Superior Rectus Research Articles

Orbital granular cell tumor involving the superior rectus muscle: a case report

Orbital granular cell tumor involving the superior rectus muscle: a case report

Heavy Duty

A 54-year-old woman with myopia, hypothyroidism, and asthma presented with intermittent double vision. Serum was positive for anti-low density lipoprotein receptor-related protein 4 (LRP4) antibodies suggesting the diagnosis of myasthenia gravis. There was no improvement with pyridostigmine, prednisone, or azathioprine. Over time her double vision became constant, and she was noted to have mild limitation of abduction in both eyes with an esotropia, left hypotropia, and excyclotorsion. Magnetic resonance imaging showed nasal displacement of the superior rectus and inferior rectus muscles, inferior displacement of the lateral rectus muscles and superotemporal globe prolapse consistent with heavy eye syndrome (HES). The differential diagnosis, clinical and radiological manifestations of HES are discussed.

Frontal nerve schwannoma in a 16-year-old girl presenting with a rapid growth for 2 years

Background: Orbital schwannomas arising from the frontal nerve are a rare but distinct entity. Case Description: A 16-year-old girl presented to our hospital with gradually progressive proptosis. Computed tomography (CT) performed 2 years ago incidentally detected a retrobulbar mass in the left orbit measuring 13 mm × 14 mm × 10 mm, which was not identified on CT performed at the age of 4 years. CT taken at presentation revealed marked tumor growth over 2 years, measuring 24 mm × 20 mm × 17 mm. On magnetic resonance imaging (MRI), the tumor appeared homogeneously isointense both on the T1- and T2-weighted sequences. The patient underwent transcranial tumor resection. Following unilateral frontal craniotomy, an osteotomy was made to the left anterior fossa floor. On reflecting, the periorbita revealed the frontal nerve with the proximal segment intermingled with the tumor. The levator and superior rectus muscles were flattened and located immediately beneath the tumor. A gross total resection was performed. Microscopic findings of the resected tumor were consistent with schwannoma. Conclusion: Frontal nerve schwannomas may grow rapidly under certain conditions. Periodic follow-up using MRI and timely resection is recommended when an asymptomatic orbital tumor, possibly a frontal nerve schwannoma, is detected in young patients.

Evaluation of the Normal Measurements of Orbital Structures in Healthy Adult Individuals by Using a Magnetic Resonance Imaging Method

Background: This study aims to determine the normal values of orbital structures according to sex in healthy adults. Methods: Diameters of extraocular muscles, the width of the optic nerve sheath diameter, the length of the inter-zygomatic line, ocular bulb length, and globe position were measured in the T1-weighed MR (magnetic resonance) images in 204 orbits of 102 individuals. Results: The mean values of the diameters of the extraocular muscles in males and females were as follows: medial rectus, 3.96 ± 0.52 and 3.58 ± 0.53 mm; lateral rectus, 3.47 ± 0.61 and 3.15 ± 0.48 mm; inferior rectus, 4.47 ± 0.53 and 4.07 ± 0.48 mm; superior rectus, 4.44 ± 0.64 and 4.01 ± 0.56 mm; and superior oblique, 3.68 ± 0.49 and 3.45 ± 0.44 mm. The length of the interzygomatic line in males and females were 102.68 ± 3.89 and 96.95 ± 3.4 mm, the ocular bulb length was 23.33 ± 1.32 and 22.83 ± 1.1 mm, the globe position was 7.66 ± 1.33 and 7.3 ± 1.39 mm, and the width of the optic nerve sheath diameter was 4.65 ± 0.62 and 4.28 ± 0.51 mm, respectively. All measurements were significantly greater for males than for females (p < 0.05). Conclusions: We believe that a practical and quantitative method will be provided by this study for the diagnosis and determination of the normative values of orbital structures.

