Strabismus in children

Definition: Strabismus is a constant or intermittent deviation of one of the eyes from the common point of fixation, characterized by impaired binocular vision. Strabismus manifests as an external defect – deviation of the eye/eyes toward the nose or temple, upward or downward [2,8].

Clinical classification [2,8]: By time of onset: congenital (infantile - present from birth or develops in the first 6 months of life); acquired.

By sign of stability of eye deviation: inconstant (intermittent); constant. By eye involvement: monolateral; alternating. Depending on direction of deviation: horizontal (esotropia, exotropia); vertical (hypertropia, hypotropia); torsional; mixed. Causes of occurrence: comitant (accommodative, partially accommodative, non-accommodative); incomitant (paralytic, non-paralytic); secondary (sensory, consecutive). Esotropia: Comitant esotropia 1) Accommodative Refractive (normal AC/A) Non-refractive (high AC/A) Mixed (Partially refractive (normal AC/A)) 2) Non-accommodative Essential infantile esotropia (begins in the first 6 months of life) Basic (simple, basic) esotropia Esotropia associated with increased convergence Esotropia associated with decreased divergence Esotropia combined with myopia Cyclic esotropia Acute-onset esotropia 3) Microesotropia 4) Nystagmus blockage syndrome Incomitant esotropia 1) Paralytic 2) Non-paralytic With A and V patterns Retraction syndromes Mechanically restrictive (congenital fibrosis of EOM, acquired restrictions resulting from trauma, myopathy, etc.) Secondary esotropia Sensory Consecutive Exotropia:

Comitant exotropia (may be constant or intermittent in nature): 1) Infantile (congenital) exotropia 2) Primary exotropia Divergence excess (deviation at distance greater than at near by 7° or more) Basic (basic) exotropia (deviation at distance and near are equal) Convergence insufficiency (deviation at distance less than at near by 7° or more) Pseudo divergence excess 3) Secondary exotropia: Sensory Consecutive Incomitant exotropia 1) Paralytic. 2) Non-paralytic (dissociated - isolated or with DVD, excyclotropia; others). CYCLOVERTICAL DEVIATIONS: Comitant vertical deviations Paretic vertical deviations Deviations with unilateral overaction of inferior oblique muscle DVD Combined vertical deviations SPECIAL FORMS OF STRABISMUS: Duane syndrome Brown syndrome Sagging eye syndrome Fixed strabismus Strabismus in high myopia EOM fibrosis Endocrine ophthalmopathy Acute orbital myositis Cyclic heterotropia Acquired motor fusion deficiency Orbital wall damage Ocular myasthenia Chronic progressive external ophthalmoplegia

List of main and additional diagnostic measures: 11.1 Main (mandatory) diagnostic measures performed at the outpatient level [3,4,5]: collection of disease and life history; (LE - C)[2,8,9,10]; determination of visual acuity without and with spectacle correction (LE - A)[2,8,9,10]; determination of the angle of strabismus without and with spectacle correction, at distance and near (cover test, cover-uncover test, compensation of refixation movements using a set of prismatic lenses, measurement of deviation angle by Hirschberg (°) or in prism diopters (∆)) in gaze positions straight ahead, right, left, up, down, right up, right down, left up, left down (LE - A)[2,8,9.10]; determination of motility and range of eye movements (LE - B)[2,8,9]; examination of convergence (LE - C)[2,8]; biomicroscopy (LE - C)[2,8,9,10]; ophthalmoscopy (direct, indirect) (LE - C)[2,8,9,10]; determination of objective refraction under cycloplegia (skiascopy or retinoscopy) (LE - A)[2,8,9.10].

