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An ophthalmological surgery system and method for performing ablative photodecomposition of the corneal surface by offset image scanning. The image of a variable aperture, such as a variable width slit and variable diameter iris diaphragm, is scanned in a preselected pattern to perform ablative scul

An ophthalmological surgery system and method for performing ablative photodecomposition of the corneal surface by offset image scanning. The image of a variable aperture, such as a variable width slit and variable diameter iris diaphragm, is scanned in a preselected pattern to perform ablative sculpting of predetermined portions of a corneal surface. The scanning is performed with a movable image offset displacement mechanism capable of effecting radial displacement and angular rotation of the profiled beam exiting from the variable aperture. The profiled beam is rotated by rotating the aperture in conjunction with the offset displacement mechanism. The invention enables wide area treatment with a laser having a narrower beam, and can be used in the treatment of many different conditions, such as hyperopia, hyperopic astigmatism, irregular refractive aberrations, post ablation smoothing and phototherapeutic keratectomy.

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1. A method of performing selective ablation of a cornea of an eye to effect a refractive correction, said method comprising the steps of:(a) directing a laser beam toward the cornea;(b) creating a treatment table containing a listing of coordinate references for the beam to effect the desired refra

1. A method of performing selective ablation of a cornea of an eye to effect a refractive correction, said method comprising the steps of:(a) directing a laser beam toward the cornea;(b) creating a treatment table containing a listing of coordinate references for the beam to effect the desired refractive correction, the coordinate references specifying a plurality of different beam axis positions;(c) sorting the listing of coordinate references from the treatment table to generate a sculpting pattern which is substantially radially symmetric while said refractive correction is only partially complete; and(d) scanning the profiled beam over the corneal surface according to said sorted treatment table to produce said refractive correction. 2. The invention of claim 1 wherein said step (b) of creating a treatment table comprises generating a number of pulses at each coordinate reference to effect said refractive correction. 3. The invention of claim 1, wherein the step (b) of creating the treatment table includes compensating for differential ablation depth. 4. The invention of claim 1, further comprising separating said refractive correction into a plurality of partial corrections and sequentially performing the partial corrections. 5. An ophthalmological surgery system for performing selective ablation of a corneal surface of an eye to effect a desired corneal shape, said system comprising:means for directing a laser beam along a path;variable aperture means for profiling said beam to produce a variable area profiled beam; andmeans for scanning the profiled beam over a predetermined area of the corneal surface, wherein scanning comprises ablating at a series of beam axis locations in the predetermined area, a plurality of the locations specified by a different coordinate reference while varying the profile of the beam, and wherein scanning is performed according to a sorted treatment table which includes a listing of coordinate references and a variable aperture configuration at each coordinate reference, the table sorted to define a series of radially symmetric partial treatments. 6. The invention of claim 5, wherein the scanning means comprises at least one member of the group consisting of a lens, a mirror, and a prism. 7. The invention of claim 5, further comprising a controller coupled to the variable aperture profiling means and the scanning means, the controller comprising the sorted treatment table. 8. The invention of claim 7, wherein the table further comprises a listing of the number of coordinate pulses at each coordinate reference to effect the desired corneal shape. 9. A method of performing selective ablation of a corneal surface of an eye to effect a desired corneal shape, said method comprising the steps of:(a) directing a laser beam having a beam axis toward a variable aperture;(b) profiling the beam with the variable aperture to produce a variable area profiled beam;(c) creating a treatment table identifying a listing of values including coordinate references for the axis of the profiled beam, a variable aperture configuration at each coordinate reference, and a number of pulses at each coordinate reference to effect the desired corneal shape;(d) sorting the listings in the treatment table to a sorted treatment table of the profiled beam, the sorted treatment table defining a series of radially symmetric partial treatments; and(e) scanning the profiled beam by moving the beam axis over a predetermined treatment area of a corneal surface while varying the profile according to the sorted treatment table. 10. The invention of claim 1, wherein the variable aperture comprises a variable width slit, and wherein said step (e) of scanning includes a step of rotating the variable width slit. 11. A method of performing selective ablation of a corneal surface of an eye to effect a predetermined myopic refractive correction, said method comprising the steps of:(a) directing a laser beam having a beam axis toward a varia ble aperture;(b) profiling the beam with the variable aperture to produce a variable area profiled beam;(c) creating a treatment table identifying a listing of values including coordinate references for the axis of the profiled beam, a variable aperture configuration at each coordinate reference, and a number of pulses at each coordinate reference to effect the desired corneal shape;(d) sorting the listings in the treatment table to a sorted treatment table of the profiled beam, the sorted treatment table defining a series of radially symmetric partial treatments; and(e) scanning the profiled beam by moving the beam axis over a predetermined area of a corneal surface while varying the size of the aperture according to the sorted treatment table to produce said myopic refractive correction. 