Optical guide and method for use in corrective laser eye surgery

Abstract

An optical guide dispenses laser light that is incident outside a selected region during laser eye surgery. The guide is formed as a body with a passageway of selected geometrical cross-section that defines a mininmum optical opening. The body has a material which circumferentially surrounds the passageway that is effective to dispense laser light incident thereto such that the energy thereof is dissipated to a level that will not affect eye tissue. A handle may optionally be provided to facilitate manipulation of the body. The passageway is preferably frustoconical. An optical system incorporates the optical guide and includes a mount that is to be placed in contact with the eye. The optical guide is secured to the mount, such as by cooperative rails and protrusions. A method is described to perform laser eye surgery using such optical guide and directing laser light along an optical path parallel to the central axis of the passageway. The laser light beam is...

Patent number: 5807380
Filing date: Apr 26, 1996
Issue date: Sep 15, 1998
Inventor: Jon G. Dishler

download



What is claimed is:

1. An optical guide adapted for use in laser surgery of an eye and operative to disperse laser light of a selected energy which is incident outside of a selected region, said optical guide comprising a body having a passageway therethrough and a sidewall surrounding said passageway, said passageway having a selected geometrical cross-section that defines a minimum optical opening having a periphery of a selected configuration through which the laser light may pass, said body constructed of a material that is effective in dispersing the laser light which is incident thereto such that the energy thereof is dissipated to a level that will not affect eye tissues.

2. An optical guide according to claim 1 wherein said body is annular in shape with said passageway defined by an inner sidewall of said body.

3. An optical guide according to claim 2 wherein said passageway is frustoconical in shape such that said sidewall is angularly divergent.

4. An optical guide according to claim 3 wherein said sidewall has an angle of divergence of about thirty degrees.

5. An optical guide according to claim 3 wherein said passageway is frustoconical in shape such that said sidewall is angularly divergent.

6. An optical guide according to claim 1 wherein the passageway extends axially through said body.

7. An optical guide according to claim 1 wherein said body portion is fabricated of a plastic material.

8. An optical system adapted for use in corrective eye surgery wherein focusing optics directs a beam of laser light from a laser light source of a selected energy along an optical path that is incident onto tissues of an eye, said energy being such that cellular eye tissue is removed by the laser light directly incident thereto, and wherein a control system is provided to control the size of the beam of laser light and a tracking path therefor, said optical system comprising:

(a) a mount operative to be placed in contact with the eye over a region targeted for laser surgery; and

(b) an optical guide adapted to be secured to said mount, said optical guide including a body portion having an axial passageway extending therethrough between a top and a bottom thereof and an inner sidewall surrounding said axial passageway, said axial passageway having a selected geometrical cross-section that defines a minimum optical opening having a periphery of a selected configuration through which the laser may pass in an axial direction, said body constructed of a material that is effective in dispersing the laser light which is incident thereto such that the energy thereof is dissipated to a level that will not affect eye tissues.

9. An optical guide according to claim 8 wherein said body is annular in shape with said passageway defined by an inner sidewall of said body.

10. An optical guide according to claim 8 wherein said mount is a suction ring.

11. A method of performing laser eye surgery for correction of hyperopia comprising the steps of:

(a) preparing an eye to have an exposed section of corneal tissue;

(b) disposing an optical guide proximate to said section of corneal tissue, said optical guide including a body portion having an axial passageway therethrough which permits unobstructed passage of axial laser light through an operative region surrounded by a sidewall of said optical guide, said operative region having a surrounding periphery of a selected configuration and a center point with said axial passageway having a central axis passing through the center point;

(c) directing a beam of laser light at a selected energy sufficient to remove corneal tissue cells along an optical path that is parallel to the central axis such that said laser beam is incident to said exposed section with said beam of laser light having a central area of maximum intensity, said beam of laser light being sized to have a diameter that is greater than a radial dimension of the operative region and positioned such that the central area thereof is offset from the center point whereby an active portion of light will pass through said axial passageway and wherein an inactive portion of said laser light will be incident to said body portion, said sidewall constructed of a material that is effective in dispersing the energy of said laser cells; and

(d) moving the beam of laser light such that the central area thereof follows a pathway that surrounds the central point whereby a recess is formed by removal of corneal tissue cells, said recess having a greatest depth along a medial area of the pathway.

12. A method according to claim 11 wherein the diameter of said beam is varied as said beam is moved along the pathway.

13. A method according to claim 12 wherein the diameter is expanded as said beam is moved along the pathway.

14. A method according to claim 12 wherein said central area is disposed 2.5-3.5 millimeters from the center point.

15. A method according to claim 14 wherein the diameter of said beam is varied between 1.0 millimeters and 5.0 millimeters.

16. A method according to claim 11 wherein said pathway is a geometrical shape selected from a group consisting of: circular pathways and ovoid pathways.

