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AssigneeTaunton Technologies, Inc.
InventorsWilliam B. Telfair, Paul R. Yoder, Jr., Clifford A. Martin, Francis A. L'Esperance, Jr.
Estimating the term…
In the context of ultraviolet-laser sculpting of the cornea to achieve optical correction through a newly shaped anterior surface, the invention subjects the laser beam to certain shaping and homogenizing operations prior to any attempt to specially characterize the beam for a particular sculpturing procedure. In a preferred embodiment, the shaping and homogenizing operations present a tolerably homogeneous beam of enlarged dimension, so that specialty-characterizing may proceed on a dimensional scale that is greater than the corresponding dimension of ultimate surgical delivery to the eye, thereby enabling greater control of the quality of specialty-characterizing. Provision is made for selectively monitoring the quality of the homogeneity and/or of the specially-characterized beam, with further provision for automated cutoff of laser beam delivery to an eye in the event that quality is not within predetermined limits of tolerance. And preferably, all beam shaping, homogenizing and characterizing operations proceed in a controlled environment which precludes ozone development and thus minimizes the beam-degrading effect of ozone and particulates or other contaminants.
Apparatus for performing an ablating sculpture of the anterior surface of the cornea of an eye, comprising an excimer laser for pulsed emission of ultraviolet radiation in a beam of rectangular section wherein intensity distribution is generally uniform in the longer-dimensional direction and is generally Gaussian about the center of its shorter-dimensional direction;
In apparatus using an ultraviolet laser to correct an optically deficient eye by volumetric ablative removal of corneal tissue from the anterior surface and with penetration of the stroma, wherein laser-beam delivery is on an optical path which terminates with a fixed cornea-impingement axis aligned with the axis of the eye, and wherein beam-characterizing means so characterizes intensity distribution within a predetermined circle of laser-radiation exposure to the cornea as in the course of a predetermined exposure time to so distribute the cumulative depth of ablation as to achieve a new and improved corneal curvature, the improvement wherein the laser is an excimer laser and wherein beam-homogenizing means for effecting a relatively uniform cross-sectional distribution of flux density is on said path downstream from the laser and upstream with respect to the characterizing of intensity distribution, said beam-homogenizing means comprising scraper means limiting beam margins to a rectangular section (a) which is elongate in one dimension and which is of substantially uniform intensity profile along said one dimension and (b) which is relatively narrow in the other dimension and which is within a substantially 2:1 range of dimensional intensity-profile variation along said other dimension, and refractive anamorphic beam-expansion means oriented to expand said relatively narrow dimension to substantially the extent of said one dimension.
In apparatus using an ultraviolet laser to correct an optically deficient eye by volumetric ablative removal of corneal tissue from the anterior surface and with penetration of the stroma, wherein laser-beam delivery is on an optical path which terminates with a fixed cornea-impingement axis aligned with the axis of the eye, and wherein beam-characterizing means so characterizes intensity distribution within a predetermined circle of laser-radiation exposure to the cornea as in the course of a predetermined exposure time to so distribute the cumulative depth of ablation as to achieve a new and improved corneal curvature, the improvement in which the laser is an excimer laser producing an output beam of generally rectangular section wherein intensity distribution is generally uniform along an elongate first dimension and is characterized by generally Gaussian distribution along a second dimension transverse to said first dimension, beam-processing means including one or more optical elements on said path, said one or more optical elements being operative (a) substantially only along said second dimension of the beam section and (b) to expand said second dimension for substantial equality with said first dimension.
In apparatus using an ultraviolet excimer laser to correct an optically deficient eye by volumetric ablative removal of corneal tissue from the anterior surface and with penetration of the stroma, wherein laser-beam delivery is on an optical path which terminates with a fixed cornea-impingement axis aligned with the axis of the eye, wherein beam-characterizing means so characterizes intensity distribution within a predetermined circle of laser-radiation exposure to the cornea as in the course of a predetermined exposure time to so distribute the cumulative depth of ablation to achieve a new and improved corneal curvature, and wherein beam-homogenizing means for effecting a relatively uniform cross-sectional distribution of flux density is interposed between the laser and said beam-characterizing means, the improvement in which computer means includes digitally stored tolerance data reflecting a predetermined level of uniformly distributed laser-beam intensity distribution across the beam prior to characterization of intensity distribution, and in which beam-monitoring means associated with said computer means includes a beam-sampling splitter positioned in said path prior to characterization of intensity distribution, said beam-monitoring means being electrically responsive to intensity distribution across the sampling beam and producing a digital output indicative of such distribution, said computer means indicating the beam-sampled distribution in relation to the digitally stored tolerance data.
In apparatus using an ultraviolet laser to correct an optically deficient eye by volumetric ablative removal of corneal tissue from the anterior surface and with penetration of the stroma, wherein laser-beam delivery is on an optical path which terminates with a fixed cornea-impingement axis aligned with the axis of the eye, and wherein flux distribution is so characterized within a predetermined circle of laser-radiation exposure to the cornea as in the course of a predetermined exposure time to so vary with time the intensity distribution across the beam so as to distribute the cumulative depth of ablation and thereby achieve a new and improved corneal curvature, the improvement in which computer means include a digital storage of a time-varying intensity distribution function across the beam that is predetermined to effect a selected curvature correction, and in which beam-monitoring means associated with said computer means includes a beam-sampling splitter positioned in said optical path after characterization of intensity distribution, said beam-monitoring means being electrically responsive to the time-varying intensity distribution in the sampling beam and producing a digital output that is indicative of the sampled distribution, said computer means indicating the beam-sampled distribution in relation to the digitally stored distribution data.
Dependencies are inferred from the claim text.