Femtosecond Lasers

Femtosecond lasers (sometimes called femtolasers) are the lasers used to create the flap during bladeless or all-laser LASIK. They are named for the length of pulse they use, which is measured in femtoseconds or quadrillionths (10-15) of a second, and are used to cut the flap in the cornea, instead of the microkeratome, a hand-operated blade instrument used for flap creation in traditional LASIK.

Femtosecond Lasers FDA-Approved for Flap Creation

The first femtosecond laser approved for use in LASIK was the IntraLase laser, which was approved in 2001. AMO, the maker of the CustomVue excimer laser acquired the manufacturer of IntraLase in 2007, and now markets them as an integrated system known as iLASIK. Other lasers currently approved for flap creation are:

Ziemer Femto LDV (Approved 2008)
FemTec laser (Approved 2004)

If you are considering bladeless LASIK, you should talk to your ophthalmologist about the rate of complications associated with individual lasers, including the doctor's own experience, since these vary widely.

Benefits of Femtosecond Lasers

Femtosecond lasers and microkeratomes seem to have comparable rates for creating good visual results through LASIK. However, the lasers do reduce the risk of some rare complications associated with microkeratome-produced flaps.

Uneven flap edges that can be created by microkeratomes can sometimes be responsible for vision defects such as astigmatism. The shape of the flap is more precisely controlled with a femtosecond laser, reducing this risk.

Buttonhole flaps, or flaps that are malformed or incompletely formed by the microkeratome, are virtually eliminated by femtosecond lasers.

Some studies show that femtosecond lasers are associated with less complications overall, but not all studies uphold this finding.

Risks of Femtosecond Lasers

Femtosecond lasers do have their own risks.

The rainbow effect, or a radiating pattern of colored lines around light sources, was reported in one study as being experienced by as many as 19% of bladeless LASIK patients, but other studies have shown the rates much less, especially with refinements in femtosecond laser technology.

Light sensitivity (photophobia) may be more common among people who receive bladeless LASIK. Exactly how common and how this compares to the rate among traditional LASIK patients is uncertain.

A unique risk of bladeless LASIK is the creation of the opaque bubble layer (OBL) in which the femtosecond laser creates an opaque film on the eye that prevents the excimer laser system from tracking the eye. When this occurs, a patient must wait until the OBL spontaneously resolves, about 30-45 minutes, before proceeding with treatment.

The incidence of these complications varies with the laser and the practitioner. To learn more about the femtosecond laser and bladeless LASIK, contact a local ophthalmologist today.