17. An optical guide adapted for use in laser surgery of an eye and operative to disperse laser light of a selected energy which is incident outside of a selected region, said optical guide comprising:

(a) a body having a passageway therethrough and a sidewall surrounding said passageway, said passageway having a selected geometrical cross-section that defines a minimum optical opening having a periphery of a selected configuration through which the laser light may pass, said body constructed of a material that is effective in dispersing the laser light which is incident thereto such that the energy thereof is dissipated to a level that will not affect eye tissues; and

(b) a handle member secured to said body and operative to facilitate manipulation thereof.

18. An optical guide adapted for use in laser surgery of an eye and operative to disperse laser light of a selected energy which is incident outside of a selected region, said optical guide comprising a body having a passageway therethrough and a sidewall surrounding said passageway, said passageway having a selected geometrical cross-section that defines a minimum optical opening having a periphery of a selected configuration through which the laser light may pass, said body constructed of a material that is effective in dispersing the laser light which is incident thereto such that the energy thereof is dissipated to a level that will not affect eye tissues, said material being selected from a group consisting of plastic and glass.

19. An optical system adapted for use in corrective eve surgery wherein focusing optics directs a beam of laser light from a laser light source of a selected energy along an optical path that is incident onto tissues of an eye, said energy being such that cellular eye tissue is removed by the laser light directly incident thereto, and wherein a control system is provided to control the size of the beam of laser light and a tracking path therefor, said optical system comprising:

(a) a mount operative to be placed in contact with the eye over a region targeted for laser surgery, said mount including a pair of parallel rail elements in spaced-apart facing relationship; and

(b) an optical guide adapted to be secured to said mount and including an engagement structure sized and configured to engage said rails thereby to assist in securing said optical guide to said mount, said mount further including a body portion having an axial passageway extending therethrough between a top and bottom thereof and an inner sidewall surrounding said axial passageway, said axial passageway having a selected geometrical cross-section that defines a minimum optical opening having a periphery of a selected configuration through which the laser may pass, said body constructed of a material that is effective in dispersing the laser light which is incident thereto such that the energy thereof is dissipated to a level that will not affect eye tissues.

20. An optical guide according to claim 19 wherein said engagement structure includes a foot portion operative to engage one of said rails.

21. An optical guide according to claim 20 wherein said engagement structure includes a shoulder portion disposed oppositely of said foot portion and operative to engage another of said rails, said mount including a retaining element operative to bear against said body portion to retain said body portion to retain said foot and shoulder portions in engagement with said rails.

22. An optical guide according to claim 21 wherein said retaining element is resiliently biased against said body portion when said optical guide is secured to said mount.

Two camera off-axis eye tracker for laser eye surgery

Abstract

Improved laser eye surgery and/or eye tracking systems, methods, and devices make use of two image capture devices, generally with both image capture devices disposed off the optical axis of the eye and/or any laser delivery system. This provides an enhanced imaging contrast for an imaging capture device such as a camera with a charge-couple device (CCD), particularly when using infrared imaging to track a pupil of the eye. The two off-axis cameras may be used independently to track movements of the pupil along two orthogonal lateral axes of the eye (often called X-Y tracking), and may also indicate a position of the eye along the optical or Z axis.

Patent number: 6322216
Filing date: Apr 7, 2000
Issue date: Nov 27, 2001
Inventors: Kingman Yee, Charles R. Munnerlyn
Assignee: VISX, Inc

download


What is claimed is:

1. An apparatus for sculpting a corneal tissue of an eye so as to effect a desired change in a patient's vision, the apparatus comprising:

an energy delivery system selectively directing an energy stream along a treatment axis toward the corneal tissue;

first and second image capture devices oriented toward the eye, each image capture device having an imaging axis angularly offset from the treatment axis by between about 10 and 70 degrees; and

a processor coupling the image capture devices to the energy delivery system so that the energy delivery system laterally deflects the energy stream along a first axis in response to movement of the eye sensed by the first image capture device, and so that the energy delivery system laterally deflects the energy stream along a second axis in response to movement of the eye sensed by the second image capture device.

2. The apparatus of claim 1, further comprising a laser generating the energy stream, the energy stream comprising a laser beam adapted for ablating the corneal tissue.

3. The apparatus of claim 2, wherein the energy delivery system comprises at least one offset imaging lens along an optical path of the laser beam, the imaging lens moving laterally relative to the laser beam in response to the signals from the first and second image capture devices.

4. The apparatus of claim 1, further comprising an infrared light source oriented toward the eye, wherein each image capture devices comprises a CCD sensitive to infrared light reflected by an iris and sclera of the eye, and wherein the processor comprises first and second tracker modules associated with the first and second image capture devices, respectively, the first and second tracker modules determining a position of a centroid of a pupil of the eye from the reflected infrared light.

