Magnetic Resonance Imaging of Idiopathic Orbital Myositis.

PURPOSE: To characterize the qualitative and quantitative features of idiopathic orbital myositis (IOM) on MRI. METHODS: This was a multicenter retrospective study of patients with active IOM with MRI. Patients with incomplete clinical records, poor-quality or interval scans without active myositis, and specific orbital myositis (i.e., orbital myositis secondary to an identified condition) were excluded. An enlargement ratio was calculated by dividing the diameters of the affected extraocular muscle (EOM) by the contralateral unaffected EOM. RESULTS: Twenty-four patients (mean age: 44.4 ± 17.8 years-old, male: 11) between 2011 and 2022 were included. One case (4.2%) was pediatric (17 years old), and 6 cases presented with recurrence. Active IOM was characterized by fusiform EOM enlargement, high T2 signal, and contrast enhancement. Average maximal EOM diameters ranged from 4.6 to 7.7 mm (enlargement ratio: 1.4-2.2). Eighteen (75%) patients had single EOM involvement, most commonly the medial rectus. Other ipsilateral structures affected included focal orbital fat (16/24, 66.7%) and lacrimal gland (8/24, 33.3%). Contralateral changes in the EOM and/or lacrimal gland were observed in 7 patients (29.2%). Patients presenting with recurrence were likely to develop ongoing recurrent episodes ( p = 0.003). CONCLUSIONS: Various radiological patterns of involvement described including EOM enlargement, contrast enhancement, abnormal signal, and involvement of other orbital structures are indicative of active IOM. IOM remains a heterogeneous spectrum of acute and chronic clinico-radiological presentations. Inflammation may involve other ipsilateral or contralateral orbital structures or may be bilateral despite presenting clinically as unilateral disease. Quantitative measurements may have utility in differentiating IOM from other causes of orbital myositis.

Antisynthetase Syndrome Causing Necrotizing Myositis Involving Extraocular Muscles.

The authors describe the clinical, histologic, and serologic findings of a patient with necrotizing myositis of the extraocular muscles in the setting of antisynthetase syndrome, as well as subsequent management. This is the first case in the literature of a systemic necrotizing myositis to have associated ophthalmic findings.

Seminoma-associated orbitopathy mimicking thyroid-associated orbitopathy: report of a case and literature review.

The authors describe a case of bilateral diffuse paraneoplastic orbital myositis induced by a stage IA left testicular pure seminoma. The patient presented with findings typical of thyroid-associated orbitopathy (TAO) and was thought to have TAO until discovery of the malignancy. Treatment included an urgent orchiectomy, as well as 7 weeks of therapeutic plasma exchange. This is the fifth reported case of seminoma-associated orbitopathy, and the second to occur while cancer was in the occult phase. Although seminoma-associated orbitopathy is exceedingly rare, it can masquerade as TAO and should be considered in the differential diagnosis of any young male with atypical TAO findings.

Orbital myositis induced by alendronate: A case report.

BACKGROUND AND PURPOSE: Bisphosphonates are widely used, notably for osteoporosis treatment. Their common side effects are well known. However, they can trigger less common effects such as orbital inflammation. Here, the case is reported of an orbital myositis triggered by alendronate. METHODS: This is a case report at an academic medical center. An orbital magnetic resonance imaging scan, a thoraco-abdominal computed tomography scan and blood sample analyses were performed. RESULTS: A 66-year-old woman treated by alendronate for her osteoporosis was investigated. She developed an orbital myositis after the first intake. Neurological examination revealed a painful diplopia with decreased downward and adduction movements of the right eye and edema of the upper eyelid. Orbital magnetic resonance imaging showed an orbital myositis of the right eye. No other cause of orbital myositis was found than the alendronate intake. After alendronate arrest and a short course of prednisone, the symptoms resolved. CONCLUSION: This case highlights that alendronate can cause an orbital myositis whose early diagnosis is of major importance because it is a treatable side effect.

Acute Bilateral Orbital Myositis Following Covid 19 Vaccination.