Instrumental studies: determination of visual acuity without and with spectacle correction – visual acuity may be reduced/within age normal range (LE - A)[2,8,9,10]; in microtropia (monofixation syndrome) there is persistent reduction of visual acuity in one (squinting) eye. In the presence of amblyopia there is reduction of best corrected visual acuity of one or both eyes of varying degrees. determination of the angle of strabismus without and with spectacle correction, at distance and near (cover test, cover-uncover test, compensation of refixation movements using a set of prismatic lenses, measurement of deviation angle by Hirschberg (°) or in prism diopters (∆)) in gaze positions straight ahead, right, left, up, down, right up, right down, left up, left down – depending on the nature of strabismus there is constant or inconstant deviation of the eye from the common point of fixation (LE - A)[2,8,9]; in accommodative strabismus the angle of deviation is compensated (eye position is symmetrical) by adequate spectacle correction. determination of objective refraction under cycloplegia (skiascopy or retinoscopy) – presence or absence of refractive error (myopia, hypermetropia, astigmatism) (LE - B)[2,8,9.10]; determination of the nature of vision – impairment of binocular vision (LE B)[2,8,9];

In the forced head position, the binocular nature of vision is preserved.

traction test – a positive result means that passive eye movements are impeded, indicating the presence of mechanical restrictive strabismus (LE - B)[2,4,8]; After local anesthesia, the eye is fixed with two forceps at the conjunctiva near the limbus and rotated in the direction opposite to the suspected mechanical restriction. The traction test is necessary for differential diagnosis of the cause of strabismus: paralysis (paresis) of the EOM or mechanical restrictive condition of its antagonist (myositis, EOM contracture, conjunctival or Tenon's capsule contracture, etc.). It is important not to exert pressure on the eye.

Bielschowsky head tilt test - a symptom characteristic of paresis of the superior oblique muscle innervated by the trochlear nerve; the patient tries to keep the head tilted toward the healthy shoulder, forward and downward; if asked to tilt the head toward the paretic shoulder and backward, the strabismus becomes especially noticeable and diplopia becomes pronounced (LE - B)[2,4,8];

Parks three-step test – has diagnostic significance in trochlear nerve lesions (LE - B)[2,4,8]; First – assess which eye is hypertropic in primary position. Second – determine where the hypertropia is greater - on right gaze or left gaze. Third - Bielschowsky head tilt test - identify the paretic muscle.

Symptoms

CLINICAL PROTOCOL FOR DIAGNOSIS AND TREATMENT OF STRABISMUS IN CHILDREN

I. INTRODUCTORY PART 1. Protocol name: Strabismus in children

correlational studies and clinical case studies.

Evidence is based on clinical cases and examples

Grade A

Indications for hospitalization with indication of hospitalization type: Indications for planned hospitalization: presence of constant angle of strabismus, including that not compensated or insufficiently compensated by adequate spectacle correction; presence of pronounced asthenopic complaints in intermittent strabismus; presence of diplopia;

presence of forced head position (ocular torticollis, allows elimination of diplopia). Indications for emergency hospitalization: none

Complaints and medical history:

Complaints: abnormal eye position (LE - B)[2]; diplopia (LE - B)[2]; torticollis (LE - B)[2]; limitation of eye movement (LE - B)[2]; asthenopic complaints (headaches, sensation of eye fatigue, discomfort, pain, grittiness, burning in the eyes, veil before the eyes, frequent inflammation of the ocular surface, children frequently rub their eyes) (LE - B)[2]. Medical history: presence of concomitant and previously suffered diseases (eye diseases, general somatic diseases) (LE - C)[2,14]; presence of ocular or head trauma (LE - C)[2,14]; previously performed surgical interventions on the organ of vision (LE C)[2,14].

Differential diagnostic features

Orbital, periorbital neoplasm (dermoids, gliomas)

Orbital phlegmon

-rapidly progressive disease; -predominantly unilateral character; -often lateral displacement of the eyeball; -impaired reposition of the eyeball when pressing on the eye through closed eyelids; -change in refraction due to change in length of the axial axis of the eyeball and radius of corneal curvature; -trauma, influenza infection, inflammatory diseases in the paranasal sinuses play a role in the development of the process; -picture of chronic nonspecific inflammation, orbital pain, eyelid edema, chemosis, limitation of eyeball movement, diplopia, often increased intraocular pressure, exophthalmos. -often picture of congestive optic disc when the posterior part of the orbit is involved. -infectious inflammatory disease of the orbit; -rapid onset within 24-48 hours -often unilateral character; -acute intoxication syndrome (high temperature, headache, lethargy); -caused by general infections, local purulent eye diseases, purulent sinusitis, orbital trauma with tissue infection, foreign bodies; -pronounced pain with movement and palpation of the eyeball; -palpebral fissure is closed; -severe edema and redness of the eyelids.

