Orbital Magnetic Resonance Imaging Research Articles

Lateral orbitotomy in the management of an intra-orbital lipoma

Introduction: Lipomas are benign subcutaneous mass, but the intra-orbital location is rarely reported in the literature and it can resemble a variety of other orbital lesions. Case report: We describe a 15-year-old girl who presented with left exophthalmia. Orbital magnetic resonance imaging showed an encapsulated intra-conal mass displacing the optic nerve medially, the external right muscle laterally and the globe anteriorly. Excisional biopsy of the mass by lateral orbitotomy approach resolved the exophthalmia, and histology revealed a primary orbital lipoma. Conclusion: The diagnosis of an intra-orbital lipoma is not easy and the surgical approach represents a challenge to achieve a total excision while avoiding complications.

Texture analysis of orbital magnetic resonance imaging for monitoring and predicting treatment response to glucocorticoids in patients with thyroid-associated ophthalmopathy.

PurposeTo evaluate the value of MRI-based texture analysis of extraocular muscle (EOM) and orbital fat (OF) in monitoring and predicting the response to glucocorticoid (GC) therapy in patients with thyroid-associated ophthalmopathy (TAO).MethodsThirty-seven active and moderate-to-severe TAO patients (responders, n = 23; unresponders, n = 14) were retrospectively enrolled. MRI-based texture parameters (entropy, uniformity, skewness and kurtosis) of EOM and OF were measured before and after GC therapy, and compared between groups. Correlations between the changes of clinical activity score (CAS) and imaging parameters before and after treatment were assessed. Receiver operating characteristic curves were used to evaluate the predictive value of identified variables.ResultsResponsive TAOs showed significantly decreased entropy and increased uniformity at EOM and OF after GC therapy (P < 0.01), while unresponders showed no significance. Changes of entropy and uniformity at EOM and OF were significantly correlated with changes of CAS before and after treatment (P < 0.05). Responders showed significantly lower entropy and higher uniformity at EOM than unresponders before treatment (P < 0.01). Entropy and uniformity of EOM and disease duration were identified as independent predictors for responsive TAOs. Combination of all three variables demonstrated optimal efficiency (area under curve, 0.802) and sensitivity (82.6%), and disease duration alone demonstrated optimal specificity (100%) for predicting responsive TAOs.ConclusionMRI-based texture analysis can reflect histopathological heterogeneity of orbital tissues. It could be useful for monitoring and predicting the response to GC in TAO patients.

Orbital anatomy magnetic resonance imaging in diplopic versus non-diplopic patients after glaucoma drainage device placement.

New-onset persistent diplopia has become a common complication after glaucoma drainage device (GDD) placement. Understanding the orbital anatomy of such patients may provide information regarding risk of diplopia, GDD selection, and post-operative management. The purpose of this study was to examine the orbital anatomic differences in diplopic and non-diplopic patients after GDD implantation using high-resolution MRI. Seven eyes (N = 4 with diplopia and N = 3 without diplopia after GDD placement) of seven patients that had undergone placement of Baerveldt 250 (B250), Baerveldt 350 (B350), or Ahmed FP7 (FP7) GDD were prospectively enrolled at a single institution. All patients underwent a 3.0T orbital MRI with 3D volumetric T1 and T2 weighted sequence. Images were analyzed for orbital volume, axial length, orbital distances, presence of superior rectus-lateral rectus (SR-LR) band, position of GDD, and SR-LR angles. Patients with diplopia had smaller mean ± SD orbital axial (911.5 ± 111.8 mm3 vs 931.7 ± 79.7 mm3) and coronal volumes (1162.5 ± 145.5 mm3 vs 1180 ± 34.6 mm3) compared to non-diplopic patients. Average orbital rim distances were larger for the diplopic group. The SR-LR displacement angle for diplopic patients was larger (101.6° ± 8.1 vs 94.7° ± 17.6) while the SR-LR quadrantic angle (86.6° ± 4.2 vs 89.1° ± 4.3) was smaller. SR-LR band was present and intact in all patients. GDD malpositioning was not evident in any patient. The decreased orbital axial and coronal volumes as well as increased orbital rim distances in diplopic patients suggests the need for further studies to understand the role of orbital anatomy in occurrence of diplopia. Dynamic MRI imaging may be helpful in identifying differences in extraocular muscle function that reveal an etiology of diplopia in patients with GDD implantation.

