Did you know that laser-assisted in situ keratomileusis (LASIK) evolved from photorefractive keratectomy (PRK)? Invented in the 1980’s and FDA approved in 1995, PRK was the first FDA approved procedure performed using the excimer laser to reshape the surface of the cornea. While LASIK and PRK are both considered refractive surgery, they access the cornea quite differently and have their own set of advantages and disadvantages.
Why choose PRK over LASIK?
Each eye is unique and as such, not everyone is a candidate for LASIK. This is often due to thin, scarred, or irregular shaped corneas. Patients found to be non-candidates for LASIK are often deemed candidates for PRK to correct their nearsightedness, farsightedness, and/or astigmatism.
What is the difference between LASIK and PRK?
PRK differs from LASIK in that no corneal flap is created with a microkeratome or femtosecond laser prior to the corneal reshaping. PRK is performed by first removing the thin outer layer of the cornea (the epithelium). The epithelium is removed by introducing a sterile solution to the cornea to loosen the tissue. Next, the excimer laser precisely reshapes the underlying corneal tissue (the stroma). A bandage contact lens is placed on the cornea to protect the eye and reduce discomfort until the cornea has healed. Over the next 3 to 7 days new epithelial cells grow back and the bandage contact lens is removed. Patients typically experience discomfort for up to the first 5 to 7 days, and will often have visual fluctuation for several weeks or more.
Long-term visual outcomes with PRK are similar to LASIK. However, since there is no corneal flap in PRK, it may be better suited for people with thinner corneas or who engage in high-impact activities or sports where a corneal flap is contraindicated.