Non-pharmacological treatment: general regimen; diet table No. 15 (in the absence of contraindications); adequate correction of ametropia with spectacles or contact lenses (LE A)[2,8,10] – is a mandatory condition in the treatment of strabismus, allows partial (partially accommodative strabismus) or complete (accommodative strabismus) elimination of the angle of deviation (eye position is symmetrical). pleoptic treatment (indicated in the presence of concomitant amblyopia – functional reduction of visual acuity) occlusion of the better eye or alternating occlusion (LE - A)[2,8,10]. orthoptic treatment (LE - C)[6,11,12]: development and training of binocular fusion reserves on synoptophore, using computer programs – conducted to restore the ability for bifoveal fusion, allows increase in fusion volume, helps develop stereovision before and after surgical treatment of strabismus; diploptic treatment (LE - C)[6,11,12]: on synoptophore, using computer programs – allows development of binocular and stereoscopic vision under natural conditions; prismatic correction for paralytic (paretic) strabismus (LE - B)[2,4,8] – is a method of pre-surgical treatment, performed to symptomatically eliminate diplopia and forced compensatory head position, especially effective in paralytic strabismus with small angle of deviation.

List of references used: 1) Kanski J. Jack Clinical Ophthalmology, Moscow, 2006. – pp.517-556 2) Guidelines for the Management of Strabismus in Childhood. The Royal College of Ophthalmologists, London, March 2012 3) Kenneth W. Wright Color atlas of strabismus surgery, USA, 2007 4) Plisov I.L. System of therapeutic and rehabilitation measures in patients with paralytic (paretic) strabismus. // Dissertation for the degree of Doctor of Medical Sciences, - Moscow, 2014, 255p. 5) T.A. Timoshenko, A.L. Shtilerman. Modern methods of amblyopia treatment in children. // Pacific Medical Journal, 2013, - No. 4, pp. 59–62. 6) Aznauryan. I.E. System for restoration of visual functions in refractive and dysbinocular amblyopia in children and adolescents: abstract of dissertation for Doctor of Medical Sciences. M., 2008. 24 p. 7) Pediatric Eye Disease Investigator Group. Treatment of severe amblyopia with atropine: results from two randomized clinical trials. J AAPOS 2009;13(3):258-63 8) Esotropia and exotropia. Preferred practice pattern. American Academy of Ophthalmology, USA, 2012, 44 p. 9) Pediatric Eye Evaluation. Preferred practice pattern Guidelines. San Francisco, CA: American Academy of Ophthalmology, 2012 10) Amblyopia. Preferred practice pattern Guidelines. San Francisco, CA: American Academy of Ophthalmology, 2012 11) Avetisov S.E., Kashchenko T.P., Shamshinova A.M. Visual functions and their correction in children. M.: Medicine. — 2005. - P. 85. 12) Kashchenko T.P. Problems of oculomotor and binocular pathology // Vestn. Ophthalmol. 2006. — No. 1. — P. 32-3

13) Aubakirova A.Zh. Vertical strabismus and methods for its treatment \\ Oftalmol Zh. 1990;(4):221-3.

14) David K. Coats, Scott E. Olitsky. Strabismus surgery and its complication. Berlin, 2007, p 318

Recommendations

Recommended by the Expert Council of the RSE on REM "Republican Center for Health Development" of the Ministry of Health and Social Development dated October 15, 2015, Protocol No. 12

Protocol code:

ICD-10 code(s) H 49 – Paralytic strabismus H 50.0 – Other forms of strabismus

Abbreviations used in the protocol USI – ultrasound investigation AP – anteroposterior size of the eyeball CBC – complete blood count UA – urinalysis ALT – alanine transaminase AST – aspartate transaminase ECG – electrocardiogram AC – accommodative convergence A – accommodation DVD – dissociated vertical deviation CT – computed tomography MRI – magnetic resonance imaging HIV – human immunodeficiency virus ELISA – enzyme-linked immunosorbent assay EOM – extraocular muscles

Date of protocol development/revision: 2015.

Patient category – children.

Protocol users – pediatricians, general pediatricians, neurologists, ophthalmologists.

