Nystagmus: Clinical Guidelines

List of Abbreviations

dpt — diopter

VEP — visual evoked potentials

MP — microperimetry

CNS - central nervous system

ERG – electroretinography

CEMAS - Classification of Eye Movement Abnormalities and Strabismus

FMNS - Fusion Maldevelopment Nystagmus Syndrome

INS – Infantile Nystagmus Syndrome

SNS - Spasmus Nutans Syndrome

Terms and Definitions

Vestibular (labyrinthine) nystagmus is a jerky nystagmus caused by stimulation of the vestibular apparatus.

Congenital nystagmus is involuntary rhythmic movement of the eyeballs detected in children during the first months of life.

Ocular torticollis is an abnormal head position caused by disorders of the oculomotor apparatus.

Null zone of nystagmus is the direction of gaze at which the nystagmus amplitude is minimal, which is accompanied by an increase in visual acuity with a forced head turn.

Infantile nystagmus is a type of early-acquired pathological optical nystagmus that occurs at 2–3 months of age.

Microperimetry is a combination of automated perimetry and retinal imaging performed using a fundus camera.

Nystagmus is involuntary oscillatory movements of the eyeball.

Optical or ocular nystagmus is a term encompassing various types of pathological nystagmus associated with primary visual impairment.

Optokinetic nystagmus is nystagmus that occurs when distinguishable visual stimuli moving at a constant speed in a specific direction are presented.

Pathological nystagmus is nystagmus caused by a dysfunction of the visual fixation mechanism and occurring due to its congenital pathology (transmitted hereditarily) or resulting from acquired lesions of various parts of the brain that regulate micro-eye movements.

Physiological nystagmus is nystagmus that occurs in healthy individuals during the fixation of a stationary point. The eye makes involuntary movements several times per second: tremor, drift, and jumps (saccades).

1. Brief information on the disease or condition

1.1 Definition of the disease or condition

Nystagmus is involuntary oscillatory movements of the eyeball initiated by a pathological slow eye movement and accompanied by a corrective fast eye movement [1,2,3].

Physiological and pathological nystagmus are distinguished. Physiological nystagmus is essential for the normal functioning of the visual analyzer. During fixation of a stationary point, the eye makes involuntary movements several times per second, such as tremor, drift, and jumps (saccades). The nature of these movements is relatively chaotic. The absence of micro-movements leads to the stabilization of the image on the retina, and the visual image seems to "fade" after a second, the visual field becomes empty—the "empty field" phenomenon occurs. After the image shifts on the retina, the perception of a light stimulus appears. To fixate an object, the eye must make movements that determine the mechanisms of gaze direction and are an integral part of the assessment of three-dimensional space [2,3,4,5,6,7].

Optokinetic and vestibular nystagmus are classified as physiological types of nystagmus. These types of nystagmus are induced and can only be provoked under certain conditions, which distinguishes them from pathological nystagmus. Optokinetic nystagmus occurs when the subject is presented with distinguishable visual stimuli moving at a constant speed in a certain direction. It is characterized by conjugate eye movements at a constant speed matching the direction of the stimulus movement, interrupted by fast saccades of the eyes in the opposite direction [2,6,8,9].

In clinical practice, optokinetic nystagmus can be induced by rotating a drum with black and white stripes printed on it horizontally (right or left) and vertically (up or down) in front of the subject's eyes. Increasing the drum rotation speed leads to an increase in the frequency of optokinetic nystagmus up to 5 beats per second, the slow-phase velocity up to 50° per second, and the amplitude up to 30° [6,8].

Vestibular (labyrinthine) nystagmus is a jerky nystagmus caused by irritation of the vestibular apparatus [2,8,10].

Pathological nystagmus is caused by a disturbance in the visual fixation mechanism and occurs in its congenital pathology, being inherited, or as a result of acquired lesions of various parts of the brain regulating eye micro-movements. The following types of pathological nystagmus can be distinguished: neurogenic, vestibular, congenital, early acquired, latent, manifest-latent, nystagmus in albinism, drug-induced nystagmus, and alcoholic nystagmus [2,8].