Coexistence of congenital superior rectus muscle fibrosis and Marcus Gunn jaw-winking phenomenon

A 6-year-old male involving a coexistence of congenital fibrosis of the superior rectus muscle (SR) with Marcus Gunn Jaw-Winking phenomenon presented with an elevation of the upper eyelid along with a chronically open mouth that had been present since early infancy. There was extropia and hypertropia, a limitation of elevation and depression in the right eye, and an abnormal head posture (AHP) with a left head tilt, right face turn, and a chin-up head position. He also displayed an upper eyelid retraction and a 2-mm lagophthalos in the right eye. Results of the forced duction test indicated a constricted SR of the right eye. A dissection of the SR from the levator palpebrae superioris and a 5-mm SR recession was performed within the right eye. At 2 months post surgery, there was a 3 prism diopters (PD) hypertropia in the right eye when the left eye was fixated on the target and a 10 PD hypotropia in the left eye when the right eye was fixated on the target, along with an improvement in his AHP. In this rare case with a coexistence of congenital fibrosis of the SR and Marcus Gunn jaw-winking phenomenon, we found that the performance of an individualized surgical protocol proved effective in reducing the vertical deviation and improving AHP.

Microsurgical Anatomy of the Common Tendinous Ring and Its Surgical Implications

BACKGROUND AND OBJECTIVES: The common tendinous ring (CTR), also known as the common annular tendon or annulus of Zinn, is a critical anatomic structure located at the convergence of the orbital apex, superior orbital fissure (SOF), optic canal, and the anterior aspect of the lateral sellar compartment. It plays a vital role in both neurosurgical and neuro-ophthalmological interventions. The aim of this study was to delineate the complex 3-dimensional (3D) topography of the CTR and explore its implications for surgical procedures. METHODS: Ten formalin-fixed skull base specimens from adult Chinese cadavers were meticulously dissected to investigate the morphology of the CTR, focusing particularly on its relationship with the 4 extraocular rectus tendons, the optic strut, the SOF, and the optic canal. Additional skull base specimens were subjected to 3D surface scanning, computed tomography, and histopathological examinations to deepen our understanding of the CTR's structural complexities. RESULTS: The CTR establishes a spatial, 3D tendinous assembly, encompassing 4 rectus tendons, 2 tendinous connections, and a singular common tendinous root. These components interlink to form a distinctive dual-ring configuration, featuring the optic foramen and the oculomotor foramen. The posterior part of the superior rectus tendon demarcates the common boundary between these 2 foramina. The oculomotor foramen itself serves as the central sector of the SOF. Precise incisions of the medial and lateral tendinous connections and fusions are essential for safely opening the CTR. CONCLUSION: The structural composition, interconnections, and dual-ring configuration of the CTR are crucial for precise and safe surgery of orbital apex and adjacent regions.

Endoscopic transnasal prelacrimal recess approach via the orbital floor to the infraorbital region: an anatomical study.

The aim of this study is to describe the maximum exposure of the infraorbital region via the orbital floor using the transnasal prelacrimal recess approach (PLRA), and to provide an anatomical basis for treating lesions in the infraorbital region. Ten freshly injected frozen heads were dissected using the PLRA. The orbital floor was removed along the border of the medial infraorbital quadrangle, and the periorbita was opened to expose the infraorbital region. The areas of the medial infraorbital quadrangles were measured and analyzed. The PLRA was applied separately on the left and right sides of each cadaver head, resulting in a total of 20 prelacrimal recess approaches. The PLRA enabled visualization of the optic nerve and the central retinal artery through the orbital floor. By integrating both medial and lateral approaches in relation to the inferior rectus muscle, all crucial anatomical structures within the infraorbital region could be clearly identified. The area of the medial infraorbital quadrangle was 420.65 ± 24.03 mm2. The PLRA provides access through the orbital floor to the maximum boundary of the infraorbital region, including the lateral orbital wall at the outermost level, the superior rectus muscle at the topmost level, and the medial orbital wall at the innermost level.

Development of Ocular Muscle Stimulation Systems and Optimization of Electrical Stimulus Parameters for Paralytic Strabismus Treatment.

