Amblyopia is a functional (non-organic), reversible visual impairment that occurs more often in childhood and adolescence. Amblyopia is not amenable to correction with the help of glasses and contact lenses, does not pass on its own, and most often is a secondary visual impairment.
What it is? When amblyopia eyes of a person see different pictures, they are differently involved in the visual process: one eye does not fully see, the brain can not reduce the visual picture in both eyes into one common, as a result, the work of one eye is completely or partially suppressed volume perception of objects, the sequence of their location in space, the sizes of objects are also evaluated inadequately.
It is precisely because of the slowing down of the development of the visual zones that the treatment should be carried out up to 7 years while the formation of the eyes takes place. In connection with the deterioration of the environment and as a consequence the presence of congenital pathologies, the disease is becoming more common, especially in children.
What is amblyopia - causes
Why does amblyopia appear, and what is it? As a rule, amblyopia develops in childhood. The main reason for the development of amblyopia - squint. But it can also develop with severe myopia or farsightedness, nystagmus (involuntary rhythmic oscillatory eye movements), as well as with astigmatism.
The risk factors for the development of amblyopia include the presence of strabismus, up to 6–8 years of age, a high degree of ametropia, and conditions conducive to deprivation (in this case, deprivation means that the visual stimulus is not received by the organ). In addition, risk factors include:
- lack of weight of the newborn;
- retinopathy of prematurity;
- cerebral paralysis;
- mental retardation;
- burdened family history in relation to anisometropia, isoametropy, strabismus, amblyopia, congenital cataracts.
Especially often amblyopia develops in people with a difference in the optical power of the eyes of more than three diopters. Sometimes the cause of amblyopia becomes an obstacle to the passage of light rays. This may be a scar, cataract, cataract, especially congenital, ophthalmoplegia (eye muscle paralysis), ptosis (eyelid ptosis).
Amblyopia can also develop in those who, with poor eyesight, do not wear glasses or lenses, whose eyes do not know what it is to "see well."
There are several types of amblyopia, each of which has certain features:
- Refractive amblyopia - the most common type, it is also called optical. The optics of the eye are broken - the rays of light of the eye refracts unequally. Occurs due to neglected astigmatism and rapidly progressive farsightedness. Doctors usually prescribe wearing glasses or contact lenses. In childhood, the disease is treated very successfully, the main thing is not to delay the start of treatment and not be shy to wear glasses.
- Disbinokulyarnaya amblyopia develops in violation of binocular vision with strabismus. One eye may suffer from severe strabismus. When this happens, the brain "turns off" this eye and the visual function completely falls on the other eye.
- Psychogenic amblyopia. Most often, this type appears in hysteria. Illness arises suddenly, often due to a very strong emotional shock. It is treatable, but with timely treatment. In this case, the patient may be recommended to visit a psychologist, as well as taking sedatives.
- Deprivation amblyopia develops when a cataract, thorn or similar disease develops, and causes vision problems. Sometimes deprivation amblyopia affects both eyes.
At the moment, there are five degrees of amblyopia, depending on the decrease in visual acuity:
- I degree - very weak amblyopia, visual acuity of 0.8-0.9.
- II degree - weak amblyopia, visual acuity of 0.5-0.7.
- Grade III - medium amblyopia, visual acuity of 0.3-0.4.
- IV degree - strong amblyopia, visual acuity of 0.05-0.2.
- V degree - very strong amblyopia, visual acuity Below 0.05.
The degree of development of ailment of the human optic organ depends largely on the level of development of associated diseases.
Symptoms of amblyopia
Pathology lies in the fact that a sore eye sees, as it were, a fuzzy picture that does not coincide with that which a healthy eye perceives. As a result of this dissonance, the brain cannot combine both pictures into one, due to which the weaker eye is gradually switched off from the process of image analysis and active work. As a result of such forced inaction, there comes a gradual decrease in vision on it.
Specialists have identified the main symptoms of amblyopia:
- Poor eyesight (one, both eyes);
- When reading, for example, a patient with amblyopia may tilt his head or close one eye;
- Violation of orientation in new unusual conditions, poor coordination of movements.
In most cases, a small degree patient with amblyopia does not even suspect its presence. Sometimes it happens, the patient accidentally reveals the different optical power of the eye, but in the initial stages of this disease is almost impossible to determine.
Diagnosis of amblyopia
Before you figure out how to treat amblyopia, you need to properly diagnose. Therefore, in order to correctly diagnose amblyopia, it is necessary to perform a comprehensive ophthalmologic examination. To do this, held ophthalmoscopy, biomicroscopy, the study of the fundus.
General information about the state of vision is obtained using ophthalmological tests: checking visual acuity without correction and against its background, color testing, perimetry, and refraction test. Depending on the decrease in visual acuity, the degree of amblyopia is determined.
Ophthalmoscopy, biomicroscopy, eye day examination with Goldman's lens are performed to examine the structures of the eye in amblyopia. To determine the transparency of refracting media (lens and vitreous body), an eye examination in transmitted light is used. When the media is not opaque, their condition is examined by ultrasound of the eye.
First of all, it should be noted that the younger the patient, the greater the possibility of obtaining a positive result of treatment of amblyopia. Treatment of amblyopia in adults is much more difficult. The whole point is that getting the fully formed components of the visual analyzer to work correctly is almost impossible. Visual problems that have not been cured in childhood are unlikely to be resolved in the adult period of life.
The best way to achieve and maintain high visual acuity is to develop normal binocular vision. For successful treatment, it is necessary to determine the type and eliminate the underlying cause of amblyopia. Most often these are the deprivation and inhibition of binocular vision.
One of the traditional and main methods of treating amblyopia is occlusion - turning off a healthy eye from an act of vision. For this purpose, special plastic occluders are used that are attached to the spectacle frame. In conjunction with occlusion, methods of light stimulation of the retina are used (stimulation of the central fossa of the yellow spot with white or monochromatic light of a flash lamp, a defocused helium-neon laser beam, classes of specially selected board games — mosaic, cubes, drawing), electrical stimulation of the optic nerve of the amblyopic eye, etc.
In general, treatment of the disease should be carried out under the constant supervision of a physician who will monitor the effectiveness of the chosen therapy, as well as its effect on the healthy eye.
If treatment is started before the age of five, then, as a rule, normal vision can be restored. However, even in this case, the child may remain a violation of the perception of the depth of objects. When treatment is started after 10 years, only partial recovery of vision can be expected.
The low result of treatment is often associated with parents ignoring the doctor’s recommendations, unwillingness to wear glasses to the child, a long search for a suitable specialist. As a result of these actions, time is missed, and the correction of the pathology should be carried out as soon as possible.