Optical nystagmus is singled out, emphasizing its connection with primary visual impairment. Optical nystagmus is a term that combines various types of pathological nystagmus associated with primary visual impairment. Among them are congenital and early-acquired nystagmus, latent and manifest-latent nystagmus, and nystagmus in albinism [2,6]. Congenital and manifest-latent nystagmus account for 62% and 33%, respectively, of all cases of optical nystagmus [2].

1.2 Etiology and pathogenesis of the disease or condition (group of diseases or conditions)

The mechanisms leading to the involuntary rhythmic oscillations of the eyes that characterize nystagmus are not fully understood. Cases of acquired neurogenic nystagmus can be explained by abnormalities in various parts of the central nervous system or the vestibulo-ocular reflex pathway [11].

The pathogenesis of optical nystagmus remains the least studied due to its complexity and ambiguity. The search for cause-and-effect relationships between CNS pathology, organic and functional disorders continues.

For a long time, it was believed that optical nystagmus is a compensatory mechanism of the body to reduced vision and the loss of the functional dominance of the fovea centralis. Based on this, to form normal visual perception at low vision, when impulses from the macular region are insufficient, nystagmus arises, stimulating a larger number of cones and forming a clearer image. It was believed that the amplitude of nystagmus is directly proportional to the degree of vision reduction. However, quite often nystagmus not only fails to compensate for low vision but worsens it even further, and a decrease or cessation of nystagmus is often accompanied by an increase in visual acuity [2].

A. Kestenbaum and A. Sorsby considered pathological optical nystagmus to be a disorder associated with an increase in physiological nystagmus due to reduced vision and other, often unknown, causes [12,13]. According to A.L. Yarbus, impairment of the extraocular muscles and drift of physiological nystagmus have a preferential direction in some direction, as a result of which it is corrected by saccades directed in the opposite direction, i.e., jerky nystagmus is observed [14].

A number of authors believe that visual fixation is associated with optical and non-optical (mainly vestibular) impulses controlled by subcortical and cortical centers [15,16]. According to V. Forssman, optical impulses play the primary role. The absence of normal conditions for visual development due to various lesions of the visual analyzer in the early period of its development prevents the correct formation of the normal fixation reflex. There is a reversion to a phylogenetically lower level of regulation of eye movements, when eye movements are controlled by non-optical stimuli, which is clinically manifested by nystagmus [16]. Partly the same point of view is held by R. Jung and co-authors, who believe that since the vestibular, optical, and reticulothalamic systems participate in the formation of gaze, fixation impairment is associated with the degeneration of the vestibulo-ocular system in the premotor area of the brainstem [17].

According to L. F. Dell'Osso and R. Daroff, patients with high vision primarily suffer from the tracking system, which is caused by the underdevelopment of visual motor pathways—an impairment of the ability of the eye to slowly follow a visual object causes corrective jerky and pendular movements [18].

The question of the causes of two different types of nystagmus (jerky and pendular) remains open to this day. Perhaps pendular eye movements occur in pathology of the sensory visual system (visual acuity is reduced due to organic defects of the visual system), and jerky movements occur in pathology of the oculomotor system (visual acuity is reduced due to nystagmoid eye movements—nystagmoid deprivation).

Some foreign authors point to the hereditary nature of optical nystagmus and describe the pathology using several family members as examples. Optical nystagmus can be inherited in an autosomal dominant, autosomal recessive, or X-linked manner. X-linked inheritance is considered the most common type. Currently, the only gene identified for the X-linked form of inheritance is FRMD7, which encodes a protein located in brain regions involved in oculomotor functions, as well as in the retina [19,20,21]. Nystagmus may be accompanied by other pathological conditions of the nervous system: spinocerebellar ataxia, intellectual disability, and syringomyelia [22,23].

According to E.S. Avetisov, in early-acquired or congenital nystagmus, the central vision apparatus suffers — the prevailing functional role of the fovea centralis is "lost", the receptive field of monocular fixation expands, and the functions of the reflexogenic zone around the fovea centralis, which provides feedback signals when the fixation point shifts from the foveal field, are weakened. As a result, the monocular function system becomes extremely unstable. In such a mechanism, peripheral factors play a prevailing role, and this type of nystagmus is always accompanied by a sharp decrease in visual acuity [2,24]. Russian and foreign authors agree with this interpretation [25,26].

