In the early 1960s, Kelman (a newly appointed staff ophthalmologist at the Manhattan Eye, Ear, and Throat Hospital in New York City) began to fantasize about a procedure that would cause less trauma, restore vision quickly, and get people back on their feet sooner. He conjured up the idea of removing a cataract through a tiny slit. To extract the lens, he would need to liquefy or fragment it inside the eye and then suck out the debris through the incision — a procedure that would become known as phacoemulsification — “phaco” for “lens” and “emulsi” for “milk out.”
For three years, he attacked this problem with a $299,000 grant from the John A. Hartford Foundation and cats as patients. In his first scheme, he snared the lens in a small rubber pouch, crushed it, and slid out the bag. But the bags broke and couldn’t be sufficiently miniaturized. Next he tried breaking up the lens using small drills and blenders.
But they sometimes snagged the iris and, even if they didn’t, Kelman had to chase the lens around inside the eye, marring other structures in the process. He realized he needed a way to hold the lens in place while he drilled — but even with that innovation, the cats went blind: Splintering the lens hurled material against other parts of the eye.
On the brink of failure — six months before his grant would run out — he visited his dentist. At the time, ultrasonic probes for removing tartar were relatively new. When Kelman felt the vibrations and heard the high-pitched noise of that apparatus, the solution popped into his head. He needed a tool that accelerated so quickly, the lens could not back away, vibrate, or rotate with the tip. An ultrasound machine would pulverize the lens without damaging the surrounding tissue, he realized.
Working with engineers, Kelman adapted the gadget for his purpose. He outfitted the unit with a small hole through which to suction off the broken up cataract. To avoid boiling the eye with heat generated by the vibrations, he devised a cooling system. He finally succeeded in removing a cat’s cataract without blinding the animal.
Eventually, Kelman developed a phacoemulsification unit from which today’s are derived. He practiced for several years, improving the apparatus so it would perform reliably enough to be used on a person.
In 1967, he carried out the procedure on his first human. This patient’s eye was blind and painful from glaucoma, and it needed to be removed. It also had a cataract. Kelman didn’t intend to fix the eye, but to find out whether the procedure was feasible. More than four-and-a-half difficult hours later, he had completed the task, but he had mangled other parts of the eye — the cornea and the iris — in the process. For the next couple of years, he refined his strategy. He realized, for example, that he needed a gentle, controlled vacuum that would suck out the broken cataract without also collapsing the cornea. Eventually he made the device work safely. He continued to improve the tool so other ophthalmologists could reliably conduct the surgery — and he began to teach the technique, thus ensuring its large-reaching impact. By 1985, about 15 percent of all cataract removals in the United States were done by phacoemulsification; by 1990, that number had risen to 50 percent, and by 1996 it had reached 97 percent.
Artificial lenses were invented in 1949 by the ophthalmologist Harold Ridley, but their implantation in patients undergoing cataract operations was relatively limited until the 1980s. By then, a number of ophthalmologists, including Kelman, had enhanced their design. The improvements led to flexible folded lenses that fit through the small incision and unfurled once within the eye. These lenses restore good peripheral vision and depth perception with minimal distortion and magnification. Advances in this realm have helped obviate the need for the unwieldy and optically inadequate glasses.
Today cataract surgery involves a 1.5–3.0 millimeter incision. Instead of submitting to eight or ten sutures, patients usually need none. They go in for cataract surgery in the morning and can be back at work in time for lunch. Visual acuity returns almost immediately and people return to their normal activities within hours or days.
In 1992, President George H.W. Bush awarded Kelman the National Medal of Technology, and this year he was inducted into the National Inventors Hall of Fame. His peers named him Ophthalmologist of the Century in 1994.
Kelman’s success marked a radical moment not only in cataract surgery, but in multiple medical specialties, turning myriad inpatient procedures into outpatient ones and bestowing on millions of people gifts of health and quality of life. Practitioners in other areas picked up on his idea of removing unwanted tissue through a tiny hole to improve, for example, gall bladder and joint surgery. Neurosurgeons have also adopted the emulsification machine to dissect tumors from the brain and spinal cord. Surgeries that used to require multiple-week hospitalizations can now be performed in minutes, thus reducing the risk of life-threatening clots and difficult-to-treat hospital-acquired infections as well as other complications.
Kelman died on June 1, 2004. At the request of his widow, Ann Kelman, the Lasker honorarium will be awarded to the International Retinal Research Foundation in his memory.
by Evelyn Strauss
Key publications by Charles Kelman
Kelman, C.D. (1967). Phacoemulsification and aspiration: A new technique of cataract removal. Am. J. Ophthalmol. 64, 23–25.
Kelman, C.D. (1969). Phacoemulsification and aspiration: A progress report. Am. J. Ophthalmol. 67: 464–477.
Kelman, C.D. (1994). The history and development of phacoemulsification. Int. Ophthalmol. Clin. 34, 1–12.
Kelman, C.D. (2000) Phacoemulsification. In The University of Miami Bascom Palmer Eye Institute Atlas of Ophthalmology, R.K. Parrish, II, ed., Current Medicine, Inc., Philadelphia, pp. 247–256.
Kelman, C.D. (2001) Kelman electromagnetic technique. In Cataract Surgery and Intraocular-lenses: A 21st Century Perspective, Second Edition, J.G. Ford and C.L. Karp, eds., 2001, American Academy of Ophthalmology, pp. 182–190.