초록 ▼

A method for performing concurrent spherical and cylindrical corrections to the corneal surface of the eye to reduce myopia and astigmatism. A laser beam irradiates the corneal surface via a variable diameter iris and a slot produced by a pair of translatable blades. The width of the slot and the di

A method for performing concurrent spherical and cylindrical corrections to the corneal surface of the eye to reduce myopia and astigmatism. A laser beam irradiates the corneal surface via a variable diameter iris and a slot produced by a pair of translatable blades. The width of the slot and the diameter of the iris are varied as the laser is pulsed to produce a toric ablation of the corneal surface. Alternatively, the laser beam is passed through a succession of apertures in a tilted variable aperture element to produce toric ablation. The total number of laser pulses required to effect both types of correction is equal to the number required for the spherical correction alone, reducing the laser power and the procedure time. The toric ablation produces no steep end walls as with standard cylindrical ablation procedures, thereby eliminating hyperopic shift and minimizing flattening along the ablated cylinder axis.

대표청구항 ▼

[ What is claimed is:] [1.] A laser eye surgical system for providing elliptical beam cross-sections for spherical and astigmatic corrections to a cornea of an eye, said system comprising:(a) a laser for producing a laser beam, said laser positioned so that said laser beam propagates along a beam pa

[ What is claimed is:] [1.] A laser eye surgical system for providing elliptical beam cross-sections for spherical and astigmatic corrections to a cornea of an eye, said system comprising:(a) a laser for producing a laser beam, said laser positioned so that said laser beam propagates along a beam path;(b) beam shaping means disposed along said beam path of said laser beam for shaping said laser beam by transmitting only a portion of said laser beam having an elliptical cross-section past said beam shaping means, said beam shaping means comprising a mask having a plurality of elliptical apertures having different dimensions from one another, at least some of said elliptical apertures having different sizes from one another; and(c) means for rotatably mounting said mask so that different ones of said apertures of said mask can be positioned along said beam path at different times, wherein said plurality of apertures are dimensioned to enable producing desired elliptic ablations from corneal tissue.