The world of optical care was revolutionized during the 1990s through the expanded use of laser-assisted in situ keratomileusis, or LASIK eye surgery. The incredibly high precision surgery offers remarkably low instances of negative side effects when compared with other optical surgeries because of the fine precision of the lasers used in these procedures. Since the use of lasers to etch and otherwise modify living tissue was first discovered in IBM research facilities in the early 1980s, a range of laser-assisted surgical procedures for vision correction have been developed, such as photorefractive keratectomy (PRK) and laser epithelial keratomileusis (LASEK). Recently, the U.S. Food and Drug Administration released the findings from its most comprehensive study to date on LASIK eye surgeries in the U.S., which showed that about 95 percent of survey respondents receiving LASIK surgery achieved 20/20 vision or better. The report also showed that ghosting, halos and other visual aura decreased in LASIK patients after their procedures as well.
November 15 of this year was the 26th anniversary of the issue of one of the seminal patents in the field of laser-assisted vision correction surgeries. However, it wouldn’t be until after the filing of the patent application that anyone would think to use this laser technology as a surgical procedure for the eyes. Here at IPWatchdog, we return to our Evolution of Technology series on with a profile of the intriguing progression of the use of LASIK procedures in vision care. The use of excimer lasers in vision correction procedures has revolutionized that field from the humble beginnings of corneal surgery in the 1940s towards today, a time when more than 16 million LASIK operations have been performed in the United States. The story of this technology involves a trio of researchers who were simply trying to find new uses for lasers, and perhaps the most practical use of Thanksgiving leftovers that the world has ever seen.
Eye Surgeries and Optic Procedures Before LASIK
Surgical methods of modifying the cornea of a patient suffering from vision problems were pursued decades prior to the use of LASIK surgery. Perhaps the earliest name in the field of corneal surgery was Father Waclaw Szuniewicz. Born in 1892, he trained in ophthalmologic care for five years at the Stefan Batory University of Wilno, Poland, leaving in 1927 and then serving as a missionary in China for nearly 20 years. While serving as the head of ophthalmology for a Chinese hospital in Shuntehfu, Szuniewicz directed a 100-bed facility and oversaw 18 outpatient facilities, interacting with as many as 145,000 patients in a year by one account.
By 1948, Szuniewicz had begun to pioneer the use of refractive corneal surgeries involving the modulation of corneal curvature in patients. He was the first to test out the theory that surgically changing the shape of a patient’s cornea could produce positive results in vision correction. By the end of the 1940s, Szuniewicz had travelled to the United States to continue his work at Yale University. He would develop refractive surgery techniques in the U.S. and Brazil until his retirement in 1954.
Another major step towards the reality of LASIK technologies would be discovered by the early 1960s, when José Ignacio Barraquer would make public the procedures he developed for keratomileusis, which means “sculptured cornea” in Greek. The keratomileusis taught by Barraquer involved the removal, modification and reinsertion of a patient’s corneal disc. The corneal disc was often frozen to enable shaving and other modification procedures. Along with refractive surgery, Barraquer also helped to improve keratoplasty, specifically corneal transplants, especially in regards to the use of sutures in these procedures.
Just prior to the discovery of the ability of excimer lasers to interact with living tissue, another development in vision correction was discovered in the Soviet Union in the 1970s. Radial keratomy (RK), which involved a series of deep and precision incisions made in a patient’s eye to reshape the cornea, was pioneered by Dr. Slava Fyodorov as a treatment for nearsightedness. Although he wasn’t able to profit on his invention until the fall of the Soviet government, Fyodorov would go on to become one of post-Soviet Russia’s first millionaires. It would eventually turn out that many of those undergoing RK procedures would become farsighted over time.
