For most people, vision is the main sensory organ. Thanks to him, we perceive almost 90% of information from the environment. Therefore, it is very important to preserve vision from an early age. Unfortunately, some pathologies arise already in childhood. To maintain the ability to see as long as possible, it is necessary to consult an ophthalmologist in time to correct vision. One of the pathologies diagnosed at an early age is complex myopic astigmatism. This condition is not a disease, but rather a defect in the shape of the eyes. Nevertheless, it violates the optical parameters necessary for normal vision.
What is astigmatism?
As you know, the ability to clearly see the image is achieved using the optical system represented by our eyes. The organ of vision has 5 refractive media, after which the image enters the retina. To ensure that the image is not distorted, the size and shape of the eye must be ideal. Unfortunately, this is not observed in all people. In some cases, the image of objects is focused behind the retina or in front of it. The result is myopia or hyperopia. Astigmatism is formed when the human eye does not have the ability to assemble the image into a single focus. This is due to the fact that the shape of some of the refracting media of the optical system is an imperfect sphere. Most often it is the lens or cornea of the eye. Complex myopic astigmatism occurs when the image is focused in front of the retina. As a result, objects seem fuzzy, blurry.
Causes of Astigmatism
In most cases, myopic astigmatism is a congenital defect, since it is laid in the prenatal period. The most common reason is heredity. In most cases, if one of the parents has astigmatism, then it is transmitted to the child. Rarely, only the baby has an irregular shape of the lens or cornea. In addition to parents, a defect can be transmitted from grandparents. Sometimes complex myopic astigmatism is formed as a result of intrauterine infections or injuries and does not depend on burdened heredity. In some cases, a defect in the optical system of the eye appears in adults. The following causes of acquired astigmatism are distinguished:
- Subluxation of the lens. Occurs during injuries.
- Scars on the cornea. May appear for various reasons (more often it is injuries and chronic dystrophic diseases).
- Changes in the shape of the upper jaw. Occur with a prolonged absence of upper teeth, malocclusion.
- Surgical interventions affecting the organ of vision.
- Inflammatory processes occurring in the cornea.
Most often, children have complex myopic astigmatism in both eyes. Visual acuity may be different. If a defect is acquired during a lifetime, then usually it is present in one eye.
The degrees of myopic astigmatism
Like all refractive errors, astigmatism has 3 degrees of severity. Depending on the age and stresses on the organ of vision, they can change throughout life. For example, in infants physiological astigmatism is observed, which is corrected independently by 2-3 years. In some cases, it develops rapidly and requires treatment in early childhood. Weak complex myopic astigmatism involves a change in visual acuity to 3 diopters. In childhood, it can be corrected. The average degree implies a decrease in visual acuity from 3 to 6 diopters. In addition to correction, it is necessary to wear special glasses. A severe degree of astigmatism begins with a decrease in severity from 6 diopters or more. This can lead to various violations. Often with a severe degree, strabismus develops, binocular and stereoscopic vision worsens .
The clinical picture with astigmatism
Symptoms of astigmatism depend on the severity. With weak severity, clinical manifestations may be absent. A change in visual acuity by 1.5-2 diopters becomes noticeable. Complaints usually occur at an early age (3 to 5 years). Children poorly see distant objects, letters. To better see the image, patients with astigmatism squint, pull their eyelids or turn their heads. Another symptom is rapid eye fatigue. It is especially noticeable after a stay at the computer, reading. Older children and adults complain of blurred vision. The following symptoms are distinguished: double objects, blur, inability to determine the approximate distance to the image. Also, after the load, patients may be disturbed by pain, a feeling of "sand in the eyes."
Complex myopic astigmatism in children: diagnosis
It is impossible to diagnose astigmatism without a special instrumental examination. Despite the characteristic complaints, you can not pick up glasses yourself. To diagnose the degree and type of astigmatism, an examination by an ophthalmologist is necessary. First of all, an assessment of visual acuity (the ability to see letters or pictures from a certain distance) is performed. Then a visometry is performed. This method consists in checking refraction by selecting lenses of different refractive powers. Each eye is examined separately (while the second is closed). It is also necessary to conduct a skioscopy. It consists in moving the shadow with swinging movements. In some cases (more often in children), refractometry is performed. To do this, pre-instill the eyes to achieve the expansion of the pupil (mydriasis). After - measure the refraction. Specialized clinics perform methods such as computed keratotopography and ophthalmometry. With their help determine the size of the lens and cornea.
What to do to maintain vision with astigmatism?
Complex myopic astigmatism requires constant correction. First of all, you need to know about the limitations of visual load. People with astigmatism should not spend much time in front of the TV and computer, reading in a dark room. It is also necessary to choose work with minimal eye strain (repair of small parts is not recommended). In severe astigmatism, you cannot drive a car and serve in the army. After visual work, it is necessary to perform special exercises for the eyes.
Complex myopic astigmatism: treatment of a defect
There are various methods for correcting this defect. Wearing contact lenses is considered the most preferred and common. They correct the shape of the cornea and help correct the complex myopic astigmatism of both eyes. Eyeglass treatment is more complicated as it is necessary to combine cylindrical and spherical lenses. Laser correction of astigmatism is also performed. It consists in changing the depth (polishing) of the cornea.