PRK (photorefractive keratectomy) is a type of refractive surgery to correct myopia (nearsightedness), hyperopia (farsightedness) and astigmatism. PRK was the first type of laser eye surgery for vision correction. It became popular worldwide in the early 1990s and in the USA in 1995. Though PRK recovery takes a bit longer than recovery from LASIK eye surgery, PRK is still commonly performed and offers advantages over LASIK for some patients.
The procedure is very similar to that of LASIK, but no flap is created.
How Is PRK Performed?
First, your eye will be numbed with numbing eye drops. Then an instrument called a lid speculum is used to keep your eyelids open. Your surgeon then removes a central area of corneal surface cells, called epithelium, with an alcohol solution and a blunt surgical instrument.
Next, the Allegretto Wave Eye Q laser is used to precisely reshape the curvature of your cornea’s surface. This computer-controlled, highly specialized laser delivers pulses of cool ultraviolet light that remove microscopic amounts of tissue in a precise pattern. The laser treatment lasts an average of 20 seconds depending on the amount of correction. Most people do not feel any discomfort, although you may feel some pressure on your eye. Your surgeon has full control of the laser and can turn it off at any time.
During the surgery, you’ll be asked to focus on a point of light. Staring at this light helps you keep your eye fixed while the laser reshapes your cornea. You may detect a distinct odor as the laser removes your corneal tissue. Some people describe smelling an odor similar to that of burning hair.
A soft “bandage” contact lens is then placed on the cornea to help protect your eye. New epithelial cells grow back in about four or five days, after which the bandage contact lens is removed by your eye doctor
After the procedure topical antibiotics as well as anti-inflammatory and pain medications will be prescribed to reduce post-operative discomfort, minimize any swelling and expedite healing. Patients should expect moderate discomfort for the first 24-48 hours.
Most PRK patients notice an improvement in their vision immediately after surgery. However, it is normal for vision to be hazy and fluctuate as the epithelium is healing. Your functional vision should return in 3-7 days while full visual results may take three weeks to several months to stabilize.
PRK VS LASIK
LASIK and PRK have very similar outcomes, with PRK taking longer to heal. PRK may be recommended over LASIK when a patient has a cornea that is too thin or if there are corneal irregularities. It may also be recommended for patients that suffer from chronic dry eye or patients with extremely active lifestyles or professions.
- Less depth of laser treatment than LASIK.
- No risk of corneal flap complications.
- Suitable for patients with a thin cornea.
- Reduced risk of compromised corneal thickness.
- Slower recovery than LASIK.
- Increased risk of post-surgery inflammation and haze.
- More eye discomfort during recovery, compared with LASIK surgery.
- The outcome is not completely predictable due to variations in individual wound healing