Delayed Sudden Blindness From Unilateral Ophthalmic Artery Vasospasm Following Endoscopic Sinus Surgery?

Keywords: ophthalmic artery; vasospasm; iatrogenic; endoscopic sinus surgery; blindness&#x0D; &#x0D; Endoscopic sinus surgery (ESS) is a generally benign, minimally invasive procedure used for management of paranasal sinus diseases, although complications may occur due to proximity of vital structures such as the brain, orbit and great vessels.1 The overall ESS major complication rate is 0.5-1%, of which orbital injury accounts for 0.09% due to direct trauma.2 We report a case of unilateral delayed sudden visual loss without orbital trauma observed intraoperatively or on post[1]operative imaging studies, following a seemingly routine endoscopic sinus surgery for chronic rhinosinusitis.&#x0D; CASE REPORT&#x0D; An 18-year-old lad with no significant medical history underwent ESS for bilateral chronic rhinosinusitis with nasal polyposis. (Figure 1 A-D) The surgery and recovery from anesthesia were uneventful. On the 12th hour post-operatively, the patient noted blurring of vision on the left. Ophthalmologic examination revealed hyperemic conjunctiva (Figure 2A) with visual acuity of counting fingers at 1 foot while fundoscopy showed retinal hemorrhages. Extraocular eye movements (EOM) and intraocular pressure (IOP) were normal (12mmHg). With an assessment of pre-retinal hemorrhages, 500 mg Tranexamic acid was intravenously infused, and a paranasal sinus (PNS) computed tomography (CT) scan and orbital magnetic resonance imaging (MRI) were requested. A few hours later, he complained of left eye pain with increasing intensity and further deterioration of vision. Repeat visual acuity testing showed light perception. There was now a constricted pupil, non-reactive pupillary light reflex, periorbital swelling and progression of conjunctival chemosis. (Figure 2B) The IOP of the left eye had increased to 30mmHg then progressed to 40mmHg with development of total visual loss and a lateral gaze limitation. With an impression of choroidal hemorrhage and retrobulbar hemorrhage, a lateral canthotomy relieved the eye pain.&#x0D; The contrast PNS CT scan with orbital cuts showed that the lamina papyracea was intact with no definite hemorrhagic collections in the intraconal or extraconal spaces of both orbits. (Figure 3A, B) A small hyper density along the lateral inferior margin of the left globe at the intraconal region with slight thickening of the anterior periorbital region represented the lateral canthotomy. The PNS MRI / magnetic resonance angiography (MRA) with orbital cuts showed retinal detachment and periorbital edema in the left eye. (Figure 4) A B-Scan ocular ultrasonogram showed retinal detachment and vitreous opacities. The diagnosis was ocular ischemic syndrome secondary to ophthalmic artery vasospasm, and the patient was given sublingual nitroglycerine and intravenous dexamethasone 8mg every 12 hours for 24 hours, with improvement of periorbital swelling. He was discharged after 12 days with no resolution of the unilateral visual loss.

Central vein sign and other radiographic features distinguishing myelin oligodendrocyte glycoprotein antibody disease from multiple sclerosis and aquaporin-4 antibody-positive neuromyelitis optica

Background: Myelin oligodendrocyte glycoprotein antibody disease (MOGAD) can radiographically mimic multiple sclerosis (MS) and aquaporin-4 (AQP4) antibody-positive neuromyelitis optica spectrum disorder (NMOSD). Central vein sign (CVS) prevalence has not yet been well-established in MOGAD. Objective: Characterize the magnetic resonance imaging (MRI) appearance and CVS prevalence of MOGAD patients in comparison to matched cohorts of MS and AQP4+ NMOSD. Methods: Clinical MRIs from 26 MOGAD patients were compared to matched cohorts of MS and AQP4+ NMOSD. Brain MRIs were assessed for involvement within predefined regions of interest. CVS was assessed by overlaying fluid-attenuated inversion recovery (FLAIR) and susceptibility-weighted sequences. Topographic analyses were performed on spinal cord and orbital MRIs when available. Results: MOGAD patients had fewer brain lesions and average CVS+ rate of 12.1%, compared to 44.4% in MS patients (p = 0.0008). MOGAD spinal cord and optic nerve involvement was lengthier than MS (5.8 vs 1.0 vertebral segments, p = 0.020; 3.0 vs 0.5 cm, p < 0.0001). MOGAD patients tended to have bilateral/anterior optic nerve pathology with perineural contrast enhancement, contrasting with posterior optic nerve involvement in NMOSD. Conclusion: CVS+ rate and longer segments of involvement in the spinal cord and optic nerve can differentiate MOGAD from MS, but do not discriminate as well between MOGAD and AQP4+ NMOSD.

