With lasers emitting pulses of light measured in quadrillionths of a second and computers guiding doctors to make precise adjustments to the eye, LASIK is one of the most advanced medical procedures available. But the science that makes today’s procedure possible can be traced back more than four decades. Read on for a look at the latest on LASIK technology and how a history of innovations led to this life-changing treatment.
Computers have replaced blades for the many doctors who use the InterLase laser to perform LASIK. The use of this leading-edge technology literally helps shape LASIK — here’s how:
Before the procedure, the doctor uses a computer to help create a three-dimensional topographical map of the patient’s cornea and eye. This provides the doctor a precise view of the irregularities that need to be reshaped to improve vision. Then, during the procedure, lasers make the tiny changes necessary to improve vision. The result? Treating the cornea while preserving its original overall shape can minimize glare, halos and night vision problems. This technology also makes the process quicker and more precise.
“When LASIK first came out, the treatment was done in the central part of the cornea to flatten it,” said Sonny Goel, M.D., a LASIK doctor based in Baltimore. This can lead to an increase in spherical aberrations — glare and halos at nighttime.
“With this technology, we can actually soften that transition to preserve the cornea’s natural shape,” Dr. Goel said. Using all-laser LASIK also leads to shorter recovery times, less discomfort and reduced risk for dry eye syndrome, because the flap created by the laser is shallower than one created with a blade.
“The technology means no blades touch the eye, “which has been huge as far as safety, precision and predictability goes, along with improved patient comfort,” Dr. Goel said.
Other advances such as eye trackers help make LASIK easier, because patients don’t have to stare at one point during surgery.
Decades earlier, doctors exploring theoretical ways to correct vision by reshaping the cornea could only dream of computers and lasers, but that didn’t stop them from the pioneering work that made today’s LASIK possible.
Imagine lying on the operating table while the doctor removes your cornea, freezes it, takes it across town to his workshop to cut it with a special tool and then returns to reattach it to your eye. That’s the method a Spanish doctor named Jose Barraquer employed in the late 1940s to test his theory that reshaping the cornea could improve vision in a process called keratomileusis (which is what the “K” in LASIK stand for).
Building on Dr. Barraquer’s work, the introduction of photorefractive keratectomy (PRK), a forerunner to LASIK, helped make refractive vision correction more common. The procedure, approved by the FDA in 1987, remains a good treatment option for some patients. Its main disadvantage is it leaves the surface of the eye exposed following the procedure, because a thin layer of the cornea is removed. Some risks from PRK include a greater chance of infection and longer recovery times.
While his work might seem crude by today’s standards, Dr. Barraquer paved the way for several advances in refractive vision correction. When his research was combined with the development of the excimer laser about 30 years later, it made refractive vision correction safer and more practical. Excimer lasers use extremely quick pulses of ultraviolet light to precisely reshape corneal tissue.
In 1991, LASIK (Laser Assisted In Situ Keratomileusis) was introduced. By using a thin metal blade to cut a flap in the cornea, a laser could reshape the cornea before the flap is replaced.
Are other advancements coming down the road? Dr. Goel believes the equipment used in LASIK is truly state of the art. “I do believe the technology isn’t going to change much in the foreseeable future, because it’s that good,” he said, adding that current research on lasers explores how to use them to remove dead tissue on burn victims. Meanwhile, the next frontier for eye surgery could involve implantable lens technologies to treat more advanced eye diseases, according to Dr. Goel.