Apparatus for performing ophthalmic laser surgery
AssigneeLri L.P.
InventorFrancis A. L'Esperance, Jr.
Life of this patent
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Abstract
The invention contemplates controlled ablation of the cornea, using ultraviolet laser radiation, wherein irradiated flux density and exposure time are so controlled as to achieve desired depth of the ablation. Sculpturing action results from controlled change of projected laser-spot size, in the course of a given treatment, wherein, in one illustrative case, projected laser-spot size ranges from a maximum which covers the entire area to be treated, down to a predetermined minimum tolerable size, wherein cornea-curvature change is myopia-corrective. Further illustrative techniques and situations are also disclosed, for achievement of hyperopia correction, for astigmatism correction, and in connection with corneal-transplant operations.
Claims48
Sculpture apparatus for curvature-correcting operation upon the anterior surface of the cornea of an eye, comprising laser means producing an output beam in the ultraviolet portion of the electromagnetic spectrum, controllable means for variably limiting the sectional area of said beam at impingement on the cornea, the area variation being over a range which at least includes a maximum curvature-correcting area to be ablated and being symmetrical with respect to a beam-projection axis which coincides with the optical axis of the eye, the intensity of laser-spot projection being limited per unit time to ablate but a fraction of a predetermined maximum depth of ablation into the stroma region of the cornea, and control means connected to said laser means and to said controllable means, for so correlating laser-beam impingement at the cornea with variation of the sectional area of said beam as to effect a diopter change at the cornea.
Apparatus for performing ophthalmological surgery by selective ablation of the anterior surface of the cornea of an eye of a patient with penetration into the stroma to achieve a volumetric removal of tissue within the optically functioning area of the cornea, said apparatus comprising laser means producing on an optical axis an output beam in the ultraviolet portion of the electromagnetic spectrum, optical means on said axis including a zoom lens with a zoom drive for variably setting the sectional area of said beam to a spot on the cornea, the area variation of said spot being within a maximum area to be ablated and being symmetrical with respect to a beam-projection axis which coincides with the optical axis of the eye, the intensity of laser-beam projection being limited per unit time to ablate but a fraction of a predetermined maximum ablation into the stroma region of the cornea, and programmable means with coordinating control connections to said laser means and to said zoom drive, whereby the integrated time of laser-beam impingement at the cornea may be so correlated with variable confined-spot area as to effect a diopter-reducing change at the cornea.
Sculpture apparatus for curvature-correcting operation upon the anterior surface of the cornea of an eye, comprising laser means producing an output beam in the ultraviolet portion of the electromagnetic spectrum, reflector means for reflecting said beam and for variably limiting the area of said beam at impingement on the cornea, said reflector means including actuating means for varying the reflector area thereof, the range of reflector-area variation at least including a maximum curvature-correcting area to be ablated and being symmetrical with respect to a beam-projection axis which coincides with the optical axis of the eye, the intensity of laser-spot projection being limited per unit time to ablate but a fraction of a predetermined maximum depth of ablation into the stroma region of the cornea, and means including a microprocessor with coordinating control connections to said laser means and to said actuating means, for so correlating laser-beam impingement at the cornea with variation of reflected-spot area as to effect a diopter change at the cornea.
Sculpture apparatus for operation upon the external surface of the cornea of an eye of a patient, comprising laser means producing an output beam in the ultraviolet portion of the electromagnetic spectrum, masking means for variably limiting the area of said beam at impingement on the cornea, said masking means including actuating means for varying the masked area thereof, the range of mask-area variation being within a maximum area to be ablated and being symmetrical with respect to a beam projection axis which coincides with the optical axis of the eye, the intensity of laser-spot projection being limited per unit time to ablate but a fraction of a predetermined maximum ablation into the stroma region of the cornea, said masking means being operative to provide cornea exposure at said maximum area and at a plurality of similarly shaped but lesser areas, said areas being circularly annular, and characterized by varying inner diameter, said areas being further defined by constant outer diameter for an area within which a hyperopia-correcting curvature change is to be effected;
- said area of curvature change being less than said maximum area thereby defining an annular area of laser-beam projection outside said area of curvature change, said masking means being further operative within said annular area to provide cornea exposure at a succession of circularly annular areas contiguous to the area of curvature change and of varying outer diameter, and means including a microprocessor with coordinating control connections to said laser means and to said actuating means, whereby laser-beam impingement at the cornea may be so correlated with variation of masked-spot area as to effect a hyperopia-correcting diopter change at the cornea, together with a smoothed surrounding annulus of transition to adjacent unexposed corneal tissue.
