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Disorders of eye movement

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Convergence micropsia. Dissociated vertical deviation. Dissociated vertical deviation (DVD) is an eye condition which occurs in association with a squint, typically infantile esotropia.

Dissociated vertical deviation

Symptoms

Etiology. Ocular tremor. Ocular microtremor tracing with burst sections underlined Ocular microtremor (OMT) is a constant, physiological, high frequency (peak 80Hz), low amplitude (estimated circa 150-2500nm (1)) eye tremor.

Ocular tremor

It occurs in all normal people even when the eye is apparently still and is due to the constant activity of brainstem oculomotor units. Progressive supranuclear palsy. Progressive supranuclear palsy (PSP) (or the Steele-Richardson-Olszewski syndrome, after the Canadian physicians who described it in 1963) is a degenerative disease involving the gradual deterioration and death of specific volumes of the brain.[1][2] Males and females are affected approximately equally and there is no racial, geographical or occupational predilection.

Progressive supranuclear palsy

Approximately 6 people per 100,000 population have PSP. It has been described as a tauopathy.[3] Symptoms and signs[edit] This patient presented with progressive dementia, ataxia and incontinence. The initial symptoms in two-thirds of cases are loss of balance, lunging forward when mobilizing, fast walking, bumping into objects or people, and falls. Other common early symptoms are changes in personality, general slowing of movement, and visual symptoms. Cardinal manifestations: Congenital fourth nerve palsy. For acquired fourth nerve palsy, see fourth nerve palsy Congenital fourth nerve palsy is a condition present at birth characterized by a vertical misalignment of the eyes due to a weakness or paralysis of the superior oblique muscle.

Congenital fourth nerve palsy

Other names for fourth nerve palsy include superior oblique palsy and trochlear nerve palsy. When looking to the right/left the nerve/muscle isn't strong enough or is too long and the eye drifts up. Duane syndrome. Duane's syndrome is a congenital rare type of strabismus most commonly characterized by the inability of the eye to move outwards.

Duane syndrome

The syndrome was first described by ophthalmologists Jakob Stilling (1887) and Siegmund Türk (1896), and subsequently named after Alexander Duane who discussed the disorder in more detail in 1905.[1] Other names for this condition include: Duane's Retraction Syndrome, Eye Retraction Syndrome, Retraction Syndrome, Congenital retraction syndrome and Stilling-Turk-Duane Syndrome.[2] Clinical presentation[edit] Patient with Duane syndrome attempting to look far right.

Internuclear ophthalmoplegia. Causes[edit] The disorder is caused by injury or dysfunction in the medial longitudinal fasciculus (MLF), a heavily-myelinated tract that allows conjugate eye movement by connecting the paramedian pontine reticular formation (PPRF)-abducens nucleus complex of the contralateral side to the oculomotor nucleus of the ipsilateral side.

Internuclear ophthalmoplegia

In young patients with bilateral INO, multiple sclerosis is often the cause. In older patients with one-sided lesions a stroke is a distinct possibility. Nystagmus. When the head rotates about any axis, distant visual images are sustained by rotating eyes in the opposite direction on the respective axis.[4] The semicircular canals in the vestibule sense angular momentum.

Nystagmus

These send signals to the nuclei for eye movement in the brain. From here, a signal is relayed to the extraocular muscles to allow one’s gaze to fixate on one object as the head moves. Nystagmus occurs when the semicircular canals are being stimulated while the head is not in motion. The direction of ocular movement is related to the semicircular canal that is being stimulated.[5] There are two key forms of nystagmus: pathological and physiological, with variations within each type. Ophthalmoparesis. Classification[edit] Ophthalmoparesis can involve any or all of the extraocular muscles, which include the superior recti, inferior recti, medial recti, lateral recti, inferior oblique and superior oblique muscles.

Ophthalmoparesis

It can also be classified by the directions of affected movements, e.g. Opsoclonus. Possible etiologies of opsoclonus include neuroblastoma and encephalitis in children, and breast, lung, or ovarian cancer in adults.

Opsoclonus

Other considerations include multiple sclerosis, toxins, or medication effects (e.g. Serotonin Syndrome. Sixth nerve palsy. The unilateral abducens nerve palsy is the most common of the isolated ocular motor nerve palsies.[1] Alternative names[edit] Lateral rectus palsyCranial nerve VI palsy Characteristics[edit] The nerve dysfunction induces esotropia, a convergent squint on distance fixation.

Sixth nerve palsy

On near fixation the affected individual may have only a latent deviation and be able to maintain binocularity or have an esotropia of a smaller size. Vision therapy. Vision therapy, also known as vision training, is used to improve vision skills such as eye movement control and eye coordination. It involves a series of procedures carried out in both home and office settings, usually under professional supervision by an orthoptist or optometrist.[1] Scope[edit] Vision Therapy encompasses a wide variety of non-surgical methods[4] which may be divided into several broad categories: Orthoptic Vision Therapy, also known as orthoptics.

Behavioral Vision Therapy, or Visual Integration Vision Therapy (also known as behavioral optometry).[6] Orthoptic visual therapy[edit] Orthoptics aims to treat binocular vision disorders such as strabismus, and diplopia. Eye movement desensitization and reprocessing. Eye movement desensitization and reprocessing (EMDR) is a psychotherapy developed by Francine Shapiro that emphasizes disturbing memories as the cause of psychopathology.[1][2] It is used to help with the symptoms of post traumatic stress disorder (PTSD).[3] According to Shapiro, when a traumatic or distressing experience occurs, it may overwhelm normal coping mechanisms.