Corrective eye surgery, performed by lasers, has been a point of interest for many bespectacled individuals since its inception. The concept of using lasers to correct vision problems normally treated with eyeglasses or contacts was approached as early as the 1970’s. But did you know that it has only been 20 years since the FDA approved the first excimer laser for vision correction, in the United States? For this week’s Throwback Thursday, we are exploring the history of lasers and vision correction, arguably one of the most well-known applications of laser technology in modern medicine.
A significant number of people suffer from refractive issues, such as myopia and astigmatism, with their vision ailments. The surgery performed is formally known as radial keratotomy. Prior to the utilization of lasers for the process, the surgery was performed using a scalpel. Early trials reported patients suffering from worse vision following the surgery.
In the 1970’s, an IBM researcher by the name of Dr. Rangaswamy Srinivasan suggested that the precise incisions that needed to be performed to correct ailments such as nearsightedness could be performed using an excimer laser. He collaborated with Steven Trokel, a New York ophthalmologist, in 1987 to perform the first ever photoreactive keratectomy surgery. This prompted the first FDA trials with excimer lasers, as researchers aimed to perfect the procedure. Just under 10 years later, the FDA approved the use of excimer lasers for vision correction in the United States.
The excimer laser is an ultraviolet laser with applications in microelectronics, micromachining, psoriasis treatment, and vision correction. The laser was invented by Nikolai Basov, V.A. Danilychev and Yu M. Popov in 1970. An excimer laser is created using a xenon dimer, which is excited by an electron beam, giving a stimulated emission at 172 nm wavelength. The laser has since been improved using noble gas halides and the use of microwaves, to excite the electron beam.
Laser corrective eye surgery is often referred to colloquially as LASIK (Laser Assisted in situ keratomileusis) and has been performed over 28 million times, worldwide, since 2009. The procedure begins with a small suctional ring attached to the cornea, which helps to hold the eye in place. A small flap is then cut into, with a metal blade or femtosecond laser, which creates a flap that exposes the middle of the cornea. The excimer laser is then used to “remodel the corneal stroma.” The tissue is evaporated by the laser, without heat or cutting. The excimer laser then uses an eye tracking system to follow the eye movement and position up to “4,000 times per second.” This helps to ensure the laser pulses are received in the correct position of the eye. Once the corneal stroma is reshaped, the flap is repositioned for healing.
Patients who receive LASIK surgery can expect vision improvement, negating the need for eyeglasses or contact lenses. In some rare cases, the procedure may not cure vision issues, leading to a second surgery. In other instances, some patients have reported ongoing pain following the procedure. Surveys say the satisfaction rates for patients who have received LASIK range from 92 to 98 percent satisfaction.
Vision correction, with the use of lasers, is still a fairly new concept. The use of excimer lasers to perform LASIK procedures has advanced leaps and bounds in 20 very short years. It is not hard to imagine how far laser technology in the healthcare industry will advance by 2036. For information on learning about laser applications, safety training and more please visit www.lia.org.