PRK Versus LASIK

PRK Versus LASIK: Which is Better?

If you are thinking about having laser eye surgery to correct your eyesight, you might be wondering whether PRK or LASIK is better. They are both elective procedures that correct your vision if you do not want to wear eyeglasses or contacts. In this article, we will review the differences between PRK and LASIK. You will also learn the benefits and drawbacks of each type of surgery.

What is PRK?

PRK stands for photorefractive keratectomy, a form of laser refractive eye surgery. This procedure can treat farsightedness (hyperopia), nearsightedness (myopia), and astigmatism. 

PRK was FDA-approved in 1995.

PRK Procedure Overview

The surgery is quick, lasting only about 15 minutes. In PRK, there is no flap creation, which is different from LASIK. Instead, the surgeon will operate directly on the surface of your cornea, which is the clear structure over your eye. 

Here is what to expect during your PRK surgery:

  • Before surgery, the clinic may give you some medication to relax you, in case you are feeling anxious.
  • In the operating room, you receive numbing drops so you do not feel any pain during the surgery. 
  • Next, the surgeon places a special solution in your eye to soften up the epithelium, which is the outer layer of your cornea.
  • Once your epithelium softens, the surgeon uses a tool to remove the epithelium, exposing the deeper layer of your cornea. You will experience some pressure on your eye during this step, but it is not painful.
  • The surgeon then uses the excimer laser to reshape your cornea. This step takes less than a minute per eye.
  • After the laser finishes, the surgeon places a soft contact lens on the cornea to act as a bandage. Since your epithelium needs time to grow back, the contact lens protects your cornea and helps with discomfort during the healing process.
  • The surgeon will also prescribe medication and lubricating drops to use over the next few weeks.
  • You will need to arrange a ride home.
diagram showing four steps in photorefractive keratectomy (PRK) surgery

What to Expect After PRK Surgery

  • You will experience the most discomfort the first few days after PRK surgery. During this time, you may also experience light sensitivity, halos around lights, and blurry vision. Many patients choose to take a few days off work for this reason. You will also want to avoid driving for about a week.
  • Around day five, most patients are feeling better, and their vision is much clearer. The surgeon removes the contact lens around this time.
  • After about a week, you can resume most normal daily activities. Though you are mostly recovered by this time, the vision takes at least a month to stabilize. You may need 3 to 6 months to be fully stable.

What is LASIK?

LASIK stands for laser-assisted in situ keratomileusis, another form of laser refractive eye surgery. Similar to PRK, LASIK can correct a wide range of prescriptions. However, some patients prefer LASIK because of the shorter recovery period.

LASIK was FDA-approved in 1996.

LASIK Procedure Overview

LASIK surgery only takes about 15 minutes and has little downtime post-surgically. One main difference compared to PRK is that LASIK involves the creation of a flap in your cornea.

Here is what to expect during your LASIK surgery:

  • The clinic may give you some medication to relax you before surgery, in case you are feeling anxious.
  • Before the procedure begins, you receive numbing eye drops so that you do not feel any pain.
  • Then, the surgeon places a device on your cornea to stabilize your eye. You will feel a suction-like pressure on your eye during this part, but it does not last very long. 
  • The surgeon then uses a femtosecond laser to create a flap on the surface of your cornea. Most modern LASIK procedures use this method, which we call bladeless LASIK. However, your surgeon may use a microkeratome instead, which is a type of surgical blade used to create the corneal flap. Both methods are effective, but studies show that bladeless LASIK tends to deliver better results.
  • Next, the surgeon carefully lifts the flap, exposing the deeper layer of your cornea. The flap has a hinge on one side so that the flap is not completely detached.
  • Similar to PRK, the eye surgeon uses an excimer laser to reshape your cornea.
  • After the laser finishes, the corneal flap is repositioned back in place. No stitches are necessary.
  • The surgeon will prescribe medicated drops and lubricating drops to use over the next few weeks.
  • You will need to have someone drive you home.

