Photorefractive keratectomy or PRK eye surgery is a type of laser vision correction in which a surgeon removes the surface layer of the cornea with a laser and reshapes it to correct any refractive errors.
For people with the thinner-than-normal cornea, PRK is a recommended alternative since these people are at risk to create the corneal flap required for LASIK.
What is Photorefractive Keratectomy (PRK) Eye Surgery?
The cornea refracts light and focuses on the retina in order to create a sharp image. Refractive errors happen when the shape of the cornea is either too steep, too flat, or irregular and prevents light from focusing on one point on the retina.
The first Laser eye surgery, also known as photorefractive keratectomy (PRK), changes the shape of your cornea so that light enters it properly. PRK surgery is a common treatment for vision problems like nearsightedness, farsightedness, and astigmatism.
PRK eye surgery was approved in 1995 by the FDA while LASIK was approved a few years later – but there are now many different types of surgery. PRK is a good option if a person is not an ideal candidate for LASIK eye surgery.
An in-depth understanding of the PRK procedure and how it differs from LASIK is necessary before deciding which type of laser eye surgery is best for your eyes. It’s important to explore all of your options. If you’re thinking of getting laser eye surgery and throwing away your glasses or contact lenses, here’s what you need to know.
Inclusion Criteria for Candidates of PRK
If you have dry eyes or thin corneas and are thinking about getting refractive surgery, PRK might be the best option for you. Though other kinds of refractive surgery (such as LASIK) would not be recommended if you have these conditions, PRK would still work.
It’s true that PRK doesn’t involve a flap, like LASIK and other surgeries do. This means it might be a better option if you have an active lifestyle or job. If you are highly active, you may accidentally dislodge a corneal flap, which can lead to problems.
Some people who have had Cataract surgery may opt for PRK vision surgery for better eyesight.
In order to have a PRK, it is important to speak with your ophthalmologist about what you can expect. In addition, the requirements for PRK are:
- healthy eyes with healthy cornea and other structures
- expectation that should meet the reality of the PRK outcome
- age must be above 18 years
- stable and constant refractive errors over a period of 1 year
Exclusion Criteria for PRK
After evaluation of overall eye health and other required tests of your eyes, the ophthalmologist will inform you whether you are a suitable candidate or not for the PRK laser eye surgery.
Some people are not good candidates for PRK. They include people with:
- unstable or fluctuating refractive errors
- corneal diseases, including corneal abrasions and corneal scars
- cataract that affects your vision’
- if you have an advanced glaucoma
- severe eye allergy, dry eye syndrome and blepharitis
- diabetes that is not under control
- pregnant and breastfeeding woman
- present or past history of infections that affects the cornea
- any systemic diseases that affect healing of the wound after PRK
Preparation for Photorefractive Keratectoy (PRK) Eye Surgery
When you are about to undergo PRK surgery, a healthcare professional will inform you about what to expect before, during, and after the procedure.
Your eye care professional will take a medical history and test your eyes for preoperative visual acuity, refractive error (myopia, hyperopia, or astigmatism), corneal topography, pupil size, and general health of your eyes.
Your eye doctor will be able to answer any questions you have. Afterward, you can schedule your procedure for PRK.
Stop wearing your rigid gas permeable contact lenses for at least three weeks before visiting your eye doctor for screening. If you wear other soft contact lenses, you’ll need to give them 3 full days off before visiting. Bring your current eyeglasses so that your prescription can be checked
On the day of your surgery, eat a light meal before coming and take all of your usual prescribed medications. Avoid wearing heavy jewelry or any makeup that will interfere with positioning your head under the laser.
If you’re not feeling well on the morning of the surgery day, make sure to contact your ophthalmologist’s office first before deciding if you need to reschedule.
Photorefractive Keratectomy (PRK) Procedures
Before your PRK surgery date, you’ll have the opportunity to speak to your doctor about what you can expect in terms of instructions about taking prescription medication. These instructions may include removing contact lenses, disposing of cigarettes, not wearing make-up, and using eye drops from time to time.
Your eye doctor will let you know about all the details before your surgery date. Make sure to follow the instructions they give to you before surgery.
Before PRK Surgery
Your doctor and you will discuss your needs related to your lifestyle. For example, if you play sports, you may want PRK surgery for better distance vision.
Another tip is to make sure to talk to your ophthalmologist about your expectations for PRK. If you’re expecting it to give you perfect vision without glasses or contacts, then you might be disappointed (or not).
PRK is a procedure for the treatment of nearsightedness, farsightedness, and/or astigmatism. It allows most people to function without having to wear glasses or contact lenses every day.
Your eye doctor will examine your eyes and discuss whether or not you are a suitable candidate for the PRK surgery. The doctor will test your vision, check for other eye problems, measure and map the corneal surface (corneal topography), and measure your pupil size.
PRK is a refractive procedure that takes around 10 minutes per eye and doesn’t require general anesthesia, and local anesthetic eye drops are used to numb your eyes prior to the surgery.
During the PRK procedure:
- To stop blinking, an eyelid holder is fixed on the eye.
- Your eye surgeon will remove the corneal epithelial cells using a laser, blade, alcohol solution, or brush.
- A laser fitted for your eyes will take the measurements needed for reshaping your corneas and will use a pulsing beam of UV light to do so. You might hear beeps while it is doing this, but don’t worry; it is doing no harm to you.
- A clear, non-prescription contacts (bandage contact lens) will be placed on each eye as a bandage. This helps to avoid infections during your healing process. The contact lenses will remain on your eyes for several days to one week.
