People interested in Lasik eye surgery might be surprised to find that there are several types of Lasik available today, and that they may have to consult with their doctor about whether they're candidates for blade versus bladeless Lasik surgery. What exactly is the difference between blade and bladeless Lasik, and what are the advantages and disadvantages of each type?

The main instrument used by an eye surgeon in traditional Lasik surgery is called a microkeratome, which can cut a thin, "hinged" flap into the cornea (the clear surface on the eye). This flap is then lifted to let the doctor apply the laser and reshape the eye for vision correction. By replacing this flap, the eye is allowed to heal very quickly.

But, another way of creating a Lasik flap uses a type of laser (femtosecond) instead of a blade. Intralase is usually advertised as "bladeless" or "all laser" Lasik, though eye surgeons who favor the microkeratome ("blade") approach are correct when they say both procedures technically penetrate the eye's surface.

Eye surgeons differ about the advantages and disadvantages of blade versus bladeless Lasik. What they do usually agree upon is the need for truth in advertising. Some medical facilities argue that where the word "bladeless" is used, it somehow implies that tradition microkeratome Lasik is more dangerous to the patient when in fact it is not considered more risky.

Back to the pros and cons for using either blade flaps or laser flaps. Some doctors prefer using the blade flap, because microkeratomes make the procedure go much faster and the suction needed to hold it up is about three seconds, whereas the suction using the laser method is at least 15 seconds; some medical professionals think the less suction used, the more comfortable it is for the patient.

Some medical professionals believe that it's more likely a doctor could induce a "buttonhole" flap (an incomplete flap with a hole in the middle), or even detached flap, with the microkeratome surgery, and that the laser technique is less likely to do this because one gets the same thickness of flap with a laser no matter what the curve of the cornea happens to be. The argument for laser continues with the assertion that the more curved the cornea is, the thinner the flap could be centrally with a blade slip and therefore the risk of a buttonhole flap is greater.

Also, a physician ostensibly has greater control in bladeless surgery, because the computerized portion of it makes it easier to visualize the flap, and to stop the procedure if necessary.

However, both detached flaps and buttonhole flaps are extremely rare in statistics compiled from expert surgeons. Experienced surgeons also concur that irregular flaps could occur with both techniques if the surgeon was rough with either the laser or microkeratome. Both tools are purportedly only as good as the surgeons who wield them.

Studies have shown that one disadvantage to the laser flap can be a slightly increased risk of more edema (swelling) of the flaps because of all the energy the laser requires to make the flap. This can possibly delay clearness of vision from a few days to a week, and does not occur with a flap made with "the blade." There are also some studies that note a low risk of light sensitivity resulting from use of the laser.

Some doctors recommend using blade versus bladeless Lasik with glaucoma patients, because the time and degree of suction is less.

In both blade and bladeless Lasik, there can be complicated cases where the patients, because of unsuccessful previous refractive surgeries, have to have them fixed with the same technology. For example, water bubbles can form during laser flap creation can filter through a previous blade flap incision, blocking the focusing lens of the laser. So, a doctor will often recommend that once a type of Lasik is decided upon, it's best to have the same type again if needed in the future.