Introduction
Astigmatism, colloquially known as astigmatism or astigmatism, is a widespread form of ametropia in addition to the classic long and near-sightedness. Until a few years ago, it was usually treated with the use of special glasses or contact lenses. For some years now, ophthalmologists have been offered another treatment option: laser treatment.
This low-complication and gentle treatment method is now very common and is offered thousands of times a year in numerous eye clinics and specialized eye laser centers. Nevertheless, its use is limited to a certain extent and usually associated with high costs. General information on this topic can be found under astigmatism, eye lasering General information on this topic can be found under astigmatism, eye lasering
Astigmatism
A sharp image can only be created on the retina if all light rays can be bundled in one point on the retina. If this is not possible, image distortion occurs, i.e. distorted or blurred images. These can be caused, for example, by a disproportion between the refractive power of the lens and the length of the eyeball.
In myopia, for example, the eyeball is relatively too long and the light rays are already focused in front of the retina. In long-sightedness, on the other hand, the eyeball is relatively too short, so that the light is focused behind the retina. In contrast to these two, widespread forms of ametropia, the cause of astigmatism is in most cases an irregular shape of the cornea, resulting in its colloquial name astigmatism.
Depending on where the light hits the cornea, it is refracted to a different degree and distorted when it hits the retina. Different forms of astigmatism are distinguished. The most common form is regular astigmatism, in which the incident light rays are not focused at a single focal point, but rather in mutually perpendicular focal lines (hence the often synonymously used term “astigmatism”).
Likewise, astigmatism can also be irregularly formed. This is why people affected by astigmatism perceive their surroundings as blurred to varying degrees. Astigmatism is usually congenital, but can also have other causes, such as scarring of the cornea as a result of inflammatory and traumatic events or after surgery.
The consequences of astigmatism are usually only noticeable when it becomes more pronounced. In addition to the obvious blurred vision, affected persons can also suffer from eye and headaches. If children are affected by a clearly pronounced astigmatism, they may also develop a permanent visual impairment.
In addition to an incorrectly curved cornea, a deformed lens or a disturbance in the function of the eye muscles can be the cause of distorted light refraction and thus astigmatism, although this is much less common. The term astigmatism as such is therefore relatively broad. Astigmatism, which does not develop until adulthood, is harmless for the person affected, even if it is unpleasant.
This is not the case with children. In theory, defective vision of any kind can lead to permanent visual impairment in the affected eye, since the visual path of this eye cannot develop in a healthy way and vision is taken over by the healthy eye. Simply put, the brain hides the weaker eye as part of its development during childhood.
The visual pathway, which is not fully developed, includes not only the retina and the optic nerve, but also the associated pathways and corresponding areas of the brain. During the first two years of life, however, the nerve cells in the brain undergo continuous remodelling processes, so that missing nerve tracts can still be formed. It is therefore extremely important to detect astigmatism in young children during the preventive examinations up to the second year of life.
However, laser treatment of astigmatism in children is not advisable and is therefore not offered. The background to this is that the eyes, like other parts of the body, are subject to a growth process until about the age of 18. An intervention is therefore only sensible in adulthood.Instead, special glasses with cylindrical lenses and masking of the healthy eye are used for children. Babies and toddlers also need special glasses made of shatterproof plastic. From around the age of five, contact lenses can then be used, provided the child cooperates and the parents take good care of the lenses.