PRK Laser Eye Surgery
Photorefractive Keratectomy (PRK) was the first form of laser eye surgery to be approved. It is still a widely performed procedure for the correction of near-sightedness, far-sightedness and astigmatism and is used in cases where LASIK is not suitable.
The key element that makes the PRK procedure unique is that the epithelium (top layer of the cornea) is removed completely before the laser is applied to correct the patient’s eyesight. The epithelium then grows back during the next few days.
PRK vs LASIK
All laser eye surgery procedures involves reshaping the cornea to allow light to properly focus on the back of the eye (the retina). The key difference between PRK and LASIK, for example, lies in how the eye is prepared for the laser treatment.
LASIK procedures require the creation of a small, hinged flap in the cornea (the delicate layer of tissue that protects the eye) which allows the laser access to the treatment area. However, in PRK the entire outer layer of the cornea is removed and left to re-grow naturally following the procedure.
The main advantage of LASIK over PRK is that it has a much quicker healing time. LASIK also has a number of other advantages over PRK:
- More comfortable healing period
- a shorter period before vision is restored
- Reduced chance of experiencing visual ‘haze’
- More predictable visual outcomes
Am I eligible for PRK?
If you are short- or farsighted or suffer from astigmatism you may be eligible for PRK. The procedure offers simlar visual results that are seen following LASIK with between:
- 80-90% of patients will achieve 20/20 vision without glasses or contact lenses.
- Upwards of 95% of patients will achieve at least 20/40 vision without glasses or contact lenses.
The Advantages of PRK
Due to faster recovery times, LASIK is often considered the preferable procedure but there are a couple of factors that may make PRK the more appropriate option. These include:
- Thin corneas: If your ophthalmologist finds that you have a thin cornea he or she is likely to recommend PRK over LASIK. With PRK there is much less chance of too much of the cornea being removed, weakening it – thereby reducing the possibility of corneal-flap complications.
- Occupation: Anyone whose occupation or hobbies puts them at increased risk of eye injuries are also likely to be offered PRK as the procedure reduces the possibility of the corneal flap being dislodged at work.
- A ‘no knife’ procedure: PRK surgery is known as a ‘no knife’ procedure as, unlike LASIK where a flap is cut in the cornea, the surgeon uses an alcohol solution to remove the tissue.
What to expect on the day of the procedure
Before: Your ophthalmologist will conduct a thorough eye examination prior to you undergoing PRK. This is to ensure that you are definitely a suitable candidate for the procedure and will confirm your eye’s prescription.
If you are a contact lens wearer you will need to stop wearing them around a week before the surgery, as they can change the shape of your cornea making it harder to take accurate measurements.
During: Anaesthetic drops will first be applied to your eyes to numb them and your eye surgeon will remove an area of the corneal tissue (epithelium) with either an alcohol solution or a surgical instrument known as a ‘buffing’ device. An excimer laser uses pulses of cool ultraviolet light to remove minute amounts of tissue, reshaping the cornea. Finally a ‘bandage’ contact lens is placed over the cornea to protect it while the new cells grow back.
You are likely to be given a mild sedative to relax you during the procedure, which should only take around 10 minutes per eye. Your vision will take a while to adjust so you will not be permitted to drive. Bearing this in mind, you should arrange for someone to drive you to and from your appointment.
After: You are likely to experience some mild discomfort for a few days after the surgery while the epithelial tissue re-grows. For the first few weeks following the procedure you may find that your vision fluctuates between clear and hazy and you will probably need to wear glasses for reading until this stabilises. You will also be given prescription drops to keep your eyes moist and to ward off infection.
Your surgeon will schedule regular check-ups and you should find that your eyesight will gradually improve over the following weeks. You will usually be permitted to start driving again within a couple of weeks of the procedure but it may take up to six months before you achieve your best visual outcomes.
Disadvantages of PRK
The most frequently cited disadvantages of PRK are:
- Slower recovery. This related to the removal of the corneal tissue since, rather than a flap that can be sealed back in place, the cells need to re-grow which takes a little longer.
- Longer wait for final outcomes. It can often take up to six months before you will achieve your best visual results.
- Increased risk of infection. While the cells are re-growing there is a slight increase in the risk of infection, although you will be given antibiotics to counteract this.
- Less predictable outcomes. PRK is not as predictable as LASIK and some patients may still need to wear glasses or contact lenses following the procedure.
Side effects of PRK
It is not uncommon for patients to experience mild discomfort in the first 48 hours following the procedure and painkillers can be prescribed to manage this. Other potential side effects include:
- Sensitivity to light
- Minor glare
- Seeing haloes around lights
These side effects usually cease within 6 months of the surgery.
How much does PRK cost?
The cost of PRK eye surgery will vary significantly depending where you get the procedure done. Typically prices range between £600 and £1000 per eye. Don’t be tempted just to go with the cheapest option – your eyesight is too vital to risk for the sake of a few pounds.
In fact, many clinics offer payment plans if you can’t afford to pay for it in one lump sum. Talk to a number of centres and ask as many questions as you need to. A reputable eye surgeon will certainly not mind and you should feel completely comfortable with whoever you choose.