The number of people who have problems with their eyesight has been significantly increasing over the years. As such the extent of research in this area has been on the rise and recently there have been significant advancements made in this field.8 The idea of getting eye surgery to remove all the hassle of continually updating and wearing contacts or glasses seems to be more and more appealing. When the concept of laser eye surgery first started becoming possible scientists had no real proof of what the long-term effects could be. Now that it has become increasingly popular around the world I was wondering to what extent patients thought it was worth it, what the process is like and what, if any, risky side effects there might be. I myself don’t need to wear eyeglasses or contacts but there is a shockingly large amount of my friends and family who do. I know someone personally who has gotten the surgery a total of three times in one eye and two times in the other and yet still uses glasses to read. I also know someone who must continuously put eye drops in to prevent the dry eye symptom that came after the surgery. These two outcomes made me wonder how effective laser eye surgery really is.
Laser eye surgery is also called vision correction surgery and is a surgical procedure used to correct a range of vision problems. These procedures often work by reshaping the clear front part of the eye, called the cornea, in order for light to be able to travel through it properly and focus correctly onto the retina, the light sensitive surface located in the back of the eye.6 However there are actually a variety of different types of surgery for vision improvement, which one you need all depends on what the problem is. I would like to focus on one of the more common surgeries known as LASIK, which was developed in the early 1990s. LASIK is short for laser in-situ keratomileusis and is used to correct vision in people who are nearsighted, farsighted and/or have astigmatism.5 Astigmatism is a vision condition that many people have to some degree; it can cause blurred vision at any distance due to either the irregular shape of the cornea or a curvature of the lens inside the eye.1
Digital Image from Fairview Health Services
During LASIK surgery, vision is corrected by reshaping underlying corneal tissue so that it can properly focus light into the eye and onto the retina. LASIK eye surgery differs from others in that a flap is made in the outer topmost layer of the cornea so that the underlying tissue can be accessed.7 There are 2 different ways to create a corneal flap in LASIK, either with a blade or the all-laser method. Bladed LASIK is performed using a microkeratome, which is an oscillating blade however the most advanced method is the all-laser LASIK method. This method uses a specialized femtosecond laser to create the corneal flap and it is more expensive. The cost of getting LASIK surgery in the United States usually generally varies between 1000$-3000$. Once the flap is created it is carefully peeled back. The laser then accurately re-profiles the corneal bed underneath the flap to correct any visual abnormality. The specific type of re-profiling is customized for each patient’s unique case. The flap is then gently placed back to its original place. Since the inner layer of the cornea acts like a natural pump there is no need for stitches. This surgery happens fairly quickly taking around 5 minutes per eye.7 The thickness of patients’ corneas must be large enough so they have enough corneal tissue to undergo this procedure.6
A study was done last December by Bethke in association with results from the FDA, NIE and DoD was done in order to see what patients thought of LASIK. They collaborated their results in order to give insight into patient satisfaction after the procedure as well as how LASIK’s outcomes compared to wearing glasses or contact lenses. They found that 98 percent of all LASIK patients and 97 percent of the contact lens patients “agree” or “strongly agree” that they’d recommend their vision correction method to a friend or family member.2
Obviously LASIK eye surgery has many benefits such as the immediate return of vision and minimal discomfort after the operations that make the process appealing to many. Before getting the surgery one must consider the risk of side effects, which may include a weakened cornea due to the creation of the flap; you do not want to lost or damage the flap. This can be especially dangerous for those participating in contact sports that do not protect themselves adequately.6 Another risk may be experiencing infection that delays healing however this happens in less than one percent of LASIK patients.2 Dry eye, which is associated with corneal denervation, is the most common complication after LASIK procedure. Patients usually however only experience compromised tear function for 1-3 months after surgery and may simply use artificial tears to prevent this unwanted symptom from causing damage.4 The second most common side effect is the development of halos. The halo effect occurs in dim light, as the pupil gets bigger, the untreated area on the outside of the cornea produces a second image. This can affect and interfere with night driving, especially in patients who have big pupils in dark conditions.2 Lastly, the procedure done to the cornea cannot be undone so often surgeries may result in undercorrections, which can be fixed with a second laser eye surgery.6 This is usually called laser enhancement. Often an enhancement will help get rid of the halos’ effect.
Although the surgery isn’t right for everyone and there may be some inconvenient short-term side effects such as dry eye or needing enhancement (repeat surgery), overall the complication rate for LASIK surgery is very low and patients end up being happy with the results.
1- Astigmatism. American Optometric Association. 2014.http://www.aoa.org/patients-and-public/eye-and-vision-problems/glossary-of-eye-and-vision-conditions/astigmatism?sso=y
2-Bethke W. What Patients Think of LASIK. Review Of Ophthalmology [serial online]. December 2014;21(12):53-55. Available from: Academic Search Premier, Ipswich, MA. Accessed March 8, 2015.
3-How the Eye Works. Fairviews. 2015. Web 8 March 2015. Digital Image. http://www.fairview.org/healthlibrary/Article/85459
4-I. Toda, N. Asano-Kato, Y. Komai-Hori, K. Tsubota. Dry eye after laser in situ keratomileusis. Am J Ophthalmol. 2001 July; 132(1): 1–7.
5-LASIK. (2015). In Encyclopaedia Britannica. Retrieved from http://academic.eb.com/EBchecked/topic/1335849/LASIK
6-LASIK Laser Eye Surgery: Procedure, Recovery, and Side Effects. Web MD. 2015. http://www.webmd.com/eye-health/lasik-laser-eye-surgery
7- Mandel. The Laser Eye Surgery Message: Clearing Up the Confusion. Mandel Vision. http://mandelvision.com/blog/laser-eye-surgery-message-clearing-confusion-blog-2
8-New Vision Problems in the U.S. Report. Prevent Blindness National. June 20 2012. Accessed March 8 2015. http://www.preventblindness.org/new-vision-problems-us-report