According to J. P. Kelly and co-authors, nystagmoid deprivation is not a cause preventing the development of visual acuity during the critical period of visual system maturation. The primary factor hindering the increase in visual acuity lies above the retina, possibly in the visual cortex of the brain [27].

Based on his own data, M. Brodsky comes to the following conclusions: 1) infantile nystagmus is isolated from the visual system; 2) infantile nystagmus begins at the age of 2–3 months when the subcortical optokinetic system is disabled; 3) in patients with infantile nystagmus, the subcortical optokinetic system continues to function; 4) in people with reduced vision due to disorders in the cortical divisions of the visual system, nystagmus is absent, which proves the necessity of the functioning of two optokinetic systems (cortical and subcortical) for the occurrence of infantile nystagmus [28]. Brodsky M.C., Dell'Osso L.F. believe that infantile nystagmus manifests as a result of the simultaneous operation of two oculomotor systems — the primitive, subcortical optokinetic pathway, and the more complex cortical tracking system. Normally, the latter system matures and replaces the former at approximately 2–3 months of age, when connections are established between the cerebral cortex and the accessory optic system in the midbrain [18,29].

Despite significant progress in understanding the causes of nystagmus, this pathology remains insufficiently elucidated and prompts many researchers and practicing physicians to further study its pathogenesis.

1.3 Epidemiology of the Disease or Condition

Pathological nystagmus occurs in 30.8%–58.8% of low-vision individuals, and in 17.6% of low-vision individuals, nystagmus serves as the leading cause of decreased visual acuity [2].

During mass screenings of children with low vision in specialized schools, camps, sanatoriums, and rehabilitation centers, congenital nystagmus is diagnosed in 20%–59% of children [30].

Optical nystagmus is detected with a frequency ranging from 0.5–2 cases per 10,000 population [2] to 24 cases per 10,000 [31].

According to observations by K. Hvid and co-authors, infantile nystagmus occurs in 6.1 per 10,000 newborns: in premature infants — 28.4 per 10,000 newborns, and in full-term infants — 4.4 per 10,000. The most common causes of infantile nystagmus are eye diseases (44%), idiopathic nystagmus (32%), neurological disorders and genetic syndromes (20%), as well as prematurity without retinopathy of prematurity [32].

1.4 Features of Coding the Disease or Condition

H55 – Nystagmus and other irregular eye movements

1.5 Classification of the disease or condition

In global practice, there are many different classifications of pathological nystagmus. Abroad, the classification of eye movement abnormalities and strabismus adopted by the working group in 2001 (Classification of Eye Movement Abnormalities and Strabismus — CEMAS) is mainly used. According to this classification, the main forms of pathological nystagmus are: Infantile Nystagmus Syndrome (INS), Fusion maldevelopment Nystagmus Syndrome (FMNS), Spasmus Nutans Syndrome (SNS), vestibular nystagmus, and forms caused by CNS disorders [33].

In our country, the classification proposed by E.S. Avetisov (2001) is used [2,34].

Types of pathological nystagmus.

1. Neurogenic, associated with primary damage to various parts of the central nervous system responsible for micro-eye movements.

2. Vestibular, occurring in diseases of the central and peripheral parts of the vestibular system.

3. Congenital nystagmus, associated with congenital developmental defects of the eye micro-movement control system.

4. Early-acquired, observed in pathology of the eye itself, leading to a violation of the foveal fixation system; according to clinical manifestations, such nystagmus can be combined with congenital into a single group.

5. Latent and manifest-latent, based on a sharp decrease or suppression of the visual function of one eye.

6. Nystagmus in albinism.

7. Nystagmus caused by certain medications.

8. Alcoholic nystagmus.

The third to sixth types of nystagmus from E.S. Avetisov's classification are classified as optical nystagmus.

Depending on the influence of certain stimuli on the eye, vestibular, or central nervous systems, nystagmus is divided into:

1. Spontaneous;

2. Reflex.

According to the nature of the oscillatory movements of the eyeball, the following forms of nystagmus are distinguished:

1. Pendular (undulating) sensory with uniform phases of oscillation;

2. Jerk, or rhythmic, with a slow phase of oscillation in one direction and a fast phase in the other direction;

3. Mixed, when an alternation of pendular and jerk movements of the eyeball is observed; a change in the direction of gaze can cause the transition of one form of nystagmus into another.

