What is LASIK Eye Surgery?

LASIK, which stands for laser-assisted in situ keratomileusis, is a type of refractive eye surgery. This procedure can correct nearsightedness (myopia), farsightedness (hyperopia), and astigmatism. Many patients choose LASIK because it is a quick and safe procedure with minimal downtime. 

To date, over 8 million Americans have received LASIK eye surgery.

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Types of LASIK

There are a few different LASIK treatment options to choose from, including:

Traditional Versus Bladeless LASIK

During LASIK, the surgeon operates on your cornea, which is the clear covering on the front of your eye. There are two ways the surgeon can cut a flap in your cornea:

  • Traditional LASIK uses a surgical blade called a microkeratome to cut a flap.
  • Bladeless LASIK uses a femtosecond laser instead of a surgical blade. 

The results of bladeless LASIK are generally more accurate, reproducible, and cause fewer side effects, such as dry eye. Overall, surgeons consider LASIK an extremely safe medical procedure, whether it is traditional or bladeless. 

Research shows LASIK eye surgery has a 96 percent patient satisfaction rate.

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Customized LASIK

Customized LASIK gives you sharper, higher quality vision than conventional LASIK. Conventional LASIK uses measurements based on your eyeglass prescription, while customized LASIK is much more detailed. The surgeon can combine customized LASIK with either a traditional or bladeless flap procedure.

There are different types of customized LASIK procedures:

  • Wavefront-guided LASIK — This procedure utilizes detailed measurements to create a 3D map of your eye. The laser uses this information to correct your vision while minimizing any optical irregularities, called aberrations
  • Wavefront-optimized LASIK — This procedure is customized to help your cornea maintain its natural shape and curvature post-surgery. Doing so typically results in better quality vision, including fewer night vision problems.
  • Topography-guided LASIK — This procedure uses detailed measurements over the entire surface of your cornea, which helps correct vision problems related to irregularities in your cornea.

Monovision LASIK

Monovision is a special LASIK technique for patients who need reading glasses, typically those in their 40s or older. This procedure corrects one eye to see distance and the other eye to see near. Your eye doctor will test your eye dominance to determine which is which. 

Ask your eye doctor to try monovision with contact lenses first to see if you can adapt.

There are some potential drawbacks to consider:

  • Vision imbalance —  If your brain has difficulty adapting to monovision, your vision may feel imbalanced. You can experience discomfort or temporary double vision. This sensation usually improves over time.
  • Blur at a distance or near — Your distance or near vision will generally be slightly less clear than with both eyes viewing at the same time.
  • Reduced depth perception — Monovision can affect activities that require depth perception, such as driving or sports. If you perform many of these activities, consider monovision carefully.

Potential monovision patients should consider their type of refractive error:

  • Farsighted (hyperopic) patients have more trouble seeing up close with age. These patients can elect monovision LASIK. They cannot correct both eyes to see up close. Otherwise, their distance vision will be blurry.
  • Nearsighted (myopic) patients have difficulty seeing far but see well up close without glasses. Myopic patients should know that a standard LASIK procedure will correct their distance vision in both eyes, but takes away the ability to see up close. You have to decide whether to have a standard LASIK procedure, and wear reading glasses afterward or to have monovision LASIK.
  • Emmetropic patients are neither hyperopic or myopic. They only need reading glasses with age. These patients only require surgery in one eye to correct their near vision.

Alternatives to LASIK

There are some alternative laser eye surgeries to LASIK, including photorefractive keratectomy (PRK) and small incision lenticule extraction (SMILE). Your eye surgeon will determine if you are a candidate for LASIK or an alternative procedure. There are some key differences between LASIK, PRK, and SMILE.

Below is a comparison of these two procedures:

  • PRK does not involve creating a flap in the cornea, unlike LASIK. The laser directly reshapes the surface of the cornea, requiring less corneal tissue.
  • PRK may be more suitable for patients with thin corneas because the surgery requires less tissue.
  • PRK may be better for those with higher prescriptions since more corneal tissue must be removed.
  • Since there is no flap, PRK may be safer for patients who engage in high-impact activities or are susceptible to eye trauma. Direct eye trauma can potentially dislodge a LASIK flap. PRK is an excellent option for professional athletes or military personnel.
  • LASIK provides a faster recovery time. Many patients return to work the next day after LASIK, while PRK patients may need 1 to 4 weeks to recover before resuming normal activities.
  • PRK recovery is more painful than LASIK. Because there is no corneal flap, PRK essentially creates an open wound on your cornea. The healing process can be uncomfortable, often requiring over-the-counter pain medications to ease the pain.
  • PRK has a higher risk of infection because there is an open wound on your cornea after the surgery. The risk is approximately six times more than LASIK. However, the overall chances of getting an infection with refractive eye surgery are low. Your surgeon will also prescribe you antibiotic drops to use after surgery.
  • PRK and LASIK visual outcomes are similar. Research shows no significant difference in quality after the one-year mark.
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LASIK Versus SMILE

SMILE is a newer type of refractive eye surgery that is gaining popularity. Below is a comparison of SMILE versus LASIK:

