Transepithelial PRK is an evolution of PRK and differs from this technique because the epithelium removal is not done manually, but with the laser. It is therefore a technique that involves less post-operative discomfort and faster healing.
In transepithelial PRK, the entire operation is performed with the excimer laser which first removes the epithelium, and then performs the surgery to correct the visual defect, modifying the curvature of the cornea. It is, therefore, a single procedure to remove the epithelium and correct the refractive error.
The advantage is that the epithelium reforms faster, post-operative contact lenses have to be worn for fewer days, and the patient experiences less pain than with the traditional technique.