How a purloined research device, an ounce of bravery, and a physician with a death grip brought about a brilliant medical enlightenment.
When a medical laser changes or saves a life, a handful of curious New York ophthalmologists and an audacious scientist are the ones to thank. Back when the laser was an exhilarating new technology—physicist Theodore Maiman created the first working laser at Hughes Research Laboratories in Malibu, Calif., in 1960—a group of doctors based at New York’s Bellevue Hospital sought to test the effects of a laser beam on a living eye. Being ophthalmologists, they feared that a direct hit could be disastrous. But the only way to know for sure was to try it.
In a loan that was not strictly aboveboard, the doctors “borrowed” the laser from the downtown Manhattan office of Technical Research Group (TRG), a defense private research firm. It was the first working example TRG had made, and they had set it aside to tackle the creation of different types of lasers. TRG physicist Gordon Gould, the man credited with hitting upon the principles that made lasers possible and invented its identifying acronym, had learned of the physicians’ request and chose to help, even though he was then fighting a tedious and ultimately fruitless battle with the U.S. government for a security clearance. (In his younger days, Gould had been associated with a Marxist study group. Unsurprisingly, this did not play well in the McCarthy era and Gould never did receive his clearance.) Many in his position would have flatly refused the doctors, not wanting to do anything that could possibly jeopardize the case, but Gould went ahead. He and another sympathetic TRG employee who had a security clearance snuck the two-piece laser out of its storage in a classified part of the building and spirited it away to Bellevue.
The doctors had already chosen a rabbit for their test subject, but were not sure how to protect their own eyes during the experiment. The very novelty of the laser stumped the highly educated medical experts, who settled on the dubious strategy of simply shutting their eyes when the time came. The role of Milton Zaret, MD, left him vulnerable: As the designated rabbit wrangler, he had to keep one eye open to ensure the test subject was correctly positioned.
When the deed was done, Dr. Zaret let go of the rabbit and found it distressingly limp. Fears that the laser was to blame melted away when he realized he had inadvertently squeezed it to death. The doctors then examined the deceased’s target eye and saw that the laser had indeed burned a hole in its retina, but not its vitreous humor or its surface structures. The truth dawned as bright and searing as the beam itself: The laser could serve as a scalpel made of light. Within months, ophthalmologists at what is now New York–Presbyterian Hospital performed the first laser surgery on a human being.
In its early days, the laser was described as “a solution looking for a problem.” It has since solved an impressive number of problems in its 55 years of existence, including many that had no solution before it came along. Not only was ophthalmology transformed by the laser, but so was dermatology, the specialty practiced by Leon Goldman, MD, the founding president of the American Society for Laser Medicine and Surgery (ASLMS). “These technologies were most rapidly adopted where you just plain could not do anything before,” says Raymond Lanzafame, MD, MBA, a general surgeon and continuing medical education director for the ASLMS. “An example from ophthalmology is the detached retina. There was not much you could do in 1960. But after 1960, there was much that you could do.”
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Although the fact is mostly forgotten now, the word laser is an acronym that stands for light amplification by stimulated emission of radiation. A range of materials are fit for “lasing,” as the verb form of the word is known. The earliest lasers relied on pink rubies; others now employ organic dyes, chemicals, or gases such as carbon dioxide, argon, and helium. Different wavelengths are suited to different medical applications. Argon gas lasers can address diabetes-related eye problems while the excimer laser, a type that usually combines a noble gas with a reactive gas, is better for eye surgeries that correct nearsightedness, farsightedness, and astigmatism. A solid-state holmium:yttrium-aluminum-garnet (or Ho:YAG) laser is the choice for breaking up kidney stones, and pulsed dye lasers are often aimed at port wine stains, unwanted tattoos, and other skin issues.
Medical lasers are also helping to combat some of the worst cancers and their effects. Claudio Tatsui, MD, assistant professor of neurosurgery at the University of Texas MD Anderson Cancer Center in Houston, has adapted a new technique—MRI-guided laser interstitial thermal therapy (LITT)—for use against the spinal tumors that can arise in patients whose cancers have metastasized. The therapy was initially used against hard-to-reach brain tumors and involves threading a laser probe directly into the malignant tissue and attacking it by, in essence, cooking it: delivering heat that denatures its proteins and melts its lipids, while leaving surrounding healthy tissue alone. The MRI lets medical personnel monitor the process in real time, and they can program the computer controlling the probe to stop when it reaches a specific temperature.
MRI-guided LITT became available to Dr. Tatsui in 2012 and has shown promise. Spinal tumors need to be cleared because they cause incontinence and paralysis, but most are best treated with radiation, and the dose that will kill the tumor is inevitably larger than what the spinal cord can withstand. Preparing and stabilizing the spinal area for radiation used to require surgery to remove enough of the tumor to permit a precisely focused dose that avoids hitting the spinal cord. This required a large incision, several days of convalescence, and cessation of chemotherapy for the main cancer while the patient recovered. MRI-guided LITT permits Dr. Tatsui to make a far smaller incision, which in turn shortens recovery time and lets patients return to chemotherapy faster. “It is amazing,” he says. “I have patients come here and get back to oncology treatment the next day.” Since November 2013, he has treated the spinal tumors of 27 patients who have stage IV cancers and only four failed. Of those, two underwent the laser procedure again and the other two received conventional surgery. “It is a very exciting technique that I think will have a role in management of spinal metastases,” he says.
