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Congenital nystagmus has traditionally been viewed as non-treatable, but medications have been discovered in recent years that show promise in some patients. In 1980, researchers discovered that a drug called baclofen could effectively stop periodic alternating nystagmus. Subsequently, gabapentin, an anticonvulsant, was found to cause improvement in about half the patients who received it to relieve symptoms of nystagmus. Other drugs found to be effective against nystagmus in some patients include memantine, levetiracetam, 3,4-diaminopyridine (available in the US to eligible patients with downbeat nystagmus at no cost under an expanded access program), 4-aminopyridine, and acetazolamide. Several therapeutic approaches, such as contact lenses, drugs, surgery, and low vision rehabilitation have also been proposed. For example, it has been proposed that mini-telescopic eyeglasses suppress nystagmus.
Surgical treatment of Congenital Nystagmus is aimed at improving the abnormal head posture, simulating artificial divergence or weakening the horizontal recti muscles. Clinical trials of a surgery to treat nystagmus (known as tenotomy) concluded in 2001. Tenotomy is now being performed regularly at numerous centres around the world. The surgery developed by Louis F. Dell'Osso Ph.D. aims to reduce the eye shaking (oscillations), which in turn tends to improve visual acuity.
Acupuncture has conflicting evidence as to having beneficial effects on the symptoms of nystagmus. Benefits have been seen in treatments where acupuncture points of the neck were used, specifically points on the sternocleidomastoid muscle. Benefits of acupuncture for treatment of nystagmus include a reduction in frequency and decreased slow phase velocities which led to an increase in foveation duration periods both during and after treatment. By the standards of evidence-based medicine, the quality of these studies can be considered poor (for example, Ishikawa has a study sample size of just six, is unblinded and without proper control), and given high quality studies showing that acupuncture has no effect beyond placebo, the results of these studies have to be considered clinically irrelevant until higher quality studies are produced.
Physical therapy or Occupational therapy is also used to treat nystagmus. Treatment consist of learning compensatory strategies to take over for the impaired system.
According to a Cochrane review of 2012, controversies remain regarding type of surgery, non-surgical intervention and age of intervention.
The aims of treatment are as follows:
The elimination of any amblyopia
A cosmetically acceptable ocular alignment
long term stability of eye position
binocular cooperation.
It is essential that a child with strabismus is presented to the ophthalmologist as early as possible for diagnosis and treatment in order to allow best possible monocular and binocular vision to develop. Initially, the patient will have a full eye examination to identify any associated pathology, and any glasses required to optimise acuity will be prescribed – although infantile esotropia is not typically associated with refractive error. Studies have found that approximately 15% of infantile esotropia patients have accommodative esotropia. For these patients, antiaccommodative therapy (with spectacles) is indicated before any surgery as antiaccommodative therapy fully corrects their esotropia in many cases and significantly decreases their deviation angle in others.
Amblyopia will be treated via occlusion treatment (using patching or atropine drops) of the non-squinting eye with the aim of achieving full alternation of fixation. Management thereafter will be surgical. As alternative to surgery, also botulinum toxin therapy has been used in children with infantile esotropia. Furthermore, as accompaniment to ophtalmologic treatment, craniosacral therapy may be performed in order to relieve tension ("see also:" Management of strabismus).
It may be acquired from:
- Diseases. Some of the diseases that present nystagmus as a pathological sign:
- Aniridia
- Toxic or metabolic reasons could be the result of the following:
- Central nervous system (CNS) disorders, such as with a cerebellar problem, the nystagmus can be in any direction "including" horizontal. Purely vertical nystagmus is usually central in origin, but it is also a frequent adverse effect of high phenytoin toxicity. Causes include:
The prognosis for each patient with esotropia will depend upon the origin and classification of their condition. However, in general, management will take the following course:
1. Identify and treat any underlying systemic condition.
2. Prescribe any glasses required and allow the patient time to 'settle into' them.
3. Use occlusion to treat any amblyopia present and encourage alternation.
4. Where appropriate, orthoptic exercises can be used to attempt to restore binocularity.
5. Where appropriate, prismatic correction can be used, either temporarily or permanently, to relieve symptoms of double vision.
