There are a number of different names for variations of LASEK surgery, including ASA LASEK (Advanced Surface Ablation) which uses an amoilis brush to sweep back the epithelial cells, and M-LASEK, which uses mitomycin, an anti-metabolite to try to reduce hazy vision after the operation for those cases where extensive correction is required. All aim to remove the epithelium out of the way before applying the excimer laser, rather than creating a corneal flap as with LASIK procedures.
LASEK can sometimes be marketed as ‘No-flap LASIK’ or ‘Blade Free LASIK’ as the term LASIK is more commonly known when referring to laser eye surgery procedures.
Another procedure, PRK (PhotoRefractive Keratectomy) laser eye surgery, is very similar to LASEK surgery and pre-dates it as a technique. In PRK surgery, the epithelium (the outer layer of the cornea) is removed completely and then the excimer laser is used to treat the cornea. This does however mean more recovery time and pain is likely with PRK than with LASEK.
With LASEK surgery, if the epithelial flap is too weak to be laid back in place after the laser treatment, it will be removed and the LASEK surgery will be converted to a PRK surgery. The epithelium can re-grow very quickly and will be replaced within a matter of days.
A Cochrane systemic review published in January 2013 comparing the safety and efficacy of LASIK and PRK eye surgery for short-sightedness by reviewing all available study and trial data concluded that; “LASIK gives a faster visual recovery and is a less painful technique than PRK. The two techniques appear to give similar outcomes one year after surgery. Further trials using contemporary techniques are required to determine whether LASIK and PRK as currently practised are equally safe.”
Another variation is epi-LASEK or epithelial LASEK. This uses an epikeratome, a similar surgical tool to the microkeratome oscillating blade used for LASIK. The epikeratome uses a blunt separator rather than a sharp blade to separate the surface sheet of epithelial cells from the permanent corneal tissue following the application of the 20% alcohol solution; (this is not included in the epi-LASIK version). Both procedures epi-LASIK and epi-LASEK are suited to those people whose corneas are too flat for traditional LASIK.
Wavefront guided technologies are used with LASEK as well as LASIK to aim to achieve an ‘optically perfect’ vision correction.