Apparatus for ophthalmological surgery

Claim 2

Apparatus for performing ophthalmological surgery by selective ablation of the anterior surface of the cornea with penetration into the stroma to achieve a volumetric removal of corneal tissue, said apparatus comprising laser means (13) for producing an output beam preferably in the ultraviolet portion of the electromagnetic spectrum and of an intensity which is limited per unit time to ablate but a fraction of a predetermined maximum ablation depth into the stroma, means (10,18,20) for directing said laser output beam onto the eye which is to be treated, and control means (16;46;57;89; 141) for determining the irradiated flux density and exposure time of laser-beam impingement at the cornea whereby to effect a controlled sculpturing action upon the cornea such as to alter the optical properties thereof, and said apparatus further comprising adjustment means including a zoom lens (14;105) with a zoom drive (15;106) provided in the laser beam path for adjustably determining the size and/or shape of the laser beam area at impingement upon the cornea, and said control means (16;46;57;89;141) being operative upon said adjustment means for adjusting the laser beam area at impingement upon the cornea in a controlled manner in the course of a surgical treatment so that sculpturing action results from a controlled variation in the area of the cornea that is irradiated and a corresponding controlled variation in the cumulative ablative flux delivered to different areas of the cornea.

Claim 3

Apparatus according to claim 1 wherein said adjustment means (14,15) is arranged to vary the laser beam area within a predetermined maximum area and symmetrically with respect to a beam-projection axis which coincides with the optical axis of the eye.

Claim 4

Apparatus according to claim 1 or 2, in which an aperture of circular section is located between said laser and said zoom lens, and in which said zoom lens (14) images said aperture into a confined circular section of area which varies in accordance with the instantaneous setting of said zoom drive (15), whereby the surgical treatment may be myopia-correcting.

Claim 5

Apparatus according to claim 1 or 2, in which an elongate aperture of constant width is located between said laser and said zoom lens, and in which said zoom lens (105) images said aperture into a confined straight line of width which varies in accordance with the instantaneous setting of said zoom drive (106), whereby the surgical treatment may be corrective of astigmatism.

Claim 6

Apparatus according to claim 4, in which said zoom lens (105) is mounted for selective bodily rotation about the zoom-lens axis, whereby the angular orientation of said straight line may be set to accord with that of required astigmatism correction.

Claim 7

Apparatus for performing ophthalmological surgery by selective ablation of the anterior surface of the cornea with penetration into the stroma to achieve a volumetric removal of corneal tissue, said apparatus comprising laser means (13) for producing an output beam preferably in the ultraviolet portion of the electromagnetic spectrum and of an intensity which is limited per unit time to ablate but a fraction of a predetermined maximum ablation depth into the stroma, means (10,18,20) for directing said laser output beam onto the eye which is to be treated, and control means (16;46;57;89;141) for determining the irradiated flux density and exposure time of laser-beam impingement at the cornea whereby to effect a controlled sculpturing action upon the cornea such as to alter the optical properties thereof, and said apparatus further comprising variable area masking means (35;50;62;75;80;101, 102,104) provided in the laser beam path for adjustably determining the size and/or shape of the laser beam area at impingement upon the cornea and actuating means (40;55;88;100) for varying the area of the opening of the masking means, and said control means (16;46;57;89;141) being operative upon said actuating means for adjusting the laser beam area at impingement upon the cornea in a controlled manner in the course of a surgical treatment so that sculpturing action results from a controlled variation in the area of the cornea that is irradiated and a corresponding controlled variation in the cumulative ablative flux delivered to different areas of the cornea.

Claim 8

Apparatus for performing ophthalmological surgery by selective ablation of the anterior surface of the cornea with penetration into the stroma to achieve a volumetric removal of corneal tissue, said apparatus comprising laser means (13) for producing an output beam preferably in the ultraviolet portion of the electromagnetic spectrum and of an intensity which is limited per unit time to ablate but a fraction of a predetermined maximum ablation depth into the stroma, means (10,18,20) for directing said laser output beam onto the eye which is to be treated, and control means (16;46;57;89;141) for determining the irradiated flux density and exposure time of laser-beam impingement at the cornea whereby to effect a controlled sculpturing action upon the cornea such as to alter the optical properties thereof, and said apparatus further comprising variable area masking means (35;50;62;75;80;101, 102,104) provided in the laser beam path for adjustably determining the size and/or shape of the laser beam area at impingement upon the cornea and actuating means (40;55;88;100) for varying the area of the opening of the masking means, and said control means (16;46;57;89;141) being operative upon said actuating means for adjusting the laser beam area at impingement upon the cornea in a controlled manner in the course of a surgical treatment so that sculpturing action results from a controlled variation in the area of the cornea that is irradiated and a corresponding controlled variation in the cumulative ablative flux delivered to different areas of the cornea.

Claim 9

Apparatus according to claim 6 wherein said masking means comprises a variable aperture diaphragm.

