Laser vision correction, also referred to as LASIK surgery, uses a precise cool beam of light from an excimer laser to remove a thin layer of cornea. Removing microns of the cornea flattens its shape and improves the eye’s ability to focus. This laser is used in the three most popular forms of refractive treatment:
Laser Assisted In-Situ Keratomileusis (LASIK)
In laser assisted in-situ keratomileusis (LASIK), the physician uses a special instrument called a microkeratome. Drops are placed in the eyes to numb the cornea. The microkeratome makes a flap in the cornea about 130 to 160 microns thick and about nine mm in diameter. The precisely cut, thin corneal flap remains attached to the cornea by a hinge. The flap is then gently folded back exposing the underlying cornea. The excimer laser is then used to achieve the desired correction. The flap is gently put back to the original position without the need of stitches. The cornea has amazing bonding power, which allows the flap to stay in place.
Laser Epithelial Keratomileusis (LASeK)
Laser epithelial keratomileusis (LASeK) is a procedure that combines features of both PRK and LASIK. Like LASIK, a flap of tissue is created that allows exposure to the inner aspect of the cornea. Rather than using a microkeratome device to create the flap, LASeK requires a dilute alcohol solution that weakens the outer layer of the cornea - called the epithelium - enough so that a flap can be created with a blunt instrument. The treatment then continues the same as a LASIK procedure, with the epithelial flap being carefully repositioned once the laser is completed.
Photorefractive Keratectomy (PRK)
In photorefractive keratectomy (PRK), the excimer laser reshapes the cornea by removing particular cells of the outer layer. In 1995, the FDA approved PRK to correct up to seven diopters of myopia. It may be used to correct hyperopia, or farsightedness, as well. Because the laser beam is so precise, only the surface of the cornea is affected. A contact lens is then put into the treated eye, acting like a bandage while the cornea is healing for the first 24 to 48 hours.
These proven procedures can help people enjoy their lives with better vision and freedom from glasses and contact lenses. Though some people are not good candidates for laser vision correction, other options such as intraocular lens implantation, refractive lensectomy, INTACS and Conductive Keratoplasty are also available.