Depending on the amplitude of deviation of the eyeball from the central position, optical nystagmus is subdivided into:

- large-amplitude nystagmus with an amplitude of more than 15°,

- medium-amplitude — with an amplitude of 5–15°,

- small-amplitude — with an amplitude of up to 5°.

According to the frequency of oscillatory movements, nystagmus is:

- low-frequency — up to 2 Hz,

- medium-frequency — from 2.1 to 3 Hz,

- high-frequency — from 3.1 to 4.5 Hz.

Congenital nystagmus can be isolated or combined with other ocular pathologies, for example, optic atrophy, albinism, congenital retinal pathology, cataract, glaucoma.

According to the direction of movements, nystagmus is distinguished:

- horizontal,

- vertical,

- oblique (diagonal),

- rotational (circular, rotatory).

According to the absence or presence of strabismus, nystagmus is distinguished:

- with strabismus,

- without strabismus.

In clinical practice, the presence or absence of a forced head turn in one direction or another, or its tilt, the so-called torticollis, is of great importance.

According to head position, nystagmus is distinguished:

- without a forced head position,

- with a forced head position,

- with a head turn,

- with a head tilt.

1.6 Clinical presentation of the disease or condition

Examination of a patient with nystagmus reveals: the presence of constant oscillatory movements of the eyes, decreased visual acuity, a forced head position, and strabismus in some patients. When combined with strabismus, binocular function impairment is noted.

Changes in the anterior segment of the eye and opacities of the media are often not detected. Changes in the retina and/or optic nerve may be found on fundoscopy [2,12,24,35,36,37].

2. Diagnostics, medical indications and contraindications for diagnostic methods

Criteria for establishing nystagmus: the presence of constant or periodic oscillatory movements of the eyes.

2.1 Complaints and Anamnesis

Comments: when assessing the history of the present illness, special attention should be paid to the age at which nystagmus was first detected. If nystagmus is detected in the first days of a child's life, it is necessary to determine whether it is hereditary or associated with abnormal pregnancy and delivery (gestosis, maternal systemic diseases, prematurity, premature or precipitous labor, birth trauma, asphyxia, medication use). Abnormal pregnancy and delivery may lead to systemic diseases and other eye lesions in addition to nystagmus. The onset of nystagmus at an older age requires investigating its potential association with disorders of the visual, oculomotor, and central nervous systems, as well as the oculomotor apparatus.

2.2 Physical Examination

Physical examination is not indicated for nystagmus.

2.3 Laboratory Diagnostics

Laboratory diagnostic tests are not indicated for nystagmus.

2.4 Instrumental Diagnostics

Comments: in children under three years of age, visometry is performed roughly by determining whether the child has object vision. More precise measurement is possible using the preferential looking test or visual evoked potentials.

Visometry in children aged three years and older is performed using charts: from 3 years of age using a chart of children's silhouette pictures, from 5 years of age using Landolt rings, "E" charts, letters, or numbers.

The value of visual acuity is taken as the chart line in which all symbols are correctly identified.

Comments: when determining refraction, double instillation of 1–2 drops of tropicamide** 1% into the conjunctival sac induces less deep cycloplegia than cyclopentolate 1% [43,44].

Comments: when evaluating oscillatory eye movements, the following characteristics of nystagmus are determined: constant or intermittent; large- or small-amplitude; low-, medium-, or high-frequency; monocular or binocular; horizontal, vertical, diagonal, or rotational (torsional); associated or dissociated; pinpoint, pendular, or mixed; whether it is blocked by convergence or not; and whether it depends on gaze direction and head position [2,6].

In jerk nystagmus, the direction of the fast phase (to the right or left) is noted, and it is termed right-beating or left-beating nystagmus, respectively [2,6,35,36].

