 95%: 1.52–30.94). An elevated risk of surgical failure was also identified in patients who underwent Inferior Oblique Weakening procedure, indicated by a 3.77-fold increase in the odds ratio for failure(OR: 3.77, CI 95%: 1.08–13.17).ConclusionIn our study, despite numerical disparities, there was no statistical difference among the success rates of all esotropia patients with different refractive errors. The patients with LRUA or IOOA showed lower success rates. Myopic patients had higher post-op overcorrection with lower reoperation rates compared to hyperopic or emmetropic patients.

Long-term comparison of horizontal rectus surgery with vertical tendon transposition and combined vertical tendon transposition and inferior oblique–weakening in V-pattern exotropia

PurposeTo compare the efficacy of bilateral lateral rectus recession with vertical tendon transposition (LRVT) and LRVT combined with inferior oblique (IO) disinsertion for V-pattern exotropia. MethodsThe medical records of patients who had mild-to-moderate (+1 and +2) inferior oblique overaction (IOOA) and underwent half-tendon-width upward LRVT (transposition group), and LRVT with IO disinsertion (combined surgery group) for V-pattern exotropia and who had at least 3 years of postoperative follow-up were reviewed retrospectively. ResultsA total of 45 patients were included: 22 in the transposition group and 23 in the combined surgery group. Preoperatively, there were no differences in V pattern, IOOA, or horizontal misalignment in primary position, upgaze, or downgaze between groups. The amount of exotropia in the primary position was 30.2Δ ± 10.7Δ in the transposition group, and 31.6Δ ± 14.1Δ in the combined surgery group (P = 0.974). A significant decrease in V pattern was observed in the combined surgery group and the transposition group at 6 months and 3 years postoperatively (P < 0.001). The reduction of V pattern in the combined surgery group at 6 months (20.2Δ ± 7.8Δ vs 15.6Δ ± 6.9Δ [P = 0.02]) and 3 years (20.1Δ ± 8.1Δ vs 15.2Δ ± 7.1Δ [P = 0.014]) was found to be greater than the transposition group. There were no differences in the success rate in the primary position at 6 months (P > 0.05). ConclusionsBoth tendon transposition with horizontal rectus surgery and combined tendon transposition and IO-weakening surgery decreased V-pattern exotropia. However, combined surgery had a greater effect on decreasing V pattern in patients with mild-to-moderate IOOA.

Цервикалгия у пациентов с мигренью – коморбидная нозология или клинический аспект центральной сенситизации?

Relevance. The phenomenon of central sensitization occurs when physiological activity in nociceptive pathways increases and leads to abnormal sensitivity; it is defined as “increased sensitivity of nociceptive neurons of the central nervous system to their normal or subthreshold afferent input,” according to the definition provided by the International Association for the Study of Pain (IASP). The excitability of spinal cord neurons significantly modifies the gain of the somatosensory system. Chronic pain syndromes, anxiety-depressive disorder, sleep disorders are currently very common in the population, significantly reducing the quality of life of the population; the pathogenesis of these nosologies lies in central sensitization. Objective. To study the clinical manifestations of central sensitization in patients with episodic migraine associated with neck pain or cervicogenic headache. Materials and methods. The longitudinal prospective study included 180 patients, divided into 3 groups: 1) patients with a combination of migraine and cervicogenic headache – 60 people (study group); 2) patients with a combination of migraine and cervicalgia diagnoses – 60 people (control group); 3) patients diagnosed with migraine without complaints of pain and limitation of movements in the cervical spine – 60 people (additional group). Results. In patients with migraine and comorbid cervical headache, more pronounced central sensitization was revealed when compared with comorbid cervicalgia. Myofascial pain syndrome involving the trapezius and temporal muscles can resolve on its own with specific migraine therapy with monoclonal antibodies, however, to relieve tension and soreness in the masseter and inferior oblique muscles, the addition of therapeutic exercises and gentle manual techniques is more effective. Taking into account the identified direct relationships of moderate strength between the number of painful points of exit of the trigeminal nerve, the muscles of the pericranial region involved, as well as the effect of treatment of migraine attacks with monoclonal antibodies, it can be concluded that central sensitization is more pronounced when the masseter and inferior oblique muscles are involved. Conclusions. During examination of patients with migraine with comorbid active cervicalgic factor or even if it is absence, it is necessary to make a thorough examination of the facial and cranioverebral region muscles, even in the absence of patient complaints of pain in the face or neck, and also prescribe specific therapeutic exercises to increase the effectiveness of treatment. In all patients with migraine, regardless of chronicity, it is necessary to assess the intensity of central sensitization for timely and more complete provision of medical care.