II. METHODS, APPROACHES AND PROCEDURES FOR DIAGNOSIS AND TREATMENT

Assessment of the degree of evidence for the recommendations provided [6].

Evidence level scale Level Type of evidence І Evidence obtained from meta-analysis of a large number of well-designed randomized studies.

Randomized studies with low levels of false-positive and false-negative errors.

ІІ

Evidence based on results of at least one well-designed randomized study.

Randomized studies with high levels of false-positive and false-negative errors.

ІІІ

Evidence based on results of well- designed non-randomized studies.

Controlled studies with one patient group, studies with historical control group, etc.

ІV Evidence obtained from non-randomized studies. Indirect comparative, descriptive

В С

Gradation Level I evidence or consistent multiple level II data. Level II, III or IV evidence Level II, III or IV evidence considered generally consistent data Level II, III or IV evidence, but data generally inconsistent Weak or unsystematic empirical evidence.

Diagnostic criteria for diagnosis: [3,4,5,6]

Physical examination: General examination: presence or absence of forced head position (torticollis); presence of strabismus; facial asymmetry.

Laboratory investigations: non-specific.

Differential diagnosis

Table No. 1. Differential diagnosis of strabismus in children.

Nosology

Treatment goals: symmetric or near-symmetric eye position; correction of forced head position (ocular torticollis); formation of binocular vision; achievement of maximally high and stable visual acuity.

Treatment tactics: [3,6,7,8] Given the great diversity of strabismus by nature, degree of visual

function impairment, sensory and motor disorders, there is no single treatment regimen.

Treatment of strabismus in children is comprehensive (EL - A)[2,5,8,9,10]. The main objectives and stages of treatment for strabismus in children are:

prevention of complications that hinder complete cure of strabismus: severe amblyopia with abnormal fixation, abnormal retinal correspondence (EL - B)[2,8,9,10]; achievement of maximally high visual acuity in both eyes (EL A)[2,8,9,10]; establishment of symmetric position of the eyeballs (EL - A)[2,8,9]; restoration of binocular and stereoscopic vision and all impaired monocular and binocular visual functions (EL - A)[2,8,9]. In the presence of infantile strabismus, early surgical treatment is indicated (before age 2 years) because this type of strabismus is characterized by gross impairment of stereopsis, which is critical for its subsequent restoration (EL B)[2, 8].

Pharmacological treatment: In the postoperative period for prevention of infectious complications: Antibacterial eye drops: tobramycin 0.3%, 5 ml – 1-2 drops 4-6 times daily for 7-14 days (EL - B)[14]; or levofloxacin 5.12mg, 5ml – 1-2 drops 4-6 times daily for 7-14 days (EL B)[14];

or moxifloxacin 0.5% 3-5ml – 1-2 drops 5 times daily for 7-14 days (EL A)[14]; or ofloxacin 0.3%, eye ointment – apply to lower eyelid 2 times daily for 7-14 days (EL - B)[14]; Anti-inflammatory eye drops: Corticosteroid agents: dexamethasone 0.1% 5.0ml – 1-2 drops 3-6 times daily for 7-14 days (EL - C)[14]. Non-steroidal anti-inflammatory drugs: diclofenac sodium 5.0ml – 1-2 drops 4 times daily for 7-14 days (EL -C)[14]; or nepafenac 0.1% 5.0 – 1 drop 3 times daily (EL - B)[14]. Combination preparations: tobramycin + dexamethasone 0.1%, 5.0ml – 1-2 drops 4-6 times daily for 7-14 days (EL - B)[14]; or gentamicin + dexamethasone 5.0ml – 1-2 drops 4-6 times daily for 7-14 days (EL - B)[14]. Moisturizing ophthalmic preparations (for moisturizing and care of the eye surface after surgical interventions): dexpanthenol 5%, eye gel, 5-10g – 1 drop 4 times daily for 5-7 days (EL - C)[14];

Other types of treatment: Pharmacological penalization (EL -A) [2,7,10]: Pharmacological penalization involves exclusion of the better-seeing eye from the act of vision by instillation of short/long-acting mydriatics to achieve paralysis of accommodation. Pharmacological penalization is indicated for mild to moderate amblyopia, most effective when there are no serious sensory disturbances in the visual system yet.

