Extraocular muscle volume on time-of-flight magnetic resonance angiography in patients with myasthenia gravis.

INTRODUCTION/AIMS: Despite being a prominent feature of myasthenia gravis (MG), extraocular muscle (EOM) has received little attention in clinical research. The aim of this study was to examine EOM volume in patients with MG and controls using time-of-flight magnetic resonance angiography (TOF-MRA). METHODS: EOM volumes (overall and individual rectus muscles) were calculated using TOF-MRA images and compared between MG patients (including subgroups) and controls. The correlation between EOM volume and disease duration was examined. Predictive equations for the selected parameters were developed using multiple linear regression analysis. RESULTS: EOM volume was lower in MG patients than controls, especially in MG patients with ophthalmoparesis (MG-O). MG-O exhibited a moderate negative correlation between EOM volume and disease duration. Multiple linear regression showed that disease duration and EOM status (ophthalmoparesis or not) account for 48.4% of EOM volume. DISCUSSION: Patients with MG show atrophy of the EOMs, especially those with ophthalmoparesis and long disease duration.

Understanding Visual Disorders through Correlation of Clinical and Radiologic Findings.

Patients presenting with visual disturbances often require a neuroimaging approach. The spectrum of visual disturbances includes three main categories: vision impairment, ocular motility dysfunction, and abnormal pupillary response. Decreased vision is usually due to an eye abnormality. However, it can also be related to other disorders affecting the visual pathway, from the retina to the occipital lobe. Ocular motility dysfunction may follow disorders of the cranial nerves responsible for eye movements (ie, oculomotor, trochlear, and abducens nerves); may be due to any abnormality that directly affects the extraocular muscles, such as tumor or inflammation; or may result from any orbital disease that can alter the anatomy or function of these muscles, leading to diplopia and strabismus. Given that pupillary response depends on the normal function of the sympathetic and parasympathetic pathways, an abnormality affecting these neuronal systems manifests, respectively, as pupillary miosis or mydriasis, with other related symptoms. In some cases, neuroimaging studies must complement the clinical ophthalmologic examination to better assess the anatomic and pathologic conditions that could explain the symptoms. US has a major role in the assessment of diseases of the eye and anterior orbit. CT is usually the first-line imaging modality because of its attainability, especially in trauma settings. MRI offers further information for inflammatory and tumoral cases. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

MRI evaluation of cranial nerve abnormalities and extraocular muscle fibrosis in duane retraction syndrome and congenital extraocular muscle fibrosis.

PURPOSE: To investigate the alterations in extraocular muscles (EOMs) by magnetic resonance imaging (MRI) among patients diagnosed with Duane retraction yndrome (DRS) and congenital fibrosis of the extraocular muscles (CFEOM), who present with various cranial nerve anomalies in an attempt to enhance the clinical diagnostic process. METHODS: A case-control study was conducted to evaluate 27 patients with DRS and 14 patients with CFEOM. All patients underwent MRI scans of the brainstem and orbital examination. Neurodevelopmental assessments were conducted through MRI, and maximum cross-sectional area and volumes of EOMs were obtained. Three types of models were constructed using machine learning decision tree algorithms based on EOMs to predict disease diagnosis, cranial nerve abnormalities, and clinical subtypes. RESULTS: Patients with bilateral CN VI abnormalities had smaller volumes of LR, MR, and IR muscles compared to those with unilateral involvement (P < 0.05). Similarly, patients with CFEOM and unilateral third cranial nerve abnormalities had a smaller maximum cross-section of the affected eye's SR compared to the contralateral eye (P < 0.05). In patients with both CN III and CN VI abnormalities, the volume of SR was smaller than in patients with CN III abnormalities alone (P < 0.05). The prediction model using EOMs volume showed a diagnostic precision of 82.5% for clinical cases and 60.1% for predicting cranial nerve abnormalities. Nonetheless, the precision for identifying clinical subtypes was relatively modest, at only 41.7%. CONCLUSION: The distinctive volumetric alterations in EOMs among individuals exhibiting distinct cranial nerve anomalies associated with DRS or CFEOM provide valuable diagnostic insights into to Congenital Cranial Neurodevelopmental Disorders (CCDDs). MRI analysis of EOMs should thus be regarded as a crucial diagnostic modality.