Excimer Lasers and a Good Use for Thanksgiving Leftovers
Back in the United States, a trio of researchers with expertise in some diverse fields were brought together by the International Business Machines Corporation at the company’s research facilities in Yorktown Heights, NY. The team consisted of materials scientist Samuel Blum, photochemist Rangaswamy Srinivasan and physicist and team manager James J. Wynne. The trio was instructed by IBM to work with excimer lasers, which had just been acquired by the company, to see what type of work they were capable of performing.
Early on, the researchers noted the ability of excimer lasers to react with materials, and Srinivasan discovered that excimer lasers could be used to etch polymer materials. The excimer laser performed this etching by emitting pulses of ultraviolet light which were created when mixing reactive gases like fluorine or chlorine with inert gases such as argon, xenon or krypton. The team discussed the potential for using excimer lasers on skin and human tissues, which share some properties with polymers. If the excimer laser could etch skin finely enough, it could create minute incisions that can heal without a scar, much like a paper cut.
Sitting at the dinner table with his family on Thanksgiving in 1981, Srinivasan looked at his turkey dinner and a brilliant thought occurred to him: a leftover bone with cartilage would provide the perfect test subject. To that point, none of the test subjects considered by the group, from goldfish tails to burger meat from the IBM cafeteria, seemed all that feasible. The cartilage and other tissues attached to the turkey bone could approximate the physical structure of human tissue, and the smoothness and rigidity of the cartilage would make it easier to read the results of the experiment.
On November 27, 1981, the team operated an argon fluoride (ArF) excimer laser to create a clean etching on the turkey’s cartilage that could be viewed when placed under an optical microscope. Further tests on the cartilage helped the team understand how many laser pulses were required to make a cut, the amount of energy delivered via the laser beam and the impacts of the laser on adjacent tissues.
The team found that, instead of burning the living matter around the cut, the laser instead disrupted the molecular bonds in such a way that effectively disintegrated those connections, producing an extremely clean cut which created no evidence of damage to surrounding tissues. Immediately, the team discussed the application of excimer laser technologies as a possible method of making surgical incisions for brain surgery, orthopedics, dermatology and dentistry. Some of the team’s research is reflected in U.S. Patent No. 4784135, entitled Far Ultraviolet Surgical and Dental Procedures. The patent claims a method for removing selected areas of a biological layer comprised of organic material by irradiating a selected area with pulses of ultraviolet radiation having wavelengths of less than 200 nanometers. The patent was issued on November 15th, 1988, jointly to Blum, Srinivasan and Wynne.
Stephen Trokel and LASIK Eye Surgery
In the 1980s, vision correction procedures had certain drawbacks. Cold steel procedures for correcting nearsightedness were imprecise and required a long recovery time for patients undergoing procedures. The use of new methods which could replace the scalpel used in these surgeries were desired.
Ophthalmologist Stephen Trokel of the Columbia Presbyterian Medical Center in NYC realized that the work done by the trio of IBM scientists could impact the world of vision correction. Trokel came to IBM’s Watson Research Center in 1983 to work with Srinivasan and researcher Bodil Braren on methods of using excimer lasers for corneal refractive surgical procedures. A December 1983 paper published by this trio discussed the use of lasers to sculpt a patient’s cornea to treat either myopia, or nearsightedness, and hyperopia, or farsightedness. Trokel, along with Richard T. Daly of Huntington, NY, is listed as an inventor on U.S. Patent No. 4638801, which is titled Laser Ophthalmic Surgical System. The patent protects an apparatus for performing microsurgery on a tissue of an eye that focuses a laser beam onto an eye with respect to the angle of a slit image. This was issued to the inventors on January 27th, 1987.
Trokel performed the first laser surgery for vision correction on a German patient in 1988. The procedure would not become an accepted medical practice in the United States until 1995, when the U.S. Food and Drug Administration granted its first approval of commercial excimer laser-based refractive surgery system. The specific procedure known as LASIK, however, wouldn’t reach FDA approval until 1999. This procedure is based on a method protected by Dr. Gholam A. Peyman of Chicago, IL, through U.S. Patent No. 4840175, which is titled Method for Modifying Corneal Curvature. It protects a method of removing a thin layer from the front of a patient’s live cornea to expose an internal surface which is ablated with a laser to remove a three-dimensional portion and replacing the corneal layer, all without freezing any eye tissues. This patent was issued on June 20th, 1989.
