مهندسی پزشکی

"A method and apparatus for modifying the curvature of a live cornea via use of an excimer laser. The live cornea has a thin layer removed therefrom, leaving an exposed internal surface thereon. Then, either the surface or thin layer is exposed to the laser beam along a predetermined pattern to ablate desired portions. The thin layer is then replaced onto the surface. Ablating a central area of the surface or thin layer makes the cornea less curved, while ablating an annular area spaced from the center of the surface or layer makes the cornea more curved. The desired predetermined pattern is formed by use of a variable diaphragm, a rotating orifice of variable size, a movable mirror or a movable fiber optic cable through which the laser beam is directed towards the exposed internal surface or removed thin layer."^[77]

The patents related to so-called broad-beam LASIK and PRK technologies were granted to US companies including Visx and Summit during 1990-1995 based on the fundamental US patent issued to IBM (1983) which claimed the use of UV laser for the ablation of organic tissues.^[77]

Implementation in U.S.

The LASIK technique was implemented in the U.S. after its successful application elsewhere. The Food and Drug Administration (FDA) commenced a trial of the excimer laser in 1989. The first enterprise to receive FDA approval to use an excimer laser for photo-refractive keratectomy was Summit Technology (founder and CEO, Dr. David Muller).^[79] In 1992, under the direction of the FDA, Greek ophthalmologist Ioannis Pallikaris introduced LASIK to ten VISX centres. In 1998, the "Kremer Excimer Laser", serial number KEA 940202, received FDA approval for its singular use for performing LASIK.^[80] Subsequently, Summit Technology was the first company to receive FDA approval to mass manufacture and distribute excimer lasers. VISX and other companies followed.^[80]

The excimer laser that was used for the first LASIK surgeries by I.Pallikaris

Pallikaris suggested a flap of cornea could be raised by microkeratome prior to the performing of PRK with the excimer laser. The addition of a flap to PRK became known as LASIK.

Further research