IBM's Excimer Laser Eye Surgery Inventors to be Inducted into National Inventors Hall of Fame

Laser Eye Surgery Improves Vision for More Than 5 Million People Within 8 Years of Commercialization

Yorktown Heights, NY, USA - 16 May 2002: Within only 8 years of commercialization, excimer laser surgery has already improved eyesight for more than 5 million people worldwide, including more than 2.5 million in the United States. Today, three IBM Researchers who invented the excimer laser surgical procedure, which laid the foundation for laser techniques to correct nearsightedness, astigmatism, and farsightedness, will be inducted in the National Inventors Hall of Fame.

Called Ablative Photo Decomposition (APD), the excimer laser procedure is a key part of LASIK (Laser in Situ Keratomileusis) and PRK (Photorefractive Keratectomy), both of which permanently re-shape the cornea using an ultraviolet excimer laser. The hallmark of this heatless, pulsed laser etching of tissue is the absence of thermal damage, which means living tissue can heal with virtually no scarring. Were scar tissue to form in the healing process, light would be scattered from cloudiness in the cornea. The patient would have deteriorated visual acuity, as if looking through a dirty pair of glasses or a dirty window.

The popularity of LASIK surgery has risen in large part because of the eye's rapid healing and the absence of pain following the procedure. Excimer laser surgery is so precise it can cut a clean pattern into a human hair without burning the strand.

IBM provided the resources, infrastructure, and exploratory environment that allowed three physical scientists working in a non-medical laboratory to discover a revolutionary technique to enhance vision, for which IBM received a patent in 1988.

The Discovery of APD
Until 1981, lasers used in eye surgery created regions of damage, resulting in the formation of scar tissue that had therapeutic value. For examples, visible lasers were used to spot weld torn and/or detached retinas, preventing further damage. However, such lasers were not suitable for corneal surgery, where scar tissue would interfere with, rather than enhance, vision.

Drs. Rangaswamy Srinivasan, James Wynne and Samuel Blum were conducting fundamental science research at IBM's T.J. Watson Research Center in 1981 when they considered the possibility of using the APD process for surgery on human and animal tissue. At Thanksgiving dinner that year, Srinivasan decided to run the first experiment on the turkey bone sitting before him. He brought the turkey bone to work, and the IBM team irradiated the cartilage on the end of the bone with both an ultraviolet excimer laser and a conventional, green laser. Looking at the startling difference between the clean incision produced by the excimer laser and the charred, damaged region produced by the green laser, the IBM team realized that they had uncovered a new phenomenon, which became the basis of their invention.

To demonstrate APD and convince the medical technology field in the most dramatic way, the team produced an image, or electron micrograph, of a highly magnified single human hair, in which precise cuts were etched by APD. Since people could relate to the heat sensitivity of hair, this image had a strong impact and was reproduced widely around the world. The U.S. FDA approved this a surgical procedure based on APD to reshape the cornea in ophthalmology in 1995, 14 years after the team's first experiment, and 7 years after the patent was assigned to IBM.

The not-for-profit National Inventors Hall of Fame® is the premier organization in America dedicated to honoring and fostering creativity and invention. Each year a new class of inventors is inducted into the National Hall of Fame in recognition of their patented inventions that make human, social and economic progress possible. Founded in 1973 by the U.S. Patent & Trademark Office and the National Council of Intellectual Property Law Associations, the Hall's permanent home is Akron, Ohio, and serves as both a museum and an educational programming resource. For more information or to nominate an inventor, go to

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