12. The method of claim 11 wherein said step (e) of scanning is performed by scanning the profiled beam over a predetermined position of the corneal surface while enlarging the size of the variable aperture. 13. The method of claim 11 wherein said step (e) of scanning is performed by scanning the profiled beam over a predetermined position of the corneal surface while reducing the size of the variable aperture. 14. The method of claim 11 wherein said step (e) of scanning is performed by establishing an axis of rotation for the profiled beam at a predetermined position on the corneal surface and scanning the profiled beam about the predetermined position by varying a displacement of the profiled beam from the axis of rotation and by varying an angular position of the profiled beam about the axis of rotation in a preselected manner. 15. A method of performing selective ablation of a corneal surface of an eye to effect a desired corneal shape, said method comprising the steps of:(a) directing a laser beam toward a variable aperture comprising a variable width slit and a variable diameter diaphragm;(b) profiling the beam with the variable aperture to produce a variable area profiled beam;(c) creating a treatment table identifying a listing of values including coordinate references for the profiled beam, a variable aperture configuration at each coordinate reference, and a number of pulses at each coordinate reference to effect the desired corneal shape;(d) sorting the listings in the treatment table to a sorted treatment table of the profiled beam, the sorted treatment table defining a series of radially symmetric partial treatments; and(e) scanning the profiled beam over a predetermined treatment area of a corneal surface while varying the profile according to the sorted treatment table, wherein scanning includes a step of selectively varying the width of the slit and a step of selectively varying the diameter of the diaphragm. 16. The method of claim 15, wherein said step (e) of scanning includes a step of rotating the variable width slit. 17. The method of claim 15, wherein at least some of the values include compensation for differential ablation depth. 18. The method of claim 15, wherein the step (b) of profiling the beam produces an elongate substantially rectangular beam shape having first and second opposed sides defined by the variable width slit and first and second rounded ends defined by the variable diameter diaphragm. 19. A method of performing selective ablation of a corneal surface of an eye to effect a desired corneal shape, said method comprising the steps of:(a) directing a laser beam toward a variable aperture comprising a variable width slit and a variable diameter diaphragm;(b) profiling the beam with the variable aperture to produce a variable area profiled beam, wherein profiling the beam produces an elongate substantially rectangular beam shape having first and second opposed sides defined by the variable width slit and first and second rounded ends defined by the variable diameter diaphragm;(c) creating a treatment table identifying a listing of values including coordinate references for the profiled beam, a variable ap erture configuration at each coordinate reference, and a number of pulses at each coordinate reference to effect the desired corneal shape;(d) sorting the listings in the treatment table to a sorted treatment table of the profiled beam, the sorted treatment table defining a series of radially symmetric partial treatments; and(e) scanning the profiled beam over a predetermined treatment area of a corneal surface while varying the profile according to the sorted treatment table, wherein scanning includes a step of selectively varying the width of the slit and a step of selectively varying the diameter of the diaphragm. 20. A method of performing selective ablation of a corneal surface of an eye to effect a desired corneal resculpting, said method comprising the steps of:directing a laser beam toward the cornea along a beam path;establishing a center of rotation for the beam;displacing said beam path from the center of rotation by a displacement, wherein the beam has an elongate substantially rectangular beam shape, and wherein the displacing step is performed so that the elongate substantially rectangular beam shape is oriented laterally relative to the center of rotation;varying the displacement of said beam from the center of rotation; andvarying an angular position of said beam about the center of rotation and rotating the elongate substantially rectangular beam shape so that the rotated elongate substantially rectangular beam shape is laterally oriented relative to the center of rotation;intercepting the beam with a variable diameter iris and a variable width slit; andvarying a diameter of the iris and a width of the slit. 21. A method of performing selective ablation of a corneal surface of an eye to effect a desired corneal resculpting, said method comprising the steps of:directing a laser beam toward the cornea along a beam path;establishing a center of rotation for the beam;displacing said beam path from the center of rotation by a displacement, wherein the beam has an elongate substantially rectangular beam shape, and wherein the displacing step is performed so that the elongate substantially rectangular beam shape is oriented laterally relative to the center of rotation;varying the displacement of said beam from the center of rotation;varying an angular position of said beam about the center of rotation and rotating the elongate substantially rectangular beam shape so that the rotated elongate substantially rectangular beam shape is laterally oriented relative to the center of rotation; androtating the variable width slit in coordination with the varying of the angular position of the beam, the slit having a first edge movable relative to an opposed second edge, wherein the slit rotating step is performed so that a first elongate side of the beam defined by the first edge of the slit comprises an inner edge oriented toward the axis of rotation and a second elongate side of the beam defined by the second edge of the slit comprises an outer edge oriented toward a peripheral boundary of said desired corneal resculpting.