After surgery, you’ll rest at a clinic and then go home. Make sure to keep everything else on standby for the day, as you’ll be in recovery mode and your comfort level is important during this time.
You may be seeing your Doctor on the day after the surgery, or sometimes days later if you notice signs that indicate an eye infection. If this is the case you need to call your doctor immediately.
If you notice the contact lens detaching or falling out, immediately notify your doctor to get it removed. You’ll need to switch back to the clinic for the removal of the contact lens.
Many people notice an improvement in vision when they have photorefractive keratectomy surgery. Initially, your vision may be better than it was before the procedure. It will, however, become somewhat blurry during the first few days of recuperation. Then it’ll improve significantly.
Make sure that no makeup, soap, shampoo, or other substances are in your eyes for at least a week before washing and talking to your doctor about the best times to do so.
Talk to your doctor about driving, reading, and computer use during the period of time that your eyes heal from surgery. These activities can initially be difficult because of vision blurriness. Driving should be avoided until the eyes no longer have this problem.
At least a week should be spent without sweating for your eyes to stay healthy and functional. Do not participate in contact sports or anything that might cause injury to avoid any risk of permanent damage to the eye.
Eye protection should always be worn when performing activities that could cause permanent damage. It is also important not to get dust or dirt in your eyes for that time.
The time it takes for eyesight to normalize is typically up to three months after surgery. After that time period, around 90% of patients will have 20/40 or better vision.
Shield your eyes from bright sunlight for about a year. Nonprescription sunglasses provide sun protection during sunny days.
Difference Between PRK and LASIK Eye Surgery (PRK vs LASIK)
LASIK is also a type of laser eye surgery done in the cornea of your eyes. Unlike LASIK, a PRK doesn’t involve making a flap in your cornea. You should opt for PRK if you have dry eyes or thin corneas, and as your lifestyle becomes more active.
All laser refractive surgeries function by reshaping the front surface of your cornea so light traveling through it is properly focused on the retinas at the posterior pole of the eyeball.
In PRK surgery, a laser is used on the surface of the cornea to reshape it. Unlike LASIK where the laser is used under the corneal flap, PRK does not require lifting of the corneal flap which makes it a little less invasive than LASIK for an eye surgeon to perform and also induces fewer post-operative side effects.
The pain from LASIK is shorter and recovery periods are faster. If you have PRK surgery, you may experience blurry vision for a short period of time. In terms of quality of vision, both PRK and LASIK have similar rates of success.
Benefits of PRK over LASIK
People usually go for PRK instead of LASIK because of the following reasons.
LASIK surgery is newer than PRK and your eye surgeon may be more experienced with photorefractive keratectomy. Talk to them about their experience with the procedure to help you decide which one would be best for you
As LASIK involves the creation of a flap, there is a risk of getting the flap displaced or dislocated by physical activities. Unlike LASIK, PRK with no flap involvement may be preferred by pilots, athletes, boxers, martial artists, wrestlers, or patients more prone to blows to the face, or anyone who does a lot of physical activity.
PRK is an alternative laser refractive surgery to LASIK for thin corneas; it may be used if your eye surgeon finds that you don’t have enough thickness in the cornea, and LASIK flap approaches will not work.
Soft corneas are much more likely to be bent out of shape and may not provide the best outcome for flap creation, which is why PRK is a better alternative.
Photorefractive Keratectomy (PRK) Disadvantages, Risks, Side Effects or Complications
Post-operative discomfort and pain are common after PRK surgery and last for at most 3 days. You can use over-the-counter medication to reduce these symptoms.
Talking to your doctor about the pain is your best bet. They will be able to recommend medication if necessary and even help you through any discomfort.
Increased light sensitivity is seen in some patients during the healing phase. Not all people experience this, but most will see halos or bright spots for a few days or weeks, especially at night.
You may experience temporary blurry vision following the surgery. This is due to corneal haze and will clear up after a short period of time.
Any laser refractive eye surgery comes with risks. Although considered safe, PRK may include the following complications.
- overcorrection or under correction of refractive error
- haze or cloudiness in the cornea
- corneal scar
- glare and halo around the light, especially at night, leading to reduced night vision
- increased sensitivity to light
- double vision
- eye pain, irritation, watering
- eye infection
- severe dry eyes
- in rare cases, permanent loss of vision
You can’t always predict the outcome of PRK. You may need corrective surgery, eyeglasses, or contact lenses if your vision is not perfect. However, this is still a very good opportunity to improve your eyesight and be confident in your vision
How Painful in PRK Eye Surgery?
PRK surgery is so quick and pain-free. You will feel mild discomfort during the surgery. Once anesthetic drops are used to numb the eyes, it can take less than five minutes per eye.
Pain and discomfort during the recovery period after surgery varies. Not everyone has the same level of pain and some might feel comfortable in a few days while others may feel pretty uncomfortable until the third or fourth day.
Some patients say the recovery process is very painful. However, there are post-operative measures in place to reduce the risk of complications and make sure that you recover quickly.
Vision After Photorefractive Keratectomy
According to research, more than 90% of PRK patients who have their vision tested within a period of one year following surgery, achieved 20/40 vision or better.
PRK cannot correct presbyopia, which is the age-related loss of near vision. Even people with perfect distance vision will need reading glasses at around 40 years of age.
Some people have PRK with monovision to help with presbyopia. This means one eye is left slightly nearsighted and the other eye (dominant eye) is adjusted for distance vision. The brain learns to adapt so that the nearsighted eye is used to see close-up things, while the other eye sees clearly for everything else at a far distance.
Not every person will be able to adapt to monovision. To see if this is right for you, you may want to try monovision contact lenses first.