6. In specific cases, and primarily in adult patients, botulinum toxin can be used either as a permanent therapeutic approach, or as a temporary measure to prevent contracture of muscles prior to surgery
7. Where necessary, extra-ocular muscle surgery can be undertaken to improve cosmesis and, on occasion, restore binocularity.
There have been cases of improvement in extra-ocular movement with botulinum toxin injection.
A rostral lesion within the midbrain may affect the convergence center thus causing bilateral divergence of the eyes which is known as the WEBINO syndrome (Wall Eyed Bilateral INO) as each eye looks at the opposite "wall".
If the lesion affects the PPRF (or the abducens nucleus) and the MLF on the same side (the MLF having crossed from the opposite side), then the "one and a half syndrome" occurs which, simply put, involves paralysis of all conjugate horizontal eye movements other than abduction of the eye on the opposite side to the lesion.
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.
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. Other causes are possible.
Esotropia is a form of strabismus in which one or both eyes turns inward. The condition can be constantly present, or occur intermittently, and can give the affected individual a "cross-eyed" appearance. It is the opposite of exotropia and usually involves more severe axis deviation than esophoria. Esotropia is sometimes erroneously called "lazy eye", which describes the condition of amblyopia—a reduction in vision of one or both eyes that is not the result of any pathology of the eye and cannot be resolved by the use of corrective lenses. Amblyopia can, however, arise as a result of esotropia occurring in childhood: In order to relieve symptoms of diplopia or double vision, the child's brain will ignore or "suppress" the image from the esotropic eye, which when allowed to continue untreated will lead to the development of amblyopia. Treatment options for esotropia include glasses to correct refractive errors (see accommodative esotropia below), the use of prisms and/or orthoptic exercises and/or eye muscle surgery. The term is from Greek "eso" meaning "inward" and "trope" meaning "a turning".
Pendular nystagmus is a sinusoidal oscillation, which refers to the waveform of involuntary eye movements that may occur in any direction. It is characterized by the multidimensional slow eye movements of the eyes (1 Hz frequency) with an equal velocity in each direction that resembles the trajectory of a pendulum. These pattern of these movements may differ between the two eyes. Depending upon the pattern of movements, pendular nystagmus has been divided into different subtypes such as congenital nystagmus, acquired pendular nystagmus, and amaurotic nystagmus.
The eye findings of Parinaud's Syndrome generally improve slowly over months, especially with resolution of the causative factor; continued resolution after the first 3–6 months of onset is uncommon. However, rapid resolution after normalization of intracranial pressure following placement of a ventriculoperitoneal shunt has been reported.
Treatment is primarily directed towards etiology of the dorsal midbrain syndrome. A thorough workup, including neuroimaging is essential to rule out anatomic lesions or other causes of this syndrome. Visually significant upgaze palsy can be relieved with bilateral inferior rectus recessions. Retraction nystagmus and convergence movement are usually improved with this procedure as well.
Colobomas of the iris may be treated in a number of ways. A simple cosmetic solution is a specialized cosmetic contact lens with an artificial pupil aperture. Surgical repair of the iris defect is also possible. Surgeons can close the defect by stitching in some cases. More recently artificial iris prosthetic devices such as the Human Optics artificial iris have been used successfully by specialist surgeons. This device cannot be used if the natural lens is in place and is not suitable for children. Suture repair is a better option where the lens is still present.
Vision can be improved with glasses, contact lenses or even laser eye surgery but may be limited if the retina is affected or there is amblyopia.