Paralysis of the extraocular muscles can lead to complications such as strabismus, diplopia, and loss of stereopsis. Current surgical treatments aim to mitigate these issues by resecting the paralyzed muscle or transposing the other recti muscles to the paralyzed muscle, but they do not fully improve the patient's quality of life. Electrical stimulation shows promise, while requiring further in vivo experiments and research on various stimulation parameters. In this study, we conducted experiments on rabbits to stimulate the superior rectus (SR) muscles using different parameters and stimulation waveforms. To provide various types of electrical stimulation, we developed the ocular muscle stimulation systems capable of both current controlled stimulation (CCS) and high-frequency stimulation (HFS), along with the chip that enables energy-efficient and safe switched-capacitor stimulation (SCS). We also developed electrodes for easy implantation and employed safe and efficient stimulation methods including CCS, SCS, and HFS. The in vivo animal experiments on normal and paralyzed SR muscles of rabbits showed that eyeball abduction angles were proportional to the current and pulse width of the stimulation. With the decaying exponential stimuli of the SCS system, eyeball abductions were 2.58× and 5.65× larger for normal and paralyzed muscles, respectively, compared to the rectangular stimulus of CCS. HFS achieved 0.92× and 0.26× abduction for normal and paralyzed muscles, respectively, with half energy compared to CCS. In addition, the continuous changes in eyeball abduction angle in response to varying stimulation intensity over time were observed.

Anterior Nasal Superior Oblique Tendon Syndrome: A Case Series

PurposeTo evaluate the clinical characteristics and management of patients with an anteriorly and nasally inserted superior oblique tendon. DesignRetrospective interventional case series. MethodsInstitutional clinical records between 2020 and 2024 were retrospectively reviewed for 9 consecutive patients in whom the superior oblique (SO) tendon was inserted anterior to the equator and nasal to the superior rectus muscle. Information collected included age, sex, ocular and surgical history, preoperative and postoperative data (ophthalmologic examinations, strabismus measurements, ductions and versions), intraoperative findings, need for additional surgery, and follow-up time. ResultsAll nine patients were found to have an anomalous insertion of the SO tendon. Three were of congenital origin and six were acquired following ocular surgery. Among the acquired cases, all but one resulted from incarceration of the tendon from post-surgical scar tissue formation. The remaining acquired case was due to a prior deliberate anterior and nasal transposition of the superior oblique. This case series demonstrated varying degrees of vertical deviations, lateral incomitance, and limited depression. Repositioning the SO to its normal insertion site yielded equivocal improvement in ocular alignment. ConclusionAnterior nasal superior oblique tendon syndrome is a rare clinical entity characterized by an anti-depressor effect. Vertical deviations, hypertropia worse in downgaze, limited depression worse in adduction for congenital cases and in abduction for acquired cases, and lateral incomitance may be indicative of this anomaly. In acquired cases following surgery, additional findings may include limited depression worse in abduction, esotropia in abduction, V-pattern esotropia, and enophthalmos in downgaze. Surgical repositioning of the SO along its normal anatomical trajectory is recommended for treatment. However, outcomes may be variable and achieving a complete resolution of this syndrome can be challenging.

Effects of Short-Term Treatment of Rabbit Extraocular Muscle With Ciliary Neurotrophic Factor.

Little is known about the effect of ciliary neurotrophic factor (CNTF) on extraocular muscles, but microarray studies suggested CNTF might play a role in the development and/or maintenance of strabismus. The effect of short-term treatment of adult rabbit extraocular muscle with injected CNTF was examined for its ability to alter muscle characteristics. Eight adult New Zealand white rabbits received an injection into one superior rectus muscle of 2 µg/100 µL CNTF on 3 consecutive days. One week after the first injection, the rabbits were euthanized, and the treated and contralateral superior rectus muscles were assessed for force generation capacity and contraction characteristics using an in vitro stimulation protocol and compared to naïve control superior rectus muscles. All muscles were analyzed to determine mean cross-sectional areas and expression of slow twitch myosin heavy chain isoform. Short-term treatment of rabbit superior rectus muscles with CNTF resulted in a significant decrease in muscle force generation, but only at the higher stimulation frequencies. Significantly decreased myofiber cross-sectional areas of the treated muscles correlated with the decreased generated force. In addition, there were significant changes to contractile properties of the treated muscles, as well as a decrease in the number of myofibers expressing slow twitch myosin heavy chain. We show that short-term treatment of a single rabbit superior rectus muscle results in decreased myofiber size, decreased force, and altered contractile characteristics. Further studies are needed to determine if it can play a role in improving alignment in animal models of strabismus.

