Ultrafast laser offers high precision for cutting corneal flap

Researchers have developed a procedure for using an ultrafast laser to make clean, high-precision surgical cuts in the human cornea. The procedure is expected to advance the popular LASIK eye surgery by reducing complications due to traditional manual cutting techniques.

The laser technology and surgical procedures were developed at the University of Michigan by a joint team of physicists and ophthalmologists from the National Science Foundation (NSF) Center for Ultrafast Optical Science (CUOS) and the university's Kellogg Eye Center. The team reports on the procedure in the June 2001 issue of Ophthalmology Clinics of North America.

“The collaborations were very important in this project, which allowed us to apply the precision of physics and materials science to a medical application that benefits a large number of people,” said CUOS Director Gerard Mourou.

LASIK surgery, or laser in situ keratomileusis, has revolutionized vision correction surgery. In traditional LASIK surgery, a mechanical blade called a microkeratome is used to cut a flap of cornea, an excimer laser is used to reshape or remove a portion of the cornea, and the flap is repositioned. Now, surgeons can use the very precise femtosecond laser to create the initial flap. The laser emits light in extremely fast pulses, each pulse roughly a billion times faster than an electronic camera flash. Use of the femtosecond laser to cut corneal flaps is more precise than previous methods, reduces the chance of uneven cuts or collateral tissue damage, and improves clinical safety.

Two members of the Michigan team, Tibor Juhasz and Ron Kurtz, founded a new company to commercialize the laser, with support from NSF, the National Eye Institute of the National Institutes of Health, and the Department of Defense in the form of Small Business Innovative Research (SBIR) grants. The IntraLase product, the Pulsion FS laser, was introduced at the American Society of Cataract and Refractive Surgery meeting in San Diego, Calif., in April 2001. It is expected to be widely available in the United States within a year.

Researchers are now exploring the possibility of extending this technique to other eye procedures, such as cornea transplants or glaucoma treatment. One potential application is creating new drainage systems in the eye when those systems are not functioning adequately. “We have barely begun to explore the myriad of uses that the femtosecond laser offers in the clinical management of glaucoma,” said Paul Lichter, director of the Kellogg Eye Center.