Joel Hunter, MD Refractive Surgeon, Hunter Vision Updated 10/04/19 2:40 PM
If we were to consider good vision as a destination, and laser eye surgery as our mode of transportation to get there, LASIK would be a commercial flight and photorefractive keratectomy (PRK) would be traveling by railway. A flight can create the illusion of a far-off destination feeling easier to get to than it should. I’m reminded of this when I talk to LASIK patients several times a day.
Not uncommonly, I’ll see someone who was near blind without glasses before their LASIK procedure. Now, less than 24 hours later, that patient's vision is better than 20/20 and the only comment on their post-op day one chart says “eyelashes feel annoying from eyedrops.”
On a few occasions, I’ve talked with a 20/20 patient—six hours after LASIK—discussing what they don’t like about the post-op sunglasses required for the first six hours. It is (and there’s no sarcasm here) genuinely delightful. The recovery was so quick and painless, the flight from here to there so fast, that it’s possible to focus on something relatively trivial compared to the miracle of modern technology.
Discussions at LASIK post-ops are often the refractive surgery equivalent of having an uneven tray table on a flight across the country.
You can’t tell these stories to the folks on the railroad. The destination is the same, (vision after LASIK or PRK is identical) but having PRK gives the distance traveled much more of a sense of accomplishment.
How recovery from PRK surgery has vastly improved
PRK predates LASIK. The procedure itself has come a long way with vast improvements in the last 20 years. It’s changed enough that it technically has a new name at this point: advanced surface ablation (ASA). It earned the new name because the recovery is so much quicker and more painless and because the final visual result is so much better. Now it’s a very speedy, finely-appointed train.
The fact that the procedure has been performed by surgeons for two decades already is a testament to PRK’s changes for the better. Take for example the severe corneal haze that patients rarely experienced during the early days of the procedure experience.
The haze appeared during the first few weeks after the surgery. They had to endure this side effect for months, or sometimes even years. However, the introduction of mitomycin C (MMC), a topical concentration applied for about 12 seconds, changed all that. I’ve literally never had a patient experience corneal haze. MMC is widely used by doctors to prevent haze brought about by refractive surgery.
But think about this: even the best train will still have passengers who aren’t going to want to hear about how your plane had to sit on the runway for 20 minutes. There are times, heaven help us, where spouses will have LASIK for one and ASA/PRK for the other. No marriage retreat obstacle course will ever compare to the intensity of patience and understanding required of those couples.
Difference between PRK and LASIK
Here’s the interesting thing about all this: modern PRK really isn’t a big deal. Everything I just wrote is true, but it’s true because LASIK is so ridiculously quick and easy, not because PRK is that hard.
It just seemed appropriate to pay homage to the difference from the beginning because chances are, if you’re a candidate for PRK and reading this, most of the people you’ve known who’ve had laser eye surgery had the LASIK version of it.
Don’t compare your journey to theirs. It’s a plane vs. a train. If you want to compare it to anything, choose radial keratotomy (RK) from the 80s. Those guys rode horseback.
But if you want to really dig into the comparison between PRK and LASIK, here are the details.
Patients with thin corneas can benefit from PRK. In terms of the average percentage of the corneal thickness removed, PRK only gets rid of about 10% compared to LASIK’s 20%, leaving more corneal tissue to be reshaped with the use of an excimer laser. That’s about 50 µm to 70 µm more corneal tissue than what is left when undergoing LASIK.
Patients who lead a very active lifestyle that exposes them to high risks of eye traumas are also good candidates for PRK. A patient who is engaged in boxing, wrestling and mixed martial arts need not worry about dislodging a corneal flap during a fight since no flap is created in the first place unlike in LASIK.
PRK only involves surgery on the cornea’s front surface while LASIK requires a flap to be created. However, if he gets hit by a sequence of blows during a match, the eye can still be injured. As an aside, I’ve never had a patient with a dislodged corneal flap after LASIK despite seeing more blunt injuries than I can count when working with boxers, MMA fighters, and parents of toddlers.
The healing period for PRK is much slower compared to LASIK, however. But don’t get frustrated. It only takes about three to five days for a PRK patient to recover completely (this is still a case-to-case basis though).
On the other hand, LASIK has a much faster recovery period since most patients can go back to work (ideally in an office space where there are low eye irritants such as dust and debris) the following day.
Advantages of PRK surgery
The nice thing about PRK is that even though the vision gets to 20/20 pretty quickly after the contact comes out, it keeps getting better from there. It doesn’t take three months to get a good vision, but the vision keeps improving for three months.
The only special rule during that extended period of time is the need for sunglasses during the first six weeks. It’s important to wear them anytime you’re outdoors during that period. If anyone asks why you’re wearing sunglasses when it’s cloudy, you can tell them you had PRK or that you’re a spy.
