From a website:
The Epi-LASIK procedure uses a unique microkeratome to mechanically separate the epithelium (top thin layer of the corneal surface) to make a flap. Unlike LASIK, no sharp blades or cutting are required.
Any procedure that "makes a flap" will very likely not be waiverable for PJ/CCT/CRO/STO/CWX because those "flaps" do not hold up at 25,000ft in sub-zero temperatures when jumping from an airplane, or at depth on a SCUBA dive when one loses their mask...or under the 80mph rotor wash of an MH-53 during water
operations...you get the idea...
The primary reason PRK is approved is because it does not involve any cutting of the cornea.