What is Photorefractive Keratectomy or PRK?
A PRK procedure fixes refractive errors by using an excimer laser to reshape the cornea. First, your surgeon will gently remove the surface cells (epithelium) on the surface of the cornea. Then, using a cool excimer laser, your surgeon reshapes your cornea to correct your vision.
PRK has identical outcomes to LASIK. The vast majority of patients who receive PRK get 20/20 vision without glasses or contacts. PRK is a better alternative to LASIK for many patients who have thin or irregularly shaped corneas, who have pre-existing chronic dry eye, or those who perform sports with a lot of direct contact to the eyes (ex: Boxers, Ultimate Fighting Champions, etc).
PRK can treat low and moderate degrees of nearsightedness, farsightedness, and astigmatism. The main downside of PRK compared to LASIK is that vision remains blurred and there is potential for some discomfort after treatment. After a PRK procedure, it takes a week for the surface cells to grow back on the surface of the cornea. It takes anywhere from two to six weeks for the cells to smooth and allow for clear vision. It can take up to three months for maximum vision after PRK.
PRK patients have the option for having both eyes treated on the same day. However, if you have both eyes treated on the same day, you will typically be out of work and unable to drive for a week while your eyes heal. For those unable to take this recovery time, you have the option of treating one eye at a time, so that you can get back to work the next day using good vision from the other eye. If you elect to have one eye done at a time, the second eye surgery will be performed two to four weeks later (depending on how quickly you recover vision).
The procedure itself takes about 10 minutes, taking about 2-3 minutes per eye. The procedure is performed under eyedrop anesthesia and a relaxing medication. You will feel a mild pressure during the PRK procedure but no pain.
First, a strong anesthetic is applied to the surface layer of the cornea (epithelium) to loosen these surface cells. The epithelial layer is then removed or moved to the site using a manual instrument.
Step 1: Layer preparation
A diluted alcohol solution is applied to the cornea to dissolve the epithelial layer.
Step 2: Layer removal
The epithelial layer is then removed or moved to the side using a manual instrument.
A cool excimer laser is then used to sculpt tissue from the cornea in order to correct your vision. Following the laser, a sponge with a medication called Mitomycin-C is placed on the cornea to help with healing. Then a bandage contact lens is placed on the eye to minimize discomfort and assist with healing. This bandage contact will be removed at our office about five to seven days later.
Step 3: Corneal sculpting
An excimer laser sculpts the corneal tissue within a matter of seconds to correct the refractive error.
Step 4: Eya protection
Finally, a protective bandage lens is placed over the eye until the epithelium heals within a few days.
After a PRK procedure, it takes a week for the surface cells to grow back on the surface of the cornea. Your vision will be blurred for the first week or two (images will appear very fuzzy). In many cases, your vision for the first one to three days is acceptable. Your vision then drops as the surface cells heal over the center of vision. It takes anywhere from two to six weeks for the cells to smooth and allow for clear vision. It can take up to three months for maximum vision after PRK.
The amount of discomfort experienced after surgery varies from patient to patient. Most PRK patients experience mild burning, stinging and tearing. Some patients will have no discomfort symptoms. In very rare circumstances, patients can experience severe pain. The bandage-like contact lens we place on your eye after surgery helps alleviate discomfort. We will also provide topical drops, called comfort drops, which are drops with a mild anesthetic.
Follow-up is performed the day after your surgery and then either 4-6 days later. At the second visit, we will monitor your healing and remove the contact lens. You will also be prescribed a topical non-steroidal drop, steroid drop, and antibiotic after your treatment.
LASEK is a type of PRK where alcohol is used to loosen the surface cells of the cornea prior to removing them. LASEK is used when patients have had previous LASIK with a flap. After 3 to 4 years, it is not safe to lift a LASIK flap because of the risk of cells growing under the flap (epithelial ingrowth). It is also not safe to attempt to recut a LASIK flap years later because of the risk of creating irregularity by cutting through the previous flap. The only safe way to enhance LASIK with laser vision correction is with LASEK. With LASEK, the alcohol is used to loosen the underlying epithelial cells so that the initial flap is not disrupted. Healing after LASEK is identical to PRK, although LASEK patients may have more discomfort due to the alcohol.
PRK at Dougherty Laser Vision
PRK is a great alternative for those who are not great candidates for LASIK. It is safe, effective, and a great option to treat nearsightedness, farsightedness, and astigmatism. If you have any questions or would like to find out if PRK is right for you, call one of our locations or schedule your complimentary consultation today.