Ocular myasthenia gravis(OMG)is an autoimmune disease caused by neuromuscular junction transmission disorders and manifested mainly as fluctuating blepharoptosis and diplopia,with the extraocular muscles as the main involveed sites.While the pathogenesis of OMG remains unclear,some antibodies,complements,and cytokines may be the contributing factors.The diagnosis and treatment of OMG have been defined in recent years.This article reviews the pathogenesis,diagnosis,and treatment of OMG.
Antibodies ; Complement System Proteins ; Cytokines ; Humans ; Myasthenia Gravis ; diagnosis ; pathology ; therapy ; Oculomotor Muscles ; pathology

Adult ; Female ; Humans ; Lymphoma ; diagnosis ; Magnetic Resonance Imaging ; methods ; Male ; Middle Aged ; Oculomotor Muscles ; pathology

OBJECTIVETo evaluate the feasibility of high-field magnetic resonance in measuring the thickness and width of extraocular muscles, calculate the ratio of thickness to width, and summarize the characters of the diameters and its ratio in patients with Graves' ophthalmopathy (GO) with upper-lid retraction.

METHODSSixteen GO patients with upper-lid retraction (GO group) and 14 healthy control group were enrolled in this study. All the patients underwent enhanced high-field magnetic resonance orbital scan. The thickness and width of extraocular muscles were measured on axial, coronal or oblique sagittal enhanced T1 weighted images. The ratio of thickness to width (R1) and width to thickness (R2) were calculated. The diameters or ratio was evaluated as enlarged when they were 2 standard deviation greater than mean values of extraocular muscle in healthy control.

RESULTSThe thickness of levator palpebrae superioris, medial rectus, and inferior rectus muscles in GO group were significantly larger than those in the control group (P=0.000, P=0.017, P=0.032, respectively. The width of superior oblique muscles in GO group was significantly larger than that in control group (P=0.000). The R1 values of levator palpebrae superioris, inferior rectus, medial rectus, and lateral rectus muscles in GO group were significant larger than those in the control group (P=0.000,P=0.037, P=0.019,P=0.032, respectively. The R2 value of superior oblique muscles was significant larger than that in the control group (P=0.027). Aslo in GO group, 32 extraocular muscles showed an increased thickness. 47% of thickened extraocular muscles had an increased R1.

CONCLUSIONSEnhanced orbit imaging with high-field magnetic resonance is helpful in the quantitative assessment of the thickness and width of extraocular muscles. In GO patients, in addition to the levator palpebrae superioris muscles, some other extraocular muscles also becomes thicker. Moreover, the increased diameters of superior oblique muscles is mainly due to the increase of its width R1 and R2 values can reflect the thickness and width of extraocular muscles and their relationship.

Adult ; Case-Control Studies ; Female ; Graves Ophthalmopathy ; pathology ; Humans ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Oculomotor Muscles ; pathology

We report two patients with unilateral vertical retraction syndrome. Magnetic resonance imaging (MRI) of the orbits of the two cases showed similar size and location of the orbital structure, but with dramatically different strabismus type. MRI sagittal reconstruction of the orbits suggested that abnormal muscle tissue arised from the inferior rectus, which might be associated with retraction and narrowing of the palpebral fissure and atypical strabismus as well.
Child ; Eyelids ; physiopathology ; Female ; Humans ; Magnetic Resonance Imaging ; Male ; Oculomotor Muscles ; physiopathology ; Orbit ; pathology ; Strabismus ; pathology ; Syndrome

OBJECTIVETo determine the mutation responsible for the congenital fibrosis of the extraocular muscles type I(CFEOM1) in a Chinese family.

METHODSDirect sequencing of exons 20 and 21 in the KIF21A gene was performed for the proband. The mutation c.2860C to T in exon 21 was examined by allele specific-PCR (AS-PCR) analysis in other family members. Haplotype analysis was performed using four STR markers (D12S1668, D12S2194, D12S331 and D12S1048).

RESULTSA heterozygous mutation c.2860C to T in the KIF21A gene was identified in all three affected members with CFEOM1. Haplotype analysis suggested that the mutation might derive from maternal germline mosaicism.

CONCLUSIONThis Chinese family with CFEOM1 may be caused by a c.2860C to T mutation in the KIF21A gene.

Alleles ; Asian Continental Ancestry Group ; genetics ; Base Sequence ; Child ; China ; Exons ; Female ; Fibrosis ; Haplotypes ; Humans ; Kinesin ; genetics ; Mutation ; genetics ; Oculomotor Muscles ; metabolism ; pathology ; Pedigree ; Phenotype ; Syndrome

Axenfeld-Rieger syndrome (ARS) is associated with ocular and systemic anomalies. PITX2 is known to be a major controlling gene in the pathogenesis of ARS and is associated with differentiation in both the neural crest and mesoderm during eye development. A 4-year-old girl with bilateral ARS had 20 prism diopters (PD) of exotropia with 30PD of A- pattern deviation, more than 20PD of dissociated vertical deviation (DVD), and severe superior oblique overaction (SOOA). During surgery we observed that the SO inserted more posteriorly than normal. We believe this finding is one of the abnormal manifestations of the development of the extraocular muscles in ARS.
*Abnormalities, Multiple ; Anterior Eye Segment/*abnormalities ; Child, Preschool ; Eye Abnormalities/*diagnosis/surgery ; Eye Movements ; Female ; Follow-Up Studies ; Humans ; Oculomotor Muscles/*abnormalities/surgery ; Ophthalmologic Surgical Procedures/*adverse effects ; Optic Nerve/abnormalities ; Postoperative Complications ; Sclera/*pathology/surgery ; Syndrome ; Tooth Abnormalities/*genetics