Blum et al v. Trokel et al
If you search the Internet you will likely find numerous references to Trokel inventing LASIK. Indeed, this seems confirmed when you look at the patent numbers. The patent to Blum et al is 4,784,135 and Trokel’s patent is 4,638,801. With Trokel’s being the smaller number that means his patent issued first, which doesn’t make sense unless the National Inventor’s Hall of Fame inducted the wrong inventors for the invention of LASIK. Blum, Srinivasan and Wynne were all inducted into the Hall of Fame for having invented LASIK in 2002, and then all receiving the National Medal for Technology from President Obama in 2013.
One of the first things that appears in the text of any patent is a claim to prior applications. If you take a look at the ‘135 patent (to Blum et al) and the ‘801 patent (to Trokel) you notice the first paragraph in the Blum text says that this patent relates to an application filed on December 9, 1982. The first paragraph of the Trokel text says it relates to an application filed on July 6, 1983. Thus, the Blum patent has the earliest filing date and is first in time even though the Trokel patent issued earlier.
What we know is that neither Trokel nor his co-inventor Richard Daly are in the National Inventors Hall of Fame, which perhaps is a serious oversight (no pun intended). Whether it was the Blum team or the Trokel team that deserves most of the credit for inventing LASIK is largely irrelevant. With any revolutionary innovation is is frequently very difficult, if not completely impossible, to accurately identify any single inventor or group of co-inventors as having been “the inventor(s)” of the innovation. By its very nature innovation and invention requires standing on the shoulders of those who come before, building on the achievements of others.
LASIK Surgery Today
LASIK surgery may be the most common form of laser-assisted vision correction procedure performed in the United States, but it is not the only one. Photorefractive keratectomy (PRK) allows a surgeon to remove a portion of a patient’s cornea or epithelial tissue without creating a flap. The procedure is better for patients with thin corneas but it requires a longer recovery time. Laser epithelial keratomileusis (LASEK) also uses lasers but starts with the application of alcohol to the corneal epithelium to loosen the outermost corneal cells, allowing them to be moved and not removed during the procedure. Surgeons have also developed a procedure referred to as Epi-LASIK, where a flap is created only in the epithelium layer of a patient’s eyes.
We did a quick search of the USPTO databases and found a few patents issued over the past year which are representative of current R&D activities in the field of laser-assisted vision correction surgeries. A higher degree of precision in LASIK surgeries is made possible by the technology protected by U.S. Patent No. 8858624, which is titled Method for Increasing the Depth of Focus of a Patient. The method protected by this patent, which was issued last month to AcuFocus Inc. of Irvine, CA, enables the use of LASIK procedures to treat presbyopia, a condition causing blurred visual focused that often comes with age. Techniques to improve the recovery time of patients after LASIK surgeries are protected by U.S. Patent No. 8591025, entitled Eye Covering and Refractive Correction Methods for LASIK and Other Applications. Assigned to NexisVision Inc. of Menlo Park, CA, in November 2013, the patent protects a method of treating patients after LASIK surgery that involves the application of a covering to the patient’s eye.
We also noted one intriguing patent that may protect a new procedure that could improve upon LASIK’s vision correction benefits. U.S. Patent No. 8882757, simply titled Eye Therapy System, protects a system of treating an eye disorder which involves the application of a thermokeratoplasty applicator for applying thermokeratoplasty therapy to a patient’s eye. Thermokeratoplasty refers to the application of electrical energy in the microwave or radio frequency to raise the corneal temperature to 60° Celsius, at which temperature the corneal collagen fibers shrink, reshaping the corneal surface. The procedure is entirely non-invasive and wouldn’t cause dry eye complications resulting from severed optical nerves.