The authors present a case of acute bilateral orbital myositis occurring 24 hours after the administration of the mRNA1273 vaccination for COVID 19. The patient was presented with right proptosis, with orbital imaging demonstrating bilateral enlargement of all the extraocular muscles. Serological investigation did not reveal a precipitating cause or underlying disease process. The presenting features resolved entirely following treatment with methylprednisolone and the patient remains asymptomatic.

Orbital inflammation following COVID-19 vaccination: A case series and literature review.

PURPOSE: The purpose of the study was to report three cases of orbital inflammation following administration of the COVID-19 vaccination, manifesting as Tolosa-Hunt syndrome (THS) and orbital myositis. METHOD: A retrospective case series and literature review of patients who developed orbital inflammation following a COVID-19 vaccination. RESULTS: One patient presented with Tolosa-Hunt syndrome (THS) 14 days following her third (booster) COVID-19 vaccination, one patient developed orbital myositis 10 days following his first COVID-19 vaccination and one patient developed recurrent orbital myositis 1 and 7 days following her second and fourth COVID-19 vaccination. All patients received the Comirnaty vaccine (Pfizer-BioNTech). A thorough systemic autoimmune disease workup in both patients was unremarkable. Two patients had a prior history of orbital inflammation, with previous involvement of other different orbital structures. Characteristic MRI features for each pathology were observed, supporting the clinical presentation of THS and orbital myositis. There was complete resolution of THS following corticosteroids, with no recurrence at 2 months. Meanwhile, one case of orbital myositis self-resolved at 2 months without use of systemic corticosteroids, while the other patient with orbital myositis required treatment with intra-orbital steroid injections and oral corticosteroids. CONCLUSION: Orbital inflammation has been recognised as a rare adverse effect following COVID-19 vaccination. We present a case series of THS and orbital myositis as varied presentations of this entity.

Bilateral orbital myositis in a patient with rheumatoid arthritis on treatment with tofacitinib: a report and review of literature.

Orbital myositis is a rare inflammatory condition affecting the extraocular muscles of the eyes. It has also been linked to systemic autoimmune diseases. We present a case of orbital myositis in a 57-year-old male undergoing treatment for rheumatoid arthritis (RA) with tofacitinib, a Janus kinase inhibitor (JAK). Prompt administration of intravenous steroids led to rapid symptom improvement. To date, only six published cases have documented the association between RA and orbital myositis. This is the first description of orbital myositis occurring during treatment with the anti-inflammatory drug tofacitinib, an increasingly used disease-modifying anti-rheumatic drug (DMARD). We review the literature and emphasize the importance of ongoing vigilance regarding adverse events linked to tofacitinib.

Idiopathic Orbital Myositis Revisited.

PURPOSE OF REVIEW: To review current knowledge regarding idiopathic orbital myositis. RECENT FINDINGS: Recent publications have focused on possible causes of orbital myositis and the process to reach a diagnosis of idiopathic orbital myositis. With inflamed and enlarged extraocular muscles, features to distinguish between competing diagnostic possibilities are based on imaging in the context of history and clinical signs. Idiopathic orbital myositis is characterized by the clinical triad of acute onset of orbital pain exacerbated on eye movement, double vision, and redness or swelling of the eyelids or conjunctiva, along with the radiological finding of homogeneous, fusiform enlargement of one or more extraocular muscles. In atypical or inconclusive clinico-radiological findings for a diagnosis of idiopathic orbital myositis, or where the clinical behavior changes or fails to respond to corticosteroid treatment, a systemic and oncologic work-up and muscle biopsy are warranted to exclude specific local or systemic disease as cause of the inflamed and enlarged muscle. As our understanding of idiopathic orbital myositis evolves, the diagnostic focus is shifting toward earlier identification of underlying local or systemic disease through systemic work-up and muscle biopsy.

Orbital myositis in systemic lupus erythematosus: a case-based review.

