Light was already used in medicine
This article describes the history of the technology. It is not medical advice and does not say what treatment suits any condition.
Doctors were interested in light long before lasers existed. In the 1940s and 1950s the German ophthalmologist Gerhard Meyer-Schwickerath experimented with focused light, first sunlight and later a xenon arc lamp, to make small burns on the retina, an approach called photocoagulation. The idea was that a tiny, controlled burn could seal or alter a spot in the eye. Results were limited by the lamp, which gave a broad, hard-to-control beam. When lasers arrived, they offered a much finer and more intense source.
The earliest laser experiments
Within a couple of years of Maiman’s 1960 ruby laser, medical researchers were testing it. Reports from the early 1960s describe experiments on the eye and on skin. At Columbia University in New York, researchers including Charles Campbell reported using a ruby laser on a retinal problem around 1961 to 1963. In dermatology, Leon Goldman in Cincinnati was among those who studied how laser pulses interacted with skin and pigment.
These were exploratory studies, often on small numbers of patients or on animals, and the technology was far from routine. Ruby lasers were also pulsed and not very convenient.
Argon, neodymium and carbon dioxide
New laser types arrived quickly, and each suited particular tissues.
- The argon laser, developed in the mid-1960s, emits blue-green light that is absorbed well by blood and pigment. It became a standard instrument for retinal photocoagulation in the 1970s.
- The carbon dioxide laser, developed by Kumar Patel at Bell Laboratories in 1964, emits infrared light that is absorbed strongly by water and therefore by soft tissue. Surgeons began using it in the late 1960s and 1970s to cut and vaporize tissue with limited bleeding, particularly in delicate procedures.
- The neodymium YAG laser, also from the mid-1960s, penetrates deeper and was used in a range of surgical and ophthalmic roles.
Fiber optic cables made it easier to bring laser light to places inside the body. Light guided through thin glass fibers could be sent through an endoscope, a slender instrument, so that surgeons did not always need to open the body widely. This progress in optical fibre also benefited non-laser tools such as imaging endoscopes.
The excimer laser and the cornea
An important later chapter began in the early 1980s, when researchers at IBM, including Rangaswamy Srinivasan, James Wynne and Samuel Blum, found that short pulses of ultraviolet light from an excimer laser could remove material with extraordinary precision, without much heat damage to the surrounding area. They had been studying the process for use in electronics and polymers.
Eye researchers recognized the potential. Experiments in the mid-1980s, including work by Stephen Trokel and collaborators, showed that an excimer laser could reshape the cornea, the clear front surface of the eye. Studies in people followed in the late 1980s, and regulatory approvals for vision correction procedures in various countries came over the 1990s. The related technique called LASIK, which uses a thin flap of corneal tissue, was developed in the same period, with Greek ophthalmologist Ioannis Pallikaris among those credited with early work. Because details of who first did what are debated, these names are best read as examples of key contributors, not a final ranking. The history of how corrective eyewear such as soft contact lenses developed is separate.
Other medical uses
Lasers entered several other areas over the following decades.
- Dermatology, including treatment of birthmarks and other skin conditions, as lasers were developed that matched the colors of particular targets in the skin.
- Dentistry and oral surgery, where lasers were tested for cutting soft tissue.
- Urology, where lasers were developed to break up stones.
- Surgery, where laser scalpels and, later, laser-assisted tools joined other instruments, sometimes alongside surgical robots.
In each area, results depend on the laser type, the procedure and the patient, and the technology sits alongside other methods rather than replacing them.
Lasers in research laboratories
Beyond clinics, lasers became basic tools for biology and medicine. They are used in microscopy techniques that build up three-dimensional images of cells, in flow cytometry, where cells are sorted as they pass through a beam, and in DNA sequencing instruments that detect fluorescent tags. Optical tweezers, which use focused laser light to hold tiny objects such as cells, were developed by Arthur Ashkin in the 1970s and 1980s and recognized with a share of the 2018 Nobel Prize in Physics. In diagnostic imaging and wider medical imaging research, laser-based methods are part of some research and clinical tools, including techniques for imaging the retina.
Safety, regulation and caution
Medical lasers can injure tissue as well as treat it, which is why their use is regulated and generally limited to trained professionals. Over the decades, medical bodies and regulators have developed standards for devices and for safety. Anyone with a medical question should consult a qualified health professional, since this article covers history only.
A pattern of cross-over
The history of the laser in medicine shows technology moving from physics laboratories into clinics, then back again as clinical needs shaped new laser designs. The excimer laser, first studied for industrial purposes and then used on the eye, is a standard example of how a tool built for one job can find its most visible use in another.