Conventional LASIK has several steps:
a) The eye is cleaned and kept open using a small instrument known as a speculum.
b) An instrument known as a microkeratome is used to create a corneal flap as shown in figure 1). The microkeratome uses a high speed oscillating blade to cut the corneal flap
c) The flap is lifted to one side, as shown in figure 2). The excimer laser is used to reshape the cornea according to the refractive error of the eye.
d) The flap is then replaced and sticks back in place. Initially, it sticks back with surface tension forces. Later, an “epithelial glue” (i.e. a glue of the eye’s own cells) holds the flap in place.
Conventional LASIK has been in practice since more than 20 years now. Initially, the microkeratomes were unsophisticated instruments, which led to many complications. Today’s modern microkeratomes are sophisticated instruments, which cut a flap with great precision and safety.
Nevertheless, if problems do occur with the LASIK procedure, they are usually with the microkeratome. A recent innovation involves creating a flap with a laser, also known as Blade Free LASIK or Intra LASIK or No Blade LASIK. This further increases the safety and predictability of the procedure.