5. An apparatus for sculpting a corneal tissue of an eye so as to effect a desired change in a patient's vision, the apparatus comprising:

an energy delivery system selectively directing an energy stream along a treatment axis toward the corneal tissue, wherein the energy stream defines a treatment axis;

first and second image capture devices oriented toward the eye, wherein the eye is disposed within first and second fields of view of the first and second image capture devices, respectively, the fields of view being angularly offset from the treatment axis; and

a processor coupling the image capture devices to the energy delivery system so that the energy delivery system laterally deflects the energy stream along a first axis in response to movement of the eye sensed by the first image capture device, and so that the energy delivery system laterally deflects the energy stream along a second axis in response to movement of the eye sensed by the second image capture device.

6. The apparatus of claim 5, wherein the second field of view is offset circumferentially from the first field of view about the treatment axis.

7. The apparatus of claim 6, wherein the second field of view is offset circumferentially by about 90 degrees from the first field of view about the treatment axis.

8. The apparatus of claim 6, the eye defining an X-Y-Z coordinate system with a Z axis along an optical axis of the eye, and X-Z plane along the first axis, and a Y-Z plane along the second axis, wherein the first image capture device is disposed along the Y-Z plane and off the X-Z plane, and wherein the second image capture device is disposed along the X-Y plane and off the Y-Z plane.

9. The apparatus of claim 8, wherein the processor generates a signal indicating a distance between the energy delivery system and a feature of the eye in response to lateral positions of the feature within the first and second fields of view as sensed by the first and second image capture devices.

10. An apparatus for sensing motion of an eye, the eye having an optical axis and first and second lateral optical axes, the apparatus comprising:

a first tracker with a first image capture device and a first processor module, the first image capture device having a first imaging optical train oriented toward the eye along a first imaging axis and generating a first image, the first imaging axis angularly offset from the optical axis, the first processor module generating a first signal indicating lateral movement of the eye relative to the first imaging axis in response to the first image; and

a second tracker with a second image capture device and a second processor module, the second image capture device having a second imaging optical train oriented toward the eye along a second imaging axis and generating a second image, the second imaging axis angularly offset from the optical axis and displaced circumferentially from the first imaging axis relative to the optical axis, the second processor module generating a second signal indicating lateral movement of the eye relative to the second imaging axis in response to the second image.

11. The apparatus of claim 10, further comprising a third processor module coupled to the first and second trackers, the third processor module calculating lateral displacement of the eye relative to the first and second lateral optical axes from the first and second signals.

12. The apparatus of claim 10, further comprising a laser directing a laser beam along the optical axis toward the eye so as to ablate corneal tissue of the eye to effect a predetermined change in an optical characteristic of the eye.

13. A method for sensing movement of an eye having an optical axis and first and second lateral axes, the method comprising:

sensing movement of the eye along the first lateral axis with a first imaging capture device, the first image capture device disposed along a first imaging path offset from the optical axis by an angle in the range from about 10 degrees to about 70 degrees; and

sensing movement of the eye along the second lateral axis with a second imaging capture device disposed along a second imaging path offset from the optical axis by an angle in the range from about 10 degrees to about 70 degrees, the second imaging path displaced circumferentially about the optical axis relative to the first imaging path.

14. The method of claim 13, further comprising directing a pattern of laser energy toward the eye so as to effect a desired change in an optical characteristic of the eye, and laterally displacing the laser energy in response to the sensed movement of the eye from the first and second image capture devices to enhance alignment between the pattern and the eye when the eye moves.

15. The method of claim 14, wherein the laser energy is laterally displaced in response to sensed voluntary movements of the eye or head, and wherein rapid saccadic movements of the eye are not tracked.

16. The method of claim 13, further comprising determining positional information of the eye along the optical axis using signals from at least one of the image capture devices.

Method for laser surgery

Abstract

A method of laser surgery, comprising the steps of selecting lasers whose output radiation has appropriate extinction lengths in the tissue to be ablated, coagulated, and/or shrunk, and directing radiation from those lasers coaxially and substantially simultaneously at the tissue.

Patent number: 5655547
Filing date: May 15, 1996
Issue date: Aug 12, 1997
Inventor: Ziv Karni
Assignee: ESC Medical Systems Ltd.
Primary Examiner: Kelly R. O'Hara

download




What is claimed is:

1. A method for surgical alteration of skin tissue by simultaneous ablation and coagulation, comprising the steps of:

(a) selecting a first coherent radiation source characterized by emitting a first coherent radiation having an extinction length in the skin tissue of between about 0.01 millimeters and about 0.001 millimeters;

(b) selecting a second coherent radiation source characterized by emitting a second coherent radiation having an extinction length in the skin tissue of between about 0.1 millimeters and about 0.01 millimeters;

(c) ablating the skin tissue by directing a first beam of said first coherent radiation at the skin tissue; and

(d) coagulating the skin tissue by directing a second beam of said second coherent radiation at the skin tissue, substantially coaxially and substantially simultaneously with said first beam.