Detailed measurements of the four extraocular rectus muscles’ contribution to the perfusion of the anterior segment of the eye

Background/aimsAnterior segment ischaemia (ASI) is a rare but serious complication of strabismus surgery, which may be caused by damage to the anterior ciliary arteries that run along the rectus muscles....

Superior rectus/levator complex in acquired anophthalmic socket repaired with spheric implant-a computed tomography scan and topographic study.

To determine whether the levator palpebrae superioris (LPS)/superior rectus (SR) muscle complex, can influence the position of the upper lid and fornix in acquired anophthalmic sockets. This comparative non-randomized and non-interventional study included retrospective data of 21 patients with unilateral acquired anophthalmic sockets repaired with spheric implants. High-resolution computed tomography (CT) measurements of the LPM/SR muscle complex and clinical topographic position of the upper lid, superior and inferior fornix depth in primary gaze position were evaluated. Demographic data were presented as frequency and percentage proportions and quantitative variables comparing the socket measurements with the normal contralateral orbit was statistically analyzed using non-parametric tests considering P<0.05. The anophthalmic orbits had a significantly shorter LPS length (P=0.01) and significantly thicker SR (P=0.02) than the normal orbit. Lagophthalmos was present in anophthalmic sockets but not in normal orbits (P=0.002), while levator function was normal in both (P>0.05, all comparisons). The superior fornix depth was similar in the anophthalmic socket and the contralateral normal orbit (P=0.192) as well the inferior fornix depth (P=0.351). Acquired anophthalmic sockets repaired with spheric implants have shorter LPS, thicker SR, and more lagophthalmos than normal orbits. The relationship of the LPS and SR with other orbital structures, associated with passive or active forces acting in the final position of the lids and external ocular prosthesis should be further investigated.

Anterior Displacement of the Eyeball in a Patient with Uncontrolled Schizophrenia

Purpose: To report a case in which vision improvement was achieved following surgery for anterior displacement of the eyeball resulting from self-mutilation in a patient with schizophrenia.Case summary: A 37-year-old female patient with schizophrenia was admitted following an attempt at self-mutilation, which led to anterior displacement of her right eyeball. Initial evaluation revealed that reduction was not feasible and visual acuity was finger count at 20 cm in the right eye. Orbital computed tomography indicated 26-mm anterior displacement of the eyeball from the center of the cornea to the interzygomatic line along with a small retrobulbar hemorrhage and edema in the superior rectus muscle. Surgical intervention, consisting of lateral canthotomy, cantholysis, and tarsorrhaphy, was performed for correction. The surgical site was reconstructed 6 days after surgery. A fundus examination conducted 1 month later revealed no abnormalities and best-corrected visual acuity improved to 20/20.Conclusions: Globe subluxation due to self-mutilation is a very rare and urgent condition in both ophthalmic and psychiatric contexts that requires immediate surgical intervention. This case demonstrates that immediate anatomical reduction when there is no direct suspicion of optic nerve damage can be beneficial for the recovery of visual acuity and may lead to a favorable prognosis.

