If you have a refractive error, such as nearsightedness (myopia), farsightedness (hyperopia), astigmatism or presbyopia, refractive surgery is a method for correcting or improving your vision. There are various surgical procedures for correcting or adjusting your eye's focusing ability by reshaping the cornea, or clear, round dome at the front of your eye. Other procedures involve implanting a lens inside your eye.
For people who are nearsighted, certain refractive surgery techniques will reduce the curvature of a cornea that is too steep so that the eye's focusing power is lessened. Images that are focused in front of the retina, due to a longer eye or steep corneal curve, are pushed closer to or directly onto the retina following surgery.
Farsighted people will have refractive surgery procedures that achieve a steeper cornea to increase the eye's focusing power. Images that are focused beyond the retina, due to a short eye or flat cornea, will be pulled closer to or directly onto the retina after surgery.
Astigmatism can be corrected with refractive surgery techniques that selectively reshape portions of an irregular cornea to make it smooth and symmetrical. The result is that images focus clearly on the retina rather than being distorted due to light scattering through an irregularly shaped cornea.
Refractive surgery might be a good option for you if you:
The best option for you should be decided after a thorough examination and discussion with your ophthalmologist.
Photorefractive keratectomy (PRK) is a type of refractive surgery where ophthalmologist uses a laser to change the shape of your cornea. This improves the way light rays are focused on the retina. PRK is used to treat myopia (nearsightedness), hyperopia (farsightedness) and astigmatism. The goal of photorefractive keratectomy is to correct your refractive error to improve your vision. PRK may reduce your need for eyeglasses or contact lenses. In some cases, it may even allow you to do without them completely.
During Lasek, a microsurgical instrument called a trephine is used to create a flap of epithelial corneal tissue, and an alcohol solution is used to loosen the epithelial cells. Once the epithelial flap is created and moved aside, the procedure is the same as PRK. After corneal sculpting, the epithelial flap is repositioned and smoothed with a small spatula, then secured with a "bandage" soft contact lens to promote epithelial healing, which takes about four days.
On the other hand, for EpiLasik a special microkeratome, the Epi-keratome, is used to precisely separate a very thin sheet of epithelial tissue from the cornea. This thin sheet is lifted to the side and the cornea is treated as with PRK. Then the thin sheet may be moved back into place to re-adhere to the cornea or removed. A "bandage" soft contact lens is applied and used for about four days to help the epithelial layer heal.
Other Option of Refractiv Surgery is Phakic IOLs that are designed for people with high degrees of refractive errors that cannot be safely corrected with corneal-based refractive surgery. Go to Phakic Intraocular Lenses (IOLs) for more information.