Neuromuscular Junction Development Differs Between Extraocular and Skeletal Muscles and Between Different Extraocular Muscles.

To determine whether development of neuromuscular junctions (NMJs) differs between extraocular muscles (EOMs) and other skeletal muscles. Mouse EOMs, diaphragm, and tibialis anterior (TA) were collected at postnatal day (P)0, P3, P7, P10, P14, and P21, and 12 weeks. Whole muscles were stained with α-bungarotoxin, anti-neurofilament antibody, and slow or fast myosin heavy chain antibody, and imaged with a confocal microscope. Images were quantified using Imaris software. NMJs in the EOMs show a unique pattern of morphological development compared to diaphragm and TA. At P0, diaphragm and TA NMJs were oval plaques; EOM single NMJs were long, thin rods. NMJs in the three muscle types progress to mature morphology at different rates. At all ages, EOM single NMJs were larger, especially relative to myofiber size. The inferior oblique and inferior rectus muscles show delayed single NMJ development compared to other EOMs. NMJs on multiply-innervated fibers in the EOMs vary widely in size, and there were no consistent differences between muscles or over time. Incoming motor nerves formed complex branching patterns, dividing first into superficial and deep branches, each of which branched extensively over the full width of the muscle. Motor axons that innervate multiply-innervated fibers entered the muscle with the axons that innervate singly-innervated fibers, then extended both proximally and distally. EOM NMJs had more subsynaptic nuclei than skeletal muscle NMJs throughout development. EOMs show a unique pattern of NMJ development and have more subsynaptic nuclei than other muscles, which may contribute to the exquisite control of eye movements.

Synergistic Therapy for Graves’ Ophthalmopathy-Associated Eyelid Retraction: Steroid, 5-FU, and Botulinum Neurotoxin a Combination

Background: Graves’ ophthalmopathy (GO) is characterized by upper eyelid retraction (UER), the most prevalent clinical sign. We aimed to assess the clinical efficacy of a multimodal combination of steroids, 5-fluorouracil (5-FU), and botulinum neurotoxin A (BoNT-A) injections in managing UER with GO and analyze the clinical factors in relation to the injection response. Methods: A total of 37 eyes from 23 patients were enrolled for UER with GO. At the endocrinology clinic, the patients were referred to the ophthalmology clinic after taking antithyroid medication for an average of 5.76 months (13 patients), while 10 patients were initially diagnosed with GO and referred to the endocrinology clinic for management of the thyroid hormone function. They performed an orbital computed tomography (CT) scan and measured the cross-sectional area of the orbit, orbital fat, and each extra ocular muscle (EOM) except for the inferior oblique muscle 4 mm behind the eyeball. Each of the EOMs and orbital fat were calculated as a ratio to the total orbit area. A total of 0.1 cc of triamcinolone (40 mg/mL), dexamethasone (5 mg/mL), 5-FU, and BoNT-A (2.5 units) was injected transconjunctivally. Medical records were examined and photographs were utilized to assess MRD1, inferior palpebral fissure (IPF), and lid lag during down gaze before and after the injection. The patients were divided into two groups: responders (more than 1 mm decrease in MRD1 after injection) and non-responders. During the follow-up period (11.0 ± 11.6 months), any potential adverse effects were monitored. Results: CAS decreased from 3.0 ± 0.8 to 1.4 ± 0.5 after the injection, and MRD1 decreased from 5.0 ± 0.9 mm to 4.5 ± 1.3 mm. Sixty percent of the patients were responders. Before and after the injection, the difference between IPF and MRD1 in responders was 0.60 ± 1.10 mm and 0.90 ± 0.90 mm, respectively, whereas, in non-responders, it was −0.57 ± 0.88 mm and −0.15 ± 0.75 mm, respectively. In the responders, pre-injection IPF and FT4 were significantly higher (p &lt; 0.05). Responders had a larger EOM cross-sectional area (153.5 ± 18.0 mm2), including a larger lateral rectus muscle cross-sectional area (37.6 ± 9.7 mm2) than non-responders (132.0 ± 27.9 mm2; 29.1 ± 8.1 mm2). In responders, the treatment effect on IPF and MRD1 remained consistent at 1.2 ± 3.4 mm and 1.2 ± 1.6 mm, respectively, during the latest follow-up assessment. Conclusions: The combination injection of corticosteroids, 5-FU, and BoNT-A would be effective, especially, in patients with hyperthyroidism and an elongated IPF. Additionally, an increase in EOM cross-sectional area on CT, up to 150 mm2, may serve as an additional positive indicator for the use of multimodal injections in UER with GO.