A case of bilateral amyloidosis localized to extraocular muscles mimicking thyroid eye disease.

BACKGROUND: Amyloidosis is a rare condition characterized by the abnormal deposition of amyloid proteins in various tissues and organs. While systemic amyloidosis has been well-documented, amyloid deposition in extraocular muscles is an exceptionally rare occurrence, with only 35 reported cases. This case report sheds light on the importance of considering amyloidosis in the differential diagnosis of patients presenting with proptosis and diplopia, which are often associated with thyroid eye disease. CASE PRESENTATION: A woman in her twenties sought medical attention due to a complaint of diplopia. Her ocular examination revealed almost normal findings except for exotropia and proptosis. Orbital magnetic resonance imaging displayed fusiform enlargement of nearly all eye muscles, a presentation typically observed in thyroid eye disease. However, despite corticosteroid therapy, her symptoms showed no improvement. Given the unusual lack of response to conventional treatment, and inhomogeneous enhancement of the muscle, an extraocular muscle biopsy was conducted. This biopsy yielded a unique finding-amyloid deposition within the muscle tissue. This discovery was particularly intriguing due to the extreme rarity of amyloidosis affecting extraocular muscles, with fewer than three dozen documented cases worldwide. CONCLUSION: This unique case underscores the critical need for a comprehensive approach to diagnosing patients with proptosis and diplopia. While these symptoms are commonly attributed to thyroid eye disease, it is essential to consider alternative diagnoses such as amyloidosis, especially when standard treatments fail to yield results. The discovery of amyloid deposition in the extraocular muscles, although exceedingly rare, emphasizes the significance of a thorough differential diagnosis. In conclusion, this case report highlights the importance of vigilance in clinical practice, encouraging ophthalmologists to explore less common diagnostic possibilities when faced with challenging cases. Further research and clinical investigation are warranted to better understand the mechanisms and potential treatments for amyloidosis affecting the extraocular muscles.

Performance of T2 mapping in the staging of Graves' ophthalmopathy based on different region of interest selection methods.

BACKGROUND: Discriminating the stage of Graves' ophthalmopathy (GO) is crucial for clinical decision. Application of conventional T2-weighted imaging in the staging is still limited. PURPOSE: To evaluate the performance of T2 mapping based on two different regions of interest (ROIs) for staging GO. MATERIAL AND METHODS: In total, 56 GO patients were retrospectively enrolled and divided into two groups according to the clinical activity score (CAS). T2 relaxation time (T2RT) of extraocular muscle (EOM) on T2 mapping based on two different ROIs (T2RTROI-1: ROIs were drawn separately in the four EOMs; T2RTROI-2: ROI was drawn in the most inflamed EOM) was measured and compared between active and inactive groups. RESULTS: Both T2RTROI-1 and T2RTROI-2 values in the active GO were significantly higher than those of inactive GO (P <0.001). T2RTROI-1 and T2RTROI-2 values were positively correlated with CAS (rs=0.73, 0.69; P <0.001). When the T2RTROI-1 value of 83.3 ms and T2RTROI-2 value of 106.3 ms were used as cutoff values for staging GO, respectively, the best results were obtained with areas under the curve (AUCs) of 0.822 and 0.827. There was no significant difference for AUCs between T2RTROI-1 and T2RTROI-2 (P = 0.751). Excellent and good inter-observer agreements were achieved in quantitative measurements for T2RTROI-1 and T2RTROI-2 values, respectively, with intraclass correlation coefficients of 0.954 and 0.882. CONCLUSION: The T2RT values derived from two different ROIs were useful for assessment of disease activity. Taking reproducibility and diagnostic performance into consideration, T2RTROI-1 would be an ideal image biomarker for staging GO compared to T2RTROI-2.

Tendon-Sparing Extraocular Muscle Enlargement Associated With Chronic Inflammatory Demyelinating Polyradiculoneuropathy.