The clinical outcomes of minor salivary gland transplantation for severe dry eye disease secondary to chronic Stevens-Johnson syndrome

PurposeTo study the outcomes of minor salivary gland transplantation for severe dry eye disease secondary to chronic Steven Johnson Syndrome. MethodsIt was an ambispective, interventional case series conducted at Rajendra Prasad Centre for Ophthalmic Sciences, Delhi, India from 2022 to 2023 evaluating the outcomes of minor salivary gland transplantation with anchorage of the minor salivary glands to superior rectus muscle in twenty cases of severe dry eye disease secondary to chronic Steven-Johnson Syndrome. The pre-operative clinical parameters were compared to those at post-operative 1 year follow-up. ResultsAt 1 year follow-up, there was an improvement in mean Schirmer-1 value (p = 0.0004), hyperemia score (p = 0.0004), keratinization score (p = 0.04), corneal epithelial defect score (p = 0.0004), corneal opacification score (p = 0.001), corneal neovascularization score (p = 0.001), palisades of Vogt score (p = 0.007), corneal keratinization score (p = 0.04) and corneal conjunctivalization score (p = 0.08). ConclusionThe minor salivary gland transplantation is a viable management option for cases with severe dry eye disease secondary to chronic Steven Johnson Syndrome with clinical improvement in corneal and conjunctival parameters of the ocular surface.

Lateral Globe Exposure Associated With Graves Upper Eyelid Retraction: The Influence of the Superior Complex Enlargement and Proptosis.

To investigate the association of the lateral exposure of the globe with proptosis and the enlargement of the superior complex (SC) (levator palpebrae superioris muscle + superior rectus muscle) in patients with Graves upper eyelid retraction. Twenty-eight patients with upper lid retraction secondary to Graves orbitopathy and 28 controls matched by age and gender participated in the study. The variables exophthalmometry, margin-reflex distance 1, and upper lid fissure temporal and nasal areas were assessed. Coronal CT scans were evaluated for the measurement of the SC area. A 5% level of significance was assumed for analysis. Abnormal temporal nasal area differences (T-N), defined as values above the superior limit of the control distribution (15.58mm2) were detected in 18 patients. Multiple regression analysis showed a significant correlation of abnormal temporo-nasal asymmetries with the SC area and the proptosis (T-N = -6.7 + 0.62* proptosis + 12.3 SC area, R2 = 0.37; p = 0.003). The etiology of the enhanced lateral globe exposure is not unifactorial. SC enlargement and, to a lesser extent, proptosis are important factors correlated to lateral globe exposure.

Deep learning methods for diagnosis of graves' ophthalmopathy using magnetic resonance imaging.

The effect of diagnosing Graves' ophthalmopathy (GO) through traditional measurement and observation in medical imaging is not ideal. This study aimed to develop and validate deep learning (DL) models that could be applied to the diagnosis of GO based on magnetic resonance imaging (MRI) and compare them to traditional measurement and judgment of radiologists. A total of 199 clinically verified consecutive GO patients and 145 normal controls undergoing MRI were retrospectively recruited, of whom 240 were randomly assigned to the training group and 104 to the validation group. Areas of superior, inferior, medial, and lateral rectus muscles and all rectus muscles on coronal planes were calculated respectively. Logistic regression models based on areas of extraocular muscles were built to diagnose GO. The DL models named ResNet101 and Swin Transformer with T1-weighted MRI without contrast as input were used to diagnose GO and the results were compared to the radiologist's diagnosis only relying on MRI T1-weighted scans. Areas on the coronal plane of each muscle in the GO group were significantly greater than those in the normal group. In the validation group, the areas under the curve (AUCs) of logistic regression models by superior, inferior, medial, and lateral rectus muscles and all muscles were 0.897 [95% confidence interval (CI): 0.833-0.949], 0.705 (95% CI: 0.598-0.804), 0.799 (95% CI: 0.712-0.876), 0.681 (95% CI: 0.567-0.776), and 0.905 (95% CI: 0.843-0.955). ResNet101 and Swin Transformer achieved AUCs of 0.986 (95% CI: 0.977-0.994) and 0.936 (95% CI: 0.912-0.957), respectively. The accuracy, sensitivity, and specificity of ResNet101 were 0.933, 0.979, and 0.869, respectively. The accuracy, sensitivity, and specificity of Swin Transformer were 0.851, 0.817, and 0.898, respectively. The ResNet101 model yielded higher AUC than models of all muscles and radiologists (0.986 vs. 0.905, 0.818; P<0.001). The DL models based on MRI T1-weighted scans could accurately diagnose GO, and the application of DL systems in MRI may improve radiologists' performance in diagnosing GO and early detection.

