PRK (photorefractive keratectomy) was performed in the mid-1980s and was the precursor to LASIK for laser vision surgery. Although LASIK has now surpassed PRK as the most common refractive surgery, PRK is still an excellent alternative for patients who cannot undergo LASIK surgery.
Simply put, PRK is LASIK without the creation of a corneal flap.
Like LASIK, PRK utilizes the same ultra-precision laser, the VISX STAR S4™ with ActiveTrak™, to reshape the cornea. In PRK, however, the first step of the procedure simply involves removing the outer "skin" layer of the cornea, called the epithelium. With LASIK, the laser is applied to the inner tissue of the cornea, whereas with PRK, the laser is used on the surface of the cornea.
Results take longer to achieve with PRK than LASIK because it takes longer for the epithelium to regenerate and be fully restored. LASIK can often produce a clear vision within hours; PRK, on the other hand, may take several days or even weeks to recover clear vision.
Despite this difference, numerous studies have been performed to demonstrate that there is absolutely no difference in the final visual results when comparing PRK to LASIK. It is therefore a fantastic alternative for patients who may not be candidates for LASIK, those with specific technical requirements, or others with specific corneal conditions.