Claim 10

Apparatus according to claim 6 or 7, in which said masking means (35;50) is operative to provide cornea exposure at a maximum area and at a given plurality of similarly shaped but lesser areas, said areas being circular, whereby the surgical treatment may be myopia-correcting.

Claim 11

Apparatus according to claim 6 or 7, in which said masking means (80;101,102,104) is operative to provide cornea exposure at a maximum area and at a given plurality of similarly shaped but lesser areas, said areas being elongate rectangular and of varying width, whereby the surgical treatment may be astigmatism-correcting.

Claim 12

Apparatus according to claim 9, wherein the orientation of the elongate direction of said areas is adjustable.

Claim 13

Apparatus according to claim 6, in which said masking means (62) is operative to provide cornea exposure a a maximum area and at a given plurality of similarly shaped but lesser areas, said areas being circularly annular and being defined by a constant outer diameter and a varying inner diameter, whereby the surgical treatment may be hyperopia-correcting.

Claim 14

Apparatus according to claim 6, in which said masking means (75) is operative to provide cornea exposure at a maximum area and at a given plurality of similarly shaped but lesser areas, said areas being circularly annular and being defined by a constant inner diameter and by a varying outer diameter which is intermediate said inner diameter and the outer diameter of said maximum area, whereby the surgical treatment may be myopia-correcting in a sculpted Fresnel annulus defined by said inner and outer diameters.

Claim 15

Apparatus according to claim 6, in which said masking means is operative to provide cornea exposure at a maximum area and at a given plurality of similarly shaped but lesser areas, said areas being circularly annular, being defined by a constant outer diameter and by an inner diameter which varies to a fixed minimum inner diameter, whereby the surgical treatment may be hyperopia-correcting in a sculpted Fresnel annulus defined by said constant outer diameter and by said fixed minimum inner diameter.

Claim 16

Apparatus according to claim 6 or any of claims 8 to 13 as dependent upon claim 6, in which said masking means (35;50;62;75;80) comprises an opaque plate having a succession of windows which are transparent to laser-beam transmission therethrough and of progressively changing area, and said actuating means (40;55;88) is microprocessor-controlled for indexing said windows into successive alignment with the axis of the laser beam.

Claim 17

Apparatus for performing ophthalmological surgery by selective ablation of the anterior surface of the cornea with penetration into the stroma to achieve a volumetric removal of corneal tissue, said apparatus comprising laser means (13) for producing an output beam preferably in the ultraviolet portion of the electromagnetic spectrum and of an intensity which is limited per unit time to ablate but a fraction of a predetermined maximum ablation depth into the stroma, means (10,18,20) for directing said laser output beam onto the eye which is to be treated, and control means (16;46;57;89;141) for determining the irradiated flux density and exposure time of laser-beam impingement at the cornea whereby to effect a controlled sculpturing action upon the cornea such as to alter the optical properties thereof, and said apparatus further comprising reflector means (135;150;162;175) provided in the laser beam path for variably limiting the area of the laser beam at impingement upon the cornea and actuating means (140;155) for varying the reflector area of said reflector means, and said control means (16;46;57;89;141) being operative upon said actuating means for adjusting the laser beam area at impingement upon the cornea in a controlled manner in the course of a surgical treatment so that sculpturing action results from a controlled variation in the area of the cornea that is irradiated and a corresponding controlled variation in the cumulative ablative flux delivered to different areas of the cornea.

Claim 18

Apparatus for performing ophthalmological surgery by selective ablation of the anterior surface of the cornea with penetration into the stroma to achieve a volumetric removal of corneal tissue, said apparatus comprising laser means (13) for producing an output beam preferably in the ultraviolet portion of the electromagnetic spectrum and of an intensity which is limited per unit time to ablate but a fraction of a predetermined maximum ablation depth into the stroma, means (10,18,20) for directing said laser output beam onto the eye which is to be treated, and control means (16;46;57;89;141) for determining the irradiated flux density and exposure time of laser-beam impingement at the cornea whereby to effect a controlled sculpturing action upon the cornea such as to alter the optical properties thereof, and said apparatus further comprising reflector means (135;150;162;175) provided in the laser beam path for variably limiting the area of the laser beam at impingement upon the cornea and actuating means (140;155) for varying the reflector area of said reflector means, and said control means (16;46;57;89;141) being operative upon said actuating means for adjusting the laser beam area at impingement upon the cornea in a controlled manner in the course of a surgical treatment so that sculpturing action results from a controlled variation in the area of the cornea that is irradiated and a corresponding controlled variation in the cumulative ablative flux delivered to different areas of the cornea.

Claim 19

Apparatus according to claim 15, in which said reflector means (135; 150) is operative to provide cornea exposure at a central circular area and at a given plurality of similarly shaped but greater areas, said areas being concentric, whereby the surgical treatment may be myopia-correcting.

Claim 20

Apparatus according to claim 15, in which said reflector means (162) is operative to provide cornea exposure at a maximum area and at a given plurality of similarly shaped but lesser areas, said areas being circularly annular and being defined by a constant outer diameter and a varying inner diameter whereby the surgical treatment may be hyperopia-correcting.

