What is strabismus?
Strabismus is an eye disorder in which one or both eyes deviate alternately when looking straight ahead.
Strabismus can occur at any age. A distinction is made between congenital and acquired strabismus.
Causes of congenital strabismus:
- Perinatal neuromuscular ocular microtraumas;
- Congenital differences in the anatomical structure of both eyes;
- Diseases of the central nervous system.
Causes of acquired strabismus:
- Concomitant conditions such as hyperopia, myopia, and moderate to high astigmatism;
- Visual acuity of one eye is significantly lower than that of the other (anisometropia);
- Sharp decrease in the visual acuity of one eye;
- Infectious diseases (measles, scarlet fever, diphtheria, flu);
- Psychological trauma (fright).
Acquired strabismus is usually diagnosed at the age of three.
Risk factors associated with strabismus in children:
- Birth trauma (central nervous system, cervical spine disorders, and others);
- Pregnancy abnormalities in the mother;
- Anisometropia (difference in eye refraction);
- Uncorrected high hyperopia;
- Retinal diseases, optic nerve lesions, opacities of the eye refractive media;
- Failure to comply with the visual regimen in early childhood.
Types of strabismus by origin
Doctors classify two types of strabismus: concomitant and paralytic.
With concomitant strabismus, the left and right eyes are squinted at the same time and the deviation from the straight position is approximately the same.
In paralytic strabismus, one eye is squinted. The main symptom of this type of strabismus is limited or no eye movement in the direction of the affected muscle (treatment of this type of strabismus usually involves a neurologist).
Strabismus also varies according to other criteria: the stability of the deviation of the visual axes (permanent and non-permanent) and the involvement of the eyes (unilateral and intermittent).
Depending on the deviation of the visual axes, strabismus can be convergent (with the visual axes pointing toward the bridge), divergent (the visual axes pointing toward the temples), vertical (the visual axes pointing up or down), or mixed (combining different types of deviations of the visual axes). According to medical statistics, the convergent strabismus is about 10 times more common than the divergent one, and about a third of those suffering from this disorder have the vertical deviation of the visual axes. It is also worth noting that the convergent strabismus is usually associated with hyperopia, and the divergent one, on the contrary, is often accompanied by myopia.
Risks of strabismus
Strabismus is far from being just a cosmetic defect. Usually, our eyes turn in a coordinated way, and the brain gets a different image from each of them. The visual areas of the cerebral cortex are capable of merging these two slightly different “pictures” into one, which allows a person to see 3D images of objects, determine their distance from each other, and distinguish their depth. This is called binocular (stereoscopic) vision. With strabismus, there is no fusion of the two images into one 3D image. One of the eyes deviates from the joint fixation point, so the brain receives two images that are very different from each other and cannot merge them into one image. Thus, binocular vision in strabismus is impaired. Strabismus often coexists with another dangerous disease, amblyopia (the so-called lazy eye), characterized by a persistent decrease in visual acuity in one or both eyes. Changes occur in the visual cortex, and they are irreversible in adults. This creates a “vicious circle”: amblyopia is provoked by strabismus and further distances the eye from its normal position. If strabismus is untreated, about 50% of children develop amblyopia and visual impairment.
What is pseudostrabismus?
Owing to the structure of the child’s face (wide nose bridge, close-set eyes), it may seem that the pupils are asymmetrically positioned and the child is squinting. This is an illusion, a so-called pseudostrabismus. There is no need for treatment in this case. The child’s face will change with age and this impression will fade. Only an ophthalmologist can determine if it is false or true strabismus.
Ways to deal with strabismus
Strabismus in children should never be neglected! It is vital to consult an ophthalmologist to prevent vision loss. Strabismus treatment may be started as soon as it is diagnosed. Be sure to seize the opportunity. In children up to six or seven years of age, the visual system is being actively formed; it is flexible and responds well to the therapy. Therefore, if treatment is correctly selected and started in time, serious vision problems may be avoided in the future. If strabismus is untreated in childhood, the consequences may be irreversible in adulthood.
To determine the origin of strabismus, a thorough diagnostic examination of the child’s visual system is performed. Depending on many factors (age of the patient, causes of strabismus, and its degree), the optimal treatment program is chosen.
How to treat strabismus in children?
Strabismus treatment may include several stages:
- Optical correction, relieving visual discomfort by wearing special glasses with bifocal, prismatic lenses.
- Occlusion aimed at including both eyes in their visual activity by wearing occluders – special stickers that cover the leading or, on the contrary, the nonoperating eye.
- Machine-assisted treatment, which allows normalizing visual functions through complex stimulation and eye training with special equipment.
- Surgery that modifies muscle balance and thereby restores symmetrical or close to symmetrical eye position.
Each stage of treatment is strictly monitored by a doctor. To maximize the benefits, treatment should take place in the same medical center, by the same doctor, and with the same equipment.
How to get rid of strabismus in adults?
Adult patients suffering from infantile strabismus or those who had developed it in adulthood most often undergo surgery as the most effective treatment method. This treatment is primarily aimed at eliminating cosmetic defects.
To restore visual function after surgery, patients are recommended to undergo a course of rehabilitative machine-assisted procedures aimed at correcting binocular visual impairment. The optimal method of treatment is selected in each case by the physician after a thorough examination of the patient’s visual system.
Strabismus prevention requires regular check-ups by an ophthalmologist, timely optical correction of ametropia, and compliance with requirements for visual hygiene and controlled visual strain. Early detection and treatment of any eye disorders, infections, and prevention of cranial trauma are vital. During pregnancy, expectant mothers should avoid adverse effects on the fetus.