Ophthalmoparesis refers to weakness (-paresis) or paralysis (-plegia) of one or more
extraocular muscles
The extraocular muscles (extrinsic ocular muscles), are the seven extrinsic muscles of the human eye. Six of the extraocular muscles, the four recti muscles, and the superior and inferior oblique muscles, control movement of the eye and the ot ...
which are responsible for
eye movement
Eye movement includes the voluntary or involuntary movement of the eyes. Eye movements are used by a number of organisms (e.g. primates, rodents, flies, birds, fish, cats, crabs, octopus) to fixate, inspect and track visual objects of interests. ...
s. It is a physical finding in certain
neurologic
Neurology (from el, νεῦρον (neûron), "string, nerve" and the suffix -logia, "study of") is the branch of medicine dealing with the diagnosis and treatment of all categories of conditions and disease involving the brain, the spinal c ...
, ophthalmologic, and endocrine disease.
Internal ophthalmoplegia means involvement limited to the pupillary sphincter and ciliary muscle. External ophthalmoplegia refers to involvement of only the extraocular muscles. Complete ophthalmoplegia indicates involvement of both.
Causes
Ophthalmoparesis can result from disorders of various parts of the eye and nervous system:
* Infection around the eye. Ophthalmoplegia is an important finding in
orbital cellulitis
Orbital cellulitis is inflammation of eye tissues behind the orbital septum. It is most commonly caused by an acute spread of infection into the eye socket from either the adjacent sinuses or through the blood. It may also occur after trauma. W ...
.
* The
orbit
In celestial mechanics, an orbit is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an object or position in space such as a p ...
of the eye, including mechanical restrictions of eye movement, as in
Graves' disease
Graves' disease (german: Morbus Basedow), also known as toxic diffuse goiter, is an autoimmune disease that affects the thyroid. It frequently results in and is the most common cause of hyperthyroidism. It also often results in an enlarged thyr ...
.
* The
muscle
Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of muscl ...
, as in
progressive external ophthalmoplegia
Chronic progressive external ophthalmoplegia (CPEO) is a type of eye disorder characterized by slowly progressive inability to move the eyes and eyebrows. It is often the only feature of mitochondrial disease, in which case the term CPEO may be gi ...
or
Kearns–Sayre syndrome
Kearns–Sayre syndrome (KSS), oculocraniosomatic disorder or oculocranionsomatic neuromuscular disorder with ragged red fibers is a mitochondrial myopathy with a typical onset before 20 years of age. KSS is a more severe syndromic variant of chron ...
.
* The
neuromuscular junction
A neuromuscular junction (or myoneural junction) is a chemical synapse between a motor neuron and a muscle fiber.
It allows the motor neuron to transmit a signal to the muscle fiber, causing muscle contraction.
Muscles require innervation to ...
, as in
myasthenia gravis
Myasthenia gravis (MG) is a long-term neuromuscular junction disease that leads to varying degrees of skeletal muscle weakness. The most commonly affected muscles are those of the eyes, face, and swallowing. It can result in double vision, dro ...
.
* The relevant
cranial nerve
Cranial nerves are the nerves that emerge directly from the brain (including the brainstem), of which there are conventionally considered twelve pairs. Cranial nerves relay information between the brain and parts of the body, primarily to and ...
s (specifically the
oculomotor
The oculomotor nerve, also known as the third cranial nerve, cranial nerve III, or simply CN III, is a cranial nerve that enters the orbit (anatomy), orbit through the superior orbital fissure and innervates extraocular muscles that enable mo ...
,
trochlear, and
abducens
The abducens nerve or abducent nerve, also known as the sixth cranial nerve, cranial nerve VI, or simply CN VI, is a cranial nerve in humans and various other animals that controls the movement of the lateral rectus muscle, one of the extraocula ...
), as in
cavernous sinus syndrome
The cavernous sinus within the human head is one of the dural venous sinuses creating a cavity called the lateral sellar compartment bordered by the temporal bone of the skull and the sphenoid bone, lateral to the sella turcica.
Structure
The cave ...
or
raised intracranial pressure
Intracranial pressure (ICP) is the pressure exerted by fluids such as cerebrospinal fluid (CSF) inside the skull and on the brain tissue. ICP is measured in millimeters of mercury ( mmHg) and at rest, is normally 7–15 mmHg for a supine adult. ...
.
* The brainstem
nuclei of these nerves, as in certain patterns of brainstem stroke such as
Foville's syndrome
Foville's syndrome is caused by the blockage of the perforating branches of the basilar artery in the region of the brainstem known as the pons. It is most frequently caused by lesions such as vascular disease and tumors involving the dorsal pons. ...
.
* White matter tracts connecting these nuclei, as in
internuclear ophthalmoplegia
Internuclear ophthalmoplegia (INO) is a disorder of conjugate lateral gaze in which the affected eye shows impairment of adduction. When an attempt is made to gaze contralaterally (relative to the affected eye), the affected eye adducts minimall ...