Nystagmography allows for precise determination of the amplitude of oscillatory eye movements and provides a more detailed characterization. In clinical practice, the amplitude of nystagmus is assessed by the degree of displacement of the ophthalmoscopic light reflex on the cornea. If the reflex shifts between the center of the pupil and the midpoint of the distance from the center of the pupil to its margin, the nystagmus is considered small-amplitude; otherwise, it is considered large-amplitude [2,6].

Comments: jerk nystagmus is a condition of extraocular muscle imbalance in which the eyes exhibit jerky movements. Slow eye movements in one direction alternate with rapid movements in the opposite direction. The mechanism of this pathology lies in the unequal tone of extraocular muscle pairs responsible for moving the eyes to the right and left, respectively. The stronger pair of muscles is involved in forming the slow phase, while the weaker pair forms the fast phase. When the eyes turn toward the slow phase, the dynamometric parameters of the muscle pairs balance out, the intensity of nystagmus decreases, and visual functions improve. This state is called the relative rest zone or null zone of nystagmus.

In order for this zone to move to the primary gaze position (directly in front of the patient), the patient makes a compensatory head turn in the opposite direction (toward the fast phase of the nystagmus). This head turn is referred to as "forced." Depending on the direction of the forced head turn or tilt, horizontal and vertical torticollis are distinguished, as well as oblique (combined) torticollis, which combines both components. Horizontal torticollis is the most common [37,46]. Frequently, when the head is turned or tilted, the amplitude of the nystagmus decreases or the nystagmus ceases entirely, leading to improved visual function. In nystagmus, there may be one or more head positions in which the nystagmus disappears or significantly decreases [37,46].

Comments: the state of convergence can be assessed by bringing an object (a finger, pencil, etc.) closer to the patient's eyes. In some cases, convergence can exert a damping (inhibiting, blocking) effect on nystagmus, and the amplitude of the nystagmus noticeably decreases. This condition is termed "nystagmus blockage syndrome." Much less commonly, convergence increases the oscillatory movements of the eyes [2,35,36,47,48,49].

Comments: electroretinography (ERG) is a highly sensitive method for assessing the functional state of the retina. ERG makes it possible to detect rod monochromacy, stationary night blindness, retinitis pigmentosa, and other diseases in patients with nystagmus, which may clinically manifest as nystagmus. To study retinal electrogenesis in nystagmus, dark-adapted full-field and local macular ERG are recorded [53,54,55]. The results of electroretinography in optical nystagmus combined with low visual acuity show a significant decrease in the "b" wave parameters of the full-field and local macular ERG. The combination of nystagmus with optic atrophy on ERG may be characterized by a normal or reduced "b" wave with a normal "a" wave. These changes are explained by transsynaptic degeneration involving bipolar cells that participate in ERG generation [55].

The method of recording visual evoked potentials (VEP) of the cerebral cortex is used to diagnose lesions of the visual pathways and pathology of the central part of the visual analyzer. Recording visual evoked potentials (VEP) of the cerebral cortex allows for a quantitative assessment of the functional state of the visual system, which cannot be achieved using other clinical research methods [38,55].

2.5 Other Procedures

Comments: microperimetry (MP) is a diagnostic method that allows for the creation of sensitivity maps by observing the actual image of the examined retina with the determination of the exact anatomical location of the stimulus. MP correlates with the patient's fundus and objectively provides the relationship between the morphological aspects of the retina and the corresponding functional aspects. Using a microperimeter, photosensitivity assessment is carried out by projecting a stable fixation target and a sequence of Goldmann-type stimuli onto the fundus (the patient's reaction to each projected "see/not see" stimulus is displayed on the stable retinal image as a sensitivity map) [60].

Microperimetry automatically evaluates fixation stability within a given standard of 2° and 4° from the foveal center. The results of the quantitative assessment of amplitude, mean displacement, and displacement velocity of the fixation point are presented in the form of a table and a graph. Studying the fixation point makes it possible to record changes over time in the position of the fixation point on the patient's retina and display this on a stable retinal image obtained at the beginning of the study using an infrared camera (to determine the fixation area and evaluate its stability over time) [61].