Apparatus for performing ophthalmological surgery by selective ablation of the anterior surface of the cornea of an eye of a patient with penetration into the stroma to achieve a volumetric removal of tissue within the optically functioning area of the cornea, said apparatus comprising laser means producing on an optical axis an output beam in the ultraviolet portion of the electromagnetic spectrum, optical means on said axis including a zoom lens with a zoom drive for variably setting the sectional area of said beam to a spot on the cornea, the area variation of said spot being within a maximum area to be ablated and being symmetrical with respect to a beam-projection axis which coincides with the optical axis of the eye, the intensity of laser-beam projection being limited per unit time to ablate but a fraction of a predetermined maximum ablation into the stroma region of the cornea, and means including a microprocessor with coordinating control connections to said laser means and to said zoom drive, whereby the integrated time of laser-beam impingement at the cornea may be so correlated with variable confined-spot area as to effect a diopter-reducing change at the cornea.
Apparatus for performing ophthalmological surgery by selective ablation of the anterior surface of the cornea of an eye of a patient with penetration into the stroma to achieve a volumetric removal of tissue within the optically functioning area of the cornea, said apparatus comprising laser means producing on an optical axis an output beam in the ultraviolet portion of the electromagnetic spectrum, masking means for variably limiting the sectional area of said beam at impingement on the cornea, said masking means including actuating means for varying the sectional area masked by said masking means, the mask-area variation being over a range of areas within a maximum area to be ablated and being symmetrical with respect to a beam projection axis which coincides with the optical axis of the eye, the intensity of laser-beam projection being limited per unit time to ablate but a fraction of a predetermined maximum ablation into the stroma of the cornea, and means including a microprocessor with coordinating control connections to said laser means and to said actuating means, whereby laser-beam impingement at the cornea may be so correlated with variation of sectional area as to effect a diopter change at the cornea.
Apparatus for performing ophthalmological surgery by selective ablation of the anterior surface of the cornea of an eye of a patient with penetration into the stroma to achieve a volumetric removal of tissue within the optically functioning area of the cornea, said apparatus comprising laser means producing on an optical axis an output beam in the ultraviolet portion of the electromagnetic spectrum, masking means for variably limiting the sectional area of said beam at impingement on the cornea, said masking means including actuating means for varying the sectional area marked by said masking means, the mask-area variation being over a range of areas within a maximum area to be ablated and being symmetrical with respect to a beam projection axis which coincides with the optical axis of the eye, the intensity of laser-beam projection being limited per unit time to ablate but a fraction of a predetermined maximum ablation into the stroma of the cornea, and programmable means with coordinating control connections to said laser means and to said actuating means, whereby laser-beam impingement at the cornea may be so correlated with variation of sectional areas as to effect a diopter change at the cornea.
Apparatus for performing ophthalmological surgery by selective ablation of the anterior surface of the cornea of an eye of a patient with penetration into the stroma to achieve a volumetric removal of tissue within the optically functioning area of the cornea, said apparatus comprising laser means producing on an optical axis an output beam in the ultraviolet portion of the electromagnetic spectrum, optical means including reflector means for reflecting said beam on said axis and for variably limiting the sectional area of said beam at impingement on the cornea, said reflector means including actuating means for varying the reflecting area thereof, the reflecting-area variation being over a range producing reflected-beam section areas within a maximum area to be ablated and being symmetrical with respect to a beam-projection axis adapted for alignment with the optical axis of the eye, the intensity of the projected beam being limited per unit time to ablate but a fraction of a predetermined maximum ablation into the stroma of the cornea, and means including a microprocessor with coordinating control connections to said laser means and to said actuating means, whereby laser-beam impingement at the cornea may be so correlated with variation of reflected-beam section areas as to effect a diopter change at the cornea.
Apparatus for performing ophthalmological surgery by selective ablation of the anterior surface of the cornea of an eye of a patient with penetration into the stroma to achieve a volumetric removal of tissue within the optically functioning area of the cornea, said apparatus comprising laser means producing on an optical axis an output beam in the ultraviolet portion of the electromagnetic spectrum, optical means including reflector means for reflecting said beam on said axis and for variably limiting the sectional area of said beam at impingement on the cornea, said reflector means including actuating means for varying the reflecting area thereof, the reflecting-area variation being over a range producing reflected-beam section areas within a maximum area to be ablated and being symmetrical with respect to a beam-projection axis adapted for alignment with the optical axis of the eye, the intensity of the projected beam being limited per unit time to ablate but a fraction of a predetermined maximum ablation into the stroma of the cornea, and programmable means with coordinating control connections to said laser means and to said actuating means, whereby laser-beam impingement at the cornea may be so correlated with variation of reflected-beam section area as to effect a diopter change at the cornea.
Dependencies are inferred from the claim text.