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Laser in situ keratomileusis (LASIK) is a laser-assisted surgical procedure for the correction of visual refractive errors. This activity will review the indications, laser, equipment, contraindications, complications, and long-term prognosis of patients who undergo LASIK. The activity will highlight the role of the interprofessional team. Objectives: Review the historical background of LASIK. Outline the preoperative screening evaluation for LASIK. Explain the general procedure of LASIK, detailing differences in equipment. Review the efficacy, safety, and predictability of LASIK in comparison to similar refractive surgical procedures. Access free multiple choice questions on this topic.

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.[1] 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.[2] Since its implementation in clinical practice, LASIK is among the most scrutinized and studied surgical procedures to have gone through FDA inspection.[3] 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.[4][5][6] 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.[7] At this time, it was still difficult to correct patients with astigmatism or the asymmetric shape of the cornea.

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.[7] 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).[2] 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.[2] 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.[2][7] 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.[8] 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.[9][10] This technique uses a noble gas combined with a halogen to create a laser to ablate the superficial layers of the cornea.[11] PRK allowed for more precise reshaping and further refractive correction.[7]

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.[8] 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.[9][10] This technique uses a noble gas combined with a halogen to create a laser to ablate the superficial layers of the cornea.[11] PRK allowed for more precise reshaping and further refractive correction.[7] LASIK is essentially a combination of ALK and PRK, which was first utilized in the early 1990s.[2] 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.[7][12]

Dry Eyes One of the most common transient side-effects from LASIK is dry eyes due to a lack of tear production. This is due to the interruption of the lacrimal reflex as a result of nervous tissue being severed during the procedure.[23][56][57][58] Various studies have shown dry eyes to occur in 85% to 98% of patients one week after surgery.[57][59][60] This number drops to around 60% at 1 month [60]. Artificial tears and/or punctal plugs are applied until the nerves regenerate. Visual Aberrations 20% of patients will report some form of visual change.[23] Some patients may suffer from visual changes such as glare, halo, or star-bursting patterns around lights, haze, and decreased contrast sensitivity. The FDA reports that visual disturbances tend to stabilize three to six months after the procedure. Diffuse Lamellar Keratitis Patients may also report blurriness and foreign body sensation that may be caused by diffuse lamellar keratitis (DLK), or “sands of Sahara” syndrome, a sterile inflammatory response.[23] Inflammatory cell infiltrates occur beneath the corneal flap interface.[61] This phenomenon may happen in as many as 1 in 50 cases of LASIK. DLK usually presents one to two days post-operatively and resolves with appropriate corticosteroid treatment after one week.[62] Corneal Flap Complications The incidence of microstriae, macrostriae, buttonholing, incomplete cap, free cap, cap dislodgement, and epithelial ingrowth after surgery, is a low-risk event, with 0.1-4% of patients reporting some form of complication.[1][23] It has been shown that corneal flap complications can lead to visual acuity loss.[56][63] Post-LASIK Ectasia A thin cornea before surgery may increase the risk of developing ectasia or further thinning of the cornea. The incidence has been reported from 0.04% to 0.6%.[44][64] Femtosecond-assisted LASIK can help prevent this complication due to the thinner flaps created.[65] The use of the Randleman criteria, as described in the preparation section, can also screen for patients who are at high risk of developing ectasia.[44] Infectious Keratitis Less than 0.1% of patients will develop an infection after LASIK.[66] The most common sources of infection come from gram-positive organisms, such as Staphylococcus species, or atypical mycobacteria, especially if the onset of infection is one-two weeks after surgery.[67] Rare Complications

A thin cornea before surgery may increase the risk of developing ectasia or further thinning of the cornea. The incidence has been reported from 0.04% to 0.6%.[44][64] Femtosecond-assisted LASIK can help prevent this complication due to the thinner flaps created.[65] The use of the Randleman criteria, as described in the preparation section, can also screen for patients who are at high risk of developing ectasia.[44] Infectious Keratitis Less than 0.1% of patients will develop an infection after LASIK.[66] The most common sources of infection come from gram-positive organisms, such as Staphylococcus species, or atypical mycobacteria, especially if the onset of infection is one-two weeks after surgery.[67] Rare Complications Ischemic optic neuropathy, retinal detachment, vitreous hemorrhage, and posterior vitreous detachment, are potential but very rare complications of LASIK, occurring in less than 0.1% of patients.[1][23][68][69][70]

The professional team in LASIK treatment typically consists of ophthalmic surgeons, optometrists, nurses, medical assistants, and technicians. Team members work together in the outpatient setting to determine the best candidates for LASIK to prevent unnecessary costs and complications to the patient. The team, on the day of surgery, is responsible for adhering to standard clinical protocols, including obtaining the patient’s informed consent for the procedure, the correct marking of which eye will receive each specific treatment, the proper placement, and preoperative evaluation of necessary equipment for the procedure, a timeout called before the operation, and patient education throughout the treatment process. Communication among team members is vital, concerning any changes in patient status at any time before, during, or after the procedure and optimizes patient outcomes.[73] [Level 5]

The team educates the patient regarding the procedure and obtains informed consent before surgery. They perform instrumentation checks with correct placement and distribution during the procedure and ensure sterility. Communication with other team members is crucial for patient safety.

The team guides the patient through post-procedure education for proper eye care, including the administration of prescribed eye drops. They assist with patient follow-up in an outpatient setting, with eye examinations to document visual acuity and visual changes.