Congenital Cataract: Clinical Guidelines

List of Abbreviations

ICD-10 – International Statistical Classification of Diseases and Related Health Problems (10th Revision)

APD – anteroposterior diameter of the eyeball

PHPV – primary persistent hyperplastic primary vitreous

US – ultrasound examination

IOL* – posterior chamber intraocular lens, pseudophakic***

Sign* – the recommendation applies to a medical device implanted into the human body during the provision of medical care under the state guarantee program for free medical care for citizens (List of medical devices implanted into the human body during the provision of medical care under the state guarantee program for free medical care for citizens, approved by Order of the Government of the Russian Federation No. 3053-r dated December 31, 2018).

Terms and Definitions

Congenital cataract is a partial or complete opacification of the eye lens, which is detected both in newborns and at a later age.

Aphakia is a pathological condition of the visual organ characterized by the absence of the lens in the eyeball of congenital or acquired origin, accompanied by refractive errors, decreased visual acuity, and loss of accommodation. In ophthalmology, an eye without a lens is referred to as aphakic.

Pseudophakia is a condition of the eye in which an artificial lens, the so-called intraocular lens (IOL), has been implanted during surgery. In ophthalmology, an eye with an implanted intraocular lens is referred to as pseudophakic.

Biomicroscopy is a method of examining the anterior segment of the eye using a slit lamp (a specialized microscope) under drug-induced mydriasis, with a focus on the state of the lens.

Galactosemia is a carbohydrate metabolism disorder characterized by altered synthesis of the enzyme galactose-1-phosphate uridyltransferase found in erythrocytes and the lens.

Intraocular lens (IOL)* is an artificial lens implanted inside the eye to restore its light-refracting function after surgical removal of the native anatomical lens, primarily for cataracts and a number of other diseases.

Microphthalmia is one of the frequent forms of concomitant visual pathology in congenital cataracts, characterized by a reduced eyeball size, various anomalies, and functional inferiority of the eye.

Microcornea is one of the frequent forms of concomitant visual pathology in congenital cataracts, characterized by a reduction in corneal diameter by 1 mm or more.

Phacoaspiration is a method of removing soft lens matter without the use of ultrasound.

1. Brief information on the disease or condition

1.1 Definition of the disease or condition

Congenital cataract is a partial or complete opacification of the eye lens, detected both in newborns and at a later age [1-4].

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

CCs are characterized by pronounced etiologic polymorphism [1-5].

Etiologic diagnosis of CC is based on a thorough history taking (maternal condition and diseases during pregnancy) and the results of immunological and virological studies.

Non-hereditary (intrauterine) cataract.

In a large number of cases (66.9%), CCs develop as a result of intrauterine pathology due to the influence of various adverse external and internal environmental factors (physical, chemical, biological) on the visual organ and the lens of the embryo or fetus. These may include various intoxications (alcohol, contraceptives and abortifacients, a number of sleeping pills and many other drugs), ionizing radiation, avitaminosis (deficiency of vitamin A, B, and others), maternal-fetal Rhesus incompatibility, and a number of other factors. Maternal diseases, such as cardiovascular, endocrine, and others, can also cause CC development.

Infectious diseases of the pregnant woman caused by bacteria, protozoa (toxoplasmosis), and viruses are of particular importance. Most viruses (pathogens of rubella, cytomegalovirus infection, chickenpox, herpes, influenza) are capable of crossing the placental barrier and infecting the embryo or fetus, causing CC and other anomalies. The most vulnerable period for teratogenic factors affecting the visual organ is the 2nd–7th week of pregnancy.

Hereditary cataract

The cause of hereditary cataract can be gene, chromosomal, and genomic mutations. Cataracts are most commonly inherited in an autosomal dominant manner, although autosomal recessive transmission is also possible, which is more common in consanguineous marriages.

With recessive X-linked inheritance, males are affected, while females are carriers. X-linked dominant inheritance is less common, where the disease manifests only in females.

Cataract in hereditary metabolic disorders

Among hereditary cataracts, a significant proportion consists of lens opacities genetically caused by metabolic disorders. CC occurs in disorders of carbohydrate metabolism (galactosemia, hypoglycemia, diabetes mellitus), connective tissue metabolism (Marfan, Marchesani, Ehlers-Danlos syndrome, congenital chondrodystrophy, Apert, Conradi-Hünermann syndromes), sulfur amino acid metabolism (homocystinuria), mineral metabolism (pseudohypoparathyroidism), tryptophan metabolism (Knapp-Comrover syndrome), lipid metabolism (Bassen-Kornzweig syndrome), and phosphorus-calcium metabolism (Lowe syndrome). Lens opacification is also part of syndromes involving other organs and tissues where the metabolic defect remains unidentified (Rothmund syndrome, congenital ichthyosis, Schäfer syndrome, pigmented dermal infantilism - Bloch-Sulzberger syndrome, Sabourin, Andogsky syndromes).

Cataracts developing against the background of systemic pathology can be congenital or early acquired, appearing at various times after birth (from several weeks to several years).

