How Does Intralase Work?

IntraLase (also called IntraLASIK or all-laser LASIK) is a way of performing LASIK. LASIK corrects your vision by reshaping the cornea – the front transparent part of the eye. But if that were to be done right on the top surface of the cornea, it wouldn’t be a permanent correction. Therefore, a corneal flap must be created to expose tissue lower down.

The cornea has layers, and the surface layer, the epithelium, is continually renewing itself. Cells are discarded and replaced with new cells, and this makes the epithelium unstable, since it is continually changing itself.

The second corneal layer, the stroma, is stable, and that is where laser vision correction is done. A corneal flap – a thin slice of corneal epithelium – is folded back for treatment, and then replaced. It is made with an oscillating blade called a microkeratome.

Corneal Requirements for a Successful Flap

1. There needs to be sufficient corneal thickness -- enough to (a) create the flap; (b) remove some corneal tissue for vision correction); and (c) still have enough left in place during treatment to avoid any eye injury.

If LASIK is done on a person with thin corneas, the eye can start bulging forward after treatment – a condition called keratoconus – because the cornea is now too thin to contain the pressure exerted by the fluid inside the eye. Measurement of corneal thickness is done as part of determining your LASIK candidacy. Too-thin corneas will disqualify a person for LASIK.

2. Moderate or mild corneal steepness is also necessary for a good flap. A severely nearsighted (myopic) eye has a very steep corneal curvature. When the flap is created, a certain amount of pressure is placed on the eye so the microkeratome can cut the flap evenly and precisely. Too much steepness makes this impossible. That is why a person with very severe myopia is not a good LASIK candidate.

If a person has corneas which are too thin or too steep for LASIK, they may well be a good candidate for Intralase.

Using a Laser to Make the Flap

IntraLase uses a second laser to create the corneal flap, instead of the microkeratome. This gives the eye surgeon more flexibility in exactly how the flap is created. The IntraLase laser is extraordinarily fast-pulsed and can be programmed to penetrate to a microscopically exact depth in the cornea.

After the treatment area is marked on the eye, the IntraLase laser is directed over it in a series of back and forth passes. Each rapid pulse creates a tiny bubble in the cornea, at a predetermined depth. In a matter of seconds, it has passed over the entire treatment area and filled it with these bubbles below the surface.

The bubbles break molecular bonds, which loosens the flap tissue. Now your eye surgeon can gently ease the flap tissue up to expose the stromal layer for treatment. This flap is thinner than a standard microkeratome flap. After treatment it is replaced and smoothed over, as in a LASIK surgery. It will heal up by itself.

If you would like to have laser vision correction, but have been told you are a poor candidate for LASIK, you may well be able to have IntraLase. Be very careful about which eye surgeon you choose. Not all surgeons screen their potential patients equally well. If your corneas are thinner or steeper than is acceptable for LASIK, you are more vulnerable to surgical error. So choose only a highly-qualified and experienced eye surgeon. Be sure to ask lots of questions when you go for your consultation, to make sure you will be thoroughly screened for safety.