Ultrafast pulse 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 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) Centre for Ultrafast Optical Science (CUOS) and the university’s Kellogg Eye Centre.

In traditional LASIK (laser in situ keratomileusis) 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 is reported to emit 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.

Lasers with ultrashort pulse durations have been researched extensively for the machining of materials on the micrometer-scale, but they are new to medicine.

In attempting to harness their intensity, the scientific team discovered they were able to cut tissue with unsurpassed precision. The laser’s intensity is said to be thousands of times greater than are those of conventional lasers used in medicine.

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.