2. The method of claim 1, wherein said first coherent radiation source is a laser.

3. The method of claim 2, wherein said first coherent radiation source is an erbium YAG laser.

4. The method of claim 1, wherein said second coherent radiation source is a laser.

5. The method of claim 4, wherein said laser is a carbon dioxide laser.

6. The method of claim 1, wherein said first beam is pulsed.

7. The method of claim 6, wherein each of said pulses has a duration of about 0.3 milliseconds, and wherein each of said pulses has an energy density of between about one Joule per square centimeter and about 50 Joules per square centimeter.

8. The method of claim 6, wherein said second beam is continuous.

9. The method of claim 8, wherein said second beam has a power density of between about one Watt per square centimeter and about 10 Watts per square centimeter.

10. The method of claim 6, wherein said second beam is pulsed, said pulses of said second beam at least partially overlapping in time with said pulses of said first beam.

11. The method of claim 10, wherein each of said pulses of said second beam has a duration of between about one millisecond and about 10 milliseconds, and wherein each of said pulses of said second beam has a power density of between about one Watt per square centimeter and about 100 Watts per square centimeter.

12. The method of claim 1, further comprising the step of directing a third beam of visible coherent radiation at the skin tissue, substantially coaxially and substantially simultaneously with said first beam.

13. A method for surgical alteration of skin tissue by simultaneous ablation and shrinkage, comprising the steps of:

(a) selecting a first coherent radiation source characterized by emitting a first coherent radiation having an extinction length in the skin tissue of between about 0.01 millimeters and about 0,001 millimeters;

(b) selecting a second coherent radiation source characterized by emitting a second coherent radiation having an extinction length in the skin tissue of between about one millimeter and about 0.01 millimeters;

(c) ablating the skin tissue by directing a first beam of said first coherent radiation at the skin tissue; and

(d) shrinking the skin tissue by directing a second beam of said second coherent radiation at the skin tissue, substantially coaxially and substantially simultaneously with said first beam.

14. The method of claim 13, wherein said first coherent radiation source is a laser.

15. The method of claim 14, wherein said first coherent radiation source is an erbium YAG laser.

16. The method of claim 13, wherein said second coherent radiation source is a laser.

17. The method of claim 16, wherein said laser is a holmium YAG laser.

18. The method of claim 13, wherein said first beam is pulsed.

19. The method of claim 18, wherein each of said pulses has a duration of about 0.3 milliseconds, and wherein each of said pulses has an energy density of between about one Joule per square centimeter and about 50 Joules per square centimeter.

20. The method of claim 18, wherein said second beam is pulsed, said pulses of said second beam at least partially overlapping in time with said pulses of said first beam.

21. The method of claim 20, wherein each of said pulses of said second beam has a duration of between about 0.3 milliseconds and about one millisecond, and wherein each of said pulses of said second beam has an energy density of about one Joule per square centimeter.

22. The method of claim 13, further comprising the step of directing a third beam of visible coherent radiation at the skin tissue, substantially coaxially and substantially simultaneously with said first beam.

Laser surgery method

Abstract

An argon-flouride excimer laser or other laser source capable of generating far-ultraviolet radiation at 193 nm is pulsed with energy densities of greater than 20 mj per cm.sup.2 at a repetition rate up to 25 pulses per second to direct its radiation through a mask and onto corneal tissue, or other biological matter, to form a groove therein of predetermined configuration and depth by a process of ablative photodecomposition. The masks are formed with a slit, circular, crescent or other openings of widths between 30 and 800 microns, and may even be formed to provide a graded intensity center to edge. The mask is reflective or composed of or faced with an organic polymer to prevent heat build-up. Each micron of the depth of a 200 micron deep groove formed in corneal tissue, for example, resulted from the application of 1 joule per square centimeter of radiation, from a series of pulses delivered at intensities of between 100 mj and 200 mj per square centimeter and at a laser...

Patent number: 5108388
Filing date: Oct 16, 1987
Issue date: Apr 28, 1992
Inventor: Stephen L. Trokel
Assignee: Visx, Incorporated

download


What is claimed is:

1. A method for producing a surgical excision of controlled depth and shape in a cornea by ablative photochemical decomposition of corneal tissue without thermal damage to the corneal tissue, said method comprising the steps of:

(a) generating a laser beam in the far ultraviolet region of the energy spectrum and at a wavelength selected to produce ablative photochemical decomposition of corneal tissue without thermal damage to the corneal tissue and

(b) directing said radiation in a controlled manner onto said corneal tissue to induce ablative photochemical decomposition thereof in a volumetric removal of said corneal tissue without thermal heating to create a surgical excision of controlled depth and shape with depth penetration into the stroma.

2. The method of claim 1 wherein said selected wavelength is 193 nanometers.

3. A method for producing a surgical excision of controlled depth and shape in a cornea by ablative photochemical decomposition of corneal tissue without thermal damage to the corneal tissue, said method comprising the steps of:

(a) generating a laser beam at a wavelength of 193 nanometers;

(b) directing said laser beam onto a predetermined area of corneal tissue; and

(c) controlling said laser beam so as to induce ablative photochemical decomposition of said corneal tissue in a volumetric removal of said corneal tissue without thermal damage to said corneal tissue to create a surgical excision of controlled depth and shape with depth penetration into the stroma.