Ocular complications occur in up to one-third of patients with systemic lupus erythematosus (SLE). Among them, orbital myositis (OM) is considered a rare manifestation that affects the extraocular muscles and causes pain and restriction with eye movement. We report a case of OM in a 48-year-old female with SLE and secondary Sjogren's Syndrome, who presented headache, periorbital edema, and painful ocular movements in both eyes, with no other systemic manifestations. An orbital magnetic resonance image revealed thickening of the right medial rectus and left lateral rectus muscles. Laboratory tests were normal and there was no further disease activity. The patient was treated with prednisone 1 mg/Kg/day with a resolution of symptoms. We found 13 additional cases of OM from our literature review (11 SLE patients and 2 with discoid lupus erythematosus). There was a female predominance in these cases with a mean age of 43.6 years (SD ± 16.9). Their main clinical features included eye pain, swelling, proptosis, diplopia, and limitations in extraocular muscles, while in most of them, there was no other active systemic manifestation. Treatment with steroids led to the complete resolution of symptoms in most of these patients. The available evidence suggests that it is essential to have a high index of suspicion for OM in SLE patients even when there is no systemic disease activity so that proper treatment is initiated early.

Bilateral Paraneoplastic Orbital Myositis Associated With Malignant Melanoma and Multiple Myeloma.

Paraneoplastic extraocular muscle enlargement has been reported in a small number of patients with cancers including breast or lymphoma, usually presenting with bilateral multiple muscle involvement. Such myositis may be autoimmune. Furthermore, orbital inflammation is a recognized complication of immune-modulation therapy used to treat melanoma, such as ipilimumab. Extraorbital myositis has been described in myeloma, and polymyositis in melanoma. We present a case of bilateral, asymmetrical extraocular muscle enlargement with spontaneous resolution in a patient with simultaneous new diagnoses of metastatic malignant melanoma and multiple myeloma. A similar episode 7 months before diagnosis also resolved spontaneously. The authors believe this to be the first reported case of paraneoplastic orbital myositis associated with multiple myeloma or untreated malignant melanoma.

Orbital giant cell myositis is an unusual and potentially lethal cause of bilateral ophthalmoplegia - A case report and literature review.

We present a case of orbital giant cell myositis (OGCM), presenting with bilateral subacute progressive ophthalmoplegia and optic nerve dysfunction. An early extraocular muscle biopsy confirmed the diagnosis and guided appropriate management. Comprehensive investigation excluded any underlying systemic disease, including myocarditis. Twenty two months after presentation, the patient remains well on azathioprine with complete resolution of orbital signs.

Histopathologic Findings in Idiopathic Orbital Myositis.

PURPOSE: To report the histologic and clinical features of idiopathic orbital myositis (IOM) patients who underwent extraocular muscle (EOM) biopsy over 20 years, to provide the first methodical reference to the expected histopathologic findings, and to discuss the histopathologic differences from common differential diagnoses. DESIGN: Cohort study. PARTICIPANTS: All patients with a diagnosis of IOM who underwent EOM biopsy from 2000 through 2019 were included. Patients who had a different final diagnosis were excluded. METHODS: Tissue samples of EOM and medical records of all participants were reviewed. MAIN OUTCOME MEASURES: Histopathologic features of muscle biopsy, including tissue morphologic features and cellular composition. RESULTS: Thirteen patients met both inclusion and exclusion criteria, and their tissue samples were revisited. Nine patients showed histopathologic findings that suggested a conclusive diagnosis of IOM, and the study focused on them. The average age at presentation was 49 years, and 66.7% of patients were women. The most commonly biopsied EOM was the medial rectus (44.4%). The most common indications for biopsy were nonresolving orbital disease with inadequate response to corticosteroids (44.4%) or a high suspicion of malignancy because of known pre-existing systemic malignancy or the presence of an atypical orbital mass in addition to enlarged muscles (44.4%). The histopathologic findings that suggested a diagnosis of IOM were splaying of muscle fibers by inflammatory infiltrates (n = 9) and mild fibrosis (n = 8) in the endomysium or replacing muscle fibers, with no granulomas or vasculitis. The inflammatory infiltrates identified were of chronic inflammatory cells, consisting of lymphocytes (n = 9), plasma cells (n = 6), and histiocytes (n = 6). Other less commonly identified cells were eosinophils (n = 4), polymorphonuclears (n = 1), and giant cells (n = 1). Muscle fiber degeneration or regeneration was evident in 5 patients. Four patients from the initial cohort showed inconclusive histologic findings on revision and were reassigned as suspected IOM. CONCLUSIONS: The histopathologic features of involved muscles in IOM resemble those seen in idiopathic orbital inflammation and differ from those seen in common differential diagnoses. Extraocular muscle biopsy should be strongly considered whenever the presentation of orbital myositis is not typical or when significant underlying conditions are a possibility.