The optokinetic response is a combination of a slow-phase and fast-phase eye movements. It is seen when an individual follows a moving object with their eyes, which then moves out of the field of vision at which point their eye moves back to the position it was in when it first saw the object. The reflex develops at about 6 months of age.
Optokinetic nystagmus (OKN) is nystagmus that occurs in response to a rotation movement. It is present normally. The optokinetic response allows the eye to follow objects in motion when the head remains stationary (e.g., observing individual telephone poles on the side of the road as one travels by them in a car, or observing stationary objects while walking past them).
Amaurotic nystagmus is defined as the nystagmus associated with blindness or the central vision defects. It is characterized by the pendular or jerky movements of the eyes in the patients who have visual impairement for a long period of time.
The number of cases is around 0.5 to 0.7 per 10,000 births, making it a relatively rare condition.
The syndrome usually results from single unilateral lesion of the paramedian pontine reticular formation and the ipsilateral medial longitudinal fasciculus. An alternative anatomical cause is a lesion of the abducens nucleus (VI) on one side (resulting in a failure of abduction of the ipsilateral eye and adduction of the contralateral eye = conjugate gaze palsy towards affected side), with interruption of the ipsilateral medial longitudinal fasciculus after it has crossed the midline from its site of origin in the contralateral abducens (VI) nucleus (resulting in a failure of adduction of the ipsilateral eye).
If an optokinetic drum is available, rotate the drum in front of the patient. Ask the patient to look at the drum as you rotate it slowly. If an optokinetic drum is not available, move a strip of paper with alternating 2-inch black and white strips across the patient's visual field. Pass it in front of the patient's eye at reading distance while instructing the patient to look at it as it rapidly moves by. With normal vision, a nystagmus develops in both adults and infants. The nystagmus consists of initial slow phases in the direction of the stimulus (smooth pursuits), followed by fast, corrective phases (saccade). Presence of nystagmus indicates an intact visual pathway.
Another effective method is to hold a mirror in front of the patient and slowly rotate the mirror to either side of the patient. The patient with an intact visual pathway will maintain eye contact with herself or himself. This compelling optokinetic stimulus forces reflex slow eye movements.
OKN can be used as a crude assessment of the visual system, particularly in infants. When factitious blindness or malingering is suspected, check for optokinetic nystagmus to determine whether there is an intact visual pathway.
Bruns nystagmus is an unusual type of bilateral nystagmus most commonly occurring in patients with cerebellopontine angle tumours. It is caused by the combination of slow, large amplitude nystagmus (gaze paretic nystagmus) when looking towards the side of the lesion, and rapid, small amplitude nystagmus (vestibular nystagmus) when looking away from the side of the lesion. It occurs in 11% of patients with vestibular schwannoma, and occurs mainly in patients with larger tumours (67% of patients with tumours over 3.5 cm diameter). Bruns nystagmus is also associated with an increased incidence of balance disturbance in patients with vestibular schwannoma. It may be caused by the compression of both flocculi, the vestibular part of the cerebellum, and improvement in both the nystagmus and balance problems occur commonly after removal of the tumour.
Bruns nystagmus is named for Ludwig Bruns (1858 – 1915).
Persistent hyperplastic primary vitreous (PHPV), also known as Persistent Fetal Vasculature (PFV), is a rare congenital developmental anomaly of the eye that results
following failure of the embryological, primary vitreous and hyaloid vasculature to regress. It can be present in three forms: purely anterior (persistent tunica vasculosa lentis and persistent posterior fetal fibrovascular sheath of the lens), purely posterior (falciform retinal septum and ablatio falcicormis congenita) and a combination of both. Most examples of PHPV are unilateral and non-hereditary. When bilateral, PHPV may follow an autosomal recessive or autosomal dominant inheritance pattern.
Parinaud's Syndrome results from injury, either direct or compressive, to the dorsal midbrain. Specifically, compression or ischemic damage of the mesencephalic tectum, including the superior colliculus adjacent oculomotor (origin of cranial nerve III) and Edinger-Westphal nuclei, causing dysfunction to the motor function of the eye.