4. The method of changing optical properties of an eye by operating solely upon the anterior surface of the cornea of the eye, which method comprises selective ultraviolet irradiation and attendant ablative photodecomposition of the anterior surface of the cornea in a volumetric removal of corneal tissue and with depth penetration into the stroma and to a predetermined curvature profile.

5. The method of using an ultraviolet laser to change the optical properties of an eye, which method comprises adjusting the intensity of laser beam projection to a level at which laser beam projection onto the anterior surface of the cornea of the eye will result in corneal-tissue ablation per unit time which is but a fraction of a predetermined maximum ablation depth into the stroma of the cornea, and directing the laser beam at the anterior surface of the cornea in a controlled manner to create at least one excision in the anterior surface of the cornea relative to the optic axis thereof by volumetric removal of corneal tissue in the course of ablative photodecomposition of the stroma causing a redefinition of the anterior surface of the cornea.

Apparatus for performing ophthalmic laser surgery

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.

Patent number: 4729372
Filing date: Jul 31, 1986
Issue date: Mar 8, 1988
Inventor: Francis A. L'Esperance, Jr.
Assignee: LRI L.P.
Primary Examiner: David Shay

download

What is claimed is:

1. 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.

2. 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.

3. 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.

4. Sculpture apparatus according to claim 3, in which said reflector means is operative to provide cornea exposure at a central circular area and at a plurality of similarly shaped but greater areas, said areas being concentric, whereby the diopter change may be myopia-correcting.

5. Sculpture apparatus according to claim 3, in which said reflector means is operative to provide cornea exposure at said maximum area of curvature correction and at a plurality of similarly shaped but lesser areas, said areas being annular and characterized by progressively changing inner radius, whereby the diopter change may be hyperopia-correcting.

6. Sculpture apparatus according to claim 5, in which the range of reflector-area variation is larger than said maximum curvature-correcting area to thereby determine an outer annulus of laser-beam projection surrounding said maximum curvature-correcting area, said actuating means also varying the outer diameter of said outer annulus such that said outer-diameter variation (i) commences at substantially the outer diameter of said curvature-correcting area and (ii) proceeds with outward diameter expansion.

7. Sculpture apparatus according to claim 3, 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 said 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 diopter change may be astigmatism-correcting.

8. Sculpture apparatus according to claim 7, wherein orientation of the elongate direction of said areas is variable.

9. Sculpture apparatus according to claim 3, in which said reflector means is operative to provide cornea exposure at said maximum area and at a 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 diopter change may be myopia-correcting in a sculpted Fresnel annulus defined by said constant outer diameter and by said fixed minimum inner diameter.

10. Sculpture apparatus according to claim 3, in which said reflector means is operative to provide cornea exposure at said maximum area and at a plurality of similarly shaped but lesser areas, said areas being circularly annular, 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 diopter change may be hyperopia-correcting in a sculpted Fresnel annulus defined by said inner and outer diameters.

11. Sculpture apparatus according to claim 3, in which said reflector means includes a transparent plate having a succession of reflecting elements on a surface thereof, said reflecting elements being of progressively changing area, and microprocessor-controlled means for indexing said reflecting elements into successive alignment with the axis of the laser beam.

12. Sculpture apparatus according to claim 9, in which said reflecting elements are in spaced rectilinear array.

13. Sculpture apparatus according to claim 9, in which said reflecting elements are in spaced array about an axis of index rotation.

14. Sculpture apparatus according to claim 3, in which said reflector means is a variable-aperture diaphragm characterized by a reflective side oriented to reflect the laser beam in a peripherally continuous annular area surrounding the instantaneous diaphragm aperture.

15. Sculpture apparatus according to claim 3, in which laser-beam incidence upon said reflector means is at 45 degrees, and in which the reflector area is always elliptical with a major-axis to minor-axis ratio of .sqroot.2:1, the laser-beam incidence being centered on the ellipse and at 45 degrees to the major-axis thereof.

16. 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.

17. Sculpture apparatus according to claim 1, in which said control means is further connected to said laser means and to said controllable means, for so correlating laser-beam impingement at the cornea with beam-section veriation in an outer annular area which is contiguous to the curvature-correcting area of diopter change as to effect a graduated radially outward transition (a) from the depth of stroma ablation at the perimeter of diopter change and (b) to substantially zero depth at the outer limit of said annular area.

18. 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.

19. Apparatus according to claim 18 or claim 2, in which said zoom lens is of a variety to convert said output beam into a confined circular section of area which varies in accordance with variation in the setting of said zoom drive, whereby the diopter-reducing change may be myopia-correcting.