Characterization of the position of the extraocular muscles and orbit in acquired esotropia both at distance and near using orbital magnetic resonance imaging.

PurposeAge-related distance esotropia (ARDE) involves acquired esotropia at distance and phoria at near. However, distance-independent esotropia (DIE) exists esotropia both at distance and near. Thus, we examined the orbital magnetic resonance imaging (MRI) findings for DIE to assess differences in its characteristics.MethodsThis study was a retrospective case-control study. We evaluated the efficacy of the standard coronal MRI in patients with acquired esotropia and control patients with optic neuritis. Cases with strabismus in the control group were excluded. DIE was defined as having esotropia both at distance and near, and an angle of more than 10 prism diopters at near. The condition of the lateral rectus-superior rectus band, position of rectus muscles, and the volume ratio of the globe to the whole orbit (G/WO) were examined.ResultsThe DIE group consisted of 12 eyes of 6 patients (77.3±7.7 years); ARDE group, 38 eyes of 19 patients (73.1±6.8 years); and control group, 34 eyes of 17 patients (70.9±4.3 years). The ratio of abnormality of the lateral rectus-superior rectus bands was higher in the DIE and ARDE groups than in the control group (p<0.01). The vertical angle of the lateral rectus deviated downwards in the control (-7.5±5.1°), ARDE (-12.2±9.1°), and DIE groups (-18.8±5.7°) (p<0.05). The tilting angle of the lateral rectus was tilted temporally in the control (-12.2±9.1°), ARDE (-20.0±8.6°) and DIE groups (-28.6±5.4°) (p<0.01). G/WO was higher in the DIE (0.28±0.01) and ARDE groups (0.27±0.02) compared to the control (0.25±0.03) group (p<0.01).ConclusionIn comparison with the ARDE and control groups, the DIE group presented with abnormalities of the lateral rectus-superior rectus band, malposition of the lateral rectus, and differences in the G/WO. The DIE group showed a more severe form of ARDE.

Optic Perineuritis and Its Association With Autoimmune Diseases

Background: Optic perineuritis (OPN) is a special optic neuropathy that has a distinct etiology from neuromyelitis optica spectrum disorders (NMOSDs) or multiple sclerosis (MS)-related optic neuritis (ON). The mechanisms of how this inflammation developed and invaded the nerve sheath remain unknown. This study is aimed to analyze the etiology and different clinical characteristics of OPN in a Chinese patient population.Methods: Neuro-ophthalmological examination, orbit magnetic resonance imaging (MRI) and a series of blood samples were used in this retrospective observational cohort study to compare characteristics of OPN with idiopathic demyelination optic neuritis (IDON).Results: Forty-four OPN cases (74 eyes) and 61 IDON cases (78 eyes) were analyzed. OPN cases included 33 cases (59 eyes) were associated with specific autoimmune diseases, 10 cases (13 eyes) were associated with infection diseases, 1 case was idiopathic disease. The causes of OPN with CTD were Graves' disease, Immunoglobulin G4-related disease (IgG-4 RD), granulomatosis with polyangiitis (GAP), systemic lupus erythematosus (SLE), Sarcoidosis, Rheumatoid arthritis, scleroderma, Behcet's disease, and gout. All patients received orbital MRI. Overall, 33 cases showed orbit fat infiltration. Specifically, nine cases with IgG-4 RD showed trigeminal nerve branch involvement, 12 cases with Graves' disease showed extraocular muscle belly enlargement, and 4 cases with GAP showed pterygopalatine fossa pseudotumor. Compared to IDON patients, OPN patients were older (p = 0.004) and more likely bilateral involvement 26 (78.79%) patients had bilateral involvement in OPN group vs. 17 (27.87%) in the IDON group (p < 0.001). Visual acuity scores using LogMAR testing was better in OPN patients compared to those with IDON, 0.55 ± 0.91 vs. 1.19 ± 1.24 (p < 0.001). Other ophthalmologic findings unique to the OPN group include 11 (33.33%) cases of ptosis, nine (27.27%) cases of diplopia, and 10 (30.30%) cases of exophthalmos, compared to zero cases of these conditions in the IDON group. Eight (13.11%) IDON patients also had multiple sclerosis (MS) and 7 (11.48%) patients had neuromyelitis which was significantly more than the zero patients in OPN group (p = 0.04).Conclusions: OPN had distinct etiologies and clinical characteristics from IDON and is more often associated with autoimmune diseases. Using OPN characteristics to diagnose autoimmune diseases should prove useful for clinicians when presented with patients that have multiorgan dysfunction that include ophthalmologic findings.