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an inflammatory, sensorimotor polyneuropathy. It has presented with a variety of orbital and neuro-ophthalmic manifestations, including cranial nerve hypertrophy and a single case of extraocular muscle enlargement. The authors present a second case of tendon-sparing, extraocular muscle enlargement, resulting in new-onset diplopia and strabismus in a teenager with CIDP. The workup ruled out alternative causes of extraocular muscle enlargement, such as hyperthyroidism, inflammation, or malignancy. As with other cases of CIDP, management involved a combination of immunoglobulin therapy and anti-inflammatory medications. The patient experienced resolution of his symptoms, and radiologic improvement was noted in the muscle enlargement. As many CIDP patients have a favorable treatment response and long-term prognosis, awareness of this rare disease with an early and accurate diagnosis is important.

A Case of Idiopathic Orbital Inflammation With Elevated Anti-Mumps Immunoglobulin M Antibody.

A 21-year-old female presented with periocular swelling, diplopia, and painful ophthalmoplegia in the OS. Orbital magnetic resonance imaging revealed an enhanced soft tissue mass involving the left medial rectus muscle. Laboratory test results revealed leukocytosis, elevated reactive C-reactive protein, and positive serum levels of anti-mumps immunoglobulin M (IgM) antibody without systemic manifestations of mumps infection. The clinical course was refractory, and the patient showed a poor response to high-dose steroids. An incisional biopsy revealed stromal fibrosis with focal lymphoid aggregates, indicating sclerosing inflammation. Myopathy of the medial rectus progressed to superior, inferior, and lateral recti involvement of the left orbit. Immunosuppressive agents, including steroids, were administered for 22 months after disease onset. The mumps IgM antibody level was positive for over 5 months and became negative upon testing performed 1 year after the first visit.

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.

Melanoma Arising Beneath the Lateral Rectus Muscle in a Teenager With Ocular Melanocytosis: Possible Origin From Intrascleral Melanocytes.

Ocular melanocytosis is a well-established risk factor for choroidal melanomas but, despite its reported associations in the literature, it is infrequently discussed in relation to orbital melanomas. The authors describe a teenage patient with ocular melanocytosis who presented with an asymptomatic ipsilateral right orbital mass associated with the lateral rectus muscle. An exploratory orbitotomy revealed a lesion lightly adherent to the underlying sclera. Histopathology demonstrated a markedly atypical epithelioid melanocytic proliferation, bound by a thin rim of superficial sclera, implying an origin from intrascleral melanocytes, likely within an emissary canal. Next-generation sequencing identified GNAQ and NF1 mutations. The histopathology and molecular genetics designated the lesion as having a uveal melanoma-like profile, suggesting that it may behave as a choroidal melanoma. This case underscores the importance of the association between ocular melanocytosis and orbital melanoma and provides additional evidence for primary orbital melanoma etiopathogenesis.

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.

Multispecialty Management of Metastatic Colon Adenocarcinoma Involving the Extraocular Muscles: Primary Excision and Simultaneous Treatment of Strabismus With a Review of the Literature.

Metastatic colon adenocarcinoma involving the extraocular muscles is extremely rare. It usually develops following the diagnosis of the systemic disease and therefore, management and treatment require a multispecialty approach. Within this manuscript, we provide a summary of cases of orbital metastasis secondary to colon cancer. We further discuss a detailed case of a 42-year-old male patient who developed recent-onset diplopia in the left gaze. Orbital CT imaging showed a localized, well-circumscribed enlargement of the right medial rectus muscle. The biopsy of the right medial rectus showed adenocarcinoma originating from the gastrointestinal system. Further workup revealed colon adenocarcinoma with multiple metastatic sites. The patient started systemic chemotherapy. After 2 months of chemotherapy (5-fluouracil, oxaliplatin, irinotecan, and leucovorin), all systemic metastatic sites regressed; however, his medial rectus muscle continued to grow, causing compressive optic neuropathy. The patient underwent excisional biopsy of the right medial rectus muscle with simultaneous repair of the strabismus with transposition of superior and inferior recti muscles. He continued with systemic chemotherapy. Follow up in 1 year revealed no local orbital tumor recurrence with excellent visual acuity and no diplopia in primary gaze.

Extraocular muscle enlargement and proptosis in carotid cavernous fistulas.

