Nystagmus in children

Nystagmus - rhythmic vibrational motion of one or both eyes around one or more axes. The movements can be pendulum-like (rhythmic) or jerky (with different phases of oscillation in terms of speed).

Nystagmus is a complex form of pathology and very often serves as a clinical-anatomical cause of vision. The frequency of nystagmus distribution, according to different authors, is from 1 to 5,000 to 1 per 20,000 population. At inspections of students in schools for visually impaired nystagmus, 6-44% were detected. Thus, despite the relative scarcity of nystagmus, it often accompanies a low visual acuity and can be both its cause and effect.

In healthy people, there is a physiological nystagmus when considering fast moving objects (railroad or optokinetic nystagmus), with irritation of the labyrinth of the middle ear (labyrinth or vestibular). Nystagmoid twitching occurs in normal and with prolonged extreme eye-out due to fatigue of the external muscles of the eye. Pathologic nystagmus is a diagnostic problem for ophthalmologists, otolaryngologists, neuropathologists and neurosurgeons, since it can be central (neurogenic), peripheral (labyrinthine or vestibular), eye (fixative), can arise on the ground of professional activity (by the miner), after intoxication , alcoholic). Therefore, nystagmus can be a symptom that allows one to suspect and reveal the pathology of the middle ear or brain structures. In such cases, treatment of the underlying disease is necessary. Nystagmus can also become a major disease in the pathology of the optic nerve and oculomotor apparatus, then the task of rehabilitation of the patient faces ophthalmologists.

Pathological nystagmus is caused by a violation of the mechanism of visual fixation and arises from its congenital pathology, transmitted by hereditary path, or as a result of acquired lesions of various parts of the brain that regulate micromotion of the eyes. We can distinguish the following types of pathological nystagmus: neurogenic, congenital, early acquired, latent, manifest-latent, nystagmus in albinism, nystagmus caused by medications, alcoholic nystagmus.

Neurogenic (central) nystagmus occurs as a result of inflammatory, degenerative, tumor and traumatic lesions of various parts of the central nervous system that are responsible for movements (with lesions in the posterior cranial fossa, cerebellum, vestibular nuclei, medial longitudinal fascicule, subcortical and cortical centers of eye movements regulation) . Manifestations of neurogenic nystagmus depend on the dynamics of the underlying disease.

Vestibular pathological nystagmus, in contrast to the physiological vestibular, which is reflex, induced, is always spontaneous and is caused by a violation of the central vestibular function or a disease of the peripheral vestibular apparatus. This kind of nystagmus is usually combined with dizziness and nausea.

[1], [2], [3], [4], [5], [6]

Congenital and early-acquired nystagmus

Congenital and early acquired nystagmus occurs with congenital pathology of the oculomotor apparatus (cataract, corneal opacity, optic nerve atrophy, etc.), transmitted by hereditary path or accompanies congenital and early acquired eye diseases. Oscillatory movements of the eyes in this nystagmus are caused by a disorder of visual fixation due to a disturbance of the regulatory mechanism or a central vision defect.

In contrast to congenital nystagmus, in which the patient does not notice the vibrational movements of the eyes, with an early acquired nystagmus, they are noticeable.

Treatment of congenital and early acquired nystagmus is aimed at reducing its amplitude, improving visual functions and visual performance. It includes optical correction of ametropia, prismatic correction, pleoptics (exercises to increase visual acuity), effects on the accommodation apparatus, medication, exercises on the principle of biofeedback and operations on oculomotor muscles. In most cases, such treatment is effective. The use of glasses with protective spectral filters (with the combination of nystagmus with albinism, diseases of the macular area, aphakia) increases visual acuity.

[7], [8], [9], [10], [11], [12], [13]

Latent and manifest-latent nystagmus in children

Latent nystagmus is a binocular nystagmus that occurs when one eye is turned off from the act of sight. With two open eyes and with the switching off of both eyes, such nystagmus does not appear. Sometimes latent nystagmus occurs only when a certain eye is turned off, usually better in sight, leading. And when the other eye is turned off, no nystagmus is present.

With two open eyes, visual acuity is high or normal, and when one eye is sighted due to a latent nystagmus, it is reduced to some extent. This kind of nystagmus is present from birth and remains unchanged throughout life. It should be considered conditionally pathological, it does not require special treatment.

With a sharp decrease in visual acuity of one eye due to anatomical causes or amblyopia, as well as suppression of visual impressions on the mowing eye, with a strabismus the latent form of the nystagmus takes the form of a manifesto-latent nystagmus. As a rule, the manifesto-latent nystagmus is accompanied by a friendly strabismus. Treatment of the manifesto-latent nystagmus often requires the elimination of strabismus and amblyopia, as well as a somewhat different tactic of surgical intervention on the oculomotor muscles

Nystagmus in albinism

At the heart of albinism is a violation of the formation of tyrosine pigment melanin. The absence of a pigment in the skin, hair and shells of the eye is a congenital defect, inherited mainly in the autosomal recessive type.

The eye manifestations of albinism are diverse: photophobia, color changes and atrophy of the iris, reddish glow of the pupil and iris (red reflex from the fundus penetrates through defects of the iris), the eye bottom is pale pink, the vascular pattern of the choroid can be clearly seen. The visual acuity is lowered mainly due to hypoplasia or aplasia of a yellow spot, color blindness is often present.

Treatment of nystagmus in albinism is the same as with congenital nystagmus. It is shown wearing light-shielded or holey glasses and dark contact lenses with a transparent center.

Nystagmus in children caused by drugs

The use of certain drugs (barbiturates, phenothiazines, tranquilizers, anticonvulsants, etc.), especially in high doses, can cause nystagmus. Perhaps the combination of nystagmus with dizziness, ataxia, dysarthria and other disorders, especially with acute intoxication. If a nystagmus of this nature is suspected, detailed inquiry and studies for the presence of drugs, as well as the determination of their concentration in the blood, are necessary. Drugs that cause nystagmus, you must cancel, reduce their dose or use other drugs. A complex of functional methods aimed at restoring visual functions, and finally, surgical intervention on the oculomotor muscles significantly expand the therapeutic possibilities in this severe disease, previously considered incurable.