Strabismus

The fact that the eyes do not look parallel is called strabismus. While one eye is looking straight, the other may look inward, outward, up or down. The deviation may be continuous or transient, it may be in one eye continuously, or it may be in both eyes alternately. Strabismus can be observed in 4% of children. It can also occur in older ages. It can be found in equal proportions in boys and girls. It may be hereditary, but many patients with strabismus problems may not have strabismus in any of their relatives.

Sight and the Brain

In normal (bilateral) vision, both eyes are directed to the same target. The visual part of the brain can combine two separate images from both eyes into one three-dimensional image. Two different images come to the brain because one eye slips in strabismus. The child's brain learns to ignore the image from the shifting eye. This causes the sense of depth to be lost and the development of laziness (low vision) in that eye. If strabismus develops in adults, since the brain has learned to perceive images from both eyes, it cannot ignore the image from the deviated eye and double vision occurs.

The Causes and Symptoms of Strabismus

The true cause of strabismus is still unknown. The movements of the eye provide 6 muscles that surround the eyeball. Two muscles in each eye pull the eye in and out, while the other 4 muscles provide up, down and rotational movements of the eye. In order for both eyes to look at the target properly, all the muscles in one eye must be in balance and work together with the muscles in the other eye doing the same job.

The brain controls the movements of the eye muscles. Strabismus is often found in children with organic problems in the brain. Strabismus may develop after a long time in situations that reduce vision in one eye, such as cataract or eye injury. The most important symptom of strabismus is eye shift. Slippage can occur in bright sunlight. Sometimes it is observed that the child develops a head position in order to keep his eyes straight. Loss of sense of depth may appear as a complaint. Double vision is the most common complaint in strabismus in adults.

Diagnosis

Children should be examined for possible eye problems by pediatricians and ophthalmologists when they are newborns and at preschool age. Especially if there is a family history of strabismus or visual laziness, this examination becomes much more important. It is difficult to distinguish between the eye (pseudo-strabismus) and true strabismus, which often seems to be slipping in infants. Pseudo-inward strabismus is a suspected condition in children with a flattened nasal root and skin remnants (epicantal remnants) on the inside of the eyelids, or in cases where the distance between the eyes is narrow and the eyes are deep, in lateral gaze positions. As the child grows, the root of the nose develops, grows, the skin folds are stretched and gain a normal appearance. The large distance between the two eyes or the protruding eyes are also causes of false strabismus. The most common types of strabismus are SLIP IN and OUTSIDE.

Introversion

It is the most common type of strabismus in children. The form that occurs up to 6 months after birth is called the infantile type and it is recommended to perform the surgery up to 1 year of age. Inward shifts are often seen with hyperopia. Hypermetropes adapt to see distant objects well. Harmony draws the eyes in. As a result of correcting hyperopia with glasses, strabismus can be completely corrected. This accommodative type is inward strabismus. In this type of strabismus, the strabismus is controlled by reducing the number of hypermetropic glasses as the child grows, and surgery is not required.

In some cases, although hyperopia can be completely corrected, a significant strabismus may remain. This is the partial accommodative type. Partial strabismus that cannot be corrected with glasses is corrected by surgery. In some children, when looking up close, the inward slip increases a lot. In this case, bifocal glasses, prisms, some eye drops, and sometimes surgery can provide complete correction. Treatment of inward strabismus with hyperopia and non-accommodation type is only surgical. If there is a need for surgery with strabismus, surgery is planned as soon as possible. The basic surgical principle of ingrown strabismus is to weaken the effect of the muscle that draws the eye in from its attachment to the eye, and/or to strengthen the effect by shortening the muscle that pulls the eye out.

Scroll Out

There are types that occur occasionally and that are permanent. The shape that occasionally appears to slip out is of two types. The type in which there is normal bilateral vision when looking at near and one eye slides out when looking away is called divergence excess. In the other type, called convergence insufficiency, while far gaze is normal, the eyes drift out when looking up close. In this type of strabismus, myopia and astigmatism are corrected first. Orthoptic treatment and prisms are used. The last resort is surgery. The same treatment methods are valid for continuous outward shifts seen both near and far. Contrary to surgical inward strabismus, it is based on the principle of weakening the attachment of the muscle that draws the eye outward and strengthening it by shortening the retracting muscle.

Strabismus Surgery

It is usually performed under general anesthesia. Local anesthesia may also be appropriate for some adults. The surgery only begins with the removal of the tissue surrounding the eyeball and reaching the muscles that move the eye. Then, necessary strengthening and weakening procedures are applied to the muscles in one or both eyes. Recovery after surgery is fast. Return to normal life in a few days. Glasses or prisms may be required after surgery. Although the recovery response of each person varies according to each eye, if the deviation is less or excessively corrected after the surgery, surgery can be performed again. In strabismus, early surgery is very important. Because in babies, normal vision and double-eye depth sense develop easily after the gliding of the eyes is corrected. Although it is not possible to fully develop vision and sense of depth as the child grows, there may be an increase in peripheral (nymphs) vision when strabismus is removed. Strabismus surgery is performed to bring the eyes to their normal parallel position. Strabismus surgery is in no way an alternative to the use of glasses and the treatment of lazy eye. The glasses used before the surgery and the treatment of amblyopia are continued in the same way after the surgery.