Orbital inflammatory disorders: new knowledge, future challenges.

PURPOSE OF REVIEW: This review aims to bring together recent advances in basic, translational and clinical research on the pathogenesis and treatment of orbital inflammatory conditions. RECENT FINDINGS: Basic science studies provide mechanistic insights into why the orbit is targeted for inflammation by autoimmune inflammatory disorders. Using Graves' disease as a test case reveals that endocrine pathways, such as the TSH and IGF1 receptor pathways play important roles in stimulating orbital inflammation. Furthermore, orbital tissues contain high concentrations of retinoids - byproducts of the visual pathway that diffuse across the sclera and can activate de novo transcription of inflammatory cytokines. Such cytokine expression places the orbit in a hyper-inflammatory 'resting' state, prone to respond to any additional systemic or local pro-inflammatory signals. The HIF2A--LOX pathway appears important for orbital tissue fibrosis. Lastly, bench-to-bedside studies of the IGF1R pathway have led to an FDA-approved drug, teprotumumab that represents a novel treatment approach for Graves' orbitopathy. Unfortunately, high drug costs and misplaced insurance company 'step-therapy' policies may block patients from receiving therapy that can protect vision and improve quality of life. SUMMARY: Improved understanding of orbital inflammatory conditions has led to a new drug and promises additional breakthroughs. Translational research is successful, but requires time, resources, and patience.

Atypical Cogan Syndrome Featuring Orbital Myositis and Dacryoadenitis.

A 39-year-old male presented with bilateral hearing loss and progressive left eye vision loss over a 14-month period. The development of systemic symptoms including arthralgias, enlarged lymph nodes, and profound leg weakness, prompted a workup for lymphoproliferative disease, infection, and autoimmune inflammatory conditions which was unrevealing. Subsequently, the right visual acuity declined from 20/25 to 20/70 and the left to hand motions due to corneal interstitial keratitis. There was limitation of left infraduction. Neuroimaging revealed dural thickening of the internal auditory canals, cavernous sinuses, cerebellum, and along the optic nerves. There was fusiform enhancing enlargement of the left inferior and medial rectus muscles and pathologic enlargement of the left lacrimal gland. Biopsy of the left lacrimal gland and left inferior rectus revealed fibrosis and lymphocytic infiltration. The patient was diagnosed with atypical Cogan syndrome and treated with oral prednisone, with improvement in visual acuity of the right eye, motility of the left eye, and systemic weakness.

Unilateral Ptosis, Proptosis, and Orbital Myositis After Shingles Vaccination.

Vaccinations for shingles are recommended for most adults over 60 years of age and are typically well tolerated. The present case describes acute onset of unilateral ptosis, proptosis, and orbital myositis developing within days after administration of shingles vaccination. The episode resolved to baseline after 1 week of treatment with steroids. To the authors' knowledge, this is first reported case of orbital inflammation following shingles vaccination. Given the temporal relationship and rapid response to treatment, this may represent an autoimmune reaction to the shingles vaccine.

Myositis of an Extraocular Muscle, a Possible Drug Reaction: Histopathologic and Immunopathologic Analysis.

