IntraLase® (All-Laser LASIK)

Jennifer Kimberley

The difference between IntraLase® and LASIK is in how the eye surgeon creates the corneal flap. IntraLase uses a laser and LASIK uses a hand-held device called a microkeratome.

Corneal Thickness

The choice between these two methods of vision correction depends largely on the thickness of your corneas. Some people have thinner corneas than average and this disqualifies them as LASIK candidates. Why?

Because LASIK improves vision by reshaping the cornea and it reshapes it by removing tiny pieces of it from the right places. This is not done on the corneal surface (epithelium), but on a deeper layer called the stroma. Therefore a surface flap is created and folded back to give access to the stroma. In LASIK this flap is the thickness of the corneal epithelium plus some of the upper stroma.

If a flap of that thickness is made in thin corneas, then some tissue is removed during vision correction, there might not be enough corneal thickness left to maintain the eyeball’s shape. Our eyes are filled with fluid which exerts outward pressure on the eyeball’s periphery. As the cornea is part of the periphery, it must be thick enough to keep its shape against the internal pressure.

Ectasia is a condition where the cornea bulges forward and distorts vision. It is similar to Keratoconus but Keratoconus is not caused by LASIK. Ectasia can be a complication if LASIK is done on thin corneas. The microkeratome cuts very precise corneal flaps, but not necessarily thin enough for safety when your corneas are thinner than average.

The IntraLase Laser

For IntraLase the eye surgeon creates a flap using an extraordinarily fast-pulsed laser. It is not the same laser used for vision correction. It is called a femtosecond laser because its pulses last only one femtosecond.

• A femtosecond is a millionth of a nanosecond and a nanosecond is a billionth of a second.
• In a femtosecond this laser light travels a distance about equal to half the thickness of a human hair.

It is infrared, meaning it vibrates beyond the red end of our visible spectrum, and is therefore invisible to our eyes. It generates less heat than other medical lasers, which is an advantage in eye surgery. The IntraLase femtosecond laser creates a very smooth and precise corneal flap. It has been improved and made even faster since the first IntraLase laser.

Advantages of IntraLase

By using this laser, IntraLase avoids the risks that come with use of a microkeratome and offers laser vision correction to people who would otherwise be unable to have it. IntraLase:

• Prevents the formation of “buttonhole” flaps which can create scars that affect vision
• Prevents uneven flap edges which can create problems such as irregular astigmatism
• Creates a flap with vertical edges, reducing the risk of epithelial ingrowth
• Creates a flap with thicker edges which are less likely to tear
• Creates a flap which is tailored to your individual eye
• Creates a flap that seals into place much better and faster than one created by a microkeratome
• Decreases the risk of infection or contamination
• Increases the chance of achieving 20/20 vision or better
• Reduces the risk of dry eye
• Reduces the likelihood of any need for touch-up procedures

After Flap Creation

The rest of an IntraLase procedure is the same as for LASIK. An excimer laser is used to ablate the exposed surface and reshape the cornea to correct refractive error. The entire procedure takes about ten minutes. Recovery periods are similar for the two methods, but the flap itself tends to re-adhere and heal more quickly after IntraLase.

Since 2006 the fourth generation IntraLase laser has been used in other corneal surgeries because of its astounding precision.

Also in 2006, VISX, the company that developed CustomVue™, a Wavefront-guided Custom LASIK procedure, was acquired by Abbott Medical Optics (AMO), the manufacturer of many vision products including the IntraLase laser.

In 2008 the two sets of technology were combined and AMO gave IntraLase the new name of iLASIK. iLASIK is an IntraLase procedure done after a Wavefront diagnosis and gives a more precise treatment than IntraLase done after a traditional diagnosis using the phoropter.

Chart of the major differences between IntraLase® and LASIK using Microkeratome

If you are interested in laser vision correction but unsure as to which procedure would be best for you, the first step would be to consult with a qualified and experienced LASIK surgeon. To find one in your area, please contact us today.