The Original Laser Eye Surgery
PRK (photorefractive keratectomy) once was the most common refractive surgery procedure before LASIK was developed as a more popular alternative. Both PRK and LASIK are grouped under the umbrella “laser eye surgery,” but each is a little different when it comes to advantages and disadvantages.
LASIK patients have less discomfort and obtain good vision more quickly — whereas, improvement with PRK is gradual and takes days, weeks or even months. But many surgeons prefer PRK in circumstances such as when patients have thin corneas, other corneal or retinal issues and dry eyes.
PRK was invented in the early 1980s. The first FDA approval of a laser for PRK was in 1995, but the procedure was practiced in other countries for years. In fact, many Americans had the surgery done in Canada before it was available in the United States.
PRK is performed with an excimer laser, which uses a cool ultraviolet light beam to precisely remove (ablate) very tiny bits of tissue from the surface of the cornea in order to reshape it. When you reshape the cornea in the right way, it more precisely focuses light into the eye and onto the retina, providing clearer vision than before.
People with nearsightedness, farsightedness and astigmatism can all benefit from PRK. With nearsighted people, the goal is to flatten the too-steep cornea; with farsighted people, a steeper cornea is desired; and with astigmatism, the irregular cornea is reshaped into a more normal, rounded shape.
If considering PRK, the first step is to have a FREE laser screening.
Then, if it is determined that you are a reasonable candidate you will proceed
to have a 3 hour evaluation by Dr. Northam. She will examine your eyes to determine exactly what kind of vision correction you need and how much laser ablation is required. A corneal topographer will be used; this is an instrument that measures the curvature of the front of your eye and creates a kind of “map” of your cornea. No one has a perfectly rounded cornea, and the topographer will display the corneal irregularities and the actual steepness or flatness of the cornea that must be addressed. Dr. Northam will also ask you about medical conditions you may have. Some conditions might disqualify you altogether as a PRK candidate; others may mean a postponement of the procedure or special care afterwards.
Custom PRK is a procedure that enables your laser vision correction surgeon to further customize the conventional PRK procedure to your individual eyes. Custom PRK provides an additional level of data about your vision requirements using wavefront technology. A device called a wavefront analyzer measures the way light travels through your eye and compares it to an eye with perfect vision. This device then creates a 3-D wavefront map that is uniquely yours, in the same way that your “fingerprint” is unique to only you. This additional data is then used by Dr. Northam to customize the PRK laser vision correction procedure to your individual vision requirements.
The actual PRK procedure process is performed the same way in both conventional PRK and Custom PRK. Conventional PRK is an excellent choice for many patients.
Your doctor will recommend which procedure is best for you based on your visual requirement; they will help you to determine if you could benefit from the higher level of customization that Custom PRK may provide.
The PRK Procedure
PRK is an ambulatory procedure; you walk into the surgery center, have PRK and walk out again. In fact, the actual surgery usually takes 7-10 minutes per eye, and you’re awake the whole time. No scalpels are used and no incisions are made.
Most people don’t feel pain during PRK. Your eyes are anesthetized with special drops prior to the procedure and during the procedure to numb the eye and prevent pain. The doctor will have you lie down, and then will make sure your eye is positioned directly under the laser, which has already been properly calibrated. One eye is operated on at a time. A kind of retainer is placed under your eyelids to keep them open throughout the procedure.
To accomplish the reshaping, the surgeon first removes the protective surface layer (epithelium) from the cornea. The epithelium is regenerated within three to five days. Dr. Northam will then smooth the area and proceed with applying computer controlled pulses of cool laser light to reshape the curvature of the eye. Deeper cell layers remain virtually untouched.
The PRK laser vision correction process is completed in approximately 30 to 60 seconds, and immediately afterwards, a clear bandage contact lens is placed on the cornea to protect it. Additional eye drops are applied. Since a layer about as slender as a human hair is typically removed, the cornea should maintain its original strength. Typically both eyes are treated the same day unless decided otherwise by Dr. Northam.
PRK Recovery: After the Procedure
After PRK, your eyes may feel irritation or a foreign body sensation for a few days, but this discomfort can usually be effectively managed with medication. The clear bandage contact lens that was placed on the cornea during surgery to protect the eye is usually worn for the first 3 to 4 days to allow the surface of the eye to heal. Once the epithelium is healed, the bandage contact lens is removed. You should expect to visit your eye doctor several times during the first several weeks, then several more times during the first 6 months following your PRK surgery.
PRK patients are placed on antibiotic drops, along with anti-inflammatory agents after PRK to promote comfort and reduce swelling. To complete the healing process, steroid anti-inflammatory drops are used for approximately 2-4 months under Dr. Northam’s direct supervision.
Your vision may fluctuate between clear and blurry for the first few weeks following surgery. You will notice glare at night for driving during your healing process and your eyes will be more light sensitive than usual. Your eyes will also be dry and artificial tears will be needed. Your vision will gradually improve, and usually will be good enough to allow you to drive a car within 5 days to 2 weeks following surgery. Keep in mind, however, that your best vision may not be obtained for up to 6 weeks to 6 months following surgery.
PRK is one of the many refractive surgery options Dr. Northam offers to our patients.