Laser In-Situ Keratomileusis (LASIK) LASIK (acronym for laser in-situ keratomileusis) treats nearsightedness (myopia) farsightedness (hyperopia) and astigmatism by using an ultraviolet wavelength laser to remove tissue from within the cornea of the eye (see INTRO page for details). It is a revolutionary form of lamellar refractive surgery, performed since 1949. LASIK uses an extremely accurate laser, the excimer laser, to remove corneal tissue. Cas Swinger, M.D., first introduced lamellar surgery for nearsightedness into the United States in 1978. Because visual recovery is so rapid following LASIK, both eyes are often treated at the same session. First (a), a thin layer of the cornea, the "corneal flap", is lifted up by an automatic microkeratome, a delicate razor-like instrument, that glides through the cornea (blue dome). Then (b), the excimer laser (yellow arrows) removes the proper amount of corneal tissue (red area) with great accuracy (to 0.25 microns, or1/2500th of a millimeter). The number of pulses and the size and shape of the laser beam control the amount of tissue removed. The thin corneal flap is then folded back into its original position (c), flattening the cornea and correcting myopia. LASIK is performed as an outpatient procedure in the laser surgical suite. Surgery is performed without stitches or injections. The entire procedure takes about 15 minutes for both eyes and the entire stay less than an hour. The eye is anesthetized using only eye drops. There is no pain during the procedure, and patients experience little or no postoperative discomfort. Visual recovery is rapid and most patients experience dramatic improvement in their uncorrected vision within 24 hours. In some cases, the vision may not stabilize for a week or more. Most patients return to work within one or two days. You will be examined the day after surgery and again after one week and 1-3 months. Because the laser acts within the cornea rather than on the surface, as in PRK, there may be less risk of scarring or corneal haze. Additional advantages of LASIK over PRK include reduced need for postoperative medication, typically only four days, and the ability to correct more severe myopia. It may also preferable for correction of farsightedness. Use of the microkeratome to create the corneal flap in LASIK, however, carries additional risks. Should the flap created be unsatisfactory to accommodate the laser portion of the procedure, the procedure may be aborted (in 1%) and completed after about three months. Typically, there are no sequelae in such instances. Should the uncorrected postoperative vision be less than expected and some prescription remain, an enhancement procedure can be easily performed by lifting the flap and applying a small amount of laser energy. This is typically done after three months. Comparison of PRK & LASIK PRK LASIK Range of Correction Low to moderate Low to severe Wound Depth Superficial 20% deep Intraoperative Pain None None Post-operative Discomfort Minimal, 12-24 hours Minimal, 12 hours Post-operative Medications 2 to 4 months 4 days Functional Vision Recovery 3 to 5 days 24 hours Return to Work 1–2 days 1 day Risk of Complications Low (less surgeon dependent) Low (more surgeon dependent) Risk of Corneal Scarring 1 ~ 2 % <1 % Patient Satisfaction High Very High .

Swinger Vision MEETH Laser Center 210 East 64th Street, NYC Tel: 212-579-5500 Fax: 212-288-6434 E-mail: laser@swingervision.com