Once you’ve gained the supervision achievable with modern PRK, the journey there feels easily worth it according to everyone I talk to who’s had it done. Plus, if you meet someone who has had LASIK, you can feel a sense of superiority because of the journey you took that they skipped. That alone is probably worth the ride.
As mentioned earlier, PRK leaves more of a patient’s cornea intact so those who have thinner corneas may be advised to consider this procedure. There is no blade or laser that is used to make a flap in the cornea as is the case for LASIK. Also, if a patient has a high intraocular eye pressure or IOP (meaning, there is higher pressure in the eyes than what is normal), the IOP may appear to be low with a thin cornea. If left undetected, it may result in vision loss or glaucoma.
While PRK uses the same laser as LASIK, the procedure is much simpler. The eye surgeon gently removes the cornea’s top surface (called epithelium) to expose the stromal layer. Then, a laser is used to reshape the cornea.
It’s as easy as that.
What happens during PRK surgery
The PRK procedure takes 10 minutes to complete for both eyes and is completely painless. Because it skips the first laser required in LASIK—the one that feels like pressure—PRK is a slightly more comfortable procedure than LASIK.
It begins by an eye surgeon examining your eye health and other factors such as the cornea’s thickness and shape to qualify you for the surgery.
Are you wearing contact lenses? Your cornea’s shape may have morphed because of your contact lenses so your doctor will ask you to refrain from wearing for some time (usually 72 hours) before you come back a follow up diagnostic imaging scan.
If you meet the minimum qualifications, then the surgery can be scheduled. On the day of the procedure, an anesthetic in the form of eye drops will be applied. Since you will be awake during the entire procedure, a “blink protector” will be used to keep your eyelids open and prevent blinking. (But what if you do? The laser will automatically pause to keep you safe. So, relax because the surgeon has got your covered.)
When you’re all set, the surgeon will position an excimer laser over your eye, which you have to focus at. The laser will then send a series of pulses to start the procedure.
At the end of the procedure, an Acuvue Oasys contact lens with no prescription is placed on the eye. It stays there for four days and during that time your vision will transition from decent to blurry, and back to almost decent.
But are results always guaranteed?
Generally, patients tend to have improved eyesight upon complete healing. But true to any type of refractive surgery, the results vary from one patient to another. Some may still be required to wear eyeglasses to have better vision, others return to work right away but with sunglasses on. From personal experience, it is exceptionally rare for a patient to have less than 20/20 after PRK.
Why PRK recovery is generally quick
When the contact lens comes out, the vision starts to rapidly recover and most people are 20/20 within a day or two of the contact lens removal. As for discomfort, there’s almost never a level that people describe as pain. It’s mostly light sensitivity and so sunglasses are helpful even indoors. The feeling of a piece of sand or eyelash in your eye varies from person to person.
Many of those who have undergone PRK surgery report experiencing very minimal discomfort during the post-op phase. For the next two to four days, dry eyes may likely occur, which is completely normal. A few eye drops prescribed by your eye doctor can provide a good remedy and you’d be using it in between your sleep if you feel any discomfort.
You may also be asked by your eye doctor to take pain relievers should the pain make you feel uncomfortable. This is often caused by what seems to be a grain of sand in your eye that I mentioned above. Some patients have greater tolerance for such minimal discomfort while others prefer to just stay at home and recharge from the hectic work schedule they have.
Are some candidates for PRK able to recover quicker?
Generally, PRK recovery is quick but it still depends on the patient’s case and background. Strong candidates for PRK are those who fit the following criteria:
Has thin corneas
The cornea helps us focus on incoming light and protects the eye from dust and irritants. It must be transparent and in the correct shape to function well. Corneas need to also have the right amount of thickness to handle eye pressure. This is a requirement in LASIK surgery since a patient must have enough cornea thickness so that a flap can be created. However, with the advances in LASIK technology, a patient with thin cornea may still be recommended to undergo such a procedure with the use of a femtosecond laser instead of a microkeratome so a thinner flap can be made as determined by an eye doctor.
When the cornea thins progressively, it develops into a cone-like appearance. This is a contra-indication to PRK and LASIK. While for some patients this is due to genetic reasons, some have developed such condition because of an autoimmune disease, bacterial infection, eye inflammation and ocular disorders. Those with keratoconus also exhibit a progressive degradation of corneal thickness.
Has a high corrective prescription
PRK is sometimes more ideal if the patient has severe nearsightedness or astigmatism. LASIK procedure can be risky in cases where an already thin cornea needs more corneal tissue removed. When the refractive error is too high, a patient is also at risk for side effects such as glare and halo.
