Photorefractive keratectomy (PRK) eye surgery
Photorefractive keratectomy, or PRK, is a type of laser eye surgery to re-shape the surface of the cornea to help correct mild to moderate short-sightedness, long-sightedness and/or astigmatism.
What are the advantages of PRK?
PRK is highly accurate in correcting many cases of short-sightedness. Approximately 80% of PRK patients have 20/20 vision without glasses or contact lenses one year after surgery; 95 to 98% have 20/40 or better vision without glasses or contacts.
What are the disadvantages of PRK?
Disadvantages of PRK include:
- Mild discomfort, including minor eye irritation and watering, for between one and three days following the procedure.
- It can be expensive.
- Somewhat longer time required to achieve best uncorrected vision (best vision is vision attained using glasses or contacts). Typically patients are 80% at one month after surgery, and 95 to 100% by three months after surgery.
- The outcome is not completely predictable and some patients may still require glasses.
What are the potential side effects of PRK?
Many PRK patients experience some discomfort in the first 24 to 48 hours after surgery and almost all experience sensitivity to light. Within the first six months after surgery, other potential side effects may include:
- Loss of best vision achieved with glasses.
- Seeing a minor glare; this can be permanent, depending on a patient's pupil size in dim light.
- Mild halos around images.
How do I prepare for PRK surgery?
Before your PRK surgery, you’ll meet with a coordinator who will discuss with you what you should expect during and after the surgery. During this session, your medical history will be evaluated and your eyes will be tested. Likely tests will include measuring corneal thickness, refraction, and pupil dilation. When you meet the surgeon, ask any further questions you may have. Afterwards, you can schedule an appointment for the PRK procedure.
Check with the clinic where you are having your procedure done but generally speaking, if you wear rigid gas permeable contact lenses, you should not wear them for three weeks before the date of your surgery. Other types of contact lenses shouldn't be worn for at least three days prior to surgery. Be sure to bring your glasses so your prescription can be reviewed.
On the day of your surgery, eat a light meal before arriving at the clinic and take all of your prescribed medications. Do not wear eye makeup or have any bulky accessories in your hair that will interfere with positioning your head under the laser. If you are not feeling well that morning, call the clinic to determine whether the procedure needs to be postponed.
What happens during the PRK procedure?
The PRK procedure is done under local anaesthetic and takes a maximum of about 10 minutes to do both eyes. During PRK, an eye surgeon uses a laser to reshape the cornea. This laser, which delivers a cool pulsing beam of ultraviolet light, is used on the surface of the cornea not underneath the cornea, as in LASIK.