20. Apparatus according to claim 18 or claim 2, in which said zoom lens is of a variety to convert said output beam into a confined straight line extending diametrically through the optical axis, said line being of width which varies in accordance with variation in the setting of said zoom drive, whereby the diopter-reducing change may be corrective of astigmatism.

21. Apparatus according to claim 18 or claim 2, in which said zoom lens is of a variety to convert said output beam into a confined straight line extending diametrically through the optical axis, said line being of width which varies in accordance with variation in the setting of said zoom drive, whereby the diopter-reducing change may be corrective of astigmatism, and in which said zoom lens has an optical axis and is mounted for selective bodily rotation about its optical axis, whereby the angular orientation of said straight line may be set to accord with that of required astigmatism correction.

22. 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.

23. 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.

24. Apparatus according to claim 22 or claim 23, in which said masking means is operative to provide cornea exposure at said maximum area and at a plurality of similarly shaped but lesser areas, said areas being elongate rectangular and of varying width, whereby the diopter change may be astigmatism-correcting.

25. Apparatus according to claim 22 or claim 23, in which said masking means is operative to provide cornea exposure at said maximum area and at a plurality of similarly shaped but lesser areas, said areas being elongate rectangular and of varying width, whereby the diopter change may be astigmatism-correcting, and wherein orientation of the elongate direction of said areas is variable.

26. Apparatus according to claim 22 or claim 23, in which said masking means is operative to provide cornea exposure at said maximum area and at a plurality of similarly shaped but lesser areas, said areas being circularly annular, being defined by a constant outer diameter and by a varying inner diameter, whereby the diopter change may be hyperopia-correcting.

27. Apparatus according to claim 22 or claim 23, in which said masking means is operative to provide cornea exposure at said maximum area and at a plurality of similarly shaped but lesser areas, said areas being circularly annular, 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 diopter change may be myopia-correcting in a sculpted Fresnel annulus defined by said inner and outer diameters.

28. Apparatus according to claim 2 or claim 23, in which said masking means is operative to provide cornea exposure at said maximum area and at a 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 diopter change may be hyperopia-correcting in a sculpted Fresnel annulus defined by said constant outer diameter and by said fixed minimum inner diameter.

29. Apparatus according to claim 22 or claim 23, in which said masking means includes an opaque plate having a succession of windows which are (a) transparent to laser-beam transmission therethrough and (b) of progressively changing area, and in which said microprocessor-controlled means is connected to index said windows into successive alignment with the axis of the laser beam.

30. Apparatus according to claim 22 or claim 23, in which said masking means includes an opaque plate having a succession of windows which are (a) transparent to laser-beam transmission therethrough and (b) of progressively changing area, and in which said microprocessor-controlled means is connected to index said windows into successive alignment with the axis of the laser beam, and in which said windows are in spaced rectilineal array.

31. Apparatus according to claim 22 or claim 23, in which said masking means includes an opaque plate having a succession of windows which are (a) transparent to laser-beam transmission therethrough and (b) of progressively changing area, and in which said microprocessor-controlled means is connected to index said windows into successive alignment with the axis of the laser beam, and in which said windows are in spaced circular array.

32. Apparatus according to claim 22 or claim 23, in which said masking means is operative to provide cornea exposure at said maximum area and at a plurality of similarly shaped but lesser areas, said areas being circular, whereby the diopter change may be myopia-correcting.

33. Apparatus according to claim 22 or claim 23, in which said masking means includes an opaque plate having a succession of windows which are (a) transparent to laser-beam transmission therethrough and (b) of progressively changing area, and in which said programmable means is connected to index said windows into successive alignment with the axis of the laser beam.

34. Apparatus according to claim 22 or claim 23, in which said masking means includes an opaque plate having a succession of windows which are (a) transparent to laser-beam transmission therethrough and (b) of progressively changing area, and in which said programmable means is connected to index said windows into successive alignment with the axis of the laser beam, and in which said windows are in spaced rectilineal array.

35. Apparatus according to claim 22 or claim 23, in which said masking means includes an opaque plate having a succession of windows which are (a) transparent to laser-beam transmission therethrough and (b) of progressively changing area, and in which said programmable means is connected to index said windows into successive alignment with the axis of the laser beam, and in which said windows are in spaced circular array.

36. 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.

37. Apparatus according to claim 36, in which laser-beam incidence upon said reflector means is at 45 degrees, and in which the reflecting area is always elliptical with a major-axis to minor-axis ratio of .sqroot.2:1, the laser-beam incidence being centered on the ellipse and at 45 degrees to the major-axis thereof.

38. 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.

39. Apparatus according to claim 36 or claim 38, in which said reflector means is operative to provide cornea exposure at a narrow elongate rectangular area centered on the optical axis of the projected beam and spanning said maximum area, said reflector means being further operative to provide cornea exposure at a plurality of similarly shaped but greater areas, said areas being elongate rectangular and of varying width which is symmetrical about the elongate direction of said narrow area, whereby the diopter change may be astigmatism-correcting.