Extraocular Muscle Enlargement in Bilateral Diffuse Uveal Melanocytic Proliferation Associated with Hepatocellular Carcinoma

A 64-year-old man with bilateral diffuse uveal melanocytic proliferation (BDUMP) (Figs A and B) associated with hepatocellular carcinoma presented with painless ocular movement limitations. Visual acuity was count fingers and 20/100, respectively. The eyelids and orbital changes were not observed. Extraocular muscle restriction was not presented on the forced duction test in both eyes. Orbit magnetic resonance imaging demonstrated tendon sparing extraocular muscle enlargement on the rectus and oblique muscles (Fig C), and the test for thyroid function and antibodies were within normal ranges.

Retina and optic nerve complications and hearing injury caused by Sclerotherapy of Facial Vascular Malformation

This report describes a complication of symptoms consistent with transiency visual acuity damage and hearing injury following sclerotherapy with a polidocanol injection to a facial vascular malformation. After the direct injection of 5cc polidocanol-room air emulsion into the subcutaneous malformation, a 3-year-old boy developed bilateral eyelid swelling the next day, and on 7 days later at referral, visual acuity in the left eye was light perception. Fundoscopy revealed retinal hemorrhage; fluorescein angiography (FA) disclosed hyperreflective leakage on the optic disk 15 days later, and OCT showed nerve fiber edema between the disk and macular. The orbital magnetic resonance imaging (MRI) demonstrated the normal extraocular muscles. In a month later, bilateral eyelid swelling resolved but the visual acuity remained 20/500, and 20/20 in two months later, but the hearing injury remained. It needs much more special attention in sclerotherapy for facial malformation because the sclerosants may cause severe toxicity or inflammation in retina and optic nerve, resulting in transiency visual acuity damage and acoustic nerve injury. The related examination including ophthalmic investigation after the sclerotherapy is necessary.

Clinical findings and mutational spectrum of neurofibromatosis type 1 patients in a single center of south part of Turkey.

The aim of this study is to determine the mutation spectrums and clinical characteristics of NF1 patients followed up in our center and to investigate whether there is a genotype-phenotype relationship. Sixty-three children and 34 relatives diagnosed with NF1 were included in the study. Age, gender, family history, clinical features, tumors detected in the patient at the time of diagnosis or during follow-up, orbital and cerebral magnetic resonance imaging (MRI) findings were recorded. Also results of the NF1 gene analysis results were recorded. Fifty-three different mutations were found as a result of the NF1 gene analysis studied from patients and their family members. Among these 53 mutations, stop codon mutation was the most frequently detected mutations. Sixteen out of 50 (32%) mutations were found to be novel mutations. Twenty-eight tumors developed in our patients. Twenty of them were optic gliomas and others were medullary thyroid carcinoma, glioblastome multiforme, pons glioma, acute lymphoblastic leukemia, pilocytic astrositoma, hypothalamic glioma, cerebral hamartoma and cardiac fibroma. No genotype-phenotype relationship was detected in patients Conclusion: Comprehensive mutation analysis of NF1 will increase our knowledge due to its different phenotypic characteristics even in the same mutation.

