Refractive surgery includes procedures that are designed to eliminate or reduce the need for glasses or contact lenses. These techniques change the curvature of the cornea and that in turn changes the focus onto the retina. These procedures have been successful in the treatment of nearsightedness and farsightedness, combined with astigmatism. At Coal Harbour Eye Centre we perform two different types of laser eye surgery - LASIK & PRK. Although the techniques are different, similar results are achieved. What makes one person a candidate for one surgery over the other is dependant on their corneal thickness or any irregularities or scars on or near the front surface of the corneal. The eye care specialists at Coal Harbour Eye Centre will be able to identify for you which procedure would best meet your refractive needs.
LASIK (Laser In-Situ Keratomileusis)
LASIK is a form of outpatient corneal surgery in which, the eye is numbed with anesthesia and a surgeon uses a specialized and precise instrument called a microkeratome, to create a thin flap of corneal tissue. This flap is raised and folded back while a portion is still attached to the cornea surface creating a hinge. The surgeon then uses an excimer laser to remove a pre-determined amount of corneal tissue from the exposed bed of the cornea. The amount of tissue to be removed is calculated based on the pre-operative determination of the power of your eye and the size of the pupil. After the laser treatment has been completed, the debris is gently removed and the flap is replaced. Within minutes the flap begins to adhere itself back to the cornea, no stitches or sutures are required. The surface epithelium of the cornea begins to grow over the incision edge of the flap to seal it into position. LASIK is used to correct nearsightedness (myopia) and farsightedness (hyperipia) and astigmatism.
PRK (Photorefractive Keratectomy)
PRK is a form of outpatient corneal surgery in which a surgeon removes the front surface of the cornea (the epithelium). Epithelium can be removed with the laser itself, and can be scraped with surgical instruments, or it can be removed with a brush that looks like a small circular sander. Or it can be wiped off after alcohol has been applied to the epithelium to loosen it up. Any of these methods work and the outcomes are very similar. Dr. Kirzner has found the alcohol method to be the best method of epithelial removal.
Please don't be under the illusion that epithelial removal is a non-surgical procedure. Anytime one removes tissue from the body, whether it is with a scalpel or with laser thermal energy, this is a surgery.
After the epithelium is removed the corneal bed is then reshaped with the laser in the same way as in LASIK. After the procedure the patient will wear a soft contact lens (bandage lens) until the epithelial layer has regenerated itself (usually within five to six days). Healing responses vary from patient to patient. This technique is usually used for people whose cornea may be too thin to allow for the creation of the corneal flap required for LASIK. The procedure is used to correct nearsightedness (myopia) and farsightedness (hyperopia) and astigmatism.