The tortuous course of the anterior ethmoidal artery in the orbit: A cadaveric study

AimThe study aimed to define the coursing pattern of the anterior ethmoidal artery (AEA) in the orbit to minimize complications during endoscopic interventions. Materials and methodsA total of ten formalin-fixed cadaveric halves were included in the study. Orbital regions were shown with a superior approach. The superior rectus and superior oblique muscles, as well as the connective tissue and vessels were removed to observe the path of the anterior ethmoidal artery. Measurements such as the width of the artery, the anterior-posterior length of the U formation, the length of the intraorbital part of the ophthalmic artery, and the distance of the AEA from its opthalmic origin to the anterior ethmoidal foramen were made. ResultsTen of the AEAs originated from the ophthalmic artery. The AEA branches originated from the ophthalmic artery approximately 18.4 mm after the orbital artery entered the orbital, and the mean width of the AEAs was 0.82 mm. In seven of the total anterior ethmoidal arteries, they coursed in the intraethmoidal cavities below the cranial base. The mean distance from the origin of AEAs to the medial wall of the orbit was 4.9 mm. After leaving the ophthalmic artery, seven of the AEAs were coursing forward and turned back ('U' turn formation), which have proximately 1.5 mm in anteroposterior direction. ConclusionThe anterior ethmoidal artery is 0.8 mm wide, originates from the distal part of the ophthalmic artery, entering the orbit after a 1.5 mm U-turn.

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.

Uncommon orbital metastasis in ductal breast carcinoma: a rare presentation 12 years after treatment

Abstract Orbital metastasis originating from breast carcinoma, particularly ductal carcinoma, represents a rare clinical entity, with lobular carcinoma usually being more common. Long-term surveillance in breast cancer patients is crucial for early detection of metastasis. Herein, we present a case of a 70-year-old woman with a history of left ductal breast carcinoma, diagnosed and treated 12 years ago. She then developed left eye vision loss, diplopia, enophthalmos, and chemosis in October 2024. Imaging revealed orbital metastasis involving the left superior and lateral rectus extraocular muscles. Biopsy confirmed the diagnosis of orbital metastases arising from ductal breast carcinoma. This case underscores the significance of long-term surveillance in breast cancer patients, as metastasis can manifest years after the initial diagnosis. Despite its rarity, orbital metastasis warrants consideration in the differential diagnosis of ocular symptoms in patients with a history of breast carcinoma. Treatment primarily aims at palliation and preserving visual function, with prognosis typically poor.

Lacrimal sac diffuse large B-cell lymphoma presenting as sudden-onset binocular diplopia

Introduction: Diffuse large B-cell lymphoma (DLBCL) is a prevalent subtype of non-Hodgkin lymphoma (NHL) affecting predominantly elderly individuals. Case description: A 68-year-old man with a history of hypertension, hyperlipidaemia and a small pituitary gland tumour presented with sudden-onset binocular diplopia and right-eye blurry vision. A magnetic resonance imaging (MRI) of the brain revealed enhancing soft tissue in the right superolateral orbit inseparable from the lacrimal gland, extending medially to the right superior rectus muscle and soft tissue. Further scanning showed widespread metastasis to the bilateral retroperitoneal lymph nodes, adrenal gland, spine and lymph nodes in the neck. A biopsy of the lacrimal gland confirmed DLBCL. Conclusion: Primary lacrimal gland DLBCL is a rare and delayed diagnosis that often stems from the resemblance of its clinical manifestations to more benign conditions such as dacryocystitis, dacryostenosis or mucocele. Timely recognition and accurate diagnosis are essential for initiating appropriate treatment and improving patient outcomes.