Strabismus is a disturbane in the position of the eyes when looking forward results in the deviation of one or both eyes. With the symmetric position of the eyes the images of objects fall on the central sections of the retinas of both eyes. The cortical sections of the visual analyzer merge the two images into a single binocular picture. In case of strabismus, this merging does not occur. In order to protect the organism against ghosting vision, the central nervous system blocks the image coming from the squinting eye. (The squinting eye functions only when the non-squinting eye is shut). The prologed existence of this state leads to amblyopia, the functional reduction in the visual acuity of the squinting eye.
Strabismus may be caused by numerous factors of an innate or acquired nature: ametropia (far sight, short sight, astigmatism) of a moderate or high degree, traumas; diseases of the central nervous system; anomalies in the development and attachment of the eye-moving muscles; their paralysis and paresis; sharp reduction in the visual acuity of one eye; infectious or somatic diseases.; stress.
There are several types of strabismus:
In terms of time of its occurrence:
In terms of deviation stability:
In terms of eye involvement:
- fixed (monolateral),
In terms of type of deviation:
- converging (the eye is pointed at the abridge of the nose),
- diverging (the eye is pointed at the temple),
- vertical (the eye is turned upward or downward),
Conjugate strabismus is subdivided into:
Accommodative strabismus occurs more often at the age of 2.5–3 years at the time when a child begins to examine objects and pictures and starts to draw. Children with weaker health may display strabismus already in their first year of life. The main reason lies in the presence of high degrees of myopia, hyperopia and astigmatism. Corrective glasses or contact lens combined with instrumental treatment facilitate the symmetric position of the eyes.
Part-accommodative and non-accommodative forms of strabismus appear on the first or the second year of life. The refraction anomaly in children is not the sole cause for the development of strabismus. Permanent optic correction does not result in full restoration of the position of the eyeballs. In this case, surgery should be a part of the treatment procedure.
Paralytic strabismus is another type and its main symptom is a limited movement or no movement of the eye due to the affected eye muscle which results in disrupted binocular vision and ghosting images. This type of strabismus may be caused by the lesion of the corresponding nerves or affected morphology and functioning of the muscles. These disruptions may be of innate nature or result from traumas and infectious diseases.
Surgical treatment for strabismus
Strabismus surgery allows to eliminate visual aspect of the disorder. However it is not always possible to restore good vision. Each human eye with normal vision acquires slightly different images (this may be illustrated by closing one eye and then the other) which are then combined into one picture by the brain. Surgery alone cannot help the patient see one combined image and not two. The brain is not accustomed to such functioning. This is why the restoration of binocular (3-D) vision requires special exercises over a lengthy period of time. The Excimer Eye Clinics cope with this problem by means of integrated stimulation of vision. The cosmetic effect of surgery alone is an important result by itself. Most of the adults and children with strabismus are exposed to constant psychology traumas because of their unusual appearance. The surgery restores normal appearance to the patient thus resolving lots of problems.
Therapeutic treatment for strabismus
The treatment for strabismus is complex and prolonged and must be started as early as possible.
The main stages in therapeutic treatment:
- integrated diagnostics for the identification of the type of strabismus and its causes
- early optic correction (glasses, soft contact lens)
- stimulation of vision acuity of both eyes (treatment of amblyopia)
- orthopia and diplopia treatment (development of binocular vision)
- allocation of monocular and binocular functions achieved
- development of stereoscopic vision
The Excimer Eye Clinics resort to surgery when other treatment does not achieve the desirable result. Correct therapeutic treatment plays an important role. Strabismus surgery may result in good cosmetic effect but fails to restore binocular vision. In order to achieve normal vision surgery alone is not enough. This is why young patients undergo special preparation for surgery and post-surgery treatment at the Excimer Eye Clinic, which makes it possible to develop a new model of visual perception with maximum results.