PRK and LASIK are the most popular modern methods to correct nearsightedness, farsightedness and astigmatism.
LASIK is an advanced laser vision correction procedure where nearsightedness, farsightedness and astigmatism can be corrected by using an excimer laser to reshape the clear corneal tissue at the front of the eye. The cornea is the clear tissue at the front of the eye that light passes through as it enters your eye. During LASIK, this laser treatment is performed beneath a very thin flap in the cornea.
PRK is an advanced laser vision correction procedure where nearsightedness, farsightedness and astigmatism can be corrected by using an excimer laser to reshape the clear corneal tissue at the front of the eye. The cornea is the clear tissue at the front of the eye that light passes through as it enters your eye. During LASIK, this laser treatment is performed beneath a very thin flap in the cornea.
What are the advantages of LASIK?
One advantage to LASIK is faster healing and this is the most common reason why Lasik tends to be more popular with patients. During LASIK, the area treated by the excimer laser is covered by a thin flap of corneal tissue. As only the edges of this corneal flap need to heal and this healing is usually is completed within hours, the healing after LASIK is generally very fast. Typical LASIK patients will recover within 24 hours so that they are able to return to work and resume normal activities including driving, reading and computer use within 1 day.
Because LASIK requires creation of a flap in the cornea, it weakens the cornea slightly more than a PRK procedure does. This is usually not a significant risk – unless the patient has an unusually thin cornea or a corneal shape that may suggest instability.
What are the advantages of PRK?
An advantage of PRK is relative safety compared to LASIK because there is no corneal flap created during a PRK procedure. Lasik is very safe (although no procedure is entirely risk free). Yet as safe as LASIK may be, PRK is even safer than LASIK in most cases. The excimer laser treatment is performed directly on the corneal surface during PRK so there is no corneal flap created as during a LASIK procedure. Therefore, without a corneal flap there is no risk of any flap related complications when PRK is performed. For example, with PRK there is zero risk of a wrinkled or short flap, displaced flap, incomplete flap, debris or material under the flap, inflammation under the flap or other flap complications like epithelial ingrowth under a flap.
These LASIK flap complications are very rare and LASIK is very safe, but PRK is even safer for the reason that there is no flap at all. With no corneal flap, more corneal tissue remains intact and the cornea is generally stronger and more stable as a result. Therefore, there is less risk of corneal thinning with PRK compared to LASIK. Corneal thinning, referred to as corneal ectasia is very rare but it is less likely to occur if PRK is performed. Also, because no tissue is used to make a LASIK flap, with PRK there is more tissue available for a second treatment or enhancement if needed in the future. Also, there is some evidence that patients may experience somewhat less short term postoperative dry eye symptoms with PRK compared to LASIK.
What is the difference in healing time?
One disadvantage of PRK is the relatively longer healing time with PRK as compared to LASIK. With PRK, patients may require an average of 3-4 days before the surface of the eye has healed. During these first 4 days or so, a bandage contact lens is worn to protect the healing corneal surface. Vision is typically better even immediately after PRK but the best vision does require at least 1-2 weeks of healing. PRK patients will usually return to normal activities within 4-5 days. By the second week following PRK, the vision has usually recovered to the same level as if LASIK had been performed.
Am I a candidate for PRK?
Nearly every LASIK candidate is generally a candidate for PRK too. Some patients are candidates for PRK only and they may not be LASIK candidates. Examples of patients who may be PRK candidates include patients with corneal scars, thinner corneas, irregular astigmatism, or prior eye surgery. Some patients with certain occupational or active sports interests might prefer PRK if there is a concern about a possibility of future eye trauma. For example, a boxer may be more likely to experience eye trauma and PRK is probably the best procedure to avoid the possibility of a traumatically displaced flap. Some patients may not be suitable for either procedure and a thorough exam performed at King LASIK will determine what options are available for each patient.
King LASIK offers our Bellevue patients both LASIK and PRK. Approximately 15 percent of patients are not suitable for either procedure but there may be other options that can correct the vision.
Patients who prefer the LASIK experience a slightly safer procedure when the LASIK corneal flap is made by a laser rather than by a blade. Although microkeratome Lasik is still commonly offered around the world, at King LASIK the LASIK flap is usually made using an advanced femtosecond laser such as the leading Intralase IFS, the first of its kind in the Bellevue area and Puget Sound. Dr. King has used other femtosecond lasers including the Ziemer femtosecond laser for flap creation.
Every patient who is interested in laser vision correction is thoroughly evaluated. Dr. King will educate you on your options and recommend whether LASIK or PRK is best for you.