3. Treatment, including drug and non-drug therapies, diet therapy, and pain management

Optical correction

Comments: the selection of optical correction in cases of nystagmus combined with ametropia is carried out based on the results of the patient's examination before cycloplegia, examination under cycloplegic conditions, and after the effect of cycloplegia has worn off. Preference is given to full correction of ametropia. Examination in the prescribed spectacles is indicated [2,40,41].

Spectral correction

Comments: spectral filters do not impair color perception. In nystagmus combined with aphakia, the prescription of a yellow spectral filter with 50% transmittance at a wavelength of 485 nm is indicated; in albinism, a brown filter with 30% transmittance in the 560 nm region, close to the total spectrum of melanin, retinal macular carotenoids, and lens beta-crystallins, is indicated. In congenital macular diseases, the prescription of an orange spectral filter with a primary transmission band above 520 nm is indicated [62,63].

Prismatic correction

Comments: in nystagmus, a compensatory forced head position (ocular torticollis) may develop to reduce nystagmus amplitude and improve visual acuity. To compensate for ocular torticollis in the straight-ahead head position, prisms of increasing power, with their bases oriented in the direction of the fast phase, are placed in a trial frame before the patient's eyes. The power of the prisms that yields a visual acuity equal to that observed in the forced head position is noted. If the prisms provide only subjective improvement but do not affect visual acuity in the straight-ahead head position, the decision on their prescription is made on an individual basis. Flexible Fresnel prisms may be used for correction [2,35,36,64].

Comments: in nystagmus, to reduce its amplitude and improve visual acuity, esotropia may develop as a nystagmus blocking syndrome. One eye fixes on the object, while the other eye deviates nasally to reduce the nystagmus amplitude. This is accompanied by decreased visual acuity in the strabismic eye. Therefore, one of the main goals in nystagmus is to maximize visual acuity and reduce nystagmus amplitude. The method of treating nystagmus based on prismatic induction of convergent fusion consists in creating a divergent shift of the visual axes, for which prisms with the base out are placed in front of the patient's eyes. With preserved binocular vision function, to eliminate the induced prismatic exodeviation accompanied by diplopia, fusion mechanisms are engaged, nystagmus stabilizes, foveal time increases, and opportunities for improving visual functions are enhanced.

For nystagmus blocking syndrome, prisms of increasing power are selected and placed in front of the patient's eye with the base toward the temple, and the amount of prismatic effect required for binocular fixation is determined. A prism is selected that provides the maximum reduction of nystagmus without the onset of esotropia. The criterion for correct prism selection is the absence of esotropia during fixation of a near object, as well as pediatric refractometer test indicators — symmetrical positioning of the visual axes and fixation of the patient's eyes. Elastic Fresnel prisms corresponding in total to the optimal prismatic correction value can be used for correction. A positive response to prismatic correction is a good prognostic factor for surgical treatment of nystagmus [35,36,48,49 64].

Functional treatment

Comments: in nystagmus, amblyopia can be relative, associated with organic defects in the visual system and/or with oscillatory eye movements (nystagmoid "deprivation"), or dysbinocular — when nystagmus is combined with strabismus.

In the pleoptic treatment of relative amblyopia in nystagmus, occlusion, penalization, flashes, laser speckles, and other methods are used, which are administered in ten-day courses 3–4 times a year with an interval of 3 months [2,8,50,52,65,66].

Surgical treatment

Comments: the essence of surgical treatment for horizontal jerk nystagmus consists in weakening the stronger horizontal muscles on the side of the slow phase and/or strengthening the weak muscles on the side of the fast phase. As a result, muscle tonus is approximately balanced. The zone of relative ocular rest shifts to the median position [2,35,36,73,74,75,76,77]. Surgical interventions on extraocular muscles for nystagmus blocked by convergence are performed to reduce nystagmus amplitude and improve visual acuity [35,36,48,49,74].

Other treatment

4. Medical Rehabilitation and Sanatorium-Resort Treatment

5. Prevention and Dispensary Observation

No convincing data on the use of diet therapy in optical nystagmus in children have been found.

6. Organization of Medical Care

Medical care for optical nystagmus is provided on a planned basis.

