ocular myopathy


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myopathy

 [mi-op´ah-the]
any disease of a muscle. adj., adj myopath´ic.
centronuclear myopathy myotubular myopathy.
distal myopathy an autosomal dominant form of muscular dystrophy, appearing in two types. The first has onset in infancy, does not progress past adolescence, and is not incapacitating. The second has onset in adulthood and is called late distal hereditary myopathy. Called also distal muscular dystrophy.
glycolytic myopathy any metabolic myopathy resulting from a defect of glycolytic enzyme activity, marked by exercise intolerance and cramping, the accumulation of glycogen in muscle, and recurrent myoglobinuria.
late distal hereditary myopathy distal myopathy that sets in usually after age 40, does not affect life span and first affects the small muscles of the hands and feet and then spreads proximally.
metabolic myopathy myopathy due to disordered metabolism, usually caused by genetic defects or hormonal dysfunction.
mitochondrial myopathy any of a group of myopathies associated with an increased number of enlarged, often abnormal, mitochondria in muscle fibers, manifested by exercise intolerance, generalized weakness, lactic acidosis, infantile tetraparesis, ophthalmoplegia, and cardiac abnormalities.
myotubular myopathy a form marked by myofibers resembling the myotubules of early fetal muscle.
nemaline myopathy a congenital abnormality of myofibrils in which small threadlike fibers are scattered through the muscle fibers; marked by hypotonia and proximal muscle weakness.
ocular myopathy a slowly progressive form affecting the extraocular muscles, with ptosis and progressive immobility of the eyes.

chron·ic pro·gress·ive ex·ter·nal oph·thal·mo·ple·gi·a (CPEO),

a specific type of slowly worsening weakness of the ocular muscles, usually associated with a pigmentary retinopathy. See: Kearns-Sayre syndrome, oculopharyngeal dystrophy.
Synonym(s): ocular myopathy

ocular myopathy

slowly progressive weakness of ocular muscles, characterized by decreased mobility of the eye and drooping of the upper lid. The disorder may be unilateral or bilateral and may be caused by damage to the oculomotor nerve, an intracranial tumor, or a neuromuscular disease.

ophthalmoplegia 

Paralysis of the ocular muscles. External ophthalmoplegia refers to paralysis of one or more extraocular muscles. If the levator palpebrae muscle is also involved, the condition is usually referred to as ocular myopathy. Internal ophthalmoplegia refers to a paralysis of the muscles of the iris and the ciliary muscle. Total ophthalmoplegia refers to a paralysis of all the muscles in the eye, which results in ptosis, immobility of the eye and pupil, and loss of accommodation. See Graves' disease; paralysis of the third nerve.
chronic progressive external ophthalmoplegia (CPEO) A rare disorder characterized by a progressive, bilateral ptosis and a loss of ocular motility. It is associated with mutation of mitochondrial DNA, which results in abnormalities in highly oxidative tissues such as the muscles and the brain. The initial sign is bilateral ptosis, followed later by strabismus. A related mitochondrial myopathy is the Kearns-Sayre syndrome in which there is CPEO, a type of retinitis pigmentosa characterized by coarse pigment clumping which principally affects the central retina, and cardiac conduction defects. This syndrome presents before age 20 years. See myasthenia gravis.
internuclear ophthalmoplegia (INO) An eye movement disorder resulting from a lesion in the medial longitudinal fasciculus, which disrupts the coordination between the oculomotor nucleus and the abducens nucleus. It is characterized by a limited adduction by the eye on the same side of the body as the lesion, and a jerky, horizontal nystagmus and overshoot by the other eye on abduction, when moving the eyes towards the side of the body opposite to that of the lesion. Convergence is usually intact, unless the lesion is widespread. Vertical gaze gives rise to nystagmus and oscillopsia. The condition is associated with multiple sclerosis, vascular disease, tumour of the brainstem or encephalitis. See ocular dysmetria; supranuclear gaze palsy; 'one and one half' syndrome.