Biomaterial Database

Ocular aspects of myasthenia gravis. 2000

J J Barton, and M Fouladvand

Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA.

Ocular myasthenia gravis is a not uncommon autoimmune disorder causing diplopia, ptosis, and weakness of lid closure. The predilection of myasthenia for the ocular muscles may be related to differences between limb and extraocular muscles in either physiological function or antigenicity. Clinically, ocular myasthenia can mimic any form of pupil-sparing ocular motility disorder. Dynamic abnormalities of myasthenic eye movements may reflect the primary hallmarks of the disease, which are fatigability and variability in strength, or secondary adaptive effects by the central nervous system. Tests to confirm the diagnosis include edrophonium challenge, repetitive nerve stimulation, single-fiber electromyography (EMG) of the frontalis, and assays for antibody directed against the acetylcholine receptor: all are less sensitive for ocular myasthenia than for generalized myasthenia. There is a higher incidence of other autoimmune conditions in myasthenia, notably thymoma and thyroid dysfunction. The differential diagnosis includes other diseases of the neuromuscular junction, such as Lambert-Eaton syndrome and botulism. Treatment consists of symptomatic use of acetylcholinesterase inhibitors and immunosuppression with steroids or azathioprine. Between 50 and 70% of patients with ocular myasthenia will eventually develop generalized disease: there is some retrospective data that steroids or azathioprine may reduce this by about 75%. The role of thymectomy in ocular myasthenia remains unclear.

UI	MeSH Term	Description	Entries
D009157	Myasthenia Gravis	A disorder of neuromuscular transmission characterized by fatigable weakness of cranial and skeletal muscles with elevated titers of ACETYLCHOLINE RECEPTORS or muscle-specific receptor tyrosine kinase (MuSK) autoantibodies. Clinical manifestations may include ocular muscle weakness (fluctuating, asymmetric, external ophthalmoplegia; diplopia; ptosis; and weakness of eye closure) and extraocular fatigable weakness of facial, bulbar, respiratory, and proximal limb muscles. The disease may remain limited to the ocular muscles (ocular myasthenia). THYMOMA is commonly associated with this condition.	Anti-MuSK Myasthenia Gravis,MuSK MG,MuSK Myasthenia Gravis,Muscle-Specific Receptor Tyrosine Kinase Myasthenia Gravis,Muscle-Specific Tyrosine Kinase Antibody Positive Myasthenia Gravis,Myasthenia Gravis, Generalized,Myasthenia Gravis, Ocular,Anti MuSK Myasthenia Gravis,Generalized Myasthenia Gravis,Muscle Specific Receptor Tyrosine Kinase Myasthenia Gravis,Muscle Specific Tyrosine Kinase Antibody Positive Myasthenia Gravis,Myasthenia Gravis, Anti-MuSK,Myasthenia Gravis, MuSK,Ocular Myasthenia Gravis
D009801	Oculomotor Muscles	The muscles that move the eye. Included in this group are the medial rectus, lateral rectus, superior rectus, inferior rectus, inferior oblique, superior oblique, musculus orbitalis, and levator palpebrae superioris.	Extraocular Muscles,Extraocular Rectus Muscles,Inferior Oblique Extraocular Muscle,Inferior Oblique Muscles,Levator Palpebrae Superioris,Musculus Orbitalis,Oblique Extraocular Muscles,Oblique Muscle, Inferior,Oblique Muscle, Superior,Oblique Muscles, Extraocular,Rectus Muscles, Extraocular,Superior Oblique Extraocular Muscle,Superior Oblique Muscle,Extraocular Muscle,Extraocular Muscle, Oblique,Extraocular Muscles, Oblique,Extraocular Oblique Muscle,Extraocular Oblique Muscles,Extraocular Rectus Muscle,Inferior Oblique Muscle,Muscle, Oculomotor,Muscles, Oculomotor,Oblique Extraocular Muscle,Oblique Muscle, Extraocular,Oblique Muscles, Inferior,Oblique Muscles, Superior,Oculomotor Muscle,Rectus Muscle, Extraocular,Superior Oblique Muscles
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D015835	Ocular Motility Disorders	Disorders that feature impairment of eye movements as a primary manifestation of disease. These conditions may be divided into infranuclear, nuclear, and supranuclear disorders. Diseases of the eye muscles or oculomotor cranial nerves (III, IV, and VI) are considered infranuclear. Nuclear disorders are caused by disease of the oculomotor, trochlear, or abducens nuclei in the BRAIN STEM. Supranuclear disorders are produced by dysfunction of higher order sensory and motor systems that control eye movements, including neural networks in the CEREBRAL CORTEX; BASAL GANGLIA; CEREBELLUM; and BRAIN STEM. Ocular torticollis refers to a head tilt that is caused by an ocular misalignment. Opsoclonus refers to rapid, conjugate oscillations of the eyes in multiple directions, which may occur as a parainfectious or paraneoplastic condition (e.g., OPSOCLONUS-MYOCLONUS SYNDROME). (Adams et al., Principles of Neurology, 6th ed, p240)	Brown Syndrome,Brown Tendon Sheath Syndrome,Brown's Syndrome,Convergence Insufficiency,Eye Movement Disorders,Internuclear Ophthalmoplegia,Ocular Torticollis,Opsoclonus,Parinaud Syndrome,Skew Deviation,Smooth Pursuit Deficiency,Brown's Tendon Sheath Syndrome,Convergence Excess,Cyclophoria,Deficiency, Smooth Pursuit,Eye Motility Disorders,Parinaud's Syndrome,Paroxysmal Ocular Dyskinesia,Pseudoophthalmoplegia,Spasm of Conjugate Gaze,Syndrome, Brown's Tendon Sheath,Tendon Sheath Syndrome of Brown,Browns Syndrome,Conjugate Gaze Spasm,Conjugate Gaze Spasms,Convergence Excesses,Convergence Insufficiencies,Cyclophorias,Deficiencies, Smooth Pursuit,Deviation, Skew,Deviations, Skew,Dyskinesia, Paroxysmal Ocular,Dyskinesias, Paroxysmal Ocular,Excess, Convergence,Eye Motility Disorder,Eye Movement Disorder,Gaze Spasms, Conjugate,Insufficiencies, Convergence,Insufficiency, Convergence,Internuclear Ophthalmoplegias,Ocular Dyskinesia, Paroxysmal,Ocular Dyskinesias, Paroxysmal,Ocular Motility Disorder,Ophthalmoplegia, Internuclear,Ophthalmoplegias, Internuclear,Parinauds Syndrome,Paroxysmal Ocular Dyskinesias,Pseudoophthalmoplegias,Pursuit Deficiencies, Smooth,Pursuit Deficiency, Smooth,Skew Deviations,Smooth Pursuit Deficiencies,Syndrome, Brown,Syndrome, Brown's,Syndrome, Parinaud,Syndrome, Parinaud's