Primary pre-medical health care for optical nystagmus is provided by medical workers with secondary medical education; primary medical health care for optical nystagmus is provided by district pediatricians and general practitioners (family physicians). When nystagmus is suspected or detected, medical workers with secondary medical education, district pediatricians, and general practitioners (family physicians) refer patients for consultation with an ophthalmologist. For optical nystagmus, primary specialized health care is provided by an ophthalmologist.

According to Order of the Russian Ministry of Health No. 211n dated April 14, 2025, "On Approval of the Procedure for Minors Undergoing Preventive Medical Examinations, Accounting Form No. 030-PO/y 'Minor Preventive Medical Examination Card', the Procedure for Its Maintenance, as well as Industry Statistical Observation Form No. 030-PO/o 'Information on Preventive Medical Examinations of Minors', and the Procedure for Its Completion," during medical examinations of minors, including upon admission to and during their studies in educational institutions, the ophthalmologist examines children at the ages of 1 month, 12 months, 3 years, 6 years, 7 years, 10 years, 13 years, 15 years, 16 years, and 17 years.

Optical nystagmus is also detected when patients independently apply to the ophthalmology office in the served area complaining of oscillatory eye movements.

The ophthalmologist in the ophthalmology office provides: consultative, diagnostic, and therapeutic care; in the presence of medical indications, refers children with optical nystagmus to the children's vision conservation office or the pediatric ophthalmology department.

Medical care for children with reduced visual functions caused by nystagmus can (if outpatient treatment is impossible) be provided in a day or round-the-clock hospital setting (at the discretion of the head of the pediatric ophthalmology department). Children are referred to the hospital for pleoptic and/or other visual function-stimulating treatment.

In the presence of jerky nystagmus accompanied by an abnormal head posture and/or reduced visual functions caused by nystagmus, children with optical nystagmus are referred for inpatient surgical treatment to receive specialized medical care.

Indications for hospitalization of children with optical nystagmus in a day hospital of a medical organization:

1) Reduced visual functions caused by nystagmus, and the need for functional and/or other visual function-stimulating treatment when outpatient treatment is not possible.

Indications for hospitalization of children with optical nystagmus in a round-the-clock hospital of a medical organization:

1) Optical nystagmus in children, if indications for surgical intervention on extraocular muscles are identified

2) Reduced visual functions caused by nystagmus, and the need for functional and/or other visual function-stimulating treatment when outpatient treatment or treatment in a day hospital setting is not possible.

The expediency of hospitalizing children with optical nystagmus in a round-the-clock hospital of a medical organization is determined by the head of the pediatric ophthalmology department.

The basis for discharging a patient from a medical organization is the complete completion of the planned treatment.

7. Additional Information

There are no preventive measures that could prevent the development of optical nystagmus. Nystagmus does not cause complications, but it affects visual functions.

In cases where optical nystagmus is accompanied by low vision, it is advisable for children to attend preschool educational institutions for children with visual impairments and schools for the visually impaired.

Criteria for Evaluating the Quality of Medical Care

Quality assessment criteria for primary health care provided to children with nystagmus are presented in Table 1. Quality assessment criteria for specialized medical care provided to children with nystagmus are presented in Table 2.

Table 1. Criteria for assessing the quality of primary health care provided to children with nystagmus

Table 2. Criteria for assessing the quality of specialized medical care provided to children with nystagmus

References

Appendix A1. Working Group Composition

1. Aklaeva Nailya Anvarovna, Candidate of Medical Sciences, Association of Ophthalmologists LLC;

2. Apaev Aleksandr Vyacheslavovich, Candidate of Medical Sciences, Association of Ophthalmologists LLC;

3. Plisov Igor Lvovich, Doctor of Medical Sciences, Association of Ophthalmologists LLC;

4. Proskurina Olga Vladimirovna, Dr. of Med. Sci., Association of Ophthalmologists LLC;

5. Stalmakhova Regina Rasulovna, Candidate of Medical Sciences, Association of Ophthalmologists LLC;

6. Tarutta Elena Petrovna, Group Head, Dr. of Med. Sci., Professor, Association of Ophthalmologists LLC.

There is no conflict of interest.

Appendix A2. Methodology for Developing Clinical Guidelines

Methods used for evidence collection/selection: search in electronic databases; analysis of modern scientific developments on the problem of nystagmus in Russia and abroad; synthesis of practical experience of Russian and foreign colleagues.