PURPOSE: To evaluate the prevalence and pattern of extraocular muscle enlargement and proptosis in patients with carotid cavernous fistulas (CCF). METHODS: We conducted a retrospective study on patients with digital subtraction angiography (DSA) confirmed CCFs with neuroimaging (computed tomography or magnetic resonance imaging) performed prior to the DSA. The maximum extraocular muscle diameters were recorded. Extraocular muscles were considered enlarged if they were greater than two standard deviations above the normal muscle diameters. Proptosis was defined as the distance between the interzygomatic line to the anterior globe of ≥2 mm compared to the contralateral orbit or ≥21 mm. RESULTS: Forty orbits from 20 patients were included. The mean age of participants was 65 ± 15 years and 13 (65%) were female. Thirteen (65%) fistulas were indirect and seven (35%) were direct. There was enlargement of at least one muscle in 11 (27.5%) orbits, and this was not correlated with the type of fistula (direct/indirect). The inferior rectus was most commonly enlarged in seven orbits (17.5%), followed by the medial rectus in five orbits (12.5%). Proptosis was found in 17 (43%) orbits and was more common ipsilateral to the fistula (58% ipsilateral group vs 19% contralateral group, p < .01). CONCLUSION: Extraocular muscle enlargement was observed in over one-fourth of CCFs. When enlarged, the inferior and medial rectus muscles are most commonly involved. These findings may help clinicians and radiologists when evaluating the CT or MRI scans of patients with suspected CCFs.

Levator palpebralis superioris histopathologic findings in congenital ptosis and surgical outcome after its resection: Is there any association?

PURPOSE: To evaluate the histopathologic findings of Levator palpebralis superioris (LPS) muscle biopsy after LPS resection for treatment of congenital ptosis and its possible relation with surgical outcomes.Please confirm if the author names are presented accurately and in the correct sequence (given name, middle name/initial, family name). Author 4 Given name: [Seyed Mohsen] Last name [Rafizadeh]. Author 6 Given name: [Seyed Ali] Last name [Sonbolestan].Also, kindly confirm the details in the metadata are correct.The author names and the sequence are correct. METHODS: Congenital ptosis patients were enrolled in this retrospective study. All of them underwent full ophthalmologic examination included of Margin-reflex distance 1 (MRD-1) and LPS function measurement preoperatively. The patients were followed for 3 months for the postoperative period and after that the measurements were repeated. Histologic parameters including percentages of fat, striated and smooth muscle, and fibrous tissue. The histopathologic findings and their possible correlation with the measurements are analyzed. RESULTS: Sixty-seven patients with unilateral congenital ptosis were enrolled. 45 patients (67.2%) were males. The mean age of patients was 16.10 ± 11.18 years. The patients' MRD-1 was improved significantly from 0.82 ± 1.26 mm to 3.85 ± 1.25 mm after LPS resection (P = 0.000). The success rate was 80.3%. There were no correlations between MRD change and histopathologic tissue percentages but significant correlation was found between success of surgery and fibrous tissue percentage of resected sample (P = 0.033). CONCLUSIONS: The histopathology of the LPS may be useful in prediction of surgical outcome after LPS resection in congenital ptosis patients. The percentage of fibrous tissue play an important role.

Asymmetric proptosis in thyroid eye disease.

PURPOSE: Patients with thyroid eye disease (TED) can present with asymmetric disease. The purpose of this study was to evaluate the prevalence of asymmetric TED in an Australian cohort and investigate clinical, biochemical, and radiological associations of asymmetric TED. METHODS: This was a retrospective study of patients with TED who underwent Hertel exophthalmometry and orbital computed tomography (CT) scans. Asymmetry was defined as a difference in the globe protrusion of ≥ 3 mm using Hertel exophthalmometry. Data was collected on patient demographics, clinical disease presentation, thyroid function tests and antibody levels. Muscles volumes were determined by manually segmenting the extraocular muscles on CT scans using a commercially available software. RESULTS: 172 orbits from 86 patients were included in the study. 28 (33%) patients had asymmetric TED. No significant differences were observed in age, gender, thyroid hormone status, anti-thyroid peroxidase levels, thyroid stimulating hormone receptor antibodies, disease activity status, or dysthyroid optic neuropathy between the asymmetric and non-asymmetric groups. The extraocular muscle volumes were significantly higher in the asymmetric orbit compared to its contralateral orbit. CONCLUSION: Asymmetric TED is a reasonably common occurrence in the course of TED. It is associated with higher extraocular muscle volumes, suggesting muscle enlargement as one of the underlying contributors to asymmetric proptosis. Thyroid eye disease should be considered in the differential of asymmetric orbital inflammatory disease.

