LASIK vision correction is one of the most common of all surgical procedures all over the world. LASIK vision correction offers major advantages such as:
- Virtually painless surgery
- Little or no pain after surgery
- Marked eyesight improvement within a day or two after treatment
Background to LASIK
One of the most major advancements was the development of LASIK or Laser in situ keratomileusis first performed in 1989. This technique revolutionised laser vision corrective surgery by providing rapid vision correction with reduced patient downtime compared to earlier PRK surface excimer laser. LASIK itself has continued to evolve so that today we have a computer controlled, highly refined procedure that takes less than ten minutes per eye and produces excellent, stable first day vision.
The LASIK procedure has three essential steps:
- The creation of a thin flap through the top layer of the cornea. Once created the flap is gently folded over to allow application of the laser treatment onto the underlying stronger corneal tissue.
- The excimer laser will then be locked to the eye and will resculpt the underlying cornea to change the optical focusing power of the eye as desired. This process generally takes around 2 to 20 seconds and the entire procedure may require the removal of just a few micrometres of corneal tissue (typically around 1-2 times the width of a human hair).
- The flap is then gently replaced into position and will settle back into normal position without any stitches being required.
Femtosecond LASIK v Standard LASIK
This is often characterised as ‘razor’ versus LASER’. There are two ways in which we can create a corneal flap – as follows:
- A mechanical device with a super sharp blade physically cuts a very thin flap- typically 0.12mm by running across the cornea- this is called a micro-keratome and was the dominant method of flap creation until the advent of,
- A advanced form of LASER called a ‘femtosecond’ laser. This device, a separate laser, creates only a ‘virtual’ flap which can be opened only if the surgeon is satisfied with its size, shape and centration. Until this is done the flap has no permanent impact on the eye. The ability to check on these parameters before flap lift is a crucial second safety step.
Our view is that the debate over ‘razor v laser’ is effectively over. Femtosecond devices have advanced so much in recent years that any previous advantages of mechanical keratome devices (principally speed) have more or less evaporated now. We believe that femtosecond laser flap creation is:
- Safer during surgery – Because sharp blades are avoided. A second check on the integrity and suitability of the flap is available prior to the ‘lift’ of the flap.
- Safer after surgery – Because femtosecond created flaps are generally sculpted and shaped in a different way to mechanical flaps which make femtosecond created corneal flaps more adherent and more resistant to movement post operatively. There may also be a reduced risk inflammation and other rare post operative problems related to flap creation.