40. Apparatus according to claim 36 or claim 38, in which said reflector means is operative to provide cornea exposure at a narrow elongate rectangular area centered on the optical axis of the projected beam and spanning said maximum area, said reflector means being further operative to provide cornea exposure at a plurality of similarly shaped but greater areas, said areas being elongate rectangular and of varying width which is symmetrical about the elongate direction of said narrow area, whereby the diopter change may be astigmatism-correcting, and wherein orientation of the elongate direction of said areas is variable.

41. Apparatus according to claim 36 or claim 38, in which said reflector means is operative to provide cornea exposure at said maximum area and at a 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 diopter change may be hyperopia-correcting in a sculpted Fresnel annulus defined by said constant outer diameter and by said fixed minimum inner diameter.

42. Apparatus according to claim 36 or claim 38, in which said reflector means is operative to provide cornea exposure at said maximum area and at a plurality of similarly shaped but lesser areas, said areas being circularly annular, 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 diopter change may be myopia-correcting in a sculpted Fresnel annulus defined by said inner and outer diameters.

43. Apparatus according to claim 36 or claim 38, in which said reflector means includes a transparent plate having a succession of reflecting elements on a surface thereof, said reflecting elements being of progressively changing area, and in which said microprocessor-controlled means is connected to index said reflecting elements into successive alignment with the axis of the laser beam.

44. Apparatus according to claim 36 or claim 38, in which said reflector means includes a transparent plate having a succession of reflecting elements on a surface thereof, said reflecting elements being of progressively changing area, and in which said microprocessor-controlled means is connected to index said reflecting elements into successive alignment with the axis of the laser beam, and in which said reflecting elements are in spaced rectilineal array.

45. Apparatus according to claim 36 or claim 38, in which said reflector means includes a transparent plate having a succession of reflecting elements on a surface thereof, said reflecting elements being of progressively changing area, and in which said microprocessor-controlled means is connected to index said reflecting elements into successive alignment with the axis of the laser beam, and in which said reflecting elements are in spaced array about an axis of index rotation.

46. Apparatus according to claim 36 or claim 38, in which said reflector means is a variable-aperture diaphragm characterized by a reflective side oriented to reflect the laser beam in a peripherally continuous annular area surrounding the diaphragm aperture.

47. Apparatus according to claim 36 or claim 38, in which said reflector means is operative to provide cornea exposure at a central circular area and at a plurality of similarly shaped but greater areas, said areas being concentric, whereby the diopter change may be myopia-correcting.

48. Apparatus according to claim 36 or claim 38, in which said reflector means is operative to provide cornea exposure at said maximum area and at a plurality of similarly shaped but lesser areas, said areas being annular and characterized by varying inner radius within said maximum area, whereby the diopter change may be hyperopia-correcting.

Method of laser cosmetic surgery

Abstract

Laser surgery is utilized to perform cosmetic surgery. A quartz fiber is used to direct the laser energy to the target area for the incision, division or resection of tissue. An endoscope may be utilized in conjunction with the quartz fiber to perform the cosmetic surgical techniques. One application utilizes laser energy to eliminate glabellar frown lines and/or forehead wrinkles. Another application employs laser energy to rectify brow descent. A further application uses laser energy to perform a neck lift. In yet another application, laser energy is utilized to reduce nasolabial folds. The use of laser energy in cosmetic surgical procedures greatly reduces the size of the incision required in the skin to perform cosmetic surgical procedures, and as a result greatly reduces the risks of potential complications.

Patent number: 5370642
Filing date: Aug 2, 1993
Issue date: Dec 6, 1994
Inventor: Gregory S. Keller
Primary Examiner: Mary Beth Jones

download




What is claimed is:

1. A method of cosmetic surgery for the treatment of frown lines and forehead wrinkles comprising:

marking on the skin the supraorbital and supratrochlear formen and nerve courses;

performing at least one small incision in the skin near the hair line for inserting a laser transmitting means beneath the skin;

inserting a laser transmitting means beneath the skin; a

directing the laser energy from the laser transmitting means to;

separate the fusion layer of fascia either above the periosteum,

divide and/or resect the corrugator and procerus muscles, and wherein the method further includes

divide the frontalis muscle with the laser-transmitting means; and

closing the incision.

2. The method of claim 1 wherein the laser-transmitting means comprises a quartz fiber.

3. The method of claim 2 wherein the quartz fiber has a diameter between 300 and 700 microns and a 100 to 250 micron tip.

4. The method of claim 2 wherein the quartz fiber has a 400 micron diameter and a 100 micron tip.

5. The method of claim 1 wherein the laser energy is characterized by a wavelength between 532 to 1060 nm.

6. The method of claim 1 wherein the laser transmitting means is an endolaser comprising an endoscope with a channel containing a laser transmitting quartz fiber.