Claim 21

Apparatus according to claim 15, in which said reflector means is operative to provide cornea exposure at a narrow elongate rectangular area centered on the optical axis of the eye and spanning a maximum area, plural said reflector means being further operative to provide cornea exposure at similarly shaped but greater areas, said areas being elongate rectangular and of varying width which is symmetrical about the elongation direction of said narrow area, whereby the surgical treatment may be astigmatism-correcting.

Claim 22

Apparatus according to claim 18, wherein orientation of the elongate direction of said areas is adjustable.

Claim 23

Apparatus according to claim 15, in which said reflector means (175) is operative to provide cornea exposure at a maximum area and at a given plurality of similarly shaped but lesser areas, said areas being circularly annular and being defined by a constant inner diameter and by a varying outer diameter which is intermediate said inner diameter and the outer diameter of said maximum area, whereby the surgical treatment may be myopia-correcting in a sculpted Fresnel annulus defined by said inner and outer diameters.

Claim 24

Apparatus according to claim 15, in which said reflector means is operative to provide cornea exposure at a maximum area and at a given plurality of similarly shaped but lesser areas, said areas being circularly annular, being defined by a constant outer diameter and by an inner diameter which varies to a fixed minimum inner diameter, whereby the surgical treatment may be hyperopia-correcting in a sculpted Fresnel annulus defined by said constant outer diameter and by said fixed minimum inner diameter.

Claim 25

Apparatus according to any of claims 15 to 21, in which said reflector means (135;150;162;175) comprises a transparent plate having a succession of reflecting elements on a surface thereof, said reflecting elements being of progressively changing area, and said actuating means (140;155) is microprocessor-controlled for indexing said reflecting elements into successive alignment with the axis of the laser beam.

Claim 26

Apparatus according to claim 15, in which said reflector means is a variable-aperture diaphragm characterised by a reflective side oriented to reflect the laser beam in a peripherally continuous annular area surrounding the diaphragm aperture.

Claim 27

Apparatus according to any of claims 15 to 22, in which laser-beam incidence upon said reflector means is at45 degrees, and in which the reflector area is elliptical with a major-axis to minor-axis ratio oH2:1, the laser-beam incidence being centered on the ellipse and at 45 degrees to the major-axis thereof.

Claim 32

Amethod, excluding the application of this method on the living human and/or animal body, of corneal sculpture by selective ablation of the corneal surface with penetration into the stroma so as to achieve a volumetric removal of corneal tissue, said method comprising: utilizing laser means (13) for producing an output beam preferably in the ultraviolet portion of the electromagnetic spectrum and of an intensity which is limited per unit time to ablate but a fraction of a predetermined maximum ablation depth into the stroma; directing said laser output beam onto the cornea which is to be sculpted; and controlling the irradiated flux density and exposure time of laser-beam impingement at the cornea whereby to effect a controlled sculpting action upon the cornea such as to alter the optical properties thereof, such control being effected by adjusting the size and/orshape of the laser beam area at impingement upon the cornea so that sculpturing action results from a controlled variation in the area of the cornea that is irradiated and a corresponding controlled variation in the cumulative ablative flux delivered to different areas of the cornea; the adjustment of the laser beam area at corneal impingement being effected by selective use of beam reflection means (135;150;162;175) defining a plurality of given different sizes and/or shapes of laser beam area at corneal impingement.

Claim 33

Amethod, excluding the application of this method on the living human and/or animal body, of corneal sculpture by selective ablation of the corneal surface with penetration into the stroma so as to achieve a volumetric removal of corneal tissue, said method comprising: utilizing laser means (13) for producing an output beam preferably in the ultraviolet portion of the electromagnetic spectrum and of an intensity which is limited per unit time to ablate but a fraction of a predetermined maximum ablation depth into the stroma; directing said laser output beam onto the cornea which is to be sculpted; and controlling the irradiated flux density and exposure time of laser-beam impingement at the cornea whereby to effect a controlled sculpting action upon the cornea such as to alter the optical properties thereof, such control being effected by adjusting the size and/orshape of the laser beam area at impingement upon the cornea so that sculpturing action results from a controlled variation in the area of the cornea that is irradiated and a corresponding controlled variation in the cumulative ablative flux delivered to different areas of the cornea; the adjustment of the laser beam area at corneal impingement being effected by selective use of beam reflection means (135;150;162;175) defining a plurality of given different sizes and/or shapes of laser beam area at corneal impingement.

Claim 35

A method according to claim 26 or 27 wherein sculpturing action is effected within a predetermined central area of the cornea and with the cornea being subjected to the least density of laser beam exposure centrally of said central area and to an exposure density which increases with increasing radius to the outer regions of said central area.

Claim 37

A method according to claim 30 wherein the fixing of the axis of elongation of the laser beam is effected automatically as a function of diagnosis of the optical characteristics of the cornea that is to be sculptured.