Whole-orbit-based multiparametric assessment of disease activity of thyroid eye disease on Dixon MRI.

PURPOSE: This study aimed to explore the diagnostic value of whole-orbit-based multiparametric assessment on Dixon MRI for the evaluation of the thyroid eye disease (TED) activity. METHODS: The retrospective study enrolled patients diagnosed as TED and obtained their axial and coronal Dixon MRI scans. Multiparameters were assessed, including water fraction (WF), fat fraction (FF) of extraocular muscles (EOMs), orbital fat (OF), and lacrimal gland (LG). The thickness of OF and herniation of LG were also measured. Univariable and multivariable logistic regression was applied to construct prediction models based on single or multiple structures. Receiver operating characteristic (ROC) curve analysis was also implemented. RESULTS: Univariable logistic analysis revealed significant differences in water fraction (WF) of the superior rectus (P = 0.018), fat fraction (FF) of the medial rectus (P = 0.029), WF of OF (P = 0.004), and herniation of LG (P = 0.012) between the active and inactive TED phases. Multivariable logistic analysis and corresponding receiver operating characteristic curve (ROC) analysis of each structure attained the area under the curve (AUC) values of 0.774, 0.771, and 0.729 for EOMs, OF, and LG, respectively, while the combination of the four imaging parameters generated a final AUC of 0.909. CONCLUSIONS: Dixon MRI may be used for fine multiparametric assessment of multiple orbital structures. The whole-orbit-based model improves the diagnostic performance of TED activity evaluation.

Application of Multiparameter Quantitative Magnetic Resonance Imaging in the Evaluation of Graves' Ophthalmopathy.

BACKGROUND: Assessment of the activity of Graves' ophthalmopathy (GO) is difficult. Existing methods need improvement. PURPOSE: Investigate the application of multiparametric magnetic resonance imaging (MRI) in GO. STUDY TYPE: Retrospective. POPULATION: A total of 235 GO patients (age: 38.8 ± 13.4 years; 90 male; 96 active patients). FIELD STRENGTH/SEQUENCE: Short-tau inversion recovery (STIR) fast spin echo, multiecho spin echo T2 mapping and 3D T1-weighted fast field echo sequences at 3.0 T. ASSESSMENT: Two physicians assessed the mean and maximum signal intensity ratio of extraocular muscles to white matter (SIR), T2 relaxation time (T2RT), extraocular muscle area (EMA), fat fraction (FF), retrobulbar fat volume (RFV), and extraocular muscle volume (EMV). Clinical activity score (CAS) â‰§ 3 was in active stage. STATISTICAL TESTS: The optimal cut-off point of diagnostic efficacy was selected using receiver operating characteristic (ROC) curve analysis and evaluated using area under the curve (AUC), compared using Student's t test, analysis of variance or Kruskal-Wallis H test. The correlation used Pearson correlation analysis. The discriminant equation used a binary logistic regression analysis. P < 0.05 was considered statistically significant. RESULTS: The SIRmean, SIRmax, T2RTmean, T2RTmax, EMA, and EMV in active GO patients were significantly higher than those in inactive and were positively correlated with CAS (r = 0.276, 0.228, 0.438, 0.388, 0.502, and 0333, respectively). The FFmax of active patients was significantly lower than that of inactive patients and was negatively correlated with CAS (r = -0.44). Logistic regression analysis indicated that T2RTmean was independently associated with GO active periods and had good diagnostic performance (area under ROC curve = 0.736, sensitivity 70.7%, specificity 69.3%). T2RTmean â‰§ 74.295 could be a diagnostic cut-off for judging GO activity (sensitivity 55.3%). CONCLUSION: SIR, T2RT, EMV, and FF can quantitatively assess the activity and severity of GO and can potentially provide a basis for clinical judgment and selection of treatment options. EVIDENCE LEVEL: 4. TECHNICAL EFFICACY: Stage 2.

