Laser In Situ Keratomileusis (LASIK)

Excerpt

Laser-assisted in situ keratomileusis (LASIK) is a common ophthalmologic surgical procedure used to correct refractive error. LASIK was patented in 1989 by Dr. Gholam Peyman. The first publication of LASIK used in patient care was by Dr. Ioannis Pallikaris et al., in the early 1990s. This procedure quickly became popular due to decreased time of recovery and post-surgical complications, with no decrease in efficacy. Since its implementation in clinical practice, LASIK is among the most scrutinized and studied surgical procedures to have gone through FDA inspection. Thirty years later, with advancements in technique and equipment, LASIK continues to provide efficient, predictable, and safe outcomes with patients reporting satisfaction with the procedure as compared to using spectacles or contact lenses.

A Historical Perspective

Understanding the impact of LASIK in refractive correction requires knowledge of its development. The first significant breakthrough in refractive therapy came in the 1930s, with radial keratotomy by Dr. Tsutomu Sato in Japan. By making incisions deep into Descemet’s membrane, the flattening of the cornea helped correct myopia. However, many complications, like corneal decompensation, came from these deep incisions. Alternative methods were developed, such as the hexagonal keratectomy by Dr. Antonio Méndez in Mexico. At this time, it was still difficult to correct patients with astigmatism or the asymmetric shape of the cornea.

Keratomileusis is the medical term for corneal reshaping, which came about in the 1950s and ’60s with the work of Spanish ophthalmologist José Barraquer. His technique initially involved the microkeratome, a mechanical instrument that, with its oscillating sharp blade, cuts the top layer of the cornea away to create a lenticule and reveal underlying stroma. An additional cut through the stroma was made, and the lenticule was sutured back into place. This technique came to be known as anterior lamellar keratoplasty (ALK). He also developed a procedure called keratophakia, which corrected hyperopia by freezing and shaping donor corneal stroma with a cryolathe and then placing it into the patient’s cornea. His microkeratome, however, was rudimentary and led to imprecise treatments. The microkeratome was further improved in the 1980s through Barraquer’s student, Dr. Luis Ruiz. Variations on corneal excision and replacement by implantation also followed through the years, but it came with the risk of tissue rejection and corneal tearing.

The excimer, or “excited dimer” laser and its medical use, was discovered in 1970 by Dr. Stephen Trokel and Dr. Rangaswamy Srinivasan in the early 1980s. These works led the way to the development of photorefractive keratectomy (PRK). Dr. Marguerite McDonald was the first to perform this in the late 1980s. This technique uses a noble gas combined with a halogen to create a laser to ablate the superficial layers of the cornea. PRK allowed for more precise reshaping and further refractive correction.

LASIK is essentially a combination of ALK and PRK, which was first utilized in the early 1990s. Advances in lenticule flap creation were made to allow for a hinged cap instead of a free cap. With the innovation of the femtosecond laser, developed by Dr. Imola Ratkay-Traub, Dr. Tibor Juhasz, and Dr. Ron Kurtz in the early 1990s, a corneal flap could be created without a mechanical blade and then replaced without sutures.