1.3 Epidemiology of the Disease or Condition

Congenital cataract (CC) is estimated to occur in 1.91 to 4.24 per 10,000 population, according to various studies. In the Russian Federation, CC is one of the frequent causes of blindness and low vision in children, accounting for 17.3% of the structure of childhood visual disability [6]. The prevalence of this disease varies across regions of the Russian Federation. According to L.A. Katargina and L.A. Mikhailova, the average detection rate of cataracts in Russia is 29.7 per 100,000 population [7].

1.4 Features of Coding the Disease or Condition

ICD-10 Coding

Q12.0 – Congenital cataract

H27.0 – Aphakia

1.5 Classification of the disease or condition

These clinical guidelines present the classification by A.V. Khvatova [1] with additions by T.B. Kruglova and A.V. Khvatova [8] (Table 1).

Table 1. Classification of congenital cataracts (etiology, clinical presentation, surgical tactics)

1.6 Clinical presentation of the disease or condition

Congenital cataract (CC) is a partial or complete opacity of the lens of the eye that develops intrauterinely. The main symptom of CC is lens opacity of varying severity, manifesting from the moment of the child's birth. The clinical presentation ranges from a barely noticeable white spot in the pupillary area to a completely opaque lens ("gray pupil"). In some cases, in progressive forms of CC, this sign may be absent and appear at a later date. Nystagmus and strabismus appear in children with CC after the sensitive period ends. Before this age, children with CC exhibit wandering eye movements. Early surgeries prevent the development of nystagmus in bilateral CC. Almost all children with bilateral CC exhibit nystagmus—rhythmic shaking of the eyeball. In unilateral CC, strabismus is frequently observed, usually convergent. CC is characterized by decreased vision or complete loss thereof. The child does not fixate on an object or turns their healthy eye toward it.

2. Diagnostics, medical indications and contraindications for diagnostic methods

Early detection of CC and, in the presence of indications, timely surgical intervention within established timeframes are critically important to increase the efficacy of treatment for this pathology.

An ophthalmologist verifies the condition according to ICD-10 criteria based on anamnestic data, patient examination, assessment of the clinical picture, and additional examination methods.

The clinical presentation is the basis for diagnosing CC. The symptoms and clinical signs specified in clause 1.6 are the clinical criteria for establishing this disease.

2.1 Complaints and Anamnesis

CC is relatively rare as an isolated lesion of the visual system.

• All patients with congenital cataracts and suspected of having this condition are recommended to collect medical history and complaints [1,2,3,4,5,9], during which it should be ascertained:

- time of detection of CC in the child;

- presence or absence of CC in relatives;

- course of pregnancy and childbirth in the mother.

When taking a history from the parents (in young children) and the patient, it is recommended to pay attention to symptoms related to the clinical presentation:

- opacity in the pupillary area (gray pupil);

- strabismus;

- nystagmus (the child's eyes dart without apparent cause);

- decreased vision (can be detected in older children).

GCR CLEL 5Grade of Recommendation C (Level of Evidence - 5)

Comments: for the early diagnosis of congenital cataract, continuity of care between obstetrician-gynecologists, neonatologists, pediatricians, and ophthalmologists is crucial.

2.2 Physical Examination

• At the diagnostic stage in children with congenital cataracts and suspected congenital cataracts, it is recommended to:

- perform an external examination of the patient to rule out syndromic pathology and perform a differential diagnosis with other eye diseases [1,2,3,4,5,9].

GCR CLEL 5Grade of Recommendation C (Level of Evidence - 5)

- perform an ophthalmological visual inspection to visually assess the eye and its adnexa [1,2,3,4,5,10].

GCR CLEL 5Grade of Recommendation C (Level of Evidence - 5)

Comments: the ophthalmological examination includes the following procedures:

- visual inspection of the eye and its adnexa, including inspection of the eyelids and tear ducts, assessment of the position of the eyeballs, examination of the pupils and their reaction to light;

- visometry — determination of distance visual acuity; in children under three years of age, this is performed approximately — determining whether the child has object vision.

More accurate measurement is possible using the preferential looking test, methods of recording optokinetic nystagmus and visual evoked potentials; in older patients, visometry is performed using charts with pictures, letters, numbers, or other symbols, and the patient names the objects pointed to by the ophthalmologist. The visual acuity score is taken as the chart row in which all symbols are correctly recognized.

Visual acuity is determined first without correction, and then, if impairments are present, with correction (using a special trial frame and lenses).

Decreased vision is an important symptom in the diagnosis of eye diseases.

2.3 Laboratory Diagnostics

Specific laboratory diagnostics for congenital cataracts are not used.

• Before hospitalization, all patients are recommended to undergo laboratory tests, including: complete blood count and urinalysis with leukocyte formula calculation, and general general-practice blood chemistry [3].

GCR CLOE 5Grade of Recommendation C (level of evidence - 5)

Comments: these tests are performed to diagnose general pathology, identify a particular syndrome of which a cataract may be one of the manifestations, and identify contraindications to surgery (detection and sanitation of chronic infection foci and decompensation of general diseases), as they may subsequently complicate the postoperative period.

