Astigmatism
General characteristics of the disease
Astigmatism is a congenital inability of the eyes to properly focus their vision. Normally, the light beam should be focused on the retina. With astigmatism of the eyes, instead of one focused point, several are formed, and the image itself looks somewhat blurred.
The reason for this type of ametropia (imperfect refractive power of the eye) is the congenital discrepancy between the force of the section of the cornea and the retina. Astigmatism of the eyes is often accompanied by other types of vision ametropia - hyperopia and myopia. The name of the disease comes from the Greek term "stigma" (dot).
In addition to blurred vision of objects, patients with eye astigmatism usually complain of headache and rapid eye fatigue. They are caused by a systematic overstrain of the oculomotor muscles during visual work. It is believed that about a sixth of the world's population suffers from astigmatism of varying severity.
Types of astigmatism
The severity of astigmatism depends on the difference between the two main meridians of the eye. The longer the focal line between the back and front focus of the eye, the worse the visual acuity. Most often, this pathology is caused by an abnormal toric structure of the cornea. This type of astigmatism is, accordingly, called corneal astigmatism.
Astigmatism, in turn, can be direct, reverse or with oblique axes, depending on the location of the meridians vertically, horizontally or along an oblique line.
There is also a classification of the types of eye astigmatism, depending on the location of the foci relative to the retina:
- Astigmatism is called complex myopic with main foci with localization in front of the retina.
- If one focus is in front of the retina and the other immediately behind it, astigmatism of the eyes is considered a simple myopic type of ametropia.
- Mixed farsighted astigmatism occurs with an anterior focus in front of the retina and a posterior focus located behind it.
- Complex farsighted astigmatism is diagnosed when both foci are located behind the retina.
The most rare form of the disease is acquired astigmatism of the eyes. It is formed as a result of an injury, a serious ophthalmic condition, or poorly performed eye surgery. With this form of ametropia, called irregular, the main meridians do not stand out, which significantly complicates the treatment of astigmatism.
Diagnostics of the eye astigmatism
Despite the fact that astigmatism is usually congenital, it is diagnosed most often in the second year of a person's life. It is at this age that the doctor is able to predict the further development of the child's visual organs.
In the diagnosis of astigmatism, an examination of the fundus is used, a test of visual acuity using tables, as well as a skiascopy or shadow test. With the help of the latter, the refraction of the eye is checked.
A more accurate measurement of the degree of distortion can be determined by refractometry. The procedure is fully automated, painless for the patient and allows using special computer equipment to measure the optical power of the eye with astigmatism with maximum accuracy.
Treatment of astigmatism
Treatment of eye astigmatism is possible in several ways. Optical vision correction for astigmatism involves the use of glasses or contact lenses. Glasses are the simplest and most economical method of treating eye astigmatism, however, it has several disadvantages: limitation of lateral vision, impaired spatial perception, discomfort when wearing, etc.
Contact lenses are a more comfortable method for correcting eye astigmatism. And yet their use is also associated with certain inconveniences. This is the sensation of a foreign body in the eye, the likelihood of infection or injury to the eye.
Surgical treatment of eye astigmatism is also possible. The most radical surgery for astigmatism is astigmatic keratotomy or AK. During it, several deep incisions are made around the perimeter of the patient's cornea. They allow you to change the curvature of the cornea. This type of surgery for astigmatism is used in patients with a vision coefficient below 2D. It is significantly inferior to the efficiency of laser technologies.
A similar procedure with a change in the curvature of the cornea can be performed using a laser, removing layers of eye tissue. This type of surgery for astigmatism is less traumatic, however, after it the patient needs a long recovery period.
The most effective among operations for astigmatism is the technique of laser keratomileusis. Its essence is to create a new lens under the protective layer of the cornea. Laser surgery for astigmatism LASIK and REIK can be carried out already in early childhood with poor tolerance of optical treatment of astigmatism.
Prevention and treatment of astigmatism in children
Defocused image in children with astigmatism can cause depression of the visual system and distorted perception of visual images. As a result, there is a secondary decrease in visual acuity, the development of amblyopia (lazy eye), strabismus - and other complications of astigmatism in children.
Such diseases can be prevented with the help of timely physiotherapeutic, optical, and in rare cases, and surgical treatment of eye astigmatism. Early initiation of therapy allows in most cases to significantly improve visual acuity, and eventually get rid of spectacle addiction.
However, it is important to remember that conservative therapy can only improve the functioning of the eye and to some extent compensate for the lack of refraction. With a high degree of astigmatism in children, it is possible to eliminate the corneal defect only with the help of surgical techniques.
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The information is generalized and provided for informational purposes only. At the first sign of illness, see your doctor. Self-medication is hazardous to health!