Classically, it has been associated with three major groups:
1. Young patients with brain tumors in the pineal gland or midbrain: pinealoma (intracranial germinomas) are the most common lesion producing this syndrome.
2. Women in their 20s-30s with multiple sclerosis
3. Older patients following stroke of the upper brainstem
However, any other compression, ischemia or damage to this region can produce these phenomena: obstructive hydrocephalus, midbrain hemorrhage, cerebral arteriovenous malformation, trauma and brainstem toxoplasmosis infection. Neoplasms and giant aneurysms of the posterior fossa have also been associated with the midbrain syndrome.
Vertical supranuclear ophthalmoplegia has also been associated with metabolic disorders, such as Niemann-Pick disease, Wilson's disease, kernicterus, and barbiturate overdose.
One form of LCA, patients with LCA2 bearing a mutation in the RPE65 gene, has been successfully treated in clinical trials using gene therapy. The results of three early clinical trials were published in 2008 demonstrating the safety and efficacy of using adeno-associated virus to deliver gene therapy to restore vision in LCA patients. In all three clinical trials, patients recovered functional vision without apparent side-effects. These studies, which used adeno-associated virus, have spawned a number of new studies investigating gene therapy for human retinal disease.
The results of a phase 1 trial conducted by the University of Pennsylvania and Children’s Hospital of Philadelphia and published in 2009 showed sustained improvement in 12 subjects (ages 8 to 44) with RPE65-associated LCA after treatment with AAV2-hRPE65v2, a gene replacement therapy. Early intervention was associated with better results. In that study, patients were excluded based on the presence of particular antibodies to the vector AAV2 and treatment was only administered to one eye as a precaution. A 2010 study testing the effect of administration of AAV2-hRPE65v2 in both eyes in animals with antibodies present suggested that immune responses may not complicate use of the treatment in both eyes.
Eye Surgeon Dr. Al Maguire and gene therapy expert Dr. Jean Bennett developed the technique used by the Children's Hospital.
Dr. Sue Semple-Rowland at the University of Florida has recently restored sight in an avian model using gene therapy.
Zonular cataract and nystagmus, also referred as Nystagmus with congenital zonular cataract is a rare congenital disease associated with Nystagmus and zonular cataract of the eye.
There is generally no treatment to cure achromatopsia. However, dark red or plum colored filters are very helpful in controlling light sensitivity.
Since 2003, there is a cybernetic device called eyeborg that allows people to perceive color through sound waves. Achromatopsic artist Neil Harbisson was the first to use such a device in early 2004, the eyeborg allowed him to start painting in color by memorizing the sound of each color.
Moreover, there is some research on gene therapy for animals with achromatopsia, with positive results on mice and young dogs, but less effectiveness on older dogs. However, no experiments have been made on humans. There are many challenges to conducting gene therapy on humans. See Gene therapy for color blindness for more details about it.
Aulus Cornelius Celsus, writing ca. 30 AD, described night blindness and recommended an effective dietary supplement: "There is besides a weakness of the eyes, owing to which people see well enough indeed in the daytime but not at all at night; in women whose menstruation is regular this does not happen. But success sufferers should anoint their eyeballs with the stuff dripping from a liver whilst roasting, preferably of a he-goat, or failing that of a she-goat; and as well they should eat some of the liver itself."
Historically, nyctalopia, also known as moonblink, was a temporary night blindness believed to be caused by sleeping in moonlight in the tropics.
In the French language, and have inverse meanings, the first naming the ability to see in the dark as well as in plain light, and the second the inability to do so. It is thought that this inversion from Latin happened during the 2nd century AD, even though the ancient greek νυκτάλωψ ("nuktálōps") has been used in both senses.
It has been suggested that the disease follows a x-linked pattern of inheritance though studies done on this particular disease are few.