PRK (photorefractive keratectomy) is a refractive eye surgery technique similar to LASIK surgery as both use the excimer laser to reshape the cornea (the front surface of the eye), in order to change its ability to focus light on the retina.
The primary difference between PRK and LASIK is that with PRK the excimer laser carefully sculpts the outer layer of the cornea to create an optimal surface for the eye’s lens. Conversely, LASIK surgery involves the creation of a corneal flap using either a microkeratome blade or a femtosecond laser prior to using the excimer laser to correct the inner surface of the eye.
PRK is used to correct mild to moderate nearsightedness, farsightedness, and/or astigmatism. Those who have been told that their corneas are too thin for LASIK and those who have concerns about the creation of a corneal flap may consider PRK as an option for vision correction. Results are generally the same between PRK and LASIK, but the healing and recovery time is significantly longer with PRK. Discomfort after PRK may be more severe and last longer (up to two weeks) than the discomfort associated with LASIK. However, the corneal flap created during the LASIK procedure may take years to heal and those with strenuous jobs and/or recreational activities may opt to have PRK rather than LASIK to avoid the risk of damaging the corneal flap. PRK is thought to leave the cornea stronger after surgery in comparison to LASIK.