The excimer laser is no turkey-it gave us scarless eye surgery.
This year, an estimated 1.5 million nearsighted Americans will trust their eyes to laser-wielding surgeons. While the so-called LASIK (laser-assisted in-situ keratomileusis) procedure carries risks, many will toss their glasses and give thanks to their doctors. What they don’t know is that a leftover Thanksgiving turkey deserves credit too.
Just a few years after the 1960 invention of the laser, doctors began to use the new tool in eye surgeries, burning off tumors, for example, or “welding” torn retinas back together. But the technology of the 1960s and 1970s wouldn’t have allowed surgeons to operate on the cornea-the clear front portion of the eye whose curvature helps determine whether a person is nearsighted, farsighted or has eagle eyes-because the colors of laser light available at the time passed right through clear materials without doing anything to them. What’s more, because the first-generation lasers worked by heating tissue, they left scars.
But in 1977, the German company Lambda Physik marketed the “excimer laser,” which beamed out ultraviolet (UV) light, capable of cutting transparent materials. Within a couple of years, a chemist named Rangaswamy Srinivasan at IBM’s Research Division noticed another interesting fact about the new laser: Instead of burning a plastic material he aimed it at, the UV light etched a clean groove. Srinivasan brought his finding to his manager, James J. Wynne, and in October 1981, Wynne, Srinivasan and colleague Samuel Blum had a brainstorm: If the excimer laser was used in surgery, it might make incisions that would heal without scars.
Srinivasan and Blum performed the key experiment just after Thanksgiving, pointing the UV beam at some cartilage from Srinivasan’s leftover turkey. Sure enough, the laser etched a smooth groove without damaging nearby tissue. That first cut is shown in two views above, to the right of a charred cut that Wynne made with a traditional laser. By New Year’s Eve, Wynne had drafted a patent application covering surgical and dental uses of the excimer laser.
Exactly what happened next has been the subject of a labyrinthine series of legal and patent battles. Suffice it to say that doctors and researchers quickly saw the potential of the excimer laser to correct vision deficits, and set about perfecting new surgical techniques. LASIK-to date the technique that works best and requires the shortest healing time-won FDA approval in 1999, becoming the most popular elective surgery in the United States.