2.4 Instrumental Diagnostics

• At the diagnostic stage, all patients with congenital cataracts and suspected congenital cataracts are recommended to undergo:

– biomicroscopy of the anterior segment of the eye (A03.26.001) — external examination of the eye using a slit lamp under miosis and drug-induced mydriasis to assess the condition of the eye [1,2,3,4,5];

GCR CLEL 5Grade of Recommendation C (Level of Evidence - 5)

Comments: using biomicroscopy, the ophthalmologist can examine such eye tissues as the conjunctiva, cornea, and deeper structures such as the iris, lens, and vitreous body at high magnification.

– ophthalmoscopy of the fundus (A02.26.003) under miosis and drug-induced mydriasis to clarify the localization, degree, and form of lens opacity, as well as to examine the condition of the vitreous body, optic disc, central and peripheral retina to assess the condition of the eye, and in cases of partial opacity, to determine the timing of surgical intervention [1,2,3,4,5];

GCR CLEL 5Grade of Recommendation C (Level of Evidence - 5)

Comments: the procedure is performed non-contact, using a special device—an ophthalmoscope with/without a lens; it allows the doctor to see the fundus (internal surface of the eye) – the retina and blood vessels.

– ophthalmotonometry (A02.26.015) — measurement of intraocular pressure (IOP) using a pneumatic or applanation tonometer to assess baseline intraocular pressure [1,2,3,4,5].

GCR CLEL 5Grade of Recommendation C (Level of Evidence - 5)

Comments: can be performed by several methods (using a pneumatic tonometer, weights (Maklakov tonometry), palpation, etc.).

• In cases of partial lens opacities, it is recommended to perform autorefractometry (A12.26.016) and/or skiascopy to determine clinical refraction [1,2,3,4,5].

GCR CLEL 5Grade of Recommendation C (Level of Evidence - 5)

Comments: the procedure is currently performed using automated refractometers.

Functional outcomes of treatment in children with congenital cataracts largely depend on early detection and timely surgical treatment (according to indications).

If lens pathology is detected, such a child must be referred to a hospital for a more detailed examination under general anesthesia (including biomicroscopy (A03.26.001), keratometry, ultrasound examinations (eye biometry (A-scan or echobiometry (A04.26.004), B-scan (A04.26.002), spatial biomicroscopy (A04.26.007)) and electrophysiological studies (general electroretinography (A05.26.001), recording of rhythmic electroretinogram complex (expanded study (A05.26.001.003)), recording of visual evoked potentials of the cerebral cortex (A05.26.002)), autorefractorkeratometry (A12.26.016), determination of the functional state of the eye, and further treatment tactics.

2.5 Other Procedures

Other diagnostic examinations are not performed in patients with congenital cataracts and suspected congenital cataracts.

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

3.1 Conservative Treatment

In cases of minor lens opacities (partial forms of congenital cataracts) that do not require early cataract extraction, the child should be monitored by an ophthalmologist.

• In unilateral congenital cataracts, for the prevention and treatment of amblyopia, it is recommended to occlude the healthy eye for half of the child's waking period [1,2,3,4,5,11].

GCR CLEL 5Grade of Recommendation C (Level of Evidence - 5)

3.2 Surgical Treatment

The main factor in determining the timing of surgical intervention for both bilateral and unilateral cataracts is the severity of lens opacities, determined by the form of congenital cataracts, which affects the development of the child's visual functions during the sensitive period.

Comments: the timing of the procedure is determined by anesthesia availability and the clinical form of congenital cataracts. If there are contraindications to repeated anesthesia in the early period, surgical intervention on the fellow eye is postponed for 1–2 months. In unilateral congenital cataracts, surgical treatment should be performed as early as possible, followed by pleoptorthoptic treatment due to the highest risk of developing severe deprivation amblyopia.

Comments: early surgeries are recommended for all forms of congenital cataracts that disrupt binocular vision development and cause moderate to severe form of stimulus-deprivation amblyopia:

- zonular forms of congenital cataracts of II–III degree lens opacity intensity;

- nuclear and anterior polar congenital cataracts with an opacity diameter of 2.5 mm or more;

- posterior polar congenital cataracts with moderate to high intensity;

- opacities;

- atypical congenital cataracts characterized by a sharp weakening or absence of the fundus reflex, where ophthalmoscopy is impossible or only peripheral areas of the fundus are visible.

Comments: these forms of congenital cataracts include: zonular congenital cataracts of grade 1 lens opacity intensity, nuclear, anterior-posterior capsular forms with an opacity diameter of less than 2.5 mm, in which retinoscopy is possible through the lens opacity disc.

Surgical treatment of congenital cataracts in infants is performed under general anesthesia. Modern congenital cataract surgery technology includes:

- Tunneled corneal or corneoscleral microincisions followed by suture fixation of the main incision, performing paracenteses at 3 and 9 o'clock;

- The use of modern viscoelastics to protect the corneal endothelium;

- The use of differentiated anterior capsulorhexis techniques;

- Instrumental or manual aspiration and irrigation of lens masses;

- Endocapsular implantation of flexible acrylic IOLs.

Comments: to achieve mydriasis on the day of surgery, mydriatic drops with different mechanisms of action (m-cholinolytics (S01FA) and sympathomimetics (S01FB)) and nonsteroidal anti-inflammatory drugs (S01BC) are instilled into the eye fractionally (over the course of 1 hour every 10 minutes).

