Lasik or Laser-Assisted In Situ Keratomileusis is based on the 1980 work of researchers at IBM Research which involved etching live tissues using an ultraviolet excimer laser with precision and without thermal damage to the surrounding area. The process was called ablative photodecomposition. Steven Trokel and his team at the Edward S. Harkness Eye Institute later published a work in 1985 that detailed a new approach to radical keratotomy or the process for making incisions in the cornea using an excimer laser.
Several patents have been issued for various techniques and applications related to excimer laser surgery. Rangaswamy Srinivasan and James Wynne of IBM Research filed one in 1986. The patent was issued in 1988. Iranian American ophthalmologist Gholam A. Peyman was granted a U.S. patent for using an excimer laser for reworking corneal curvature. Several American companies like Visx and Summit were also granted patents for various broad-beam laser refractive surgery and photorefractive surgery technologies from 1990 to 1995.
Understanding the Effectiveness, Safety, Limitations, and Risks of Lasik: Studies on Laser Eye Surgery for Refractive Correction
Notable Advantages: Effectiveness and Safety
It was in 1990 when Greek ophthalmologist Ioannis G. Pallikaris performed the first-ever Lasik procedure on a human eye in Greece. The United States FDA approved the use of excimer laser for photorefractive keratectomy in 1995 and later approved Lasik in 1999. Lasik has since become a popular surgical procedure to correct refractive vision problems like myopia or nearsightedness, hyperopia or farsightedness, and astigmatism.
There are millions of Lasik procedures performed across the world each year. The wide popularity of this procedure stems from a combination of marketing efforts by ophthalmological clinics and further improvements in its safety and effectiveness. These are also anchored on the fact that vision problems like myopia and astigmatism have been increasing among children and young adults due to genetic, environmental, and lifestyle factors.
Below are the advantages of Lasik eye surgery:
• Reduce or Eliminate Dependence on Corrective Lenses: People with myopia, hyperopia, or astigmatism are dependent on glasses or contacts. Some dislike wearing them. One of the main advantages of Lasik is that it provides lifestyle improvement.
• Fast and Painless Out-Patient Procedure: Lasik often takes 10 to 15 minutes per eye, and there is also minimal discomfort during and after the procedure. Most patients experience improved vision after 24 hours. Downtime lasts for a day or two.
• High Success and Satisfaction Rates Based on Studies: Over 90 to 95 percent of patients achieve drastic improvements in vision. Several studies have also shown that more than 95 percent of patients reported satisfaction a year after the procedure.
• Investment from Long-Term Cost Savings: Lasik costs between USD 2000 and 3000 per eye. However, considering that its effect is long-term, it recues or eliminates the need for regularly changing prescription glasses or contact lenses.
• Widespread Accessibility and Technological Advancements: Another advantage of this procedure is that it is widely available in developed and developing countries. Technological advancements have also improved precision, outcomes, and availability.
Remember that Lasik has high success and satisfaction rates. K. D Solomon et al. of the American Society of Cataract and Refractive Surgery and other researchers from the Joint Lasik Study Task Force did a systematic literature review of more than 3000 peer-reviewed studies. Details are discussed in a 2008 paper that appeared in Ophthalmology. Findings specifically showed an 85.4 percent patient satisfaction rate among Lasik patients.
A. Sugar, C. T. Hood, and S. I. Mian also did a meta-analysis of relevant studies. Their findings showed that 97 percent of patients achieved an uncorrected visual acuity of 20/40, and another 62 percent achieved 20/20 uncorrected visual acuity. It concluded that Lasik overall resulted in a decrease in preoperative symptoms and excellent vision correction. Details are discussed in a 2017 paper published in the Journal of the American Medical Association.
Critical Disadvantages: Limitations and Risks
The separate studies of Solomon et al. and Sugar et al. also indicate that there is still a small number of patients who were either not satisfied with the procedure or did not experience improvements in their vision problems. One of the main causes of dissatisfaction is chronic severe dry eye. This involves intense grittiness or a feeling that there is dirt or sand stuck in the eye, and a burning or stinging sensation that is similar to severe conjunctivitis.
A New York Times article featured the ordeal of graphics designer Geobanni Ramirez who has to put eye drops every half-hour because his eyes have become severely dried and sore after a Lasik surgery. The Associated Press also reported an FDA meeting in 2008 in which patients who received Lasik testified about impaired vision and chronic pain. These post-operation issues have severely affected the quality of lives of a notable number of patients.
Below are the disadvantages of Lasik eye surgery:
• Dry Eyes and Visual Disturbances: Lasik can reduce tear production. This leads to dry eyes. Others report visual disturbances like glares and halos. These reduce low-light vision performance. Most post-operation symptoms improve over time, but in some cases, these conditions become persistent and chronic.
• Undercorrections or Overcorrections: It is important to note that blurred vision is still possible if not enough or too much tissue is removed. A second surgery or enhancements may be needed to correct the issue.
