Astigmatic laser ablation of surfaces
AssigneeSummit Technology, Inc.
InventorsTheo Seiler, Peter J. Klopotek
Life of this patent
Estimating the term…
Abstract
Laser surface ablation methods and apparatus are disclosed reprofiling surfaces astigmatically. An optical system includes cylindrically-powered elements to form an elliptical laser irradiation pattern on a target surface. By successively altering the area of the elliptical irradiation, an astigmatic, bi-powered ablation profile is achieved. Preferably, the invention is used with an excimer laser for excimer laser keratoplasty, keratomileusis or other ablative eye surgeries.
Claims17
A method for ablating a surface astigmatically by laser energy, the method comprising the steps of:
- aligning a surface with a laser means, which is operable to deliver a beam of photoablative pulses of laser energy along a path to the surface;
- varying the size of the beam;
- disposing a cylindrically-powered, optical system along said beam path such that a beam of laser energy passing through the cylindrical system is shaped into an elliptical form having a major and a minor axis;
- adjusting the axial position of said cylindrically-powered, optical system along said beam path to select an astigmatic ratio of said major and minor axes on said surface;
- and
- operating said laser while varying the beam size to deliver a radiation beam to said cylindrically-powered, optical system thereby forming a time-varying, elliptical distribution of energy on said surface.
A method for providing astigmatic ablation to an area of the cornea of an eye for correcting myopic astigmatism, the method comprising the steps of:
- fixing an eye relative to laser means operable to deliver a beam of photoablative pulses of laser energy along a path to said cornea;
- varying the size of the beam;
- disposing a cylindrically-powered, optical system along said beam path such that a beam of laser energy passing through the cylindrical system is shaped into an elliptical form having a major and a minor axis;
- adjusting the axial position of said cylindrically-powered, optical system along said beam path to select an astigmatic ratio of said major and minor axes on said cornea;
- and
- operating said laser while varying the beam size to deliver a radiation beam to said cylindrically-powered, optical system thereby forming a time-varying, elliptical distribution of energy on said cornea.
A laser system for astigmatically reprofiling a surface, said laser system comprising:
- laser means for generating pulses of laser light along a beam path at an energy level, such that the pulses can be absorbed at a surface to induce photoablation;
- beam control means for controlling said beam dimensions at said surface;
- cylindrically-powered optical means disposed along the beam path for adjusting said beam dimensions in one axis for creating an astigmatic irradiation pattern at said surface;
- and
- adjustment means for axially shifting said cylindrically-powered, optical means to select an astigmatic ratio to be applied to said surface.
Dependencies are inferred from the claim text.