What to Expect After LASIK Surgery

  • Immediately after LASIK, your vision will be a bit hazy. Still, you will notice you can see better already. Patients experience light sensitivity and a significant burning sensation after surgery, but this usually improves in several hours. 
  • The clinic will give you eye shields to use while sleeping. It is crucial to avoid rubbing your eyes for the first few weeks after surgery. You do not want to dislodge the corneal flap. If this occurs, you must contact your eye surgeon immediately so the flap can be repositioned.
  • You should avoid heavy exercise, pools, and hot tubs for about two weeks.
  • Most patients notice dramatic improvement within 24 hours. If you are feeling well enough, you can even drive and go back to work the next day.
  • Though many patients see as well as 20/20 by the next morning, your eyes may need a few months for the vision to fully stabilize. During this time, any light sensitivity or halos should improve.
  • You may experience dryness even months after surgery and should continue using lubricating drops.

Sample bladeless LASIK animation videos:

Icon of a person versus another person

Comparing PRK Versus LASIK

There are advantages and disadvantages to both types of surgeries. Your eye surgeon will perform a series of tests to determine if PRK or LASIK is best for you. 

Advantages of PRK Over LASIK

  • Cost. PRK generally costs less than LASIK since the procedure is older, less complex, and requires fewer instruments.
  • Suitable for thinner corneas. Patients with thin corneas may not be eligible for LASIK but may receive PRK instead. Because of the flap creation, LASIK requires thicker corneal tissue.
  • Suitable for higher prescriptions. The higher your prescription, the more corneal tissue the laser needs to remove. If your corneas are thinner and you have a significant amount of prescription, your surgeon may recommend PRK instead of LASIK.
  • Safer option for athletes or military personnel. If you engage in high-impact activities like basketball, martial arts, or football, you might want to consider PRK. Eye trauma can dislodge a LASIK flap, which is a serious complication. With PRK, you do not have to worry about this risk.
  • Fewer dry eye symptoms. During LASIK, the creation of the flap can increase your risk of dry eye. Since PRK does not involve a corneal flap, patients usually have less dry eye issues.

Advantages of LASIK Over PRK

  • Faster recovery time. If you cannot take time off work or school, LASIK is an excellent option. Many patients return to work the next day, while PRK patients may need to take a week off to recover.
  • Less discomfort during recovery. After LASIK, the corneal flap allows your eye to heal quickly, with most burning and irritation going away within several hours. With PRK, some patients even take oral pain medication to manage their discomfort.
  • Less risk of infection and inflammation. Since PRK leaves your cornea more exposed, you have a higher risk of infection and inflammation after surgery. However, most patients who follow instructions carefully do not experience complications with either PRK or LASIK.
  • Fewer eye drops required. After PRK, you may need to take steroid eye drops for a longer period versus LASIK. This is because a common side effect of PRK is haze in the cornea, and the steroid drops help to minimize this problem.

Studies show that after the recovery period, both LASIK and PRK yield comparable visual results.

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

Resources

Alio, J L, et al. “Ten Years after Photorefractive Keratectomy (PRK) and Laser in Situ Keratomileusis (LASIK) for Moderate to High Myopia (Control-Matched Study).” British Journal of Ophthalmology, vol. 93, no. 10, 2009, pp. 1313–1318., doi:10.1136/bjo.2007.131748.

Herz, Natasha H, and Brad H Feldman. “Photorefractive Keratectomy.” EyeWiki, 22 Jan. 2020, https://eyewiki.aao.org/Photorefractive_Keratectomy

Moshirfar, Majid, et al. “A Prospective, Contralateral Comparison of Photorefractive Keratectomy (PRK) versus Thin-Flap LASIK: Assessment of Visual Function.” Clinical Ophthalmology, 21 Apr. 2011, pp. 451–457., doi:10.2147/opth.s18967.

Shortt, Alex J, et al. “Laser-Assisted in-Situ Keratomileusis (LASIK) versus Photorefractive Keratectomy (PRK) for Myopia.” Cochrane Database of Systematic Reviews, no. 1, 31 Jan. 2013, doi:10.1002/14651858.cd005135.pub3.

Xia, Li-Kun, et al. “Comparison of the Femtosecond Laser and Mechanical Microkeratome for Flap Cutting in LASIK.” International Journal of Ophthalmology, vol. 8, no. 4, 18 Aug. 2015, pp. 784–790., doi:10.3980/j.issn.2222-3959.2015.04.25.

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