Features of anterior capsulorhexis performance: the most important stage of the operation is performing the anterior capsulorhexis, the difficulty of which in children, especially in the first years of life, is due to the age-related features of the eyeball and the large clinical polymorphism of the anterior capsule. It is not technically possible to perform a traditionally executed continuous circular anterior capsulorhexis in adults for all forms of congenital cataracts in children. Taking into account the clinical picture, differentiated techniques of anterior capsulorhexis are used. Capsulorhexis using a YAG laser and a femtosecond laser is possible.

Comments: when removing lens masses, the clinical picture of lens opacity, its shape, and the presence of concomitant ocular pathology are evaluated. Pediatric cataracts are generally of soft consistency, which does not require fragmentation. However, in atypical congenital cataracts, there are dense calcifications in the thickness of the cloudy lens, and in membranous cataracts, a strong fibrous capsule, which require removal using various instruments.

Comments: the advisability of opening the transparent posterior capsule during congenital cataract surgery remains debatable, as the risk of postoperative complications increases, and the possibility of spontaneous closure of the posterior capsulorhexis and the development of secondary cataract even when performing anterior vitrectomy has already been proven. Microsurgical tactics are determined by the clinical picture of the posterior lens capsule.

• If IOL implantation is not planned for a young child, it is recommended to perform a posterior capsulectomy with a diameter of 3–3.5 mm in combination with the formation of an optical window in the anterior hyaloid membrane and a limited anterior vitrectomy [1,2,3,4,12,13,19,20].

LeR CLoE 4Level of Recommendation C (Level of Evidence — 4)

Comments: this serves as a reliable method for preventing secondary cataract.

• In the presence of "calcifications" on the posterior lens capsule, in order to achieve transparency of the preserved posterior capsule and reduce the risk of postoperative complications, it is recommended to remove them using 23G spring-action forceps followed by polishing the capsule with the aspiration and irrigation tip of the surgical unit [1,2,3,4,12,13,19,20].

LeR CLoE 4Level of Recommendation C (Level of Evidence — 4)

Comments: "congenital fibrosis" of the posterior lens capsule most often manifests as a localized central opacity in the form of a "plaquelike" opacity on the posterior capsule, or fibrosis of the capsule itself. If posterior lens capsule opacity is detected during surgery, it should be removed while preserving the remnants of the transparent capsule. The "plaque" on the posterior capsule can be removed with spring-action forceps. Occasionally, it is even possible to do this without damaging the integrity of the posterior capsule. Minor fibrous opacities remaining after surgical manipulations are subsequently removed by opening the posterior capsule using a YAG laser 1–2 months after surgery. In the case of opacity of the capsule itself, it is removed by performing a posterior capsulorhexis with spring-action forceps or using a vitrectome, followed by mandatory anterior vitrectomy. Anterior vitrectomy should also be performed in case of spontaneous damage to the posterior lens capsule during cataract removal.

Optical correction of aphakia

Primary intraocular correction

In order to create optimal visual conditions for aphakia after congenital cataract removal, one should strive for full correction of the ametropia. Despite the fact that modern ophthalmology has a wide range of methods for correcting aphakia: glasses, contact lenses, and intraocular lenses, the question of choosing the optimal method for correcting aphakia in young children continues to be debated.

Primary and secondary IOL implantation are possible, the indications for which are determined by the clinical and anatomical features of the lens and the child's eye.

Primary intraocular correction

Comments: primary intraocular correction (A16.26.093.002) is the optimal method for correcting aphakia in children with congenital cataracts, creating conditions closest to natural ones, which is of great importance for the normal physiological development of the child's eye.

Comments: during primary implantation, it is recommended to place the IOL in the capsular bag. In case of severe congenital pathology or disruption of the integrity of the anterior and/or posterior lens capsule during surgery, IOL implantation can be performed in the posterior chamber of the eye with sulcus fixation [3,4,13,19,20,21,22].

• Phacoaspiration with IOL implantation (A16.26.093.002) in young children, as a method of aphakia correction, is recommended in the presence of certain anatomical and topographical parameters of the child's eye [3,4,13,19,20,21,22]:

1) corneal diameter of 9.5 x 10.0 mm or more;

2) with normal axial length (AL) or reduced by no more than 2.0 mm compared to the age norm;

3) absence of gross concomitant ocular pathology (presence of elongated ciliary body processes occupying less than ¼ of the posterior chamber of the eye);

4) absence of gross neurological pathology that precludes functional visual rehabilitation.

LeR CLoE 4Level of Recommendation C (Level of Evidence — 4)

• Phacoaspiration with IOL implantation (A16.26.093.002) in infants is not recommended in the presence of [3,4,13,19,20,21,22]:

1) significant reduction in the volume of the posterior chamber and capsular bag in eyes with a corneal diameter of 9.0 x 9.5 mm or less;

2) reduction in the axial length of the eye from the age norm by more than 2.0 mm;

3) concomitant ocular pathology in the form of elongated ciliary body processes fused with the anterior lens capsule in persistent fetal vasculature (PFV) syndrome, occupying a significant part of the posterior chamber of the eye.

