The invention relates to equipment for the correction of astygmatism by remodelling the corneal surface by means of photo-ablation.
The prior art teaches laser apparatus, known as excimer lasers, able to generate beams of radiation to vaporize, very exactly and regularly, very thin, microscopic layers (measurable in micrometers) of the eye corneal tissue. Such apparatus is used to remodel the external part of the cornea with the aim of eliminating various refraction defects.
The prior art teaches the use of masks and/or diaphragms which, correctly applied, allow the laser beam to reach and ablate the corneal surface in pre-established areas. By means of the use of such masks or diaphragms, whose aperture can be controlled and co-ordinated together with programmed laser-beam application times, it is thus possible to realise step-like sculptures in the cornea through a succession of photo-ablation removal operations of single uniform layers, of different-sized areas of the cornea itself.
USPTO Backgrounds
USPTO Backgrounds