, an occasional finding in
multiple sclerosis
Multiple (cerebral) sclerosis (MS), also known as encephalomyelitis disseminata or disseminated sclerosis, is the most common demyelinating disease, in which the insulating covers of nerve cells in the brain and spinal cord are damaged. This d ...
.
*
Dorsal
Dorsal (from Latin ''dorsum'' ‘back’) may refer to:
* Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism
* Dorsal, positioned on top of an aircraft's fuselage
* Dorsal co ...
midbrain
The midbrain or mesencephalon is the forward-most portion of the brainstem and is associated with vision, hearing, motor control, sleep and wakefulness, arousal (alertness), and temperature regulation. The name comes from the Greek ''mesos'', " ...
structures, as in
Parinaud's syndrome
Parinaud's syndrome is an inability to move the eyes up and down. It is caused by compression of the vertical gaze center at the rostral interstitial nucleus of medial longitudinal fasciculus (riMLF). The eyes lose the ability to move upward and ...
.
* Certain parts of the
cerebral cortex
The cerebral cortex, also known as the cerebral mantle, is the outer layer of neural tissue of the cerebrum of the brain in humans and other mammals. The cerebral cortex mostly consists of the six-layered neocortex, with just 10% consisting of ...
(including the
frontal eye field
The frontal eye fields (FEF) are a region located in the frontal cortex, more specifically in Brodmann area 8 or BA8, of the primate brain. In humans, it can be more accurately said to lie in a region around the intersection of the middle front ...
s), as in
stroke
A stroke is a medical condition in which poor blood flow to the brain causes cell death. There are two main types of stroke: ischemic, due to lack of blood flow, and hemorrhagic, due to bleeding. Both cause parts of the brain to stop functionin ...
.
* Toxic
envenomation
Envenomation is the process by which venom is injected by the bite or sting of a venomous animal.
Many kinds of animals, including mammals (e.g., the northern short-tailed shrew, ''Blarina brevicauda''), reptiles (e.g., the king cobra), spider ...
by
mamba
Mambas are fast moving highly venomous snakes of the genus ''Dendroaspis'' (which literally means "tree Asp (reptile), asp") in the family Elapidae. Four Neontology, extant species are recognised currently; three of those four species are essen ...
s,
taipan
Taipans are snakes of the genus ''Oxyuranus'' in the elapid family. They are large, fast-moving, highly venomous, and endemic to Australia and New Guinea. Three species are recognised, one of which, the coastal taipan, has two subspecies. Taipan ...
s, and
krait
''Bungarus'' is a genus of venomous elapid snakes, the kraits ("krait" is pronounced , rhyming with "kite"), found in South and Southeast Asia. The genus ''Bungarus'' has 16 species.
Distribution
Kraits are found in tropical Asia, from near Ira ...
s.
Thiamine
Thiamine, also known as thiamin and vitamin B1, is a vitamin, an essential micronutrient, that cannot be made in the body. It is found in food and commercially synthesized to be a dietary supplement or medication. Phosphorylated forms of thi ...
deficiency can cause ophthalmoparesis in susceptible persons; this is part of the syndrome called
Wernicke encephalopathy
Wernicke encephalopathy (WE), also Wernicke's encephalopathy, or wet brain is the presence of neurological symptoms caused by biochemical lesions of the central nervous system after exhaustion of B-vitamin reserves, in particular thiamine (vita ...
. The causal pathway by which this occurs is unknown. Intoxication with certain substances, such as
phenytoin
Phenytoin (PHT), sold under the brand name Dilantin among others, is an anti-seizure medication. It is useful for the prevention of tonic-clonic seizures (also known as grand mal seizures) and focal seizures, but not absence seizures. The intr ...
, can also cause ophthalmoparesis.
Diagnosis
Classification
Ophthalmoparesis can involve any or all of the extraocular muscles, which include the
superior recti,
inferior recti,
medial recti,
lateral recti,
inferior oblique
The inferior oblique muscle or obliquus oculi inferior is a thin, narrow muscle placed near the anterior margin of the floor of the orbit. The inferior oblique is one of the extraocular muscles, and is attached to the maxillary bone (origin) and ...
and
superior oblique muscle
The superior oblique muscle, or obliquus oculi superior, is a fusiform muscle originating in the upper, medial side of the orbit (i.e. from beside the nose) which abducts, depresses and internally rotates the eye. It is the only extraocular musc ...
s.
It can also be classified by the directions of affected movements, e.g. "vertical ophthalmoparesis".
Treatment
Treatment and prognosis depend on the underlying condition. For example, in thiamine deficiency, treatment would be the immediate administration of vitamin B1.
See also
*
Paresis
In medicine, paresis () is a condition typified by a weakness of voluntary movement, or by partial loss of voluntary movement or by impaired movement. When used without qualifiers, it usually refers to the limbs, but it can also be used to desc ...
References
External links
{{Authority control
Disorders of ocular muscles, binocular movement, accommodation and refraction