A 58-year-old man presented with left-sided orbital inflammation, including chemosis and a lateral rectus abduction defect. Initially presumed to represent cellulitis, the condition responded poorly to oral and intravenous antibiotics. CT showed the epicenter of an infiltrate to involve the lateral rectus. The patient improved dramatically when oral prednisone was added. Lateral rectus biopsy displayed intramuscular polyclonal lymphoid infiltrates, rich with eosinophils. Complete resolution of the inflammatory process was confirmed by a follow-up CT. The presumptive diagnosis was idiopathic orbital myositis, an uncommon condition of unknown etiology. However, the patient had taken rosuvastatin, which has been rarely associated with diplopia and ophthalmoplegia, raising the question of whether this case was truly idiopathic.

Granulomatosis with polyangiitis presenting as recurrent, multifocal orbital myositis.

A 43-year-old woman was referred with a 10 month history of persistent pain in the left orbit. Two years prior, she experienced similar pain in the right orbit. Magnetic resonance imaging (MRI) at the time revealed an enlarged right medial rectus muscle. She was diagnosed with idiopathic orbital myositis and was successfully treated with oral corticosteroids. A year later, she developed symptoms in the left orbit with similar imaging findings. For ten months, she remained on high dose corticosteroids for presumed left medial rectus myositis before presenting to our service. Computed tomography (CT) imaging after corticosteroid taper revealed enlarged left medial rectus and left lateral rectus muscles. Orbital biopsy established a diagnosis of granulomatosis with polyangiitis (GPA), for which she was successfully treated with rituximab. This case underscores the importance of not only proceeding with biopsy in atypical cases of orbital myositis but to also taper steroids prior to biopsy.

Suspected orbital myositis associated with COVID-19.

A 44-year-old male patient developed proptosis, edema, and erythema progressing to complete ptosis and supraduction deficit 2 days after positive COVID-19 test. He failed to improve on systemic antibiotics. MRI showed thickening and T2 enhancement of the superior rectus/levator complex consistent with orbital myositis. He improved on intravenous corticosteroids and experienced continued gradual improvement on oral steroids.

Case report: Orbital myositis triggering oxygen-responsive cluster headache.

BACKGROUND: Orbital myositis is an idiopathic, non-infectious condition, typically seen in young females and usually affecting one extraocular muscle. Orbital myositis mimicking cluster headache is a rare clinical entity, and this is the first description of a case of a secondary trigeminal autonomic cephalalgia from orbital myositis responsive to high-flow oxygen. CASE: A young woman presented with new-onset, oxygen-responsive headache, periorbital pain and autonomic features. She had associated vertical diplopia on downgaze and subtle ocular misalignment. An initial diagnosis of cluster headache was made. Initial brain MRI was unrevealing, but dedicated MRI of the orbits showed enhancement of orbital muscles. The diplopia and the imaging findings were consistent with orbital myositis. CONCLUSION: Orbital myositis mimicking cluster headache is rare, and not previously reported as an oxygen-responsive headache.

Orbital Myositis: A Comprehensive Review and Reclassification.

PURPOSE: Orbital myositis occurs in typical and atypical forms. This review summarizes and updates the current state of knowledge of all forms of inflammation affecting extraocular muscle, excluding thyroid-associated orbitopathy. METHODS: A comprehensive literature review of orbital myositis was performed. RESULTS: Orbital myositis typically occurs in an idiopathic acute form, with painful diplopia due to inflammation in 1 or more extraocular muscles of young adult females, which usually responds to a course of oral corticosteroids. Atypical forms include idiopathic chronic or recurrent orbital myositis, and myositis related to systemic autoimmune, inflammatory, and infective conditions. The commonest associated autoimmune condition is inflammatory bowel disease. Immunoglobulin G4-related ophthalmic disease often affects extraocular muscle. Drug reactions and rarely paraneoplastic disease may also cause extraocular muscle inflammation. CONCLUSIONS: Orbital myositis occurs in a typical acute steroid responsive form, but atypical forms related to specific autoimmune and inflammatory conditions are increasingly recognized. Orbital myositis has many similarities to uveitis and would benefit from a systematic approach to nomenclature, diagnosis, and treatment.