A 53-year-old woman complaining of vertical diplopia, presented with a localized swelling in the right lower lid. Magnetic resonance imaging studies demonstrated a relatively well-defined mass in the inferior rectus with similar signal characteristics to the muscle. Excisional biopsy of the mass revealed granular cell tumor composed of S-100 positive cells with acidophilic granular cytoplasm and a peripheral lymphocytic infiltration. Granular cell tumor, which is very rare in the orbit, should be considered in the differential diagnosis of tumors adjacent to or within the extraocular muscles, particularly in the inferior orbit.
Biopsy ; Diagnosis, Differential ; Eye Neoplasms/*pathology ; Female ; Follow-Up Studies ; Granular Cell Tumor/*pathology ; Humans ; Magnetic Resonance Imaging ; Middle Aged ; Muscle Neoplasms/*pathology ; Oculomotor Muscles/*pathology

PURPOSE: To analyze innervated myotendinous cylinders (IMCs) in the extraocular muscles (EOMs) of normal subjects and strabismic patients. METHODS: The rectus muscles of 37 subjects were analyzed. Distal myotendinous specimens were obtained from 3 normal subjects, 20 patients with acquired strabismus, 11 with infantile strabismus, and from 3 with congenital nystagmus, and were studied by using light microscopy. Some specimens (6 rectus muscles) were also examined by transmission electron microscopy. RESULTS: IMCs were found in the distal myotendinous regions of EOMs. The IMCs of patients with acquired strabismus showed no significant morphological alterations. However, significant IMCs alterations were observed at the distal myotendinous junction of patients with congenital strabismus and congenital nystagmus. CONCLUSIONS: This study supports the notion that IMCs in human EOMs function mainly as proprioceptors, along with effector properties, and a disturbance of ocular proprioceptors plays an important role in the pathogenesis of oculomotor disorder. We suggest that a proprioceptive feedback system should be stimulated and calibrated early in life for the development of binocular vision.
Adolescent ; Adult ; Child ; Child, Preschool ; Female ; Humans ; Infant ; Male ; Microscopy, Electron, Transmission ; Middle Aged ; Oculomotor Muscles/*innervation/physiopathology/ultrastructure ; Proprioception/physiology ; Strabismus/*pathology/physiopathology ; Young Adult

BACKGROUNDWith the technical advances, magnetic resonance imaging (MRI) is now sensitive enough to detect subtle structural abnormalities of ocular motor nerves arising from the brainstem and orbits of living subjects. This study was designed to delineate the MRI characteristics in patients with special forms of strabismus.

METHODSA total of 29 patients with special forms of strabismus underwent orbital and intracalvarium MRI. Imaging of the ocular motor nerves in the brainstem was performed in 0.8 mm thickness image planes using the three-dimensional fast imaging employing steady-state acquisition (3D-FIESTA) sequence. Nerves to extraocular muscles (EOMs), EOMs and their associated connective tissues were imaged with T1 weighting in tri-planar scans by dual-phased coils within 2.0 mm thick planes.

RESULTSPatients with congenital fibrosis of the extraocular muscles exhibited hypoplasia of the oculomotor (CN3), abducens (CN6), trochlear (CN4) nerves, and the EOMs; hypoplasia of CN6 in the brainstem and an extra branch of the inferior division of CN3 to the lateral rectus were the most common but not the only presentation of Duane's retraction syndrome. Hypoplasia of CN6, facial (CN7) and hypoglossal (CN12) nerves were revealed in patients with Möbius syndrome. In a rare case of bilateral synergistic convergence and divergence, an enlarged branch of CN3 to the medial rectus and a questionable branch of CN3 to the inferior rectus bilaterally were found.

CONCLUSIONMRI can reveal subtle structures of the ocular motor nerves and their corresponding EOMs. This can provide valuable information regarding pathogenesis in some special forms of strabismus.

Adolescent ; Adult ; Child ; Child, Preschool ; Cranial Nerves ; pathology ; Female ; Humans ; Magnetic Resonance Imaging ; methods ; Male ; Oculomotor Muscles ; pathology ; Prospective Studies ; Strabismus ; pathology

We report a case of acute comitant esotropia in a child with a cerebellar tumor. A 3-year-old boy was referred for management of a 9 month history of acute acquired comitant esotropia. On first presentation, the patient's angle of esodeviation was 50 prism-diopters (PD) at distance and near fixation without any lateral incomitance. The cycloplegic refraction revealed +0.75 diopters in both eyes. Very mild bilateral papilledema was found on the fundus examination, but the neurological examination did not reveal any other pathological findings. Brain MRI showed a 5 cm mass located in the midline of the cerebellum as well as hydrocephalus. The mass was completely excised and histological examination confirmed the diagnosis of pilocytic astrocytoma. Despite neurosurgery, the patient's strabismus remained unresolved. One year after neurosurgery, both medial rectus muscles were surgically recessed by 6 mm, resulting in esotropia of 8PD at distant and near fixation without restoration of bifoveal fusion at follow-up 2 years after the eye muscle surgery. Therefore, acute onset comitant esotropia in a child can be the first sign of a cerebellar tumor, even without any other neurological signs and symptoms.
Acute Disease ; Astrocytoma/*complications/surgery ; Brain/pathology ; Cerebellar Neoplasms/*complications/diagnosis/surgery ; Child, Preschool ; Esotropia/*etiology/pathology/physiopathology/surgery ; Humans ; Magnetic Resonance Imaging ; Male ; Neurosurgical Procedures ; Oculomotor Muscles/surgery ; Refraction, Ocular ; Time Factors