Preventive measures: timely scheduled examination of children at designated times; timely and adequate correction of refractive anomalies.

Treatment effectiveness indicators: improvement in visual acuity; reduction in strabismus magnitude, correct or near-correct (no more than 5° by Hirschberg) eye position (orthotropia); presence of binocular vision.

III. ORGANIZATIONAL ASPECTS OF PROTOCOL IMPLEMENTATION 16. List of protocol developers: 1) Tuletova Aigerim Serikbaevna – Candidate of Medical Sciences, Head of the Pediatric Department of the branch of JSC "Kazakh Research Institute of Eye Diseases" (Astana). 2) Bakhytbek Raushan Bakhytbekovna – ophthalmologist of the Pediatric Department of JSC "Kazakh Research Institute of Eye Diseases" (Almaty). 3) Mun Galina Anatolyevna – Head of City Polyclinic No. 6, Astana. 4) Zhusupova Gulnara Darigerovna – Candidate of Medical Sciences, Associate Professor of the Department of Pharmacology of JSC "Astana Medical University".

Reviewer: Shusterov Yuri Arkadyevich – Doctor of Medical Sciences, Head of the Department of Ophthalmology of RSE on REM "Karaganda State Medical University".

Conditions for protocol revision: Revision of the protocol 3 years after its publication and from the date of its entry into force or in the presence of new methods with evidence level.

When to see a doctor

Additional diagnostic examinations performed at the outpatient level:

autorefractokeratometry (LE - C)[2,8,9,10]; - determination of the nature of vision (Bagolini test, 4-dot test, stereoscopic vision) (LE - C)[2,8]; - Bielschowsky head tilt test (LE - C)[2,8]; - Parks three-step test (LE - C)[2,8]; - determination of objective and subjective angle of strabismus (LE - C)[6,12]; - traction test (as indicated) (LE - B)[2,4,8]; - A-scan (echobiometry) (as indicated) (LE - C)[9]; - B-scan of the eye, adnexa, orbit (as indicated) (LE - C)[9]; - CT or MRI of the brain and orbit without/with contrast administration (as indicated) (LE - C)[2,8,9].

Minimum list of examinations required when referring for planned hospitalization:

according to the internal regulations of the hospital, taking into account the current order of the authorized body in the field of healthcare[14].

Indications for specialist consultations:

neurologist consultation – in the presence of concomitant CNS pathology (LE - B)[2,8]; - ENT consultation – in the presence of concomitant diseases of the paranasal sinuses, oral cavity and teeth (LE - B)[2,8]; - pediatrician consultation – in the presence of concomitant somatic diseases (LE - B)[2,8].

Surgical intervention (name of operation, indications and contraindications and operation code according to KZG):

Considering the variety of strabismus by nature and degree of sensory and motor disorders, there is no single scheme for surgical treatment of strabismus. Operations for strabismus are divided into: Weakening the action of EOM: - tenotomy (LE - B)[2,3,8,14]; - myotomy (LE - C)[2,3,8,14]; - recession (LE - A)[2,3,8,14]; - lengthening (LE - C)[2,3,8,14]; - transposition (LE - B)[2,3,8,14]; - chemodenervation (LE - B)[2,3,8,14]; - faden operation (LE - C)[2,3,8,14]. Strengthening the action of EOM: - resection (LE - A)[2,3,8,14]; - transposition (LE - B)[2,3,8,14]; - fold formation (LE - C)[2,3,8,14].

Indications for surgical treatment:

Strabismus, in the presence of:

constant angle of deviation, including that not compensated or insufficiently compensated by adequate spectacle correction;
pronounced asthenopic complaints in intermittent strabismus;
presence of diplopia;
presence of forced head position.

Contraindications to surgical treatment:

general somatic diseases in which there are contraindications to anesthetic management.

Further management:

within 2 weeks to 1 month after surgery, instillation of antibacterial and anti-inflammatory drugs; - in the presence of concomitant disease, monitoring by a specialist; - scheduled follow-up with an ophthalmologist (monitoring of visual acuity, refraction, eye position, nature of vision); - adherence to appropriate therapeutic and protective regimen as indicated.

This information is for educational purposes only and does not replace a consultation with an ophthalmologist.