Customizing the LASIK flap

Key Points

Femtosecond laser technology has evolved tremendously over the last six years. The first clinical femtosecond laser (6 kHz) enabled surgeons to create a 9 mm flap in over three minutes, while the 2006 launch of the 60 kHz laser (IntraLase; AMO) allowed surgeons to make a flap in around 17 to 20 seconds. Now, with the latest addition to the femtosecond portfolio (5th generation iFS laser; AMO), a flap can now be made in as little as 10 seconds.

The properties of this fast-evolving technology mean that surgeons cannot only increase the speed of the flap-creation procedure, but they can also customize the flap by controlling its shape (diameter, hinge size and location, side cut architecture, oval or round), location, and thickness while increasing safety.

Why does speed matter?

In general, placing less total energy into the eye is believed to decrease the incidence of late onset light or Transient Light Sensitivity Syndrome (TLSS) while reducing the incidence of the opaque bubble layer (OBL). Less energy also creates less flap edge wound healing, making enhancements easier. Furthermore, there is less suction time on the eye, which decreases the risk of suction loss and subconjunctival haemorrhages.

The importance of flap architecture

New software also allows users of the latest generation femtosecond laser to customize the shape of the flap based on the patient's corneal diameter and shape. This spares peripheral tissue because surgeons do not have to cut as much of the cornea in the one meridian with an oval flap.