• Pre-Lasik Surgery Regression Issue: Eyes may progressively return to their pre-surgery state or may require prescription glasses or contact lenses. This is especially in patients with strong prescriptions or unstable vision. The regression of vision varies. It can transpire months or years after the procedure.
• Flap and Vision Loss Complications: Lasik creates a flap in the cornea. This can shift or become dislodged during healing and further lead to infection. There are also rare cases of vision loss and reduced contrast sensitivity.
• It is Not a Reversible Procedure: Another notable disadvantage of Lasik is that it is not a reversible procedure since it involves reshaping the cornea. This tissue does not regenerate and it cannot be replaced. The effect on the cornea is permanent. This means that corrective options are limited in case of complications.
• Certain Complication Predispositions: The procedure may be unsuitable for those with thin corneas, severe dry eyes, large pupils, unstable prescriptions, or certain autoimmune conditions. These people are more prone to Lasik complications.
A detailed pre-operative screening is essential for patients wanting to undergo Lasik to ensure they are suitable candidates. This involves assessing corneal thickness, shape, and refractive error. The entire Lasik procedure has become more precise due to technological advances like using more sophisticated lasers and wavefront-guided systems. This has resulted in a customized treatment plan for each eye, better patient outcomes, and reduced complications.
The National Institute for Health and Clinical Excellence of the United Kingdom declared Lasik and similar photorefractive or laser refractive surgeries safe and effective in 2006. This is based on all available evidence. However, in considering the merits of this declaration, it also notes that it is indeed safe and effective for use in appropriately selected patients. This underscores the need for proper patient screening and thorough patient education.
Alternatives to Lasik for Refractive Correction
More than 40 million Lasik procedures were performed across the world between 1999 and 2009 according to data from the American Academy of Ophthalmology. However, according to a study by K. J. Corcoran, which was published in Current Opinion on Ophthalmology, it appeared to be a declining option based on 2015 data. It is also important to note that there are other alternatives to Lasik. These include photorefractive keratectomy or PRK and Lasek.
Both PRK and Lasek are very similar to Lasik. All three are laser eye surgeries designed to correct refractive errors. PRK differs because it does not involve creating a corneal flap. It involves gently removing the outermost corneal layer, called epithelium, to access and reshape corneal tissue. This eliminates the risk of flap complications. Lasek is somewhat similar to PRK but involves epithelial flap creation and epithelial positioning to correct refraction.
Both PRK and Lasek are recommended for people with thin corneas, those at high risk of physical or eye trauma due to occupations, patients who are worried about long-term dry eyes, and those with certain corneal conditions. The newer procedure called SMILE or small incision lenticule extraction is considered a less risky and less invasive procedure. The main disadvantage of SMILE is that it only corrects nearsightedness or myopia and astigmatism.
Other alternatives include phakic intraocular lenses, which involve implanting permanent contact lenses, and refractive lens exchange, which involves removing the natural lens and replacing it with an artificial intraocular lens. Both are more invasive than laser eye surgeries. The former is reversible. Another alternative to these invasive procedures is orthokeratology or Ortho-K. This involves wearing contact lenses overnight to temporarily reshape the cornea.
FURTHER READINGS AND REFERENCES
- Associated Press. 25 April 2008. “Witnesses Tell of Suffering After Lasik.” The New York Times. Available online
- Corcoran, K. J. 2015. “Macroeconomic Landscape of Refractive Surgery in the United States.” Current Opinion in Ophthalmology. 26(4): 249-254. DOI: 1097/icu.0000000000000159
- Cotliar, A. M., Schubert, H. D., Mandel, E. R., and Trokel, S. L. 1985. “Excimer Laser Radial Keratotomy.” Ophthalmology. 92(2): 206-208. DOI: 1016/s0161-6420(85)34052-6
- n.d. “Excimer Laser Surgery.” IBM Heritage. International Business Machines Corporation. Available online
- National Institute for Health and Clinical Excellence. 2006. “Photorefractive Surgery for the Correction of Refractive Errors.” NICE Guidance. National Institute for Health and Clinical Excellence. Available online
- Rabin, 11 January 2018. “Blurred Vision, Burning Eyes: This Is a Lasik Success?” The New York Times. Available online
- Solomon, K. D., Fernández de Castro, L. E., Sandoval, H. P., Biber, J. M., Groat, B., Neff, K. D., Ying, M. S., French, J. W., Donnenfeld, E. D., and Lindstrom, R. L. 2009. “LASIK World Literature Review. Ophthalmology.” 116(4): 691-701. DOI: 1016/j.ophtha.2008.12.037
- Stuart, A. 2009. “A Look at Lasik Past, Present, and Future.” EyeNet Magazine. American Academy of Ophthalmology. Available online
- Sugar, A., Hood, C. T., and Mian, S. I. 2017. “Patient-Reported Outcomes Following LASIK.” JAMA. 317(2): 204. DOI: 1001/jama.2016.19323