LeR CLoE 4Level of Recommendation C (Level of Evidence — 4)

Comments: the advent in recent years of flexible IOL models implanted in adult patients has made it possible to perform implantation through small incisions, significantly reducing surgical trauma, while the fundamentally new chemical composition of the lens, consisting of a higher quality, inert material biologically compatible with ocular tissues (hydrophobic acrylic), has allowed IOL implantation in infants of the first months of life. However, if the anatomical and topographical parameters of the eye in young children do not match the sizes of commercially available IOL models, an individualized approach is required, and the surgeon must make the final decision regarding the feasibility of IOL implantation during surgery. Relative contraindications to IOL implantation in infants after congenital cataract removal include: the presence of a persistent vascular sheath of the lens, hyaline membranes and membranes on the iris, and pupillary membranes requiring additional reconstructive interventions (if mild, IOL implantation is possible).

IOL Calculation

Comments: the calculation of IOL optical power is mainly performed using the SRK/T formula, which takes into account the sagittal size of the eyeball (AL), corneal refractive power, and individual constants of the chosen IOL model, as well as Barrett Universal II (Barrett), Hoffer Q, and Holladay I, depending on the child's age. When calculating the optical power of the implanted IOL in children of the first year of life, the degree of undercorrection (from +4.0 D to +14.0 D) of the formula-calculated IOL power is determined, taking into account the corneal optical power and the difference between the initial AL and the predicted AL after the completion of physiological eye growth.

• If primary IOL implantation is not performed in a child, correction of aphakia with glasses or contact lenses is recommended [1,2,3,4,12,13,19,20].

GCR CLEL 5Grade of Recommendation C (Level of Evidence - 5)

Comments: see Section 4. "Medical rehabilitation and sanatorium-resort treatment, medical indications and contraindications for the use of medical rehabilitation methods, including those based on natural healing factors".

• Considering the restless behavior of the child in the postoperative period of cataract extraction in infancy, it is recommended to ensure reliable wound closure with mandatory suture fixation [1,2,3,4,12,13,19,20].

LeR CLoE 4Level of Recommendation C (Level of Evidence — 4)

Comments: the use of modern minimally invasive technologies for congenital cataract extraction allows for faster postoperative recovery, which proceeds with virtually no noticeable inflammatory manifestations.

To prevent endophthalmitis and the development of inflammation at the end of surgery, instillations of an antimicrobial agent (S01A) and subconjunctival injections of an antimicrobial agent (S01A) combined with an anti-inflammatory agent (S01B) are used.

In accordance with the formulary system of the Federal Drug Guide, instillations of various antibacterial (S01A), nonsteroidal, and glucocorticosteroid (S01B) anti-inflammatory drugs, including combination drugs, are used in the postoperative period, depending on the age of the children at the time of surgery.

To prevent the formation of posterior synechiae, instillation of a short-acting mydriatic (S01FA) 2-3 times a day is effective. In case of posterior synechiae formation or fibrin appearance in the anterior chamber in the early postoperative period, fibrinolytic and collagenolytic drugs (B01AD) are used as subconjunctival injections and electro- (A17.26.001) or magnetophoresis (A17.30.040). Upon discharge from the hospital, outpatient follow-up treatment for 1.5 months is recommended with a gradual reduction in the frequency of instillation of combination drugs.

4. Medical Rehabilitation and Sanatorium-Resort Treatment

• In the treatment of congenital cataracts in children, in addition to surgery followed by medical therapy, it is recommended to include a set of measures aimed at creating optimal conditions for visual development [1,2,3,4,9,23]:

  • optical correction of aphakia (secondary correction of pseudophakia), including spectacles and contact lens correction, is recommended for all patients;

  • timely and high-quality pleoptics and orthoptics treatment;

  • elimination of strabismus, treatment of nystagmus;

  • detection and treatment of complications (secondary cataract, secondary glaucoma, iridocyclitis, IOL dislocation, and others).

GCR CLEL 5Grade of Recommendation C (Level of Evidence - 5)

Comments: functional treatment aimed at combating amblyopia through ametropia correction and pleoptics is important.

Spectacle Correction

• Glasses are recommended for the correction of bilateral aphakia and in cases requiring additional refractive correction in pseudophakic children after IOL implantation [3,4,5,9,13,14,15,19,20,21,22,23,24,25].

GCR CLEL 5Grade of Recommendation C (Level of Evidence - 5)

Comments: glasses are prescribed to children based on objective refraction data with subjective verification of tolerance in older children (after 4-5 years of age). In children under 3-4 years of age, one has to rely solely on objective data.

To create the most favorable conditions for visual development, one should strive for complete correction of aphakia. Therefore, optimal correction corresponds to the degree of refractive error according to data obtained by retinoscopy (skiascopy) or keratorefractometry. Astigmatism should be corrected completely or nearly completely.

Since refraction frequently changes in the first 3-4 months after surgery, mainly due to axial length growth in infants as well as corneal astigmatism, it becomes necessary to re-evaluate it during this period and make adjustments to the lens power. Thereafter, refraction assessment and refinement of spectacle correction should be performed annually.

