PRK (photorefractive keratectomy) is a type of refractive surgery to correct myopia (nearsightedness), hyperopia (farsightedness), and astigmatism. It was the first surgery developed for vision correction and came before the popular LASIK procedure. PRK works by reshaping the cornea using an excimer laser. It’s similar to LASIK in that they both use lasers during treatment; however, PRK surgery takes slightly longer to recover from. PRK’s are still commonly performed and, in some cases, offer advantages over LASIK eye surgery.
Both LASIK and PRK work by reshaping the cornea using an excimer laser, allowing light to enter the eye to focus on the retina for clear vision. The main difference between PRK and LASIK is the first step of the procedure. During PRK, the thin layer of the cornea (epithelium) is removed before reshaping the underlying corneal tissue with an excimer laser. The epithelium regenerates itself (grows back over the cornea) within a few days after surgery. With LASIK, a thin flap is created on the cornea using a microkeratome or a femtosecond laser. The flap is lifted to expose the underlying corneal tissue and is replaced after the cornea is reshaped with an excimer laser.
LASEK (with an e) is essentially another version of PRK; however, this procedure entails removing the outer layer of the epithelial layer of the cornea. As with PRK, LASEK involves lifting the epithelial layer by using a trephine, a type of surgical instrument. The epithelial layer is preserved during surgery and then placed back on the eye’s surface once the procedure is complete. LASEK has decreased in popularity due to the slower recovery of vision compared with PRK. The epithelial layer that is placed back on the eye takes longer to recover in LASEK than the growth of a new layer as in PRK.
Outcomes of PRK and LASIK are very similar. Many people can achieve 20/20 vision once they have had the procedure, and almost all patients achieve a 20/40 visual acuity or better. After PRK and LASIK surgery, complications are rare but can occur. Complications can include infection and starbursts or halos around lights at night. Reading glasses may also still be required after PRK surgery once you reach your 40s, due to an age-related loss of near vision called presbyopia.
When it comes to corrective vision, LASIK is by far the most popular option for the majority. However, it’s essential to follow the guidance and judgment of your eye surgeon regarding whether PRK or LASIK is the best option for your individual needs.