How high is the corrective prescription to be considered an ideal candidate? This will depend on your eye doctor so, for example, patients within the range of -7.00 to -9.00 typically proceed with PRK.
Has stable vision for at least 12 months
Along with having a high prescription, it should not have fluctuated or changed within the year. This is another reason why older patients are eligible for PRK since younger ones (those below 18) have more frequent changes in their eyeglass or contact lens prescriptions than adults or what is known as refractive instability. It also occurs among those with diabetes, pregnant or breastfeeding mothers, and those whose current medications lead to such side effects.
Has no eye complications or diseases
Patients with eye issues such as advanced state of glaucoma, severe corneal scarring or abrasions, and cataracts may lead to further complications under PRK.
In a healthy state
Naturally, undergoing any refractive surgery requires the patient to be in good health condition. Anything that may further complications will certainly be not allowed by the surgeon.
An eye doctor will conduct several tests to determine if the patient is a good candidate for PRK, which includes examinations on eye health, cornea thickness and curvature measurements, and refractive error.
So, depending on your specific measurements, your eye surgeon may confirm your candidacy for PRK surgery if LASIK is not an appropriate option.
PRK post-surgery care for faster recovery
To speed up recovery, patients must observe proper self-care even before the surgery begins. For example, inform your boss that you’ll have to be absent so that you can avoid from working in front of the computer screen or you won’t be exposed out in the field.
After the surgery, have someone accompany and drive you home. In addition, make sure to make the most out of the time to take a well-deserved rest.
The eyes shouldn’t be rubbed to avoid dislodging your contact lens. Makeup, hair color, and perm are highly discouraged as well as face creams or lotions that may contain chemicals harmful to the eyes.
If your fitness coach is asking you to go back to the gym, now is the perfect time to make that excuse. You can be a couch potato for a few days to avoid sweat getting in your eyes can cause irritation. The same holds true for swimming at the pool or beach, dusting your furniture, or gardening. But you can still take a shower as long as you don’t get water in your eyes.
Your eye doctor will be the one to assess when you can resume doing regular strenuous activities or you’re ready to wear makeup.
But what about meds? Patients should always consult their eye doctor first before taking anything–even an aspirin. This is to make sure that you’re free from any side effects that can harm your eyes.
Never miss any follow-up consultation so your eye’s condition is monitored. If you’re feeling any unbearable pain, contact your doctor right away.
Potential side effects of PRK
So are there side effects from a PRK surgery? Yes, but since any surgery brings potential complications, your best bet is to find a doctor who can reduce the risks of possible eye issues.
With PRK, some of the known side effects include seeing halos around lights (most especially when you’re driving at night) and dry eyes. You may also have cornea infection or keratitis although this is unlikely to occur if your eye doctor provides you with proper post-surgery care. In fact, the risk of having such infection is higher when you regularly wear contact lenses.
There are also cases where one’s astigmatism or nearsightedness may regress after the surgery. The surgeon would then have to examine the eye and provide guidance on what treatment to pursue such as an enhancement
The following paragraph is required, but I am also allowed to tell you I have never seen any of the following happen in many, many thousands of cases. In some (rare) cases though, serious complications such as perforation of the cornea, cataracts under the lens, and a raised area in the corneal center (known as a central island) may occur. For some patients, corneal thinning may develop after the procedure in the form of keratoconus.
However, these can be prevented with the proper monitoring by the doctor, and the patient’s dedication to following the surgeon’s instructions for post-surgery care.
How much does PRK surgery cost
So the end question when it comes to any refractive surgery is always the same: Can I afford it?
I suggest asking a different question though: What’s your vision worth?
My patients who have successfully undergone eye surgeries are always delighted by the results in terms of restoring their eyesight. There is no better investment they’ve made in their lives – not even the new car they bought – then choosing to get eyes that can see great without any need for glasses or contacts. (As a side note, if you want to learn more about it, read about the top 8 reasons why people choose us for vision correction.)
And getting an eye surgery doesn’t involve burning a hole in your pocket these days. We have payment plans available that make vision correction surgeries affordable for almost everyone. We know tight budgets make it tough to come up with a “chunk” of money rather than paying overtime in bite-sized bits.
Our affordable payment plans for vision correction surgeries including LASIK can fit your tight budget. That's why we offer payment plans for as low as $130 per month - yes, that's not a typo - so you can start and end your day without your eyeglasses.
Author: Joel Hunter, MD is an Ophthalmologist, Refractive Surgeon, and the Founder of Hunter Vision, a LASIK Orlando Clinic in Florida. A recognised and respected specialist in vision correction who has performed a countless number of refractive surgeries, Joel gives lectures across the country and trains fellow doctors in the newest LASIK surgery techniques.