Children and strabismus

We are the only one in the region to carry out surgeries for all types of strabismus (horizontal, vertical, palsy, nystagmus, double vision) together with the team of eye clinic „Svjetlost“ Croatia. We also perform strabismus surgeries on adults and the surgery of opening and irrigating the tear duct in children under a short-term general anesthesia. We use the same methods and surgical techniques used in the world’s best centers.

Children’s eye examination – a necessary step for the proper development of vision

Children’s eye examination is one of the most important examination that should be done up to the age of four. The intensive development of vision lasts until the end of six years of age; since the plasticity of the eye and brain is more intensive in younger children a child is never too young for eye examination. During the vision development, disorders must be treated in order to allow normal development of child’s eyes and vision.

If disorders are not detected in time, the results of treatment in older children are much less successful. Examination is adjusted to the age of the child and is not painful. In the clinic Svjetlost, subspecialists of pediatric ophthalmology and strabismology are carrying out the examination using the most modern equipment, through which children are entertained and educated.

Among the most common eye diseases that must be treated in childhood are strabismus, lazy eye, (amblyopia), children’s cataract, nystagmus (wobbly eyes). If surgical treatment is necessary, the clinic Svjetlost offers the possibility of a accommodation for children and their parents. All kinds of examinations and procedures are performed in the shortest possible time, without waiting lists.

Assessment of refractive error

The most common reason why children come to the eye examination is refractive error (nearsightedness, farsightedness, astigmatism). Usually in young children parents notice that the child  watches television from a short distance or try to squeez eyes or blink frequently while attempt to fix distant objects. Older children usually complain that they can not read properly from the blackboard. 

Children, who have refractive error, sometimes complain of headaches after reading or playing computer games for a long time. The reason for that is exceptional flexibility of child eye, so child unconsciously corrects its diopter and sees well, but makes an extra effort that tires him, and in some cases this can even lead to the damage in the vision system.

Taking into consideration that child’s eye is not fully developed, any refractive error has to be corrected properly and immediately. In order to correct refractive errors, children are given glasses or contact lenses.

Strabismus is a disorder of the position or movement of eyes in which both eyes do not have a common viewing direction. In healthy eyes, both eyes are directed at the same point, and the movements are coordinated. In some cases, strabismus occurs because the mobility of an eye in a particular direction is limited. In children, strabismus is usually congenital or developed in early childhood, but it can also be consequence of mechanical injuries (during birth) or various neurological and internal diseases. In adults, strabismus often develops after head or eye injury due to paralysis of some muscle that moves the eye.  It can also develop during some endocrine and immune diseases (thyroid disease). The most common types of strabismus are esotropia (eyeturned inwards) and exotropia (outwards), vertical deviations are also possible (eye turned up or downwards). Strabismus is also often connected with other vision disorders (amblyopia, refractive errors, and nystagmus).

When surgery is needed?

Strabismus in children interferes with the healthy development of vision and therefore is highly important to start the treatment as soon as possible. It is often combined with other vision problems in children, and has to be treated in combination with other necessary procedures.  One of the most seriusconsequences of strabismus is development of amblyopia in the squinting eye . . Strabismus can influence the development of the stereovision in children as well. In adult patients surgery is requiredfor double vision, when causingasthenopia (eyestrain) and headaches or sometimes for aesthetic reasons.

The eye is run by six muscles, impulse for the movementsarederived from the brain, and in normal conditions the impulsshoud be same for both eyes. Coordinated eye movements ensure the perfect co-operation of both eyes, which enables the development of binocular vision, i.e. collaboration while viewing with both eyes at the same time.  If everything is perfectly aligned, two slightly different images (from two eyes) merge in the brain where a single image is created in three dimensions (stereo, 3D vision). If both eyes are not straight or the mobility of eyes are limited or not well coordinated patieentwill have double vision.

In such cases the brain cannot merge two different images together. In such situation adults will have double vision so they often have to cover one eye in every day’s activities. .  Children’s brain, which is much more flexible, will automatically exclude the eye that is not straight, so there is a danger that the previously mentioned amblyopia will occur in the excluded eye. As a result, binocularity and stereo vision will not develop.

Strabismus surgeries are performed in adults even when they do not have any disturbances (double vision), even though the vision development is already completed. In such cases, surgeries are being performed because of aesthetic and socioeconomic reasons (social stigma and exclusion). By removing strabismus, a better aesthetic appearance and easier social adjustment is offered to the patient.

How does the surgery look like? 

In cases when the surgery is the best solution, after accurate preoperative examination, surgery on the muscles that move the eye is performed. Strabismus surgery is performed under general anesthesia and lasts, depending on the complexity of the procedure, from half an hour to an hour and a half. The aim of the surgery is to set the eyes in the desired position, and in the case of muscle palysis, better position and mobility is achieved. In order to achieve desired position of the eye, muscles are weakend or strengthen by moving their insertions, shortening, splitting of the muscles or creating a double insertion.  In the case of muscle paralysis (reduced mobility), to the paralyzed muscles are joined together with healthy surrounding muscles in order to improve reduced mobility. Strabismus surgery helps the patient to keep both eyes straight and working together. In most cases, complete cure is achieved. 

