January 7, 2004
Kellogg acquires cutting-edge equipment that eliminates the blade in LASIK surgery
Medical application for the ultrafast laser was developed at UM
Ann Arbor—Patients looking for the ultrafast laser, the newest technology in LASIK surgery, can now find it at the University of Michigan Kellogg Eye Center.
The IntraLase FS laser, which is available in just a handful of Michigan eye centers, represents an advance over conventional LASIK systems because it uses extremely rapid laser pulses rather than a blade in the critical first step of LASIK surgery.
Surgeons typically use a microkeratome with a blade to create and fold back a flap in the cornea. While the traditional system has a very low incidence of complications—less than 1 percent—the IntraLase FS is so precise that it virtually eliminates complications associated with the flap.
Paul R. Lichter, M.D., Director of the Kellogg Eye Center, expects to see gradual, widespread adoption of this technology. “For the moment, just a few ophthalmology practices have made the investment in the IntraLase unit. That will change as consumers demand the most advanced and nearly risk-free technology for vision correction.” Dr. Lichter, who participated in the early stages of research, says that the ultrafast laser also has potential for changing the way physicians perform certain glaucoma procedures and other cornea surgeries.
IntraLase representatives report that 85 units have been installed nationwide, and some 100,000 LASIK surgeries have been performed since the company was formed in 1997.
Traditional LASIK procedures begin by placing a suction ring on the eye, creating a vacuum to hold the cornea while the surgeon uses a metal blade on the microkeratome to cut a flap. The flap is folded back and then the laser corrects the patient’s vision. By contrast, the ultrafast laser creates the flap by using rapidly fired, very short pulses that can focus on a spot size of only 3 microns. The speed is measured in femtoseconds, a measurement equal to one quadrillionth of a second.
As a result the surgeon can create an exceptionally precise incision in the cornea. In addition, the ultrafast laser applies less energy to the corneal tissue so that there is little risk of damaging surrounding tissue. Because the edge of the incision is exceptionally smooth, the flap is more easily realigned when it is returned to its place after the surgery.
The idea for using the femtosecond laser in medical applications occurred to Ron Kurtz, M.D., while he completed a residency in the Department of Ophthalmology at the Kellogg Eye Center. He and several colleagues in Ophthalmology and the Center for Ultrafast Optical Science (CUOS) in the College of Engineering developed and patented the concept, eventually leading to the formation of IntraLase Corp. The UM Office of Technology Transfer office helped to bring the concept to market.
Tibor Juhasz, associate professor, Biomedical Engineering and IntraLase co-founder, explains that the femtosecond laser creates a string of three-micron bubbles just below the surface of the cornea. These bubbles then create a precise and well-defined incision through a process known as photodisruption. Dr. Juhasz explains that the ultrashort pulses of the femtosecond laser are made much more intense by a technique developed at the College of Engineering called chirped-pulse amplification. “These pulses are focused inside the cornea and vaporize tissue at the focal point. The result is a short-lived bubble of gas, which dissolves into the water in the cornea. A rapid sweep of the focus creates a surface of bubbles that define the underside of the flap, and a second cut, which is cylindrical, enables the surgeon to fold back the flap.”
In addition to its regular use for refractive surgery, the instrument installed at Kellogg will be used to research new applications for the femtosecond laser technology, such as posterior corneal transplants and a new procedure to treat glaucoma. These new research projects received NIH support as well.
For more information on LASIK and other surgery options at the UM Kellogg Eye Center, select www.kellogg.umich.edu/LASIK, call 734-615-6914 or email lasik@umich.edu.
Contact: Betsy Nisbet, 734.647.5586, bsnisbet@umich.edu.
Tibor Jushasz, Ph.D., Alan Sugar, M.D., and Paul R. Lichter, M.D.
But the installation of the new system means something more to Kellogg physicians and scientists. It represents technology developed at Michigan, a collaboration of scientists at the Eye Center and the U-M College of Engineering that led to the formation of IntraLase Corp., in Irvine, California.
