When the flap is created using an IntraLase brand femtosecond laser, the method is called IntraLASIK; other femtosecond lasers such as the Ziemer create a flap similarly. Proponents of this method assert its superiority over "traditional" LASIK, but there have been no conclusive independent studies to prove that this is a true statement. One supposed criticism of the use of the microkeratome is the deposition of microscopic metal fragments from the blade into the surgical site.[citation needed] Refractive Lenticule Extraction (ReLEx): ReLEx "FLEx" (Femtosecond Lenticule Extraction): A femtosecond laser cuts a lenticule within the corneal stroma.