To Study Presentation of Ocular Cysticercosis and Evaluate Its Demographic Data, Diagnosis, Treatment and Outcome in a Hill Population of Northern India

<i>Aim:</i> To study presentation of ocular cysticercosis and to evaluate its demographic data, diagnosis, treatment and outcome in hill population of Northern India. <i>Materials and methods:</i> This is a retrospective study carried out in Dehradun, Uttarakhand in a tertiary eye care hospital over 4 years from 2016-2020. The study involved 38 patients who presented with unilateral eye disease and were diagnosed to have ocular or adenexal cysticercosis. We analysed retrospectively their geographical data, clinical presentation, serology, imaging, response to treatment and clinical outcome. <i>Results:</i> Age of patients ranged from 16-54 years. Male to female ratio was 1:3.75. Total no. of eyes affected were 38. All were unilateral presentation. 30 eyes (78.94%) presented with extraocular cysticercosis and 8 eyes (21.05%) with intraocular cysticercosis. 27 of the patients (71.05%) were from lower socioeconomic status with poor hygiene and sanitation conditions. 32 (89.21%) patients gave history of association with non-vegetarian diet. Extraocular cysticercosis group had restriction of ocular motility as most prevalent presentation seen in 16 eyes (53.33%) and proptosis as the most prevalent sign seen in 17 eyes (56.66%). Cyst prevalence was most frequently detected in superior rectus muscle seen in 14 eyes (53.84%). Intraocular cysticercosis group had blurring of vision as the most prevalent presenting symptom in 8 eyes (100.0%). Panuveitis in 6 eyes (75%) and presence of subretinal cyst in 4 eyes (50%) was the most prevalent sign seen in intraocular cysticercosis group. Enzyme linked immunosorbent assay test confirmed serology in 35 cases (92.10%). The USG B-scan detected presence of scolex in 36 eyes (94.73%). Magnetic resonance imaging (MRI) confirmed deep seated extraocular cysticercosis lesions and neurocysticercosis (NCC) undetected by computerized tomography (CT). CT was diagnostic for NCC in 5 cases (13.15%). Oral Albendazole and prednisolone were successful in management of extraocular cysticercosis. Intraocular cysticercosis was treated well with pars plana vitrectomy surgery with good visual recovery. <i>Conclusion:</i> Extraocular cysticercosis was more prevalent than intraocular cysticercosis. Early diagnosis and treatment made a difference in final outcome of the two groups. Imaging studies of orbital B-scan ultrasonography (USG B scan), CT and MRI with immune serological test of enzyme linked immunosorbet assay (ELISA) and Western blot for anticysticercus antibodies helped in confirming the diagnosis. Extraocular cysticercosis can be managed well medically with good clinical outcome. Intraocular cysticercosisis is best treated surgically. Safer and modern vitreoretinal surgical techniques promise good surgical outcome and visual recovery. Timely intervention and frequent postoperative follow up would help in keeping a watch on development of complications and maintenance of good vision.

The effect of nonsteroidal anti-inflammatory drugs on eye pain and migraine headache caused by trochleitis.

PURPOSE:Trochleitis has been recognized as one of the causes of eye pain and migraine headaches. This study attempts to investigate the effect of ibuprofen on reducing eye pain and migraine headaches caused by trochleitis.METHODS:In this before-after clinical trial, out of 1100 clinically examined patients with eye pain and migraine symptoms, 33 patients were diagnosed with having trochleitis and trochleodynia confirmed by orbital magnetic resonance imaging images. Ibuprofen (400 mg/6–8 h) was prescribed to the subjects for 15–30 days. The main outcomes were a reduction in tenderness and pain that were evaluated 2 weeks, a month, and 6 months after the prescription. The data were analyzed by STATA (version 14) and using Wilcoxon and McNemar tests.RESULTS:The results revealed that 28 of the subjects (84.8%) experienced a significant reduction in tenderness 2 weeks after undergoing the treatment (P < 0.001). Standard deviation and average of headache scores before and after the treatment were 7.85 ± 1.75 and 0.64 ± 0.61 based on the visual analog scale. The difference between the pain scores before and after the treatment was statistically significant (P < 0.001). Clinical symptoms such as induration (P < 0.001), photophobia (P < 0.001), upward gaze (P < 0.001), and pain after reading (P < 0.001) were reduced significantly. Six months after the treatment, none of the mentioned symptoms was reported by the subjects.CONCLUSION:The findings revealed that noninvasive treatment (ibuprofen) has reduced eye pain, tenderness, and migraine headaches caused by trochleitis. What is important to mention is that trochleitis should be diagnosed properly.

Isolated retro-orbital granulocytic sarcoma relapse of Acute Myeloid Leukemia after allogeneic hematopoietic stem cell transplantation: a case report.