When selecting publications as potential sources of evidence, the methodology used in each study is examined to ensure its reliability. The result of this examination affects the level of evidence assigned to the publication, which in turn affects the strength of the recommendations derived from it.

A preliminary version of these guidelines was reviewed by independent experts who were asked to comment primarily on whether the interpretation of the evidence underlying the recommendations is reliable and accessible to practicing physicians and patients.

Comments were received from ophthalmologists dealing with the problem of nystagmus and primary care physicians regarding the clarity of presentation and the importance of recommendations as a working tool in daily medical practice.

The received comments were carefully systematized and discussed by the working group members. Changes and additions recommended as a result of the discussion were introduced into the text of the guidelines.

Target audience for these clinical guidelines:

1. Ophthalmologists;

2. General practitioners (family physicians);

3. Pediatricians;

4. District pediatricians.

Table 1. Levels of Evidence (LoE) grading scale for diagnostic methods (diagnostic interventions)

Table 2. Scale for grading levels of evidence (LE) for prevention, treatment, and medical rehabilitation methods, including those based on natural therapeutic factors (preventive, therapeutic, and rehabilitation interventions)

Table 3. Scale for grading grades of recommendation (GR) for prevention, diagnostic, treatment, and medical rehabilitation methods, including those based on natural therapeutic factors (preventive, diagnostic, therapeutic, and rehabilitation interventions)

The mechanism for updating clinical guidelines provides for their systematic revision at least once every three years, as well as upon the emergence of new evidence-based medicine data on the diagnosis, treatment, prevention, and rehabilitation of specific diseases, or in the presence of justified additions/comments to previously approved clinical guidelines, but no more frequently than once every 6 months.

Appendix A3. Reference Materials

These clinical guidelines were developed taking into account the following regulatory legal documents:

1. Order of the Russian Ministry of Health No. 614n dated October 9, 2025, "On approval of the Procedure for providing medical care to children in the profile 'ophthalmology'."

2. Order of the Russian Ministry of Health No. 203n dated April 14, 2025, "On approval of criteria for assessing the quality of medical care."

3. Order of the Russian Ministry of Health No. 211n dated April 14, 2025, "On approval of the procedure for minors undergoing preventive medical examinations, accounting form No. 030-PO/u 'Minor's Preventive Medical Examination Card', the procedure for its maintenance, as well as the industry statistical reporting form No. 030-PO/o 'Information on Preventive Medical Examinations of Minors', and the procedure for its completion."

4. Order of the Government of the Russian Federation No. 3867-r dated December 18, 2025, "On approval of the list of vital and essential drugs, as well as lists of medicinal products for medical use and the minimum assortment of medicinal products required for the provision of medical care."

5. State Register of Medicines (as of April 3, 2026).

6. Order of the Ministry of Education of the Russian Federation No. 763 dated November 1, 2024, "On approval of the Regulations on the psychological, medical and pedagogical commission."

Appendix B. Physician Action Algorithms

Appendix C. Patient Information

Nystagmus is a term originating from the Greek word nustagmos, which means "nodding" and "drowsiness". It is a rhythmic involuntary oscillation of the eyeballs in various directions, for example, side to side or up and down.

The development of optical nystagmus is associated with various causes, including intrauterine developmental anomalies, heredity, congenital ophthalmological diseases, diseases affecting the brain or nervous system, traumatic brain injuries, vitamin deficiencies, and the use of certain medications. Congenital forms of nystagmus are more common.

In addition to oscillatory eye movements, optical nystagmus may be accompanied by strabismus, abnormal head posture (torticollis), head nodding, double vision or image oscillation in the eyes, reduced vision and hearing, dizziness, spatial disorientation, nausea, and other symptoms.

Treatment of optical nystagmus depends on the cause of its occurrence and may include spectacle or contact lens correction, spectral vision correction, drug therapy, prismatic correction, surgical treatment, and other methods.

Congenital optical nystagmus cannot be completely cured, but through a system of measures to improve visual functions in nystagmus, the quality of life of patients can be improved.

Appendix G. Assessment Scales, Questionnaires, and Other Evaluation Tools

Not used.