Abstract

Picosecond lasers working at wavelengths which are not absorbed in the refractive components of the eye have great potential for corneal intrastromal surgery due to their well localized surgical effect. The damage mechanism of the picosecond lasers begins with optical breakdown in the focus of the laser beam. The plasma creation is followed by the generation of the shock wave and cavitation bubble. As is suggested by previous results [1,2] tissue removal is due to the effect of the laser plasma. Using multiple picosecond pulses it is possible evaporate a disk-shaped volume inside the cornea by delivering the pulses along a spiral pattern. The collapse of the created intrastromal cavity results in a thinning of the central cornea and, therefore, a myopic refractive correction. The method is referred as intrastromal photorefractive keratectomy (IPRK). IPRK is attractive because it obviates the need for removal of the corneal epithelium, therefore it has the potential for avoiding wound healing responses which results in scarring and regression after surface ablation.

© 1994 Optical Society of America