Granulocytic sarcoma (GS) is rare as an isolated presentation of relapse after allogeneic hematopoietic stem-cell transplantation (allo-HSCT), particularly in adult patients with acute myelogenous leukemia (AML). We report here the case of a 37-year-old man who developed a GS of the retro-orbital as an isolated manifestation of AML relapse 27 months after allo-HSCT. A 37-year-old man was diagnosed with AML and subsequently received allo-HSCT after clinical chemical remission. The patient suddenly presented with painless exophthalmos of the left eye twenty-seven months after allo-HSCT. Orbital magnetic resonance imaging (MRI) revealed left retro-orbital masses. Histopathology revealed diffused infiltration of leukemic blasts. Further systemic investigation showed no leukemic involvement of his other organs. Isolated retro-orbital relapse of AML was diagnosed. Despite treatment using retro-orbital irradiation, the patient died 6 months after presentation. Our patient had a poor survival prognosis, even with timely diagnosis and proper treatment. Although the ophthalmologist has a secondary role in the diagnosis and treatment of leukemia, a prompt recognition of the ocular manifestations and their significance as a sign of possible extramedullary lesion is crucial.

A case report of thyroid-associated Orbitopathy with elevated TPO antibodies

BackgroundThyroid associated orbitopathy (TAO) is defined as an immune mediated inflammatory process affecting the extraocular muscles, connective and adipose tissue of uncertain etiopathogenesis. TAO are classically described in Grave’s disease (GD) however it may occur in euthyroid and hypothyroid patients. Those patients usually test positive for Thyroid Stimulating Hormone receptor antibodies (TRAb). For instance, only few cases of severe Hashimoto’s thyroiditis (HT) associated orbitopathy with negative TRAb are reported to date.Case presentationHerewith we report a rare case of a middle-aged female who presented with bilateral progressive upper and lower palpebral edema and a unilateral marked proptosis associated with asthenia, headache and decrease in visual acuity. Biological investigation was notable for high levels of anti-thyroid peroxidase antibodies (Anti-TPO) in an otherwise euthyroid patient with negative TRAb. Orbital Magnetic resonance imaging revealed edema of the extraocular muscles and inflammation of periorbital soft tissue. The patient received a treatment with intravenous methylprednisolone followed by oral treatment with prednisone. This regimen was both effective and safe with minimal metabolic side effects in our patient.ConclusionMinor ocular manifestations of HT are common; however, severe sight threatening ophtalmopathy in the absence of TRAb is rare. Multiple differential diagnosis should be considered and investigated before diagnosing this rare entity. Management of similar cases is currently based on reports and no clear guidelines have been elaborated, corticosteroids is the mainstream of treatment with a potential benefit of selenium supplementation in mild to moderate cases.

Bilateral idiopathic orbital pseudotumour in a child: a case report

BackgroundIdiopathic orbital pseudotumour is rare in children. We report a case of bilateral paediatric idiopathic orbital pseudotumour and review the characteristics of this case.Case presentationA 14-year-old female patient presented at our Department of Pulmonary and Critical Care Medicine (PCCM) with complaints of recurrent severe cold and cough for 3 weeks, which had been treated with an intravenous antibiotic. Meanwhile, the patient developed swelling of both eyelids during the period of cold and cough, but her symptoms did not improve after the ocular administration of tobramycin dexamethasone eye drops. The patient was referred from the respiratory medicine ward to our department because of gradually worsening ocular pain, visual deterioration, increased intraocular pressure and serious nausea/vomiting within 24 h of hospitalization. The diagnosis of bilateral idiopathic orbital pseudotumour was made ultimately because of the course of the disease, exclusion of diagnoses such as bacterial ocular infection or malignant tumours and subsequent evidence from orbital magnetic resonance imaging (MRI). Favourable progress in the ocular tension and eyelid swelling was achieved through treatment with intravenous dexamethasone. The binocular intraocular pressure gradually declined to approximately 15 mmHg, and there was favourable progression in the patient’s vision to 20/40 in both eyes on the ninth day of hospitalization.ConclusionsOur patient developed rapidly progressive acute orbital signs and symptoms and anterior inflammation, such as pain, proptosis, limited ductions, periorbital oedema, chemosis, vision loss and high intraocular pressure. This case highlights that idiopathic orbital pseudotumour is an uncommon but important cause of acute orbital syndrome in children.

