In the forms of laser eye surgery generally classed as surface ablation (as opposed to LASIK which cuts a flap of stromal tissue), the epithelium has to be removed before the laser treatment begins. There are several ways in which it can be removed. In traditional PRK, it is removed physicially (i.e. scraped off). In LASEK, an alcohol solution is used to soften it and it is removed manually. In transepithelial PRK, an excimer laser is used both to remove the epithelium and to perform the laser ablation. And in Epi-LASIK, the epithelium is lifted with a separator.
Transepithelial PRK is unique amongst these procedures in that it is a bit of a "boutique" procedure, that is, it was developed by a clinic in Canada in the 1990s and has not been popularised more broadly. |
