involves the creation of a superficial partial thickness corneal flap
(see figure). The flap is created with a "microkeratome", a specilaised
highly refined instrument which uses an oscillating blade.
Laser is performed underneath the flap, and then the flap is replaced.
The disadvantage compared to ASA is that it is a slightly more complicated and invasive procedure.
A thick and very regular cornea is required for this technique.