Diagnostic accuracy of B-scan in predicting retinoblastoma in children, taking Magnetic Resonance Imaging of orbits as gold standard.

The objective of this study was to determine the diagnostic accuracy of B-scan in predicting retinoblastoma (Rb) taking Magnetic Resonance Imaging (MRI) as a gold standard. A cross-sectional validation study was conducted in the Radiology Department of Fauji Foundation Hospital from May 20 to Nov 20, 2017. Children fulfilling the inclusion criteria were selected after informed consent and detailed history was taken for investigation of Rb. B-scan of both eyes was done using 7.5-10 MHz probe, followed by MRI of both eyes in the same patients using 1.5 Tesla MRI machine with the help of qualified MRI technicians. Data analysis was done by SPSS version 16.0. The diagnostic accuracy, sensitivity, specificity, PPV and NPV of B-scan in prediction of Rb as compared to MRI was 90.45%, 82.28%, 90.54% and 90.28% respectively. The study concluded that diagnostic accuracy of B-scan as compared to MRI is substantial in Retinoblastoma.

Positional Change of the Eyeball During Eye Movements: Evidence of Translatory Movement.

Purpose: To investigate the positional change of the eyeball induced by horizontal and vertical gazing to deduce translatory movement, using three-dimensional (3D) magnetic resonance imaging (MRI).Methods: In this prospective observational study participants underwent orbital MRI during central, right, left, up, and down gazing. MRI scans were processed using self-developed software; this software enabled 3D MR image reconstruction and the superimposition of reconstructed image sets between different gazes. After acquiring the coordinates of the eyeball centroid in each gaze, the changes in centroid coordinates from central gaze to the other gazes were estimated, and correlations with associated factors were evaluated.Results: The mean distance of centroid movement was 0.69 ± 0.27 mm in abduction, 0.68 ± 0.27 mm in adduction, 0.43 ± 0.23 mm in elevation, and 0.44 ± 0.19 mm in depression. The mean angle of centroid movement in horizontal gaze, measured in terms of the movement of the left eye centroid in the axial plane, was 228.7° in abduction and −4.2° in adduction. In vertical gaze, the mean angle of centroid movement was −96.8° in elevation and 101.8° in depression. Axial length and ocular volume were negatively correlated with the distance of centroid movement in horizontal gaze.Conclusions: The position of the eyeball moved in the same direction as the gaze during horizontal gaze, but in the opposite direction during vertical gaze. For accurate eye movement analyses, such as the measurement of the deviation angle in strabismus, translation should be considered in addition to rotation.

Myelin Oligodendrocyte Glycoprotein Antibody-Associated Optic Neuritis in Canada.

To describe clinical characteristics of Canadian patients with myelin-oligodendrocyte glycoprotein immunoglobulin-G optic neuritis (MOG-IgG ON). Retrospective observational case series of MOG-IgG seropositive patients with ON referred to tertiary neuro-ophthalmology practices. Outcome measures included clinical characteristics, radiologic findings, and visual outcomes. Forty-six eyes of 30 patients were included. Twenty-three (76.7%) were women, mean onset age was 40.7 years (range 16-77), and most were Caucasian. Seventeen (56.7%) presented with their first ON episode. Sixteen (53.3%) had bilateral eye involvement. Isolated ON without associated neurological symptoms occurred in 90.0%. In 22 patients with acute ON (seen within 1 month of onset), presenting mean visual acuity (VA) was 20/258 (logMAR 1.11), mean deviation (MD) on Humphrey visual fields was -16.90 ± 10.83 dB, and peripapillary retinal nerve fiber layer (RNFL) thickness on ocular coherence tomography (OCT) was 164.23 ± 46.53 um. Orbital magnetic resonance imaging (MRI) within 1 month of symptom onset for 19 patients demonstrated orbital optic nerve enhancement in 11 (57.9%) and perineural enhancement in 11 (57.9%). Brain MRI was normal in 28 (93.3%) patients. Twenty out of 22 patients with acute presentation were treated with high-dose glucocorticoids and 5 with plasma exchange in addition to corticosteroids. Long-term immunosuppression was utilized in 9 (30%) out of all 30 patients. Final VA was 20/30 (logMAR 0.18), MD was -7.17 ± 8.85 dB, and RNFL thickness was 72.15 ± 20.16 um. MOG-IgG ON in Canada has a variable presentation with most patients having substantial initial vision loss with good recovery. This is the largest characterization of the disease in Canada to date.

