Eye amblyopia – causes, symptoms, diagnosis, treatment, prevention

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Eye amblyopia is a consequence of untreated strabismus. If the eye deviates from the normal position, the image of the outside world falls on a different part of the retina than in the normal eye looking straight ahead. This causes severe visual impairment and excludes the squinting eye from binocular vision. After some time, the amblyopia becomes permanent and the treatment becomes ineffective.

What is eye amblyopia?

Amblyopia is a condition characterized by a significant reduction in visual acuity for no specific cause, such as eye or optic nerve disease. The deviation of the eye from the correct position causes the image of the outside world to fall on a different part of the retina than in the healthy eye looking straight ahead. An eye that is partially sighted sees worse than a healthy eye by at least two rows on the Snellen chart. Amblyopia is a problem that manifests itself at the stage of visual development and may affect children up to the age of eight. The intensity of amblyopia depends mainly on the patient’s age, the younger the child, the greater the chance of amblyopia.

The causes of amblyopia

The most common causes of amblyopia are listed below.

1. One-sided strabismus – amblyopia develops due to inhibition of visual stimuli located in the cerebral cortex, most often located in the macula of the retina of the affected eye. Additionally, visual impairment is affected by the loss of the reflexive ability to position the eye in a way that allows the image of the observed point to fall onto the central area of ​​the retinal macula.

2. Myopia – if a person has a visual impairment whose difference between one and the other eye is more than 2,5-3D, the eyes perceive the outside world in a different size and sharpness, which unfortunately often causes problems with binocular vision. This situation causes the visual stimuli of the eye with a higher defect to be inhibited in the visual cortex (ultimately it is this eye that becomes visually impaired). Attention! In some group of children, amblyopia may be due to the presence of strabismus and optics at the same time.

3. Irregularity and hyperopia – these two conditions contribute to binocular amblyopia because blurry images appear on the retinas.

4. Limiting the use of the eye – vision problems in this case are related to the lack of appropriate stimuli affecting the development of visual efficiency and central retinal fixation. Limited use of the eye may be related to a drooping eyelid, cataracts, or covering the eye with a dressing for a long period of time.

Is amblyopia common?

Yes, amblyopia is one of the leading causes of poor visual acuity. According to the data, about 2 percent. the entire population suffers from amblyopia.

How is eye amblyopia manifested?

The main symptom of amblyopia is impaired visual acuity. However, we can distinguish several degrees of amblyopia.

1. High-grade amblyopia – occurs when your visual acuity is 0,1 or worse.
2. Moderate amblyopia – in this case, the visual acuity is more than 0,1, up to a maximum of 0,3.
3. Low degree of amblyopia – visual acuity ranges from 0,3 to 0,8.

Eye amblyopia – diagnosis

Eye amblyopia is diagnosed on the basis of an ophthalmological examination, which determines both the cause of the disease and its severity. The degree of amblyopia depends on age – younger children are more prone to this problem. The physician must always determine the defect of reflux after accommodation paralysis, no matter what the cause of the amblyopia. For this, the patient is administered tropicamide drops 1%.

The diagnosis of amblyopia involves the following tests:

1. determination of visual acuity from far and near (using black and white stripes),
2. monocular fixation,
3. contrast sensitivity,
4. electrophysiological test,
5. assessment of spatial vision,
6. assessment of binocular vision,
7. assessment of visual spatial location (the so-called fly test),
8. general ophthalmological examination,
9. crowding phenomenon.

How to cure eye amblyopia?

Eye amblyopia is treatable in children up to the age of ten. The sooner the treatment is introduced and the less advanced the disease is, the better the results are. Diagnosing a patient too late and starting treatment does not provide such improvement, and the disturbed visual acuity remains. If amblyopia is caused by strabismus, the patient should be treated in order to obtain the correct eye alignment.

The following are treatments for eye amblyopia:

1. amblyopia due to optically above 3D – the treatment aims to correct the refractive error using contact lenses, which reduce the difference in the size of the images seen with both eyes,
2. amblyopia due to not using the eye – in this situation, the doctor orders surgery, e.g. drooping eyelid,
3. wearing glasses or contact lenses at the explicit request of the doctor and according to his guidelines,
4. covering the healthy eye according to the doctor’s recommendations, it may be several hours a day or the whole day (depending on the degree of amblyopia). The healthy eye is covered with non-allergenic plasters glued on the eyelids or with a soft obturator attached to glasses,
5. the use of targeting exercises to improve eye coordination with the hand. The child draws, writes, paints looking at the visually impaired eye,
6. wearing glasses with incorrect lenses that will worsen your vision (penalisation)
7. localization exercises – they consist in setting the eye in a position that causes the eye to fix with a spot and locate visual stimuli straight ahead,
8. instillation of atropine in the eyes,
9. performing pleoptic exercises with the help of, for example, a euryscope. They consist in illuminating the retina of the visually impaired eye with a sharp light with the area of ​​disturbed fixation, while the retina in the macular area is blocked from the light, which is where the healthy eye fixes the image,

Eye amblyopia and prevention

The prevention of amblyopia involves the performance of appropriate preventive examinations, as well as the implementation of early treatment. It is also important to monitor your child and consult a doctor in the event of any disturbing symptoms. Early ophthalmological examinations are carried out in premature babies, who are at greater risk of strabismus and refractive errors. Also children with family history of amblyopia; squint; refractive errors and congenital eye diseases – all tests should be performed.

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