Astigmatism - is a pathology of view, the resulting infringement of the lens structure (less cornea), the deformation of its shape, consisting in Defocus optical rays passing through eye protection. As a result, the image is not exactly falls on the retina, and enables distortion. Astigmatism often combined with visual impairments in the form of nearsightedness or farsightedness.
general information
Normal healthy cornea and the lens surface are in the form of flat areas eye with astigmatism has curved surfaces. As a result, passing through the distorted cornea and the lens, the image is formed on the retina is defective: it takes part of the retina, the part is focused in front of her. As a result, one sees a distorted image - partly clear, partly - blurred. Rough idea of astigmatism can be obtained by looking at herself in the reflection on a teaspoon.
Astigmatism referred to ametropia - eye refractive power disturbance and distortion in the rear chamber, wherein image focus is formed. Disease occurs in about 8-12% of all vision problems, today there are highly effective methods of its correction.
Causes
Astigmatism origin is congenital, hereditary character and the acquired.
play a role in congenital astigmatism:
- century uneven pressure over the ocular unit,
- disruption of the eye muscles,
- violation of the orbital bone formation.
Acquired astigmatism is the result:
- scarring of the cornea,
- eye injuries,
- eye surgery,
- corneal dystrophy,
- corneal opacity,
- keratitis (Corneal inflammatory process).
Kinds
According to defeat refracting medium astigmatism divided into corneal and lenticular.
By origin share:
- congenital (otherwise known as the "right" - the two mutually perpendicular axes are arranged in a straight line)
- Acquired (incorrect - two perpendicular meridian arranged in skew positions).
The correct astigmatism can be divided into simple form - in one of the awns normal vision, complicated - in both axes reduced eyesight, mixed - along different axes differently vision.
Astigmatism can also be divided into:
- saline, to a maximum of 0.5-1D, it has no effect on visual acuity and often in children,
- pathological - a 1D, most often it is acquired origin.
When combined with visual impairment astigmatism say myopic (nearsightedness) and hyperopia (farsightedness), astigmatism.
According to the severity of astigmatism share:
- low degree of distortion to 3D,
- moderate distortion with 3 to 6D,
- heavy distortion above 6D.
symptoms of astigmatism
Astigmatism in children
Symptoms usually occur in children are as follows:
- confusion of letters when reading or writing,
- replacing letters in syllables,
- complaints of blurred vision,
- distortion of objects, their lack of clarity,
- bouts of headaches,
- unpleasant sensation around the eyebrows,
- rapid visual fatigue,
- feeling cramps in the eyes,
- discomfort from wearing glasses with their frequent replacement.
Symptoms in adults
Especially alert in adulthood should:
- of Defocus,
- eye fatigue,
- loss of picture clarity,
- roughness and deformation of objects,
- blurred images,
- pain in the eyes with redness,
- double vision when visual load,
- violation of determining distances to objects.
Diagnostics
First of all - requires an ophthalmologist consultation with the definition of visual acuity and a comprehensive assessment of the state of the eye. apply:
- Inspection structures of the eye,
- study of refraction,
- viziometriya with correction and without it,
- skiascopy (shadow sample) with spherical or cylindrical lenses,
- refractometry with artificial mydriasis,
- biomicroscopy of the eye to determine the cause of astigmatism,
- ophthalmoscopy to investigate the state of the vitreous body,
- US all eyes and Oftalmometres (determination of its size).
- computer corneal topography to determine the degree of corneal defects.
treatment of astigmatism
Diagnosis and treatment of astigmatism, ophthalmologists engaged. Apply a few basic types of correction:
- glass correction,
- lens correction,
- mikrohirugicheskaya correction
- laser surgery.
Correction is needed when astigmatism of one diopter or more, while a progressive process, eyestrain.
Glasses and lenses picked individually, an operation performed after failure points in the progression or correction process.
The prognosis for a favorable time begun treatment - can be completely correct or eliminate astigmatism.
