PRK vs. LASIK: Uses, Benefits, Side Effects and More

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You may be considering undergoing refractive laser surgery to correct your nearsightedness (myopia), farsightedness (hyperopia), or unevenness in the shape of your cornea or lens (astigmatism).

With the aid of an excimer laser, a surgeon can reshape the cornea, the clear dome of the eye, so that light properly hits the retina (the nerve-rich layer that relays images to the brain). The idea is to be able to free you either entirely or somewhat from glasses or contacts.

Both photorefractive keratectomy (PRK) and laser-assisted in situ keratomileusis (LASIK) use the excimer laser to correct vision. You may wonder which of these would be best suited to your needs.

This article will explain how PRK and LASIK work, what to expect during each treatment, which would more likely suit you, and what to know about potential side effects.

Ophthalmologist examines eye

FG Trade / Getty Images

What to Know About PRK

PRK was the first refractive excimer laser procedure to be performed and remains a solid option.

How Does It Work?

PRK aims to reshape the cornea's surface using an excimer laser. The laser ablates (removes) the cells on top of the cornea to help sharpen vision.

The reshaped cornea can then help incoming light land right on the retina instead of in front of it or behind it, as occurs with nearsightedness or farsightedness. The laser can also smooth corneal irregularities that may occur with astigmatism and otherwise cause distortion.

PRK Delivery

During this procedure, the outermost layer, known as the corneal epithelium, is first removed. Then the excimer laser is used to reshape the cornea. The corneal epithelium grows back over the reshaped cornea in about three to four days.

When you undergo the PRK procedure, which takes about 15 minutes, your ophthalmologist (medical doctor trained to diagnose and treat eye conditions, as well as perform surgery on the eyes) will:

  • Numb the surface of your eye
  • Insert an instrument (speculum) to hold the lid open.
  • Remove the outer epithelial layer with the aid of a special blade, brush, alcohol solution, or laser
  • Reshape the cornea's surface with the excimer laser while you stare at a target light to keep your eye from moving. During the use of the excimer, you will hear a clicking sound. When this stops, the corneal reshaping is done.

Side Effects

While the PRK procedure may go smoothly, there is always the risk of complications. These include:

  • Developing corneal haze, in which the typically clear tissue becomes cloudy
  • Noticing halos around lights or glare at night
  • Corneal scarring
  • Corneal infection

These complications can be treated. In rare instances, complications can lead to vision that is not as good as before the surgery. Very rarely, blindness may occur.

Prices and Where to Get the Procedures

As a rule of thumb, PRK has fewer steps and tends to be slightly less expensive than LASIK. The cost of this procedure may vary depending on your location and the specific center you choose.

Fees range from around $1,500 to $3,000 per eye. Since this is considered an elective procedure, it is unlikely to be covered by insurance.

You can find PRK services at private outpatient eye institutes and university centers.

What to Know About LASIK

LASIK, which applies excimer laser energy to a slightly different area than PRK, is also a very viable option for helping to reduce the need for wearing glasses and contacts.

How Does it Work?

With LASIK, the excimer laser energy is not applied on the cornea's surface as in PRK. Instead, a flap of corneal tissue is created and flipped temporarily back.

The excimer laser energy is then aimed at the corneal tissue beneath the flap. The laser reshapes it to compensate for nearsightedness or farsightedness and to correct irregularities associated with astigmatism. Once this is done, the flap is then returned to its usual position.

The reshaped cornea can then focus the light on the retina.

LASIK Delivery

During the LASIK procedure, a corneal flap will be created and lifted out of the way. The excimer laser will be aimed at the tissue beneath it to reshape the cornea.

As part of the LASIK procedure, you can expect the following:

  • The ophthalmologist will numb the surface of the eye with drops.
  • A device (speculum) will be placed in your eye to keep your lids open, and another device (microkeratome) will be placed on the eye in order to create the corneal flap.
  • You will feel some firm pressure on your eye, and your vision will temporarily dim.
  • Your ophthalmologist will create a flap using what's known as a microkeratome (or possibly a laser). Next, this thin flap will be folded back.
  • While you stare at a light to help ensure you keep your eye still, the ophthalmologist will aim the excimer laser at the area underneath the flap to reshape the cornea. As the excimer is in use, you will hear a clicking sound.
  • The ophthalmologist will finish by laying the flap down and gently smoothing it in place. Within two or three minutes, the flap will begin to reattach and will continue to heal over the upcoming weeks.

