Treatment of Astigmatism

Astigmatism is one of the three main refractive errors of the eye, along with myopia (nearsighted) and hyperopia (farsighted). Astigmatism means that light is focused into two points of light inside the eye, rather than one. This occurs because the front of the eye, the cornea, is oval or football shaped rather than round. A less common type of astigmatism is due to the lens inside the eye being oval shaped rather than round (lenticular astigmatism).

Since astigmatism rarely exists alone, its treatment usually involves treating the entire refractive error in which it resides, such as myopia with astigmatism or hyperopia with astigmatism. Except for extreme types of astigmatism, almost all degrees of this refractive error can be corrected with Laser Vision Correction, such as LASIK, at the same time myopia or hyperopia is corrected.

Astigmatism can also be corrected during cataract surgery with a special intraocular lens (IOL) made by Alcon Surgical, or by an extra incision in the cornea that rounds it out (Limbal Relaxing Incision or Astigmatic Keratotomy). Uncorrected astigmatism, like uncorrected myopia or hyperopia, causes blurred vision and can be corrected by eyeglasses.

Astigmatism is caused by a corneal curvature that is oval-shaped rather than perfectly round. An astigmatic cornea is football-shaped, focusing light to two different points on the cornea which creates blurry vision. To achieve clear vision, glasses or contact lenses fuse these two points of light and move that single point onto the retina. Astigmatism can blur both nearsightedness and farsightedness, and can be corrected in the same manner with the excimer laser.