  • SMILE does not require a corneal flap. Instead, a laser targets the inner layer of the cornea, creating a lenticule, which is a thin, round piece of tissue. The surgeon then removes this lenticule via a small incision on the side of your cornea.
  • SMILE has less risk of dry eye. Since SMILE does not affect your corneal nerves as much as LASIK, this helps your cornea maintain normal tear function post-surgery.
  • SMILE is less invasive because the surgeon only needs to make a tiny incision in your cornea, as opposed to cutting a flap.
  • LASIK can correct a more extensive range of prescriptions. SMILE is only approved in the United States to treat certain amounts of myopia. SMILE does not correct hyperopia or astigmatism at this time, at least in the United States.
  • LASIK and SMILE have similar recovery times. Both surgeries have little downtime, often just 1 to 2 days.
  • LASIK and SMILE provide similar outcomes. Research shows the two procedures yield comparable results. However, many of these studies had a limited amount of participants and only followed patients over a short postoperative period. More studies are needed to evaluate the long-term outcomes of SMILE. For this reason, many surgeons still recommend LASIK over SMILE.
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Post-LASIK Recovery

There is minimal downtime after LASIK eye surgery. Many patients can see well within a day. If you feel comfortable, you may even drive and go back to work the next day.

You will take a regimen of antibiotics and steroid eye drops for a few weeks after surgery. Your doctor will also recommend lubricating eye drops to help with any dryness.

The most common side effects include:

  • Dry eye — Symptoms include burning, itching, gritty sensation, pain, redness, or watering.
  • Halos — Halos are bright rings around a light source such as a street lamp. They are usually more apparent in dim lighting conditions.
  • Glare and light sensitivity — Bright lights can cause visual discomfort or difficulty seeing.
  • Difficulty with night vision — Halos and glare are more pronounced in dim lighting, making night vision more difficult.
  • Hazy vision — As your corneas heal after surgery, any cloudy vision will improve over time.

Author: Melody Huang, O.D. | UPDATED April 21, 2020

Resources

Eydelman, Malvina, et al. “Symptoms and Satisfaction of Patients in the Patient-Reported Outcomes With Laser In Situ Keratomileusis (PROWL) Studies.” JAMA Ophthalmology, vol. 135, no. 1, 23 Nov. 2016, pp. 13–22., doi:10.1001/jamaophthalmol.2016.4587.

Gudgel, Dan T. “Facts About LASIK Complications.” American Academy of Ophthalmology, 20 Dec. 2018, www.aao.org/eye-health/treatments/facts-about-lasik-complications. Accessed 17 Dec. 2019.

Liu, Manli, et al. “Clinical Outcomes After SMILE and Femtosecond Laser-Assisted LASIK for Myopia and Myopic Astigmatism.” Cornea, vol. 35, no. 2, Feb. 2016, pp. 210–216., doi:10.1097/ico.0000000000000707.

 Moshirfar, Majid, et al. “Meta-Analysis of the FDA Reports on Patient-Reported Outcomes Using the Three Latest Platforms for LASIK.” Journal of Refractive Surgery, vol. 33, no. 6, 1 June 2017, pp. 362–368, doi:10.3928/1081597x-20161221-02. 

Ozulken, Kemal, et al. “Comparison of Wavefront-Optimized Ablation and Topography-Guided Contoura Ablation With LYRA Protocol in LASIK.” Journal of Refractive Surgery, vol. 35, no. 4, 1 Apr. 2019, pp. 222–229., doi:10.3928/1081597x-20190304-02.

Pieramici, Sean, and Brad H Feldman. “Monovision LASIK.” American Academy of Ophthalmology, 22 Oct. 2019, https://eyewiki.aao.org/Monovision_LASIK. Accessed 7 Jan. 2020.

Roe, Joshua R., and Edward E. Manche. “Prospective, Randomized, Contralateral Eye Comparison of Wavefront-Guided and Wavefront-Optimized Laser in Situ Keratomileusis.” American Journal of Ophthalmology, vol. 207, 4 June 2019, pp. 175–183, doi:10.1016/j.ajo.2019.05.026.

Shortt, Alex J, et al. “Laser-Assisted in-Situ Keratomileusis (LASIK) versus Photorefractive Keratectomy (PRK) for Myopia.” Cochrane Database of Systematic Reviews, 31 Jan. 2013, doi:10.1002/14651858.cd005135.pub3.

Solomon, Renée, et al. “Microbial Keratitis Trends Following Refractive Surgery: Results of the ASCRS Infectious Keratitis Survey and Comparisons with Prior ASCRS Surveys of Infectious Keratitis Following Keratorefractive Procedures.” Journal of Cataract & Refractive Surgery, vol. 37, no. 7, July 2011, pp. 1343–1350., doi:10.1016/j.jcrs.2011.05.006.

Sun, Chi-Chin, et al. “Dry Eye After LASIK with a Femtosecond Laser or a... : Optometry and Vision Science.” Optometry and Vision Science, vol. 90, no. 10, Oct. 2013, pp. 1048–1056, doi:10.1097/OPX.0b013e31829d9905. 

Toda, Ikuko, et al. “Visual Outcomes After LASIK Using Topography-Guided vs Wavefront-Guided Customized Ablation Systems.” Journal of Refractive Surgery, vol. 32, no. 11, Jan. 2016, pp. 727–732, doi:10.3928/1081597x-20160718-02.

Zhang, Yu, et al. “Comparison of Corneal Flap Morphology Using AS-OCT in LASIK With the WaveLight FS200 Femtosecond Laser Versus a Mechanical Microkeratome.” Journal of Refractive Surgery, vol. 29, no. 5, 1 May 2013, pp. 320–324, doi:10.3928/1081597x-20130415-03.

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