Another possibility is undergoing custom LASIK. This approach involves creating a three-dimensional map of your eye and any unique aberrations it may have.

Then the eye surgeon will use what's known as wavefront-guided laser technology to customize the LASIK and treat any unique aberrations (imperfections) that may be interfering with your best vision.

Side Effects

After undergoing LASIK, there is the possibility of the following common complications:

  • Dry eye
  • Hazy vision
  • Starbursts or halos around lights
  • Glare
  • Light sensitivity
  • Flap dislocation
  • Improper microkeratome corneal flap incision

With LASIK, while most complications can be quickly resolved, there's also the possibility of infection. You might have worse vision than before surgery, even with glasses or contacts. There's also the possibility of vision loss.

Prices and Where to Get it

Traditional LASIK prices can vary from around $1,000 to $4,000 per eye. If you have custom LASIK, costs will be at the upper part of this range and possibly even beyond.

You can get LASIK at outpatient surgery facilities, as well as at university centers.

Which Treatment Is Best for You?

Should you undergo PRK or opt for LASIK? That's an individual decision to be made with the assistance of an ophthalmologist. Factors to consider include:

  • How nearsighted or farsighted are you? If your prescription is very high, such as a minus 8 (written as "-8") or a minus 9 (written as "-9") for someone who is nearsighted, you may be advised to undergo PRK since this takes less corneal tissue than LASIK.
  • Are you at risk of getting hit in the eye, such as an athlete who may risk getting clocked by a stray ball? If so, PRK is the better option because the LASIK flap may dislodge.
  • Are you looking for instant visual gratification? If you are, then LASIK is better since you get relatively clear vision just a few minutes to hours after surgery. PRK, where surface healing is needed, takes more time.
  • Is a quick recovery important to you? With LASIK, you'll likely be well on your way to healing after a week, while PRK takes more time.
  • Do you work outside? If so, keep in mind that with PRK, you will be advised to stay out of bright sunlight for one month or more since you will be at risk of developing visual haze.

Can PRK and LASIK Be Used Together?

While you may initially opt to undergo a LASIK procedure, if you need to have your prescription changed later, it's not uncommon to undergo what's known as an enhancement.

At that point, your ophthalmologist may recommend PRK to avoid lifting the LASIK flap, which brings with it some risks. Lifting the flap may cause it to become damaged in the process, especially if it has been several years since the initial LASIK was performed.

Coping With Side Effects

If you find yourself contending with side effects after laser refractive surgery, these options may help:

  • To alleviate haze, undergo a procedure in which the corneal surface is scraped.
  • If you see glare, halos, or rings around lights at night after refractive surgery, you should notice an improvement after about three months.
  • For those with dry eye after LASIK, this will likely improve as the eye heals. In the meantime, you can manage your dry eye in the same way as you might if this occurs for other reasons. Try using artificial tears, or your healthcare provider can prescribe anti-inflammatory drops.
  • To help ward off infection with either PRK or LASIK, take the antibiotic drops prescribed for you during the postoperative period. If an infection develops, be sure to contact your ophthalmologist promptly. They can determine the right medication and whether a LASIK flap may need to be removed.

Summary

PRK and LASIK are two forms of excimer laser refractive surgery that can address common vision problems such as nearsightedness, farsightedness, and astigmatism. Either can potentially reduce your need for glasses and contact lenses. Both use an excimer laser to reshape the cornea.

The key difference between them is that PRK is done on the eye's surface, while LASIK is performed beneath a corneal flap. Deciding which is right for you means weighing your unique eye needs and your lifestyle.

A Word From Verywell

With an elective procedure such as PRK or LASIK, provided nothing about your eye rules out one or the other, the choice of which of these to undergo will be yours. There's not necessarily a right answer—in many cases, it will simply come down to preference.

The good news is that either of these procedures can ultimately sharpen your vision and make you less dependent on glasses or contact lenses. You should still continue to see your eye doctor regularly for comprehensive eye exams afterward to ensure you are not developing other eye conditions.

10 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Maxine Lipner
Maxine Lipner is a long-time health and medical writer with over 30 years of experience covering ophthalmology, oncology, and general health and wellness.