Schielen bei Kindern– verschiedene Formen vom Schielen
Strabismus
Strabismus can have different causes. Two types of strabismus can be classified:
1. Concomitant strabismus (Strabismus concomitans)
2. Paralytic strabismus (Strabismus inconcomitans)
While concomitant strabismus can only occur during infancy, paralytic strabismus is possible at all ages.
Concomitant strabismus
Strabismus during infancy is known as concomitant strabismus. The causes and the basic characteristics of this type of strabismus differ significantly from those of paralytic strabismus. The most important difference is the age of the patient. While concomitant strabismus always develops during infancy, paralytic strabismus can occur at all ages (also during infancy). Mostly the visual system in the brain of patients suffering from concomitant strabismus is already fully developed. Consequently, the images received from both eyes are processed simultaneously, in contrast to the suppressed information from the misaligned eye of paralytic strabismus patients.
Concomitant strabismus can result from farsightedness (hyperopia), an impairment of the binocular vision or a decreased vision of one eye (amblyopia). However, it may also be inherited.
The treatment of strabismus depends strongly on the point in time of emergence. In case binocular vision is not fully developed during infancy, the misaligned eye has to be “forced” to see properly. This is the only way for the visual centre in the brain to receive the optical stimuli that are essential for its complete development. For this, the healthy eye is covered for a few hours every day (occlusion of one eye).
During strabismus surgery the affected muscles are aligned. Muscle groups that exert too much traction are loosened (muscle recession) and muscles that do not pull enough are tightened (muscle resection).
Paralytic strabismus
This type of strabismus is caused by ocular palsy, which can either be total or fractional. Strabismus due to ocular palsy, also called “strabismus inconcomitans”, can manifest itself either as (a) a total palsy (paralysis) or as (b) a weakness of the ocular muscle or fractional palsy (paresis). In any case a thorough examination of the possible causes should be undertaken. This includes an extensive neurological examination, a check-up at an ENT (ear-nose-throat)-physician and possibly a radiological clarification. Ocular palsy can heal up spontaneously. Out of this reason, surgery is normally only taken into consideration approximately a year after the palsy emerges. During this time the reasons for the palsy are examined and investigated. It is important to exclude diseases of the central nervous system, since they may also result in palsy. This is the only possibility for a specific therapy of the ocular palsy.
Veni Vidi - octors of Ophthalmology