Due to the lack of accommodation, in addition to distance correction, near-vision glasses must be prescribed at the time of hospital discharge. They are typically +2.0 to +3.0 diopters stronger than the distance lenses. It should be borne in mind that near-vision glasses must be prescribed not only to school-age children, but also to preschoolers and even toddlers.

In cases of unilateral aphakia with a second, healthy eye, spectacle correction cannot be used due to high aniseikonia (25-35%). However, if other types of correction are unavailable, these children should be prescribed glasses to train the operated eye for the prevention and treatment of amblyopia for 1-2 hours a day or longer with simultaneous occlusion of the healthy eye.

When implanting IOLs in infants and young children, spectacle overcorrection of residual ametropia for distance and near is necessary.

Correction of Aphakia with Contact Lenses

• Contact lenses are recommended both for the correction of aphakia and for additional correction of residual ametropia in pseudophakic eyes [3,4,5,9,21,23,24,25].

GCR CLEL 5Grade of Recommendation C (Level of Evidence - 5)

Comments: Considering the infant and young age of the patients, soft contact lenses made of silicone hydrogel materials or high-hydrophilic hydrogels with a high Dk/t are prescribed. Their advantage is that they form a single optical system with the eye. Contact lenses are used for both unilateral and bilateral aphakia. In the majority of patients with unilateral aphakia, restoration of binocular vision can be achieved. Patients tolerate soft contact lenses better, and they can be prescribed shortly after surgery. However, contact lenses are expensive, require regular replacement and ophthalmological follow-up, and demand immense patience and motivation from parents for the daily insertion and removal procedure. It should be borne in mind that in some cases contact lens intolerance may occur, and there is also a risk of corneal damage, toxic-allergic and hypoxic reactions, and infectious complications.

Pleoptics and orthoptics treatment

• All children are recommended regular courses (2 times a year) of pleoptic and orthoptic treatment (laser pleoptics, training exercises, modern methods—video-computer autogenic training, "Visotronic", transcutaneous electrical stimulation of the optic nerve (A17.26.003), magnetotherapy (A17.26.002), bioresonance treatment using endogenous and exogenous electromagnetic fields, color stimulation, monochrome color therapy, EHF biotherapy, etc.) [3,4,5,23,24].

GGR CLEL 5Grade of Recommendations C (Level of Evidence - 5)

Comments: in the absence of systematic treatment for amblyopia in bilateral aphakia, the vision of one of the eyes may decrease due to the fact that a large number of children use the single, better-seeing eye. Restoration of binocular vision is possible after the removal of bilateral congenital lamellar and progressive cataracts. Therefore, alongside pleoptic treatment, orthoptic treatment should be carried out, the indications for which are: 1) visual acuity not lower than 0.2–0.3 in the worse-seeing eye; 2) absence of pronounced nystagmus.

Surgical correction of strabismus and treatment of nystagmus

• If children have strabismus and nystagmus, it is recommended to perform their surgical correction (extraocular muscle resection (A16.26.030), recession, tenorrhaphy of the extraocular muscle (A16.26.031)) [3,4,5,9,23,24,26].

GCR CLEL 5Grade of Recommendation C (Level of Evidence - 5)

Comments: surgical treatment of strabismus in children with aphakia after congenital cataract extraction pursues two goals:

1) changing the position of the eye to create more favorable conditions for pleoptic treatment;

2) elimination of the cosmetic defect. Due to the possibility of complications developing in the long-term follow-up period after congenital cataract extraction, surgical treatment of strabismus should be undertaken no earlier than 1–2 years after the optical surgery. As a result of strabismus surgery, a reduction in nystagmus is often observed, which also has a favorable effect on visual acuity.

Detection and treatment of complications

Complications may be detected both in the first years after surgery and in subsequent years of life.

Comments: during the examination, the anterior segment of the eye is assessed (with special attention to the pupil area, vitreous body, fundus, and intraocular pressure). If necessary, additional examination methods are used (echobiometry, electroretinography). If complications are detected (iritis and iridocyclitis, secondary cataract, secondary glaucoma, IOL dislocation and its haptic elements, etc.), they are timely identified and referred, as indicated, to a hospital for treatment of complications in accordance with the clinical guidelines relevant to each disease.

Comments: sanatorium-resort treatment includes aero- and heliotherapy, as well as climatotherapy (moderately continental climate).

5. Prevention and Dispensary Observation

There is no specific prevention for congenital cataracts.

Table 11. Frequency of examinations for children with aphakia and pseudophakia after congenital cataract removal

GCR CLEL 5Grade of Recommendation C (Level of Evidence - 5)

Comments: children with aphakia and pseudophakia remain under dispensary surveillance and are not discharged from it. Parents must understand that surgery is only the first step toward visual rehabilitation. Following surgical intervention, the primary focus must be on the prevention and treatment of amblyopia. This process takes more than one year and in most cases continues until the child reaches 14–16 years of age, being most effective under the age of 3.

See Section 4. "Medical rehabilitation and sanatorium-resort treatment, medical indications and contraindications for the use of medical rehabilitation methods, including those based on the use of natural therapeutic factors."

6. Organization of Medical Care

Forms, types, and conditions of medical care:

Form of medical care: elective.

Type: primary health care, specialized care, including high-tech medical care.