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Lasers have also been quite useful in the hands of trained specialists for even routine general surgery tasks. Wavelengths suitable for delivery via fiber optics are helpful for procedures like gallbladder removal: The carbon dioxide laser can be carried by a waveguide or used as a beam of light focused by lenses. “You can use it like a noncontact scalpel,” says Dr. Lanzafame as he recounts the carbon dioxide laser’s merits: It can cauterize and sterilize tissue; it can reduce bleeding and inflammation; its beam can shrink to a size smaller than a human hair, allowing for exceptionally precise targeting of diseased tissue; and it eliminates the risk of the surgeon accidentally dragging tumor cells, bacteria, or other nasty stuff across the surgical wound. And as with the cancer patients who underwent Dr. Tatsui’s laser treatment, hospital stays are often shorter, too.
While lasers have zapped cancerous cells, airway obstructions, and other potential killers, a great deal of their medical uses are life-changing rather than lifesaving. No one will die for lack of LASIK, but the impact of sight-improving operations on individual patients is far from trivial. “We routinely correct the vision of policemen, pilots, firemen, astronauts, people who need good vision if their glasses fly off,” says Marguerite McDonald, MD, clinical professor of ophthalmology at NYU School of Medicine and a past president of the American Society of Cataract and Refractive Surgery.
Dr. McDonald recalls from her training days some pushback from the medical community on the idea of attacking maladies that cause anguish, but not death. “What got some people anxious was using lasers to get rid of glasses,” she says. “And there was a romantic notion that any doctor would have to be better than a laser in surgery.” On the contrary; sometimes modern lasers can prevent costly, tragic errors. “The lasers have all these fail-safes in them,” she says, explaining that it is possible to load an ophthalmology laser with information about the unique appearance of a patient’s eye: “If the next person lies down [on the operating table] and the live image of the eye does not match the image that has been loaded into the laser’s computer, the laser turns itself off.” She says the weight of the evidence—many thousands of eye surgeries that successfully corrected patients’ vision and resulted in few side effects—ultimately stemmed the concerns. “In retrospect, it is kind of laughable to read the past letters to the editor of medical journals, but [people] were genuinely worried,” she says.
Five decades onward, the laser is still yielding novel treatments for intractable problems as well as pointing the way toward solving them. In 2013, laboratory researchers at the National Institutes of Health and the Ernest Gallo Clinic and Research Center at the University of California, San Francisco, reported they might have found an on-off switch for cocaine addiction by aiming lasers at a specific region of the brains of rats. Scientists first inserted light-sensitive proteins into the rats’ prelimbic prefrontal cortexes. Stimulating the region with laser light activated the proteins, killed the cravings, and wiped away the addictive behavior, while using the same process to alter the brain activity in nonaddicted rats turned them into compulsive cocaine-seekers.
Recently, a company called Stroma Medical announced human testing for a laser procedure that will literally make brown eyes blue by removing a layer of pigmentation from the iris. Dr. McDonald confirms that the endeavor is legitimate. “It is in the earliest phases,” she says, explaining that human trials needed to earn U.S. Food and Drug Administration approval for use in the United States would not happen anytime soon, but “the early data from outside the U.S. are looking very good.”
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Prometheans Abound
It is not unusual for great minds to reach the same discovery close at each other’s heels. The laser is a marvelous example of this phenomenon. Albert Einstein had long ago predicted that wave energy could be amplified and directed when the maser—the “m” standing for microwave—was devised, arising from a 1954 experiment at Columbia University’s physics department by professor Charles Townes and some of his graduate students. Its success prompted scientists to wonder if its underlying principles could apply to waves of light. Townes and Columbia student Arthur Schawlow won acclaim when their 1958 paper Infrared and Optical Masers explained how a laser could be made. All that remained was for someone to accomplish the task.
Unbeknownst to Townes and Schawlow, another Columbia graduate student, Gordon Gould, had figured it out first in an epiphany that came as he was nearing the completion of his doctorate work. He set aside his studies to chase this tantalizing idea that he christened the laser, and once he had committed his revelations to paper, he dated his notebook (Nov. 13, 1957) and had it notarized. In an ironic twist, it had been Townes who advised Gould to protect his ideas by having them formally witnessed.
Less than two months after Townes and Schawlow received a patent based on their optical maser (aka laser) work, Theodore Maiman, a physicist at Hughes Research Laboratories in California, won the laser race. His creation, which relied on a tiny rod of ruby, produced a 10,000-watt beam for a few millionths of a second. Townes, Schawlow, and Maiman were celebrated; Gould received the anonymous honor of having coined the device’s name but embarked on what was dubbed “the 30-year patent war” to establish, and then defend, his place in the laser’s brilliant history. —S.G.S.
