Microkeratome vs femtosecond laser
Femtosecond laser flap creation compared to microkeratome flap creation
When the LASIK procedure was first done in the mid 1990s the only method of creation of the LASIK flap was to use a mechanical microkeratome. Microkeratomes involve a suction ring holding the eye and attaching to the suction ring is a mechanical device similar in principle to a “carpenter’s plane” that cuts the flap with a steel blade. Many clinics used the same steel blade for both eyes to save money and this is still done today.
The first femtosecond lasers used to create LASIK flaps arrived in New Zealand in 2006. Every excimer laser clinic that bought a femtosecond laser quickly stopped using microkeratomes as it was very clearly much safer and more accurate.
Femtosecond laser technology involves an infrared laser pulsing between 150,000 and 500,000 times a second. Each pulse lasts about 100 femtoseconds and creates a tiny gas bubble. Virtually all of the disastrous complications of LASIK surgery including partial flaps, free caps, button hole flaps, lost flaps etc. were due to bad flaps from microkeratomes after loss of suction. In contrast, if suction is lost with a femtosecond laser then all that happens is that there are a gas bubbles in the cornea that diffuse out leaving no harm done. This is why femtosecond lasers are a much safer method for creating LASIK flaps.
The accuracy of the flap thickness is much better with femtosecond laser as well. As a result it is safe to create the thinnest possible LASIKs flaps that remove the least amount of cornea and leave the cornea much structurally stronger than with microkeratome flaps.
Today all the leading excimer laser clinics in the developed world use femtosecond lasers to create LASIK flaps. Microkeratomes are much cheaper to buy and use so they are either only used in either the developing world or in excimer laser clinics providing a cheaper procedure. You should not expect to pay a high price for LASIK if the excimer laser clinic continues to use the older, less modern, less accurate and less safe steel bladed microkeratome to create the LASIK flap.