The clinical observation of external scleral plaque radiotherapy in patients with uveal melanoma

Objective: To investigate the safety and efficacy of external scleral plaque radiotherapy (PRT) in the treatment of uveal melanoma (UM). Methods: This was a retrospective case series study. The data of 819 patients who underwent ophthalmic PRT from July 2007 to November 2017 at Tongren Hospital Affiliated to Beijing Capital Medical University was collected, including preoperative visual acuity, intraocular pressure and slit lamp microscope, color fundus photography, indirect ophthalmoscopy, color Doppler ultrasound, fundus fluorescein angiography, indocyanine green angiography, orbital nuclear magnetic resonance imaging, PRT times and time, complications, follow-up time, the maximum basal diameter and height of the tumor UM half a year after the applicator was removed, tumor metastasis rate, mortality and visual acuity observed at the last follow-up. The tumor growth was considered when the tumor height increased by 2.0 mm or the extension of any boundary of the tumor was 2.5 mm; otherwise, the treatment was defined as effective. The paired t test and Kaplan-Meier survival curve were used for statistical analysis. Results: There were 408 males and 411 females. The age ranged from 13 to 85 years (mean, 47 years). Nine patients had ciliary body melanoma, 43 patients had choroidal melanoma involving the ciliary body, and 767 patients had choroidal melanoma. In all 819 eyes, the tumor was medium-sized in 697 eyes and large in 110 eyes. All patients were treated with PRT only one time. The average radiotherapy time was 15 days (range, 6 to 50 d). All operations were successfully completed, with no active bleeding, infection, adjacent tissue injury and other related complications. At 6 months after the treatment, the maximum basal diameter of the tumor was (12.41±3.20) mm, which was significantly different from that before treatment (12.82±3.21) mm (t=2.40, P<0.01); the tumor height was (6.18±2.55) mm, which was significantly different from that before treatment (7.21±2.57) mm (t=4.05, P<0.01). The average follow-up time was (34±24) months (range, 1 to 125 months). Twenty-five patients lost follow-up at 2 years after the PRT, and 71 patients underwent enucleation. The effective rate of the PRT treatment was 88.3% (723/819), and the eyeball retention rate was 91.1% (723/794). The visual acuity remained stable in 393 eyes, decreased in 344 eyes, and improved in 82 eyes. Sixty patients had systemic metastasis (liver, bone or breast metastasis). Twenty-two patients died of tumor metastasis. The 5-year metastasis rate was 12.8%; the 5-year mortality rate was 5.8%; the 10-year metastasis rate was 20.6%; the 10-year mortality rate was 5.8%. Conclusions: PRT is safe and effective in the treatment for UM and can preserve some useful visual acuity. PRT can be used as the main treatment for medium-sized UM.(Chin J Ophthalmol, 2020, 56: 670-675).

Optic Nerve Sheath Diameter Measured by Point-of-Care Ultrasound and MRI.

Ultrasound (US) measurement of the optic nerve sheath diameter (ONSD) and optic nerve diameter (OND) is a method frequently used to screen for an increased intracranial pressure. The aim of this study was to assess the accuracy of US measurements of ONSD and OND, when compared to magnetic resonance imaging (MRI) measurements as the criterion standard. In this prospective, single-institution study, orbital US was performed for those patients requiring an emergent brain MRI. ONSD and OND of both eyes were measured in the axial and coronal planes in straight gaze by US. ONSD and OND from brain and orbital MRI were measured by two neuroradiologists. Correlation and agreement between readings were assessed using Pearson's correlations. Eighty-two patients met inclusion criteria. The mean axial and coronal ONSD in the MRI examinations was 5.6 and 5.7 mm at 3-5.9 mm behind the globe, respectively. The mean ONSD from the US measurements was 6.22 and 5.52 mm in the axial and coronal planes, respectively. The mean OND in US examinations was 4.31 mm (axial) and 3.68 mm (coronal). Axial versus coronal measurements of ONSD had a modest correlation in US assessment with an r2 of .385 (P < .001) but there were no correlations between any of the US and MRI measurements. In measuring ONSD and OND, US measurements showed a modest correlation between axial and coronal measurements, but no concordance was found between US and MRI in our setting.