Quantitative assessment of extraocular muscles in Graves' ophthalmopathy using T1 mapping.

OBJECTIVE: To evaluate the performance of T1 mapping in the characterization of extraocular muscles (EOMs) of Graves' ophthalmopathy (GO) patients and investigate its feasibility in assessing the response to glucocorticoid therapy in active GO patients. METHODS: A total of 133 participants (78 active GO, 23 inactive GO, 18 Graves' disease (GD) patients, and 14 healthy volunteers) were consecutively enrolled from July 2018 to December 2020. Native T1 (nT1) and postcontrast T1 (cT1) values of EOMs were measured and compared. The variations in T1 mapping metrics of EOMs were compared pre/post glucocorticoid treatment in 23 follow-up active GO patients. Logistic regression analysis and receiver operating characteristic (ROC) curve analysis were performed. RESULTS: The nT1 of EOMs in GO patients was higher than that in GD patients and healthy volunteers. The nT1 of superior rectus (SR) in active GO was higher than that in inactive GO patients, and it could be used as a potential marker of GO activity (OR: 1.003; 95% CI: 1.001, 1.004), with a diagnostic sensitivity of 86.3% and specificity of 43.7%. Meanwhile, the cT1 of SR, inferior rectus (IR), and medial rectus (MR) in inactive GO patients were higher than those in active GO patients. The nT1 of EOMs achieved sufficient diagnostic performance in evaluating the response to glucocorticoid therapy for follow-up active GO patients (AUC, 0.797; sensitivity, 71.9%; specificity, 85.7%). CONCLUSIONS: T1 mapping could quantitatively assess the activity of GO and the response to glucocorticoid therapy in active GO patients and may even potentially reflect the fibrosis of EOMs. CLINICAL RELEVANCE STATEMENT: T1 values can reflect the pathological status of the extraocular muscle. T1 mapping could help to quantitatively assess the clinical activity of GO and the response to glucocorticoid therapy in active GO patients. KEY POINTS: • Graves' ophthalmopathy patients had greater nT1 of extraocular muscles than Graves' disease patients and healthy volunteers, and nT1 of the superior rectus could be a potential marker of Graves' ophthalmopathy activity. • The cT1 of extraocular muscles in inactive Graves' ophthalmopathy patients was higher than that in active Graves' ophthalmopathy patients, and it might be associated with muscle fibrosis. • nT1 of extraocular muscles could offer sufficient diagnostic performance in evaluating the response to glucocorticoid therapy for follow-up active Graves' ophthalmopathy patients.

Extraocular muscle volume index at the orbital apex with optic neuritis: a combined parameter for diagnosis of dysthyroid optic neuropathy.

OBJECTIVES: To evaluate the diagnostic performance of the extraocular muscle volume index at the orbital apex (AMI) and the signal intensity ratio (SIR) of the optic nerve in dysthyroid optic neuropathy (DON). METHODS: Clinical data and magnetic resonance imaging were collected retrospectively from 63 Graves' ophthalmopathy patients, including 24 patients with DON and 39 without DON. The volume of these structures was obtained by reconstructing their orbital fat and extraocular muscles. The SIR of the optic nerve and axial length of eyeball were also measured. The posterior 3/5 of the retrobulbar space volume was used as the orbital apex to compare parameters in patients with or without DON. Area under the receiver operating characteristic curve (AUC) analysis was used to select the morphological and inflammatory parameters with the highest diagnostic value. A logistic regression was performed to identify the risk factors of DON. RESULTS: One hundred twenty-six orbits (35 with DON and 91 without DON) were analyzed. Most of the parameters in DON patients were significantly higher than in non-DON patients. However, the SIR 3 mm behind the eyeball of the optic nerve and AMI had the highest diagnostic value in these parameters and are independent risk factors of DON by stepwise multivariate logistic regression analysis. Combining AMI and SIR had a higher diagnostic value than a single index. CONCLUSIONS: Combining AMI with SIR 3 mm behind the eyeball's orbital nerve can be a potential parameter for diagnosing DON. CLINICAL RELEVANCE STATEMENT: The present study provided a quantitative index based on morphological and signal changes to assess the DON, allowing clinicians and radiologists to monitor DON patients timely. KEY POINTS: The extraocular muscle volume index at the orbital apex (AMI) has excellent diagnostic performance for dysthyroid optic neuropathy. A signal intensity ratio (SIR) of 3 mm behind the eyeball has a higher AUC compared to other slices. Combining AMI and SIR has a higher diagnostic value than a single index.

