OVERVIEW

Using advances in laser technology and the technical and theoretical developments in refractive surgery made since the 1950's, LASIK surgery was developed in 1990 by Lucio Buratto (Italy) and Ioannis Pallikaris (Greece) as a melding of two prior techniques, keratomileusis and photorefractive keratectomy (PRK). It has quickly became popular because of its greater precision and lower frequency of complications in comparison with these former two techniques.

The technique

After instillation of a drop of anaesthetic, the area is cleaned and sterilised. The eyelids are held widely open by a speculum to allow good access. A suction ring is applied to the eye this stabilises the eye, increases the pressure in the eye and securely attaches to the eye. Once the microkeratome (a motorised plane) is attached to the suction ring it can pass across the cornea, cutting a thin flap as it goes. The flap consists of the surface epithelium and some of the anterior stroma of the cornea. The flap is left attached (hinged) at one edge so it can be gently reflected.

The layer of the cornea deep to the flap is then reshaped using the excimer laser (very similar to PRK). The flap is then repositioned and sticks back in place. Because the front surface has been replaced there is less pain than in PRK and vision recovers very rapidly with good vision common after one day.

Excellent results can be expected in the range to +4 to -10 diopters provided corneal thickness is adequate. Sufficient remaining corneal thickness must be left deep to the flap after ablation with the laser. This may limit treatment range and compromise optical zone especially in thinner corneas and higher corrections. The corneal flap does not become totally secure for some time and there is a small risk of trauma displacing the flap especially in the first few weeks.

The LASIK procedure >>