General characteristics of the disease
Astigmatism - is a congenital inability of the eye to correct focusing view. Normally, the light beam must be focused on the retina. With astigmatism, the eye instead of a single focused point, formed a few, and the image is somewhat blurred.
The reason for this type of refractive error (imperfect refractive power of the eye) is the innate power section mismatch cornea and retina. Astigmatism is an eye often accompanies other types of refractive error - nearsightedness and farsightedness. The name of the disease comes from the Greek word "stigma" (point).
Also fuzzy vision subjects, patients with astigmatism usually complain of headaches and eye fatigue. These results systematic overvoltage eye muscles when visual work. It is estimated that about one sixth of the world's population suffering from various degrees of astigmatism.
Types of astigmatism
Intensity of astigmatism depends on the difference between the two main meridians of the eye. The longer the focal line between the rear and front focus his eyes, the worse visual acuity. Most often, this pathology causes abnormal structure of toric cornea. This form of astigmatism, respectively, called corneal astigmatism.
Astigmatism in turn happens, forward, backward or oblique axes, depending on the location of the meridians in vertical, horizontal or oblique line.
There is also a classification of types of astigmatism, depending on the focus position relative to the retina:
- Astigmatism is called a complicated short-sighted when the main focus of the localization front of the retina.
- If one focus is in front of the retina and the other directly behind her, astigmatism myopic eye is considered to be a simple kind of refractive error.
- Mixed hyperopic astigmatism is formed at the front focus of the front of the retina and posterior focus located behind it.
- Difficult farsighted astigmatism is diagnosed at the location of both tricks behind the retina.
Most rare form of the disease - acquired astigmatism. It is formed as a result of trauma, a serious eye disease or poorly conducted eye surgery. In this form of refractive error, referred to as irregular, the main meridians are not allocated, which greatly complicates the treatment of astigmatism.
Diagnosis of eye astigmatism
Despite the fact that the astigmatism is usually congenital, it is most often diagnosed in the second year of life. At this age the doctor is able to make a prediction of further development of the system of the child.
In the diagnosis of astigmatism is used fundus examination, visual acuity test using tables and skiascopy or shadow sample. With last checked refraction.
A more accurate measurement of the degree of distortion in the position to determine refractometry. The procedure is fully automated, painless for the patient and allows you to use a special computer equipment to measure as accurately as possible the optical power of the eye with astigmatism.
Treatment of astigmatism
Treatment of astigmatism possible in several ways. Optical vision correction at astigmatism involves the use of glasses or contact lenses. Points - the most simple and economical method of treating astigmatism, but it has several drawbacks: limiting the lateral view, the violation of spatial perception, discomfort when wearing, etc.
Contact lenses - a more comfortable method of correcting astigmatism. Yet their use is also associated with opredёlёnnymi inconvenience. This sensation of a foreign body in the eye, the chance of infection or injury to the eyes.
It is also possible surgical treatment of astigmatism. The most radical surgery for astigmatism - is astigmatic keratotomy, or AK. During her around the perimeter of the cornea of the patient made some deep cuts. They allow you to change the curvature of the cornea. This type of surgery for astigmatism is used in patients with a coefficient of less than 2D. It is significantly inferior to the effectiveness of laser technology.
A similar procedure to change the curvature of the cornea can be performed using a laser, removing them tissue layers of the eye. This type of surgery for astigmatism less traumatic, however, and after the patient needs a long period of recovery.
The most effective among the operations in the astigmatism method is considered the laser keratomileusis. Its essence is to create a new lens under the protective layer of the cornea. Laser surgery for astigmatism LASIK and REIK may be held as early as infancy in poor portability of optical treatment of astigmatism.
Prevention and treatment of astigmatism in children
Rasfokussirovannoe image with astigmatism in children can cause suppression of the visual system and distorted perception of visual images. The result is a secondary decrease in visual acuity, the development of amblyopia (lazy eye), strabismus - astigmatism and other complications in children.
Prevent such diseases can be through early physiotherapy, optical, and in rare cases, and surgical treatment of astigmatism. Early initiation of therapy in most cases, significantly improve visual acuity and eventually get rid of the spectacle dependence.
However, it is important to remember that conservative therapy can only improve the eye and to some extent compensate for the shortcomings of refraction. With a high degree of astigmatism in children eliminate corneal defect only possible through surgical techniques.