Clinical significance of CTGF and Cry61 protein in extraocular muscles of strabismic patients.

PURPOSE: To investigate the relationship between clinical features and protein amounts of Cysteine-rich 61 (Cyr61/CCN1) and connective tissue growth factor (CTGF/CCN2), which are vital components and regulators of the extracellular matrix in resected muscles from strabismus surgery. METHODS: Strabismus patients who were diagnosed with horizontal concomitant strabismus or inferior oblique overaction (IOOA) and required extraocular muscles (EOMs) resection to correct eye position were included in this study. The protein amounts were measured by enzyme-linked immunosorbent assay (ELISA) in resected EOMs. Multivariable linear regression was used to investigate the associations, adjusting for gender, age (continuous), amblyopia, and disease duration. RESULTS: A total of 141 muscles (including 38 lateral, 81 medial rectus, and 22 inferior oblique muscles) from 128 patients were collected in this study. The amount of Cry61 and CTGF per millimeter was significantly negatively associated with deviation angle in intermittent exotropia patients (Cry61: ß, - 1.44; 95%CI, - 2.79 to - 0.10, p = 0.035; CTGF: ß, - 3.14; 95%CI, - 5.06 to - 1.22, p = 0.002). The same relationship was also detected in the partially accommodative and non-accommodative esotropia patients, although it was not statistically significant (Cry61: ß, - 2.40; 95%CI, - 5.05 to 0.24; p = 0.073; CTGF: ß, - 3.47; 95%CI, - 9.18 to 2.87; p = 0.269). The amount of Cry61 and CTGF per millimeter showed significant associations with the degree of IOOA (p < 0.05). CONCLUSIONS: Taken together, our results demonstrated a significant relationship between deviation angle and protein amount of Cry61 and CTGF and implied that Cry61 and CTGF may play important roles in modulation of EOM contractility, which provide new insights into strabismus pathogenesis.

Orbital Involvement in Multiple Myeloma.

PURPOSE: To characterize clinical and radiographic features, management, and outcomes of patients with orbital involvement of multiple myeloma (MM). METHODS: A retrospective chart review identified patients with MM and orbital involvement confirmed by histopathology at a single institution between 1995 and 2021. A comprehensive literature review was performed via PubMed to identify all previously reported cases of orbital MM. RESULTS: Retrospective review identified 7 patients (43% male, mean age 68.7 years). Presenting symptoms included proptosis and diplopia. Orbital lesions were primarily located laterally (42.8%) with associated extraocular muscle (57.1%) or lacrimal gland (42.9%) involvement. Five patients (71.4%) had a previous diagnosis of systemic MM. Six patients received chemoradiation (85.7%). All patients had improvement of orbital disease with 2 patients deceased due to disease at follow-up (mean 8.9 months). Literature review identified 111 cases (46.8% male, mean age 58.6 years). 48.6% presented with orbital disease as the first manifestation of systemic MM. Lesions were most commonly located superolaterally (20.2%) with extraocular muscle infiltration (25.2%), lacrimal gland involvement (7.2%), and orbital bony destruction (39.6%). Treatments included chemoradiation, chemotherapy, or radiation alone. Approximately half (51.4%) of patients experienced improvement in orbital disease following treatment, and 48.6% were deceased at follow-up (mean 20.1 months). CONCLUSIONS: This study provides a new retrospective study and updated comprehensive literature review regarding orbital MM. Given its poor prognosis, characterization of orbital MM is essential for early diagnosis. Orbital MM is often unilateral, located superolaterally, and may represent the first manifestation of systemic disease. Treatment includes chemotherapy and radiation, which may improve orbital disease; however, the overall prognosis remains poor.