Differences between PRK and LASIK

Because PRK does not create a permanent flap in the deeper corneal layers (the LASIK procedure involves a mechanical microkeratome using a metal blade or a femtosecond laser microkeratome to create a ‘flap’ out of the outer cornea), the cornea’s structural integrity is less altered by PRK.

The LASIK process covers the laser treated area with the flap of tissue which is from 100 to 180 micrometres thick. This flap can mute the nuances of the laser ablation, while PRK performs the laser ablation at the outer surface of the cornea. The use of the anti-metabolite mitomycin can minimize the risk of post-operative haze in persons requiring larger PRK corrections.

PRK does not involve a knife, microkeratome, or cutting laser as used in LASIK, but there may be more pain and slower visual recovery. Unlike LASIK, PRK does not create the risk of dislocated corneal flaps which may occur (especially with trauma), at any time after LASIK.

An evolved form of PRK is called No Touch laser vision correction. It also treats the surface of the cornea but unlike other techniques, requires no assistance from manual surgical instruments. It is the only technique to use exclusively an excimer laser from start to finish