Conditions of medical care: inpatient, day hospital, outpatient.

Medical care for congenital cataract is provided on an elective basis. The provision of medical care to patients with congenital cataract and aphakia\pseudophakia is carried out in accordance with the Procedure for Providing Medical Care to Children with Diseases of the Eye, Its Adnexa, and Orbit, approved by Order No. 442n of the Russian Ministry of Health dated October 25, 2012.

Issues related to the organization of medical care for congenital cataract are primarily associated with early diagnosis and timely referral of the child to a specialized institution for surgical treatment when indications are present. Continuity of care between obstetrician-gynecologists, neonatologists, pediatricians, and ophthalmologists is of critical importance for the early detection of children with congenital cataract and their timely referral for surgical treatment.

Primary diagnosis is performed prenatally during routine ultrasound screening of pregnant women. Already in the second trimester of pregnancy, fetal ultrasound can detect lens opacification.

After the child's birth, the neonatologist and pediatrician can detect dense centrally localized lens opacification in the pupillary area and refer the child for a consultation with an ophthalmologist.

In accordance with Order No. 514n of the Russian Ministry of Health dated August 10, 2017, "On the Procedure for Conducting Preventive Medical Examinations of Minors" (as amended by Orders of the Russian Ministry of Health No. 410n dated July 3, 2018, No. 396n dated June 13, 2019, No. 1235n dated November 19, 2020), during medical examinations of minors, including upon admission to and during their studies in educational institutions, an ophthalmologist examines children at the age of 1 month, 12 months, 3 years, 6 years, 7 years, 10 years, 13 years, 15 years, 16 years, and 17 years.

The ophthalmologist assesses the condition of the eye and conducts an examination, including visual inspection and instrumental diagnostic methods to verify lens opacification, refine the diagnosis, and rule out clinically similar conditions. If examination is difficult due to the child's young age or uncooperative behavior, and diagnostic procedures require anesthesia, children are referred to a pediatric ophthalmology department.

When there are indications for surgical treatment in a child with congenital cataract, such treatment is performed in an inpatient setting—in a pediatric ophthalmology department. After receiving inpatient medical care and in the absence of indications for continued inpatient treatment, children are referred to the pediatric ophthalmology office at the outpatient clinic. Subsequently, the child is under the dispensary observation of the pediatric ophthalmologist at the outpatient clinic.

7. Additional Information

The prognosis of congenital cataract in children is determined by the child's age, the time of disease detection, the stage and severity of glaucomatous damage to the child's eye at the time of glaucoma detection, and the timeliness of diagnosis and surgical treatment.

Criteria for Evaluating the Quality of Medical Care

Group name: congenital cataract

ICD codes: Q12.0, H27.0

Age group: children

Conditions of medical care: inpatient, day hospital, outpatient

Diagnostic, therapeutic, and preventive measures at the diagnostic stage may be performed on an outpatient basis or in a day hospital setting. More detailed examination of infants can be performed under anesthesia in specialized inpatient units. Surgical treatment is recommended to be performed in specialized inpatient units with anesthetic support. Dispensary follow-up including preventive and therapeutic measures in the late postoperative period

References

Appendix A1. Working Group Composition

Katargina Lyudmila Anatolyevna – Chief freelance pediatric ophthalmologist of the Russian Ministry of Health, Deputy Director for Research at the National Medical Research Center for Eye Diseases named after Academician V.M. Helmholtz of the Russian Ministry of Health, Professor, Doctor of Medical Sciences, Moscow. Association of Ophthalmologists;

Kruglova Tatyana Borisovna – Senior Researcher at the Department of Eye Pathology in Children, National Medical Research Center for Eye Diseases named after Academician V.M. Helmholtz of the Russian Ministry of Health, Doctor of Medical Sciences, Moscow. Association of Ophthalmologists;

Egiyan Naira Semyonovna – Head of Department, Ophthalmologist, Operating Unit No. 3, National Medical Research Center for Eye Diseases named after Academician V.M. Helmholtz of the Russian Ministry of Health, Candidate of Medical Sciences, Moscow. Association of Ophthalmologists;

Brzhesky Vladimir Vsevolodovich – Head of the Department of Ophthalmology, Saint Petersburg State Pediatric Medical University of the Russian Ministry of Health, Professor, Doctor of Medical Sciences, Saint Petersburg. Association of Ophthalmologists;

Markova Elena Yuryevna – Head of the Department of Microsurgery and Functional Rehabilitation of the Eye in Children, S.N. Fyodorov Eye Microsurgery Federal State Institution of the Ministry of Health of the Russian Federation, Doctor of Medical Sciences, Moscow;

Zaydullin Ildar Saitgalievich – Head of the Pediatric Department, Ufa Research Institute of Eye Diseases of the Academy of Sciences of the Republic of Bashkortostan, Doctor of Medical Sciences, Ufa.

There is no conflict of interest.

Appendix A2. Methodology for Developing Clinical Guidelines

Methods used for evidence collection/selection: electronic database search; analysis of current scientific developments on congenital cataracts in Russia and abroad, generalization of practical experience of Russian and foreign colleagues.

