Astigmatism eye surgery, also called refractive or laser eye surgery, refers to several types of surgical procedures that reshape the cornea, the clear front surface of the eye, when it has an abnormal curvature. Abnormal curvatures, or astigmatism, of either the cornea or the lens immediately behind it cause blurred vision. The goal of each type of astigmatism eye surgery is to correct the irregularly shaped cornea or lens, allowing light to travel through the cornea so that it properly reaches the retina located in the back of the eye. Different types of astigmatism eye surgery might be recommended, depending on the degree of astigmatism present. Among the different types of astigmatism eye surgery are laser-assisted in situ keratomileusis (LASIK), photorefractive keratectomy (PRK), laser epithelial keratomileusis (LASEK), laser thermokeratoplasty (LTK) and astigmatic keratotomy (AK).
During LASIK surgery, the most common type of astigmatism eye surgery, astigmatism is corrected by reshaping the corneal tissue so that it can properly direct light into the eye and back to the retina. The corneal tissue is reshaped by scraping it with a highly focused laser beam of light. A flap is then created in the outer layer of the cornea, so that the underlying tissue can be accessed. LASIK eye surgery is very effective for people who are nearsighted and farsighted, as well as those with astigmatism.
PRK surgery is a type of laser eye surgery that is used to correct mild to moderate astigmatism, nearsightedness and farsightedness. During this type of laser eye surgery, the eye surgeon reshapes the superficial and inner layers of the cornea with a pulsing beam of ultraviolet light. No cutting is required during a photorefractive keratectomy.
LASEK surgery is a newer form of astigmatism eye surgery that is used to treat astigmatism, nearsightedness and farsightedness. It combines many of the benefits of LASIK and PRK. During the LASEK procedure, there is no scraping or cutting of the eye. An epitheal flap is created with a 20 percent alcohol solution that removes a small amount of corneal tissue by vaporizing it.
LTK surgery is a type of non-contact laser refractive eye surgery that is used to treat astigmatism and farsightedness. During LTK surgery, a laser beam shrinks and reshapes the cornea in seconds, without any cutting or removal of corneal or lens tissue. It is a quick procedure, but LTK is not a permanent laser eye surgery solution, because eyes change with age. Additional surgery might eventually be required.
AK surgery is a surgical procedure used to correct astigmatism rather than a form of laser eye surgery. During AK surgery, one or two incisions are made at the steepest section of the cornea. The cornea then relaxes, taking a rounder shape. AK refractive eye surgery might be used alone or in conjunction with laser eye surgeries.