LASIK is a surgical procedure performed on the cornea of the eye to decrease a patient’s need for contact lenses or glasses. This procedure can be performed for nearsightedness, some farsightedness and some astigmatism.
The term LASIK is an acronym for Laser In-situ Keratomileusis, which simply means to shape the cornea by using a laser. The laser procedure is performed with an Excimer laser which produces a cool or nonthermal light beam to remove corneal tissue with accuracy up to .25 microns with each pulse of the Excimer laser. There is a tremendous amount of precision, control and safety in treating nearsightedness, farsightedness and astigmatism with the Excimer laser. The Excimer laser’s ability to remove corneal tissue has an accuracy up to .25 microns with each pulse of laser energy, making the Excimer laser well suited for correcting vision.
The LASIK laser vision correction is performed after obtaining accurate measurements of the eye’s curvature and refractive error. This information and its accuracy is absolutely necessary to provide for a good surgical and visual result. After the eye has been numbed with topical anesthesia, an eyelid speculum is used to separate the eyelids. A small suction ring is placed around the cornea and serves as a platform for an instrument known as a microkeratome. The microkeratome separates the surface layers of the cornea creating a protective flap that is folded back and, while the patient is asked to look at the target light, the laser performs its preprogrammed correction. The corneal flap is then placed back into its original position and allowed to dry for a few minutes. Additional eyedrops are prescribed and the eye or eyes are shielded for protection. The vision will probably be a little blurry at first; however, it improves as the day goes on and continues to improve over the next several days.
Nearsightedness (myopia) is treated by applying most of the laser pulses to the central cornea. This flattens the cornea, reducing its focusing power which allows light to focus further back in the eye. Farsightedness (hyperopia) is treated by applying most of the laser pulses to the peripheral cornea. This deepens the cornea, thus increasing its focusing power and allowing light to focus more towards the front of the eye. Astigmatism is treated by flattening axes that are too steep, and steepening other axes that are too flat, or a combination of the two.
LASIK is a popular procedure, but making the decision about whether to undergo LASIK is not about “hype”. This is a very personal decision about your vision. Not everyone can have refractive surgery, and eligibility depends on the amount of refractive error, the curvature and thickness of the cornea, and a number of other factors that an opthalmologist must evaluate.
LASIK is a surgical procedure and, like all surgeries, it possesses the potential for risks and complications. Despite the high success rate with laser corrective surgery, every patient should weigh the chance of experiencing complications against the potential benefits LASIK can provide.