The operation

The operation is performed with the patient awake and mobile; however, the patient typically is given a mild sedative (such as Valium or diazepam) and anesthetic eye drops.

Lasik is performed in two steps. The initial step is to create a flap of corneal tissue. This process is achieved with a mechanical microkeratome using a metal blade, or a femtosecond laser microkeratome that creates a series of tiny closely arranged bubbles within the cornea. A hinge is left at one end of this flap. The flap is folded back, revealing the stroma, the middle section of the cornea.

The second step of the procedure is to use an excimer laser (193 nm) to remodel the corneal stroma. The laser vaporizes tissue in a finely controlled manner without damaging adjacent stroma by releasing the molecular bonds that hold the cells together. No burning with heat or actual cutting is required to ablate the tissue. The layers of tissue removed are tens of micrometers thick.

Currently manufactured excimer lasers use a computer system that tracks the patient's eye position up to 4,000 times per second, redirecting laser pulses for precise placement. After the laser has reshaped the cornea, the Lasik flap is repositioned over the treatment area by the surgeon. The flap remains in position by natural adhesion until healing is completed.

Performing the laser ablation in the deeper corneal stroma and under the Lasik flap fools the cornea into not knowing that it has had surgery. The wound response is muted, thus the patient is typically provided rapid visual recovery and virtually no pain.

What is LASIK

The LASIK technique was made possible by Dr Jose Barraquer, who around 1970 developed the first microkeratome, used to cut thin flaps in the cornea and alter its shape, in a procedure called keratomileusis.

LASIK surgery was developed in 1990 by Dr. Lucio Buratto (Italy) and Dr. Ioannis Pallikaris (Greece) as a melding of two prior techniques, keratomileusis and photorefractive keratectomy. It quickly became popular because of its greater precision and lower frequency of complications compared with those techniques.

In 1991, LASIK was performed for the first time in the United States by Drs. Stephen Brint and Stephen Slade. The same year, Drs. Thomas and Tobias Neuhann successfully treated the first German LASIK patients with an automated microkeratome.