How does the recovery look like and how long does it last?

After strabismus surgery, the patient usually stays in th hospital during the night. The first control examination is performed the next morning. Children stay in the clinical accommodation together with a parent. In early postoperative period (up to seven days), feeling of discomfort and sensitivity to light is common. It takes several weeks of postoperative healing that eye becomes completely white.
In the period of up to three weeks after surgery, t eye drops are prescribed. During this period it is recommended to avoid serious physical efforts (gyms, exercising), pools and crowded rooms. Another control is carried out after a week, and third control is scheduled a month after the surgery.

Children can usually go again to kindergarten or school after two weeks.  Return to the work depends on the type of job. In office jobs, it is possible to come back to work already after seven days. 

What is amblyopia?

If the visual acuity is decreased in both eyes, a child clearly shows signs of poor vision so parents seek a medical examination. But if the vision is poor in only one eye, parents do not notice the problem; the child uses the better eye and unconsciously ignores the weaker eye. In such a process , the brain takes the information coming from the better eye and due to the fact that cannot merge two different images,  information from the weaker eye is suppressed  leading to the development of amblyopia, i.e. delay in the development of the eye that is not used.

If this is happening at an early age when the brain and the eye are not yet developed, vision in the affected eye may remain very weak as weaker eye is being neglected from the normal development. The chance that a child will have such a problem is higher if someone in the family has a similar problem.

Treatment of amblyopia

When amblyopia or, as some call it, a lazy eye is detected, it is necessary to prescribe appropriate correction with eyeglasses and perform patching (occlusion) of a healthy eye in order to force the child to use the weaker eye for watching, and thereby, to develop. The period of prescribed patching depends on the depth of amblyopia and the age of the child, and it extends from one hour to six hours a day.

The patch (occluders) must cover the whole eye and noteyeglasses in order to prevent the child to peek on the sides. It has been verified that the effect of occlusion is better if the child is doing something at the reading distance (drawing, reading, playing computer games). Taking into account that children often resist wearing the patch, it takes a lot of patience and persistence in order to achieve the desired effect. Child who has low vision on affected eye  will resist more on closing of the better eye than the child with not so bad  visual acuity. For parents thatcan be a sign to have even more persistence and patience.

In some cases, strabismus surgery has a positive effect on the amblyopia.  If amblyopia is detected in the older age of the child, a chance for vision improvement and development is lower. In children in early age, eye and vision centers in the brain are still in the sensitive (plastic phase), and cells are still able to learn how to watch and process visual information and make up for lost time.

Why does the congenital cataract develop?

Sometimes a child be born with a cataract in one or both eyes. Such congenital cataracts occur usually due to developmental disorders or some infections even while the child is in the womb.Cloudy lens prevents entering of the light in the eye, soeven if the rest of the eye is completely healthy, vision of the child will not be able to develop and will remain highly amblyopic even after the surgery is successfully performed. Therefore, the congenital cataract surgery is necessary to perform as soon as possible, even in babies.  

What does the congenital cataract surgery look like?

During the surgery an incision of only a few millimeters is made, and with the help of ultrasound a cloudy lens is removed.Through a small incision, an artificial lens is implanted. The artificial lens is located at the same place where the natural lens was positioned, it is not visible in the eye and it lasts the whole life. After cataract surgery is performed, a treatment should be continued (glasses, patching in order to improve the development of visual acuity in the operated eye. The surgery is performed under general anesthesia and it takes up to ten minutes per eye.  As the natural lens in babies is softer than in older patients in whom such a surgery is usually carried out, ultrasonic part of the surgery can be made with considerably less energy and therefore it is even less traumatic to the eye.

Why „Sistina Ophthalmology“?

In order to be as close as possible to the physiology and function of a child’s eye we implant lenses that are closest to our natural vision (adjustment for looking at all distances). By implanting such lenses, a child preservs the ability to adjust the eye tohave a sharp vision in all distances (short, middle and long distance) and enable a good vision. There are several types of such lenses from which the most recent are Symfony lenses with extended range of vision.

Congenital nasolacrimal duct obstruction

Parents often come with newborn babies complaining that the child has ”watery eye”. Immediately after birth the reason for that can be infection in the birth tract and requires treatment with topical antibiotics. However, much more often the reason is obstructed duct which is located between the eye and the nose (nasolacrimal duct), the obstruction causes accumulation of excess tears in lacrimal sac located at the beginning of the duct and return of the excess tears to the eye.

If there are no signs of inflammation of the anterior eye segment the parents are instructed how to perform massage of the area covering the duct so the pressure can help opening of the obstruction.With such a procedureIn 90% of children, a duct spontaneously opens during the first year of life. . In a small number of children a duct does not open during the first year and in such cases probing of the duct under general anestezia is mandatory.. The procedure takes about ten minutes and it is carried out with very thin probes adjusted to the age of the child. After such a surgery, massage and hygiene are still needed.

In rare cases in which the duct after probing does not open, the procedure can be repeated with the installation of silicone tube that stays in the eye for six months in order to prevent spontaneous closure again.