The history or development of refractive surgery as we know it today did not begin until the latter half of the 20th century, but there were some early attempts at surgical correction of vision problems dating back to the early 1900s.
One of the earliest attempts at refractive surgery for the correction of vision problems was a procedure called keratotomy, which involved making radial incisions in the cornea to change its shape and correct refractive errors. Radial incisions are incisions arranged like rays that originate from a common center. This technique of radial incisions in the cornea was first used by a Japanese ophthalmologist named Tsutomu Sato in 1939.
In the following decades, keratotomy was refined and improved, but it remained a relatively crude and unpredictable procedure. In the 1970s, the development of the excimer laser provided a new tool for ophthalmologists to correct refractive errors and advance the evolution of refractive surgery.
An excimer laser is a type of ultraviolet laser that emits pulses of light in the ultraviolet range. The word “excimer” is short for “excited dimer,” which refers to the type of molecule used to generate laser light.
Excimer lasers use a combination of gasses, usually a noble gas such as argon or xenon, and a halogen gas such as fluorine or chlorine, to create a gas mixture that is excited by a high-voltage electrical discharge. This creates a laser beam that is extremely precise and can be finely controlled.
Excimer lasers have a unique property in that they can remove tissue from surfaces without causing any thermal damage. This makes them well-suited for use in medical procedures that require precise removal of tissue, such as in ophthalmology for the correction of refractive errors like nearsightedness, farsightedness, and astigmatism.
In 1980, a team of researchers at IBM discovered that the excimer laser could be used to precisely remove tissue from the cornea without causing thermal damage. This discovery laid the groundwork for the development of laser refractive surgery, including LASIK.
The first excimer laser surgery on a human eye was performed in the United States in 1988 by Dr. Marguerite McDonald, who used the laser to reshape the cornea of a patient with nearsightedness. The procedure was a success, and it opened the door to further research and development of laser vision correction techniques.
Over the next several years, researchers and surgeons around the world experimented with different ways to use the excimer laser to correct refractive errors. This led to the development of PRK, LASEK, and eventually LASIK, which has become one of the most common and effective vision correction procedures in the world.
Laser Reshapes Cornea
PRK (photorefractive keratectomy), LASEK (laser epithelial keratomileusis), and LASIK (laser-assisted in situ keratomileusis) are all types of laser refractive surgery that aim to correct vision problems, such as nearsightedness, farsightedness, and astigmatism.
The main difference between these procedures is the way the laser is applied to reshape the cornea.
PRK was the first laser vision correction procedure and involved removing the thin outer layer of the cornea (the epithelium) to expose the underlying tissue. The laser is then used to reshape the cornea, and a bandage contact lens is placed on the eye to protect it while it heals. PRK has a longer recovery time compared to LASIK, and some patients may experience discomfort and blurry vision for a few days after the procedure.
LASEK is similar to PRK, but instead of removing the epithelium, it is loosened and lifted before the laser is applied to the cornea. Once the laser has reshaped the cornea, the epithelium is repositioned, and a bandage contact lens is placed on the eye to protect it during the healing process. LASEK has a shorter recovery time than PRK but a longer recovery time than LASIK.
LASIK is the most popular type of laser refractive surgery and involves creating a thin flap in the cornea with a microkeratome or femtosecond laser. The flap is lifted to expose the underlying tissue, and the laser is then used to reshape the cornea. The flap is then replaced, acting as a natural bandage, and heals quickly without the need for stitches. LASIK has a shorter recovery time compared to PRK and LASEK, with most patients experiencing improved vision within a few hours after the procedure.
The choice of which procedure to use depends on various factors such as the severity of the vision problem, corneal thickness, and patient preference, and it is important to discuss these options with an experienced ophthalmologist.