Astigmatism

Astigmatism

Astigmatism is part of a group of diseases caused by refractive disorders: the flow of light does not pass correctly through the optical media of the eye, with its refraction distorted.

Astigmatism is a widespread disorder of vision: it is diagnosed in about 80% of the population, often combined with myopia or hyperopia.

With astigmatism, the shape of the cornea changes, less often – of the lens. It is accompanied by incorrect breaking and scattering of rays, as a result of which an incorrect image is formed on the retina. The beams are deprived of the ability to focus on one point, so people with astigmatism see objects a little blurry. Some lines can be clear, while others are blurry, with objects stretching in different positions, etc.

Classification

Specialists, depending on the severity of the changes, distinguish three degrees of astigmatism:

• weak degree – up to 2 dioptres;
• medium – from 2 to 5 dioptres;
• high – more than 5 dioptres.

The more apparent the symptoms of vision disorder, the harder it is for the ophthalmologist to correct the changes.

By its nature, one can distinguish congenital and acquired astigmatism.

There is clinically insignificant astigmatism, which does not need any correction, since it does not affect visual acuity and is not accompanied by other abnormalities of health. Astigmatism of 1 dioptre and above requires treatment. It is especially important to take this into account in childhood, since information is perceived with distortions, and this can affect the child’s mental development, and also increase the risk of other eye diseases. At the same time, the child will not always complain to the parents, since he or she cannot imagine what normal vision is.

Acquired astigmatism appears after suffering eye diseases, trauma, eye surgery, etc.

Symptoms of astigmatism

The basic symptoms of astigmatism:

• the need to squint for a better vision of objects;
• deterioration of near and far vision;
• eye strain when working with a computer or telephone;
• tension headaches when trying to focus on one point;
• disorders of the psychological and emotional state;
• the need to tilt your head to get a better look at objects;
• difficulties at work or school due to the rapid fatigue.

Diagnosis of astigmatism

For a timely diagnosis, you should see an ophthalmologist once a year: symptoms are not always apparent, and children cannot always express their complaints.

For the diagnosis of astigmatism, the ophthalmologist can perform:

• refractometry – with the help of the device, the refractive power of the eye is analysed;
• test of visual acuity using projection tables – it is performed for everyone who goes to the ophthalmologist;
• sciascopy – it is performed in a dark room with a preliminary dilation of the pupil, and is an effective way to identify refractive pathologies;
• keratopography – an examination of the shape and curvature of the cornea;
• computed tomography – you can examine all eye tissues with maximum accuracy and determine their configuration.

Astigmatism treatment

The choice of treatment depends on the severity of the disease, on the patient’s complaints, as well as on concomitant vision disorders. Doctors try to compensate for the disorders by conservative methods which are non-surgical and have fewer risks of complications. Surgical techniques are used in neglected cases when it is impossible to effectively help the patient in other ways.

The basic treatments for astigmatism are:

1. Correction with glasses – they are prescribed for permanent wear.
2. Wearing special rigid contact lenses. These lenses are effective even with a high degree of astigmatism.
3. Surgery – at this stage, there are many techniques which enable you to quickly and effectively change the configuration of the lens or cornea. In severe cases, these tissues can be replaced, with a permanent lens inserted into the eye to correct the disorder. The surgery is performed when other treatment options are ineffective. All risks are necessarily assessed, with a full package of documents and necessary test results collected, to assess the readiness for a surgery.