The preliminary version of these guidelines was reviewed by independent experts who commented on the accessibility and interpretability of the evidence underlying the guidelines for practitioners and patients.

The comments received from experts were carefully systematized and discussed by the chair and members of the working group. Each point was discussed, and appropriate changes were made to the guidelines.

In these clinical guidelines, all data are ranked by level of reliability (evidence) depending on the quantity and quality of studies on the issue.

Target audience of the clinical guidelines:

1. Ophthalmologist;

2. Pediatrician, general practitioner (family physician);

3. Medical students, residents, postgraduate students.

1. Scale for evaluating levels of evidentiary validity (LEV) for diagnostic methods (diagnostic interventions)

2. Scale for assessing levels of evidence reliability (LER) for prevention, treatment, and medical rehabilitation methods, including those based on the use of natural therapeutic factors (preventive, therapeutic, and rehabilitation interventions)

(as amended by Order of the Russian Ministry of Health No. 617n dated June 23, 2020)

3. Scale for assessing levels of recommendation persuasiveness (LRP) for methods of prevention, diagnostics, treatment, and medical rehabilitation, including those based on the use of natural therapeutic factors (preventive, diagnostic, therapeutic, and rehabilitation interventions)

(as amended by Order of the Russian Ministry of Health No. 617n dated June 23, 2020)

Procedure for updating clinical guidelines

The guideline update mechanism provides for their systematic review—at least once every three years or upon the emergence of new information on the management tactics of patients with this disease. The decision to update is made by the Russian Ministry of Health based on proposals submitted by professional medical non-profit organizations. The submitted proposals must take into account the results of a comprehensive assessment of medicinal products and medical devices, as well as the results of clinical approbation.

Appendix A3. Reference Materials

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

1) "Order of providing medical care to children with diseases of the eye, its adnexa and orbit", approved by Order of the Ministry of Health of the Russian Federation No. 442n dated October 25, 2012;

2) International Statistical Classification of Diseases and Related Health Problems, 10th Revision (ICD-10) (World Health Organization) 1994;

3) Nomenclature of Medical Services (Ministry of Health and Social Development of the Russian Federation) Order of the Ministry of Health of the Russian Federation No. 804n dated October 13, 2017 (as amended on September 24, 2020, with rev. dated October 26, 2022) "On Approval of the Nomenclature of Medical Services" (Registered with the Ministry of Justice of Russia on November 7, 2017, No. 48808);

4) Federal Law No. 323-FZ dated November 21, 2011 "On the Fundamentals of Protecting the Health of Citizens in the Russian Federation";

5) Decree of the Government of the Russian Federation No. 2406-r dated October 12, 2019 (as amended on April 16, 2024) "On Approval of the List of Vital and Essential Medicines, as well as Lists of Medicinal Products for Medical Use and the Minimum Assortment of Medicinal Products Required for Medical Care";

6) Order of the Ministry of Health of the Russian Federation No. 143n dated March 27, 2024 "On approval of the classification of natural therapeutic resources specified in paragraph 2 of Article 2.1 of Federal Law No. 26-FZ dated February 23, 1995 "On natural therapeutic resources, health-resort areas and resorts", their characteristics and the list of medical indications and contraindications for sanatorium-resort treatment and medical rehabilitation using such natural therapeutic resources".

Appendix B. Physician Action Algorithms

Congenital cataract in children

Appendix C. Patient Information

Congenital cataract is a congenital disorder that is one of the leading causes of blindness, low vision, and visual impairment in children from an early age. Functional outcomes of treatment for children with congenital cataracts largely depend on early detection and timely surgical treatment based on indications. Congenital cataracts relatively rarely occur as an isolated organ-of-vision lesion, and for early diagnosis, continuity of care between obstetrician-gynecologists, neonatologists, pediatricians, and ophthalmologists is crucial. When lens pathology is detected, such a child should be referred to a hospital for a more detailed examination under general anesthesia and to determine further treatment strategy. If pronounced lens changes causing significant visual deprivation are identified, early surgical intervention is recommended—phacoaspiration, extracapsular congenital cataract extraction with/without IOL implantation, depending on the nature of the lens opacity and the presence of concomitant eye pathology.

In the treatment of congenital cataracts in children, in addition to surgical intervention followed by drug therapy, a set of measures aimed at creating optimal conditions for visual development is recommended:

- optical correction of aphakia (refinement of pseudophakia correction);

- timely and high-quality pleoptico-orthoptic treatment;

- elimination of strabismus, treatment of nystagmus;

- detection and treatment of complications (secondary cataract, secondary glaucoma, iridocyclitis, IOL dislocation, and others).

After surgical treatment, children are registered for follow-up (dispensary observation) at the outpatient clinic. The ophthalmologist must examine the child 2 times in the first month after hospital discharge, once every 2 months during the first year after surgery, 2 times a year for 3 years, and once a year thereafter. It should be remembered that children with aphakia and pseudophakia are not removed from the follow-up registry. Parents must know that surgery is only the first step on the path to visual rehabilitation. After surgical intervention, it is necessary, first of all, to carry out the prevention and treatment of amblyopia. This takes more than one year and in most cases lasts until the child reaches 14–16 years of age, being most effective under the age of 3 years.

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

Not used.