IntraLASIK, also known as Femto-LASIK or All-Laser LASIK, is a form of refractive eye surgery similar to LASIK that creates a corneal flap with a femtosecond laser microkeratome rather than with a mechanical microkeratome, which uses a steel blade. The only difference between LASIK and IntraLASIK is the method by which the LASIK flap is created. The actual refractive correction by corneal ablation can then be performed with any excimer laser that is able to perform LASIK, including conventional, wavefront-optimized, or wavefront-guided ablation. IntraLASIK can be used to surgically create monovision to enhance the ability to see objects both distant and near for those affected by presbyopia.

History

Intelligence Surgical Laser (ISL) approached Arturo S. Chayet M.D. (Mexico) in 1994 with the idea of using a picosecond laser as an alternative to the excimer laser for the correction of refractive errors. Soon enough, however, after a series of clinical trials, Chayet concluded that the picosecond laser was not well suited for refractive corrections, but rather for the creation of corneal flaps, which at the time were created with the mechanical microkeratome (Chayet is credited with the conception of Intralasik). The creation of the corneal flap with the picosecond laser, in conjunction with the use of the excimer laser for the corneal ablation, was the first step to creating a spin-off of LASIK. Researchers at the University of Michigan, however, realized that the picosecond laser was inadequate for Chayet's idea and discovered that the femtosecond laser would work more effectively. In 2000, a corneal flap created by the femtosecond laser along with a refractive error corrected by the excimer laser was conducted on a patient for the first time, in which case Intralasik or All Laser LASIK was conducted for the first time.

The term IntraLASIK is derived from IntraLase, the name of the first manufacturer to achieve Food and Drug Administration approval of a femtosecond laser for use in the United States, and the surgical procedure 'LASIK'. Although additional femtosecond laser manufacturers have entered the US market, the name IntraLASIK is commonly used.

The Procedure

The computer-guided infrared femtosecond laser is focused just below the surface of the cornea. Each laser pulse creates a tiny bubble there. A pattern of many overlapping bubbles is created, allowing the flap to be lifted off the cornea. The procedure then continues as in traditional LASIK, with an excimer laser removing material from the exposed surface beneath the flap.

Claimed advantages

A LASIK flap created with a femtosecond laser is regarded by many ophthalmologists as an improvement over traditional LASIK because of a greater accuracy in flap size, shape, and thickness.

Contradictory information exists as to whether the use of femtosecond lasers in LASIK achieves statistically better visual acuity and refractive outcomes than with microkeratomes.

Although the final long-term clinical outcome of LASIK with a mechanical microkeratome and IntraLASIK with a femtosecond laser may be similar, the increased accuracy of the flap with the femtosecond laser provides an added margin of safety. LASIK with a flap that is thinner has been shown to provide outcomes superior than a thicker LASIK flap. A thinner LASIK flap requires greater accuracy and predictability.

Complications

A small percentage of IntraLASIK patients develop Transient Light Sensitivity (TLS), "Although there is no loss of uncorrected visual acuity, symptoms can be prolonged, especially without prompt steroid therapy.TLS causes severe photophobia for a period of weeks, however normally resolves with healing and treatment.