Photorefractive Keratectomy (PRK) is surgery aimed at correcting myopia, hyperopia and astigmatism. This form of refractive surgery was the first freely available type of laser eye correction - and it's still widely available today.
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Illustration of photorefractive keratectomy.
Illustration of photorefractive keratectomy.
Photorefractive Keratectomy Quick Details
WHO IS THIS FOR
People who are short-sighted.
People who are far-sighted.
People with astigmatism.
People who'd rather not wear spectacles or contact lenses.
In most cases, PRK surgery takes around 15 minutes per eye.
Initial improvements in vision can take days or weeks to materialise.
The full effects of surgery can take up to six months to materialise.
Up to 90% of patients report near 20/20 vision without visual aids a year after surgery.
Up to 95% of patients report 20/40 vision after surgery.
POTENTIAL RISKS & SIDE EFFECTS
Temporary sensitivity to light.
Blurred vision (usually temporary).
Failure of the procedure.
Infection within the cornea.
Scarring on the cornea. This can lead to blurred or cloudy vision.
What Is Photorefractive Keratectomy (PRK)?
Photorefractive Keratectomy (PRK) is laser surgery aimed at correcting refractive problems in the eyes. Put simply, lasers are used to reshape the lens and ensure light hits the retina at exactly the right spot. Among the errors corrected by surgery are far-sightedness, short-sightedness, astigmatism and presbyopia. In recent years, LASIK and LASEK surgery have both become more popular than PRK. While the recovery process associated with PRK takes longer than the alternatives, it is still a safe and reliable method of refractive surgery.
How Does Photorefractive Keratectomy (PRK) Work?
Before you can undergo PRK surgery, you'll need to undergo an assessment and an examination. Your surgeon will perform several tests to assess your particular problems. You'll need to provide a detailed medical history at this point. Most patients will have to submit to a range of testing before surgery takes place. Your surgeon will definitely check the thickness of your cornea. An eye pressure check, corneal mapping and refraction testing are all also necessary.
2. Removal of the Corneal Epithelium
Your surgeon needs direct access to your cornea in order to make the necessary changes to your eye. This access is gained by flushing the eye with an alcoholic solution. Once the epithelium lifts away from the rest of the eye tissue, the surgeon scrapes it away with a special type of "buffing" instrument.
3. Laser Treatment
The next stage involves the use of excimer lasers to change the cornea's curvature. While the surgeon is always in control of the proceedings, the actual movements of the laser are tightly controlled by computers. Beams of ultraviolet light work by removing tiny amounts of tissue. Over a period of around 15 minutes, this painstaking removal process changes the shape of the eye.
4. Bandaging Surgeons
The next stage is bandaging, but this doesn't usually mean you'll have to wear a physical bandage. In order to protect the newly-corrected eye, a soft contact lens is inserted. This gives the cornea and the epithelium a chance to heal without being exposed to contaminants. In most cases, new cells grow back in around five days - after which time the lens can be removed.
Are There Different Types of Photorefractive Keratectomy (PRK)?
The main alternatives to PRK refractive surgery are LASIK and LASEK. Both are very similar. However, in the case of LASEK, the epithelium is moved to one side, before being moved back into place. This process can shave several days off the recovery process.
What Should I Expect?
Once you've chosen a licensed and reputable surgeon, you'll be expected to undergo a series of tests. These are essential, as they allow the surgeon to map your specific laser treatment with pinpoint accuracy. The initial exam will involve your surgeon measuring the size of your pupils, as well as the curvature and thickness of your corneas. The surgeon will also gauge the moistness of your eyes. This procedure can involve dryness in the eyes afterwards. If you already have dry eyes, you might be deemed unsuitable for treatment.
Your overall health and medical history will also be assessed. It's essential that you're as open as possible about these issues. Failing to disclose health issues might put your health or the results of surgery in jeopardy. Whether you have one or both eyes done during the same session is entirely up to you. If you're nervous about the procedure, it might be best to get the second eye corrected at a later date.
It's important to temper your expectations. This type of refractive eye surgery can fail, although such cases are rare. You might have to continue wearing glasses or contact lenses for several weeks after surgery - until your eyes heal. And even if the surgery is a complete success, you may still suffer from presbyopia (blurred vision when reading).