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| Astigmatism Treatment | Astigmatism can be diagnosed while examing routine eye, checking eye’s refraction (ability for proper focusing of light rays on the retina) and the sharpness of vision. You will be asked a lot of questions about your vision. The examination can be performed with a visual acuity test, a keratometer or keratoscope to assess the curvature of cornea and find out if astigmatism is moderate or severe.
Astigmatism can be treated with corrective lenses, eyeglasses and refractive surgery. There are such corrective lenses as contact lenses and eyeglasses. Contact lenses are very helpful in the correction of both corneal and lenticular astigmatism. Your eye doctor helps you to choose between hard, soft, extended wear, disposable, rigid gas permeable and bifocal lenses. People with astigmatism should wear special corrective lenses known as toric lenses that contain an additional power element known a cylinder. They have greater light-bending power in one axis than in others. Contact lenses are necessary in a procedure known as orthokeratology, or Ortho-K. In orthokeratology, you should wear rigid contact lenses for some hours a day. As soon as the curvature of your eye gets better, you may wear the lenses only for the maintainance of the new shape. But if you stop wearing them, your eyes will have their previous shape. People with severe astigmatism are advised to wear only rigid contact lenses (RGPs, also called GP lenses).
In the case of slight degree of astigmatism and the absence of any problems of refraction, such as nearsightedness or farsightedness, one may not apply corrective lenses. In the case of the great degree of astigmatism and the availability of eyestrain, headache, or distortion of vision, lenses are required.
Your eyeglass or contact lens prescription may contain three parts, for example -2.75 -1.25 x 90.
* The first part is your main spherical correction, it is the quantity of power (in diopters) necessary to make your vision better.
* Part two is the extent of the astigmatism in diopters. The minus sign is required when a concave lens is required.
* Part three is the axis (in degrees) of the cylinder necessary for bending light rays to compensate for the cornea's oval shape.
Refractive surgery is also very helpful in the correction of some forms of astigmatism. It is the change of the shape of the cornea using refractive or laser eye surgery. Refractive surgeries should also be performed on healthy eyes that do not have any retinal problems, corneal scars and any eye illnesses.
There are such refractive surgery methods as LASIK surgery, Photorefractive keratectomy (PRK) and Laser-assisted subepithelial keratomileusis (LASEK).
* LASIK surgery. Laser-assisted in-situ keratomileusis (LASIK) is a procedure of correction with an instrument known as a keratome for a thin, circular hinged cut into your cornea. A special cutting laser can also do a cut. The surgeon lifts the flap and with an excimer laser chanches the shape of the cornea under the flap. An excimer laser is much better comparing with other lasers, because it is not the source of heat.
* Photorefractive keratectomy (PRK). In PRK, there is a removal of the outer protective layer of the cornea before an excimer laser is applied for the change of the cornea’s curvature.
* Laser-assisted subepithelial keratomileusis (LASEK). In LASEK a much thinner layer of cornea is used. It is less vulnerable for the eye and helps to avoid damage. It is advised for those who have thin corneas or those who are prone to an eye injury at work or from sports activity.
Radial keratotomy is a procedure of astigmatism correction applied earlier. It is not used nowadays.
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