Although LASIK eye surgery only formally began being performed in 1992, its roots date back to the 1960s when eye Dr. Jose Barraquer of Colombia developed a technique called keratomileusis to correct vision deficiencies. During this vision correction procedure, an instrument called a microkeratome was used to shave off a thin cap of corneal tissue. This cap was treated similarly to a contact lens – it was removed, reshaped, and finally replaced onto the eye. This procedure was the precursor of LASIK and followed the same principles of removing tissue to reshape the cornea to correct optical errors.
In the late 1970s, the arrival of the excimer laser allowed refractive surgery to take a new turn. Although it was first developed by the computer industry for the etching of computer chips, this precise laser was the long-awaited tool that eye Drs. needed to take refractive surgery to the next level. The excimer laser was capable of producing exact, clean cuts without thermal damage to surrounding structures. This led to the arrival of a new technique, Photo Refractive Keratectomy (commonly referred to as PRK).
During the PRK laser procedure, an eye Dr. first removes the front surface of the cornea, called the epithelium, and then reshapes the corneal bed with the excimer laser. In order to reshape the cornea, the laser beam vaporizes predetermined tissue away, without burning or affecting any other part of the eye. This tissue bed does not regenerate itself. However, the outer layer replaces itself over time.
The first international use of the excimer laser on the human eye to correct myopia occurred in 1987, and the laser was approved by Health Canada for the treatment of myopia and astigmatism in 1990. It was during that year that several centers across the country began to use it. Eye Drs. still use PRK to correct nearsightedness (myopia), farsightedness (hyperopia), and astigmatism in individuals who cannot safely undergo LASIK and it gives similar long term results to LASIK.
In the early 1990s, eye Dr. Buratto of Italy and eye Dr. Pallikaris of Greece combined techniques, keratomileusis and PRK surgery, thereby creating the basic concept of LASIK surgery. In contrast to PRK surgery, a laser eye surgeon uses a specialized and precise flap-making instrument, called an automated microkeratome, to cut a thin flap of corneal tissue. This flap is raised and laid back while still attached to the cornea. The surgeon then uses the 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 refractive error of the eye. The flap is replaced and within minutes, natural forces hold the flap down onto the cornea. Within a few hours, the surface epithelium of the cornea begins to grow over the cut edge of the flap to seal it into position.
In comparison to PRK laser vision correction, LASIK eye surgery is a more comfortable vision correction procedure characterized by less complications and significantly faster visual recovery. Just like PRK laser eye surgery, LASIK laser vision correction is used to correct nearsightedness (myopia), farsightedness (hyperopia), and astigmatism.