Photorefractive Keratectomy (PRK)
Written by Heather Mayer
What is PRK eye surgery?
Have you been told that you’re not a good candidate for LASIK surgery, but are looking for an option that will allow you to reduce your dependence on contacts or eyeglasses? If yes, you may want to consider photorefractive keratectomy also known as PRK surgery. PRK eye surgery is used to correct nearsightedness, farsightedness and astigmatism.
How does it work?
The cornea is the clear outermost layer of the eye that covers your iris and pupil. In people with normal vision, the cornea helps focus light emitted from an object directly on the retina, resulting in clear vision of that object. Refractive errors that result in blurry vision occur when the shape of the cornea affects the way light is bent so that light does not focus directly on the retina.
In people with nearsightedness, their cornea is too curved and so light is focused in front of the retina instead of on it. This results in the ability to see nearby objects clearly, but makes distant objects blurry.
In contrast, farsightedness is due to the cornea being too flat, causing light to focus in back of the retina. This is why people who are farsighted see distant objects more clearly than objects that are closer to them.
PRK alters the way light is bent by changing the shape of the cornea (making it more flat or curved).
Is it right for you?
PRK is well suited for people who have mild nearsightedness, farsightedness or astigmatism and would like to be less reliant on glasses or contacts. Your doctor may recommend this procedure if you are not a good candidate for LASIK.
The LASIK procedure requires cutting into the cornea to create a “flap” that is folded back to expose underlying cornea tissue. Because this procedure requires part of the cornea to be used in the creation of this “flap,” it is not recommended for people who have thin corneas. The replacement of the “flap” following LASIK surgery may also lead to complications such as “flap” dislocation in people like athletes who have increased risk for physical contact with the eye. PRK does not require the formation of a “flap” and is a less complicated procedure.
Your doctor will go over your medical history and give you an eye exam to determine your eligibility for PRK.
Who may not be a good candidate?
It is usually advised to not have this procedure if you have any of the following:
- Significant cataract
- Dry eye syndrome
- Abnormalities of the cornea
- Scars or inflammation on the cornea
- Steep or flat corneas
- You are pregnant or nursing
- Uncontrolled diabetes or other conditions that could lead to poor wound healing
- Unstable refraction error for the past year
What to expect before surgery
Prior to the procedure, your doctor will take a detailed medical history to determine your eligibility for PRK. Your doctor will also do an eye exam that will involve measuring your refractive error, the thickness of your cornea, your cornea’s shape and your pupil size.
If you wear rigid contact lenses you will be asked to stop wearing them 3 weeks before your procedure. All other contact lenses should not be worn for at least 3 days before the procedure.
You should not wear eye makeup or anything else that can interfere with your eyes or the ability for the doctor to access your eyes during the procedure.
You will be allowed to eat before the procedure, so ensure you have had a light meal and have taken all your necessary prescriptions.
PRK Treatment details
The procedure will likely be done in an outpatient surgery center. Your eye will be placed in a holder to keep it open throughout the entire procedure. You will be asked to remain still and stare at a target light to prevent your eye from moving. You will be awake for the procedure, but will be given a local anesthesia to prevent you from feeling any pain. PRK consists of the following steps:
- The outermost layer of the cornea, called the epithelium, is removed, typically with an alcohol-based solution to access the underlying cornea tissue
- The laser that has been preprogrammed using your cornea measurements will remove microscopic pieces of tissue from your cornea to reshape it
- A soft bandage contact lens will be placed on the surface of the cornea to help the epithelium grow back
Following surgery, you should be driven by someone else and go home to rest. Your vision may be blurry while the epithelium heals. You can expect the epithelium to complete healing within a week after surgery, but you may still have blurry vision for a few weeks.
During this time of healing it is important to maintain good eye hygiene and wear sunglasses to avoid eye damage from the sun. You may also need to take a week off from work and avoid driving for 1-2 weeks.
You will be given anti-inflammatory eye drops as well as antibiotic drops to prevent infection. It is not likely you will experience pain after surgery, though it has been reported that 10% of people experience mild to moderate pain up to 36 hours after surgery.
Expect to have multiple follow-up visits with your doctor to check your progress.
Risks & side effects
Although PRK is considered a safe procedure, there is a chance, as with any other procedure, that complications may arise. Glare, shadows, halos, cornea haze (cloudiness) and dry eye are less serious side effects seen after PRK eye surgery. Other less common but more serious complications include:
- Mild pain
- Central corneal islands which may blur vision
- Corneal erosion
- Delayed epithelium healing
- Cornea infection
- Persistent refractive errors
When will you see results?
It has been reported that 80% of people showed improved vision 1 month after surgery and 95% showed improvement by 3 months.
How long will your results last?
It’s been shown that 90% of people who underwent PRK had 20/20 vision after 1 year. The results are expected to be long-term; however, if vision does start to regress, adjustments can be made with repeat surgery called enhancement surgery when refraction is stable.
Alternatives to PRK
PRK tends to have a longer recovery time and may result in a higher likelihood of pain and haze compared to other similar treatments. For these reasons, some people may choose LASIK or LASEK instead. They work in a much similar way to PRK and achieve comparable results but have slight differences, as explained below:
LASIK: Instead of removal of the epithelium, a “flap” is created from the cornea. The “flap” is pushed back and is replaced after cornea tissue is removed with a laser.
|Results are typically seen within the first 24 to 48 hours after treatment.||More complicated procedure than PRK|
|Can treat higher levels of nearsightedness||Can result in more complications including vision loss, eye infections, and detached retinas.|
|Shorter recovery time||Is not a viable procedure for people with a thin cornea|
LASEK: A combination of PRK and LASIK. LASEK creates a “flap” from the epithelium instead of the cornea. The “flap” is pushed back and replaced after cornea tissue is removed with a laser.
|Outcomes for LASIK and LASEK patients are similar.||Longer healing time compared to LASIK|
|Technique lessens the risks of certain side effects such as dry eye and ectasia.||LASEK is typically more expensive|
Cost of PRK eye surgery
On average the total cost of PRK eye surgery is between $1,500 to $3,000 per eye. The cost will vary depending on the surgeon’s skill level and the location in which you get the procedure.
PRK surgery is not usually covered by insurance. Most insurers consider PRK to be an elective cosmetic surgery and not medically necessary.
Ready to take the next step?
Contact a local ophthalmologist near you to setup a PRK surgery consultation.
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- Boyd K. What is photorefractive keratectomy (PRK)? American Academy of Ophthalmology Website. September 27, 2017. Accessed October 7, 2020. https://www.aao.org/eye-health/treatments/photorefractive-keratectomy-prk
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- How expensive is PRK? Costs to expect in 2020. NVISION website. Accessed October 7, 2020. https://www.nvisioncenters.com/prk-laser-surgery/costs/