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Femtosecond Laser



Air Force SBIR/STTR Program Manager

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IntraLase Success Story

In the past, countless hopes of becoming a military pilot or astronaut were dashed by a single, unwavering requirement: naturally good eyesight. For those born with poor eyesight, standards as strict as 20/40 vision without glasses or contacts barred them from ever flying the fighter jet or space shuttle of their dreams.

But with the advent of corrective eye surgery — in particular, a cutting-edge, all-laser procedure — candidates previously considered ineligible can have their shot. By far, the most popular corrective eye surgery performed today is LASIK, or laser-assisted in situ keratomileusis.

Originally, a mechanical blade was used to cut a flap in the outer layer of the eye, which is then folded back to expose the underlying cornea. The cornea is then microscopically reshaped by an ultraviolet laser: flattened for nearsightedness, steepened for farsightedness, and uniformly smoothed for astigmatism. The flap is then replaced and left to heal.

However, blades have been associated with complications such as uneven edges and incomplete flaps. A bladeless system that uses a laser to cut flaps, first developed and commercialized by Irvine, CA-based IntraLase Corp., has boosted the quality and safety of eye surgeries worldwide. It can create accurate and consistent flaps with less complications and rapid recovery time.

The IntraLase FS Laser System makes precision cuts using femtosecond laser technology — an infrared light beam that pulses at 60,000 times per second. The system works in tandem with a reshaping tool called an excimer laser that uses ultraviolet light to shave off thin slices of the cornea. Together, the two lasers make up the key tools for the all-laser LASIK procedure.

"You're basically putting the prescription of your glasses into the cornea," said former President and CEO of IntraLase Randy Alexander. "I've had the procedure, and it's painless — just a drop of anesthesia on the eye, and it takes less than a minute."

Over 5 million surgeries and counting have been performed using the IntraLase system, and 75% of U.S. surgeons use a femtosecond laser for the majority of their LASIK cases. Recovery time after LASIK is rapid, and most patients notice improved vision within a few days.

Also, about a half dozen bladeless laser systems now exist on the market manufactured by IntraLase's competitors.

"The technology is now getting diffused into a number of different companies, and that's a good sign," said Dr. Ronald Kurtz, co-founder and former Vice President of IntraLase. He started the company in 1997 with laser physicist Dr. Tibor Juhasz.

A year later, the company received funding from multiple sources, including the Air Force Small Business Innovative Research (SBIR) program, which helped take femtosecond lasers from the confines of research laboratories to the offices of ophthalmologists worldwide. In 2001, the IntraLase FS Laser System received approval from the Food and Drug Administration.

"We knew we had something revolutionary that would take the LASIK procedure to another level in precision and safety," recalls Alexander.

The market agreed. The company went public in 2005, growing from $18 million to $100 million. After two years, the company was acquired by eye care product manufacturer Abbott Medical Optics Inc. for $877 million.

IntraLase traces its humble beginnings to the campus of University of Michigan in Ann Arbor, where two decades ago, Kurtz was an ophthalmology resident on the hunt for an interesting patient case. He examined a researcher who had suffered an accidental retinal injury from a femtosecond laser in the lab, and a lightbulb went off.

At the time, corrective eye surgery was a growing field, so Kurtz considered the possibility of using a femtosecond laser for making fine incisions. He teamed up with laser expert Juhasz to found a start-up company based around the development of a such a tool to correct refractive errors.

Refractive errors are those that occur when the shape of the cornea or lens prevents the eye from focusing correctly. Types of refractive errors include myopia (nearsightedness), hyperopia (farsightedness), and astigmatism. An irregularly shaped eye can cause blurry vision by preventing light from focusing properly on the retina, the light-sensitive surface at the back of the eye.

The LASIK technique to reshape the eye was originally pioneered around 1950 by Colombia-based ophthalmologist Jose Barraquer. At his Bogota clinic, he developed the first mechanical tool for cutting corneal flaps, a small rotating blade called a microkeratome.

Alexander became familiar with the pitfalls of the microkeratome early on in his medical device career, before joining IntraLase. When he met Kurtz and Juhasz in 1998, he was fully convinced that their product would provide a safe, precise alternative to the complication-prone microkeratome.

"With my background of LASIK, I understood the imprecision of the microkeratome and the drawbacks of that technology," describes Alexander. "Then I saw the IntraLase technology, which was very precise."

The device is like a remote-controlled, high-precision scalpel that uses light instead of a blade. A computer-guided infrared laser is focused to an area within the cornea where it emits extremely fast light pulses to create an incision. The laser's small spot size translates to a minimum of amount of damage to surrounding eye tissue.

"Essentially, the femtosecond laser allows you to make incisions in transparent materials and tissues like the cornea with very high precision and accuracy," Kurtz explains. "This can't be done with a traditional laser."

The femtosecond laser cuts a flap, which is opened to expose the inner cornea. Then an excimer laser reshapes the eye by removing very fine, quarter-of-a-micron slices of tissue. The flap then is put back to its original position, where it is left to heal.

Kurtz and Juhasz performed proof-of-concept studies using eyes from animals, with promising results. They secured funding from venture capital firms, as well as small business grants from the National Institutes of Health, the Department of Defense, and the National Science Foundation.

An early grant included the Air Force's SBIR award in 1998 to improve the system's laser source. For instance, early systems had slower pulses that created more of a perforated corneal flap, whereas today's laser pulses are rapid enough to make a continuous incision.

"It was very early, and we needed those funds to really get the project going," said Alexander. "In those days, femtosecond lasers were completely new, so developing that took a lot of work in optics and power sources, and all aspects of the laser had to be refined."

Also the price was a hurdle that had to be overcome — a femtosecond laser cost $450,000 in those days, versus a $50,000 microkeratome. They got the price down to the range of $300,000 over the years using volume and purchasing improvements.

The company came full-circle when the Air Force and Navy approved LASIK for flight training candidates. Previously, having the procedure disqualified applicants due to concerns about flap stability and quality of vision with LASIK. Also, such extreme conditions faced by aviators were worrisome, such as dry air, low air pressures, or ejection from a high speed aircraft.

Numerous thorough studies were conducted on the safety and recovery time of all-laser LASIK compared to an older technique called photorefractive keratectomy (PRK). PRK, which removes the entire outer layer of the cornea without creating a flap, had previously been the only corrective surgery approved for aviators.

Results showed that all-laser LASIK was safe, effective, and consistent. After the procedure, patients had rapid visual recovery and excellent quality of vision. LASIK was approved for Air Force and Navy pilot candidates in 2007, and later that year, NASA approved the surgery for astronaut applicants.

"This technology that the Air Force supported a decade earlier eventually came to actually have some direct benefit for expanding the pool of aviators," said Kurtz. "It was an incredible challenge to take such a complex technology and bring it to everyday medical practice."

The technology developed by IntraLase continues to have an impact greater than the extent of the company itself, as more medical applications of femtosecond lasers are discovered. For instance, Kurtz left IntraLase to found LenSx Lasers Inc., a company that developed the first femtosecond laser cleared for use in cataract surgery.

And in 2005, the FDA approved the IntraLase FS Laser System for corneal transplants, a procedure that can replace diseased or scarred tissue in the cornea to combat blindness.

"Those incisions have to be made very precisely, and so [corneal transplant is] a really elegant application," said Alexander. "These are patients that are blind, so that's really treating a disease versus someone who is near-sighted or far-sighted."