Method and apparatus for precision laser surgery

Abstract

A system for effecting precision laser surgery includes an intensified surgical video microscope directed at the tissue to be operated upon and having zoom capability. The surgical microscope presents a microscopic image on a video screen in front of the surgeon. Preferably, the video screen is divided into multiple separate sections, with the microscopic video image in one section and precise cross sectional and plan views indicating location presented in the other sections of the screen. These additional views may be generated using Moire interferometry by projecting a Ronchi ruling on the surface of the tissue, in viewing the projection with a camera to obtain all necessary information for contour tracking of the subject surface. Interior elements and interfaces of, for example, the eye are also sensed by a light beam and precisely located and mapped by a computer forming a part of the device. The imaging system of the invention enables the surgeon to have before him abundant...

Patent number: 5098426
Filing date: Feb 6, 1989
Issue date: Mar 24, 1992
Inventors: H. Alfred Sklar, Alan M. Frank, Olga M. Ferrer, Charles F. McMillan, Stewart A. Brown, Fred Rienecker, Paul Harriss, Steven Schiffer
Assignee: Phoenix Laser Systems, Inc.

download


What is claimed is:

1. A system for use in ophthalmic diagnosis and analysis and for support of ophthalmic surgery, comprising,

three dimensional mapping means for sensing locations, shapes and features on and in a patient's eye in three dimensions, and for generating data and signals representing such locations, shapes and features,

display means receiving signals from the three dimensional mapping means, for presenting to a user images representative of said locations, shapes and features of the eye, at targeted locations including display control means for enabling a user to select the target location and to display a cross section of portions of the eye,

position analysis means associated with and receiving signals from the three dimensional mapping means, for recognizing the occurrence of changes of position of features of the eye,

target tracking means associated with the position analysis means, for searching for a feature of target tissue and finding said features new position after such a change of position, and for generating a signal indicative of the new position, and

tracking positioning means for receiving said signal from the target tracking means and for executing a change in the aim of the three dimensional mapping means to the new position of said feature of the target tissue, to thereby follow the feature and stabilize the images on the display means.

2. The system of claim 1, wherein the display means is a video display, and further including surgical microscope means directed at the patient's eye, for taking video microscopic images of target areas of the ocular tissue and for feeding video image information to the video display means to cause such video microscopic images to be displayed, assisting the user in diagnosis and analysis.

3. The system of claim 1, further including display control means for enabling the user to cause to be displayed on the display means different cross sections of the patient's tissue, as selected by the user.

4. The system of claim 1, wherein the tracking positioning means includes a turning mirror under automatic control, and the system including an objective lens assembly associated with the mapping means and having a final focussing lens, with the turning mirror positioned within the objective lens assembly and movable with respect to the final focussing lens.

5. An instrument and system for high precision ophthalmic laser surgery at a surgical site, comprising,

a laser pulsed source for producing a visible light laser beam having a power capable of effecting a desired type of surgery in an eye,

laser firing control means for enabling a surgeon/user to control the aim, depth, and timing of the firing of the laser to effect the desired surgery,

three dimensional mapping means directed at a patient's eye, for obtaining data representing the location and shapes of features on and inside the eye,

microprocessor means for receiving data from the three dimensional mapping means and for converting the data to a format presentable on a screen and useful to the surgeon/user in precisely locating features of the eye and the aim and depth of the laser beam within those features, and

display means for displaying microprocessor-generated images representing the topography of the eye and the aim and depth of the laser beam before the next pulse of the laser is fired to the surgeon/user in preparation for and during surgery, with display control means for enabling the surgeon/user to select areas of the eye for display, including images of cross sections of portions of the eye.

6. The instrument and system of claim 5, wherein the display means comprises a single video screen divided into multiple displays.

7. The instrument and system of claim 5, wherein the three dimensional mapping means, the microprocessor means, and the display means include means for presenting images to the surgeon/user indicating precise current location of laser aim and depth in computer generated views which comprise generally a plan view and selected cross sectional views of the eye representing features of the eye at different depths.

8. The instrument and system of claim 5, including an optical path with a focusing lens capable of controlling the focus of the laser beam on the eye tissue, and thus the depth at which the laser beam is effective, within about 5 microns, with depth control means for the surgeon to vary the focus of said lens to control the depth at which the laser beam is effective.

9. The instrument and system of claim 8, including system program means enabling the surgeon/user to pre-program a pattern of lesions in the ocular tissue along three axes in three dimensions and to activate the laser to follow the preselected pre-programmed path of surgery automatically.

10. The instrument and system of claim 5, further including tracking means for following movements of the eye during surgery and for following the movement of features at the surgical site of the eye with the three dimensional mapping means and with the laser, including means associated with the microprocessor for recognizing features at the surgical site after said features have moved and redirecting the three dimensional mapping system and the laser to the new location of said features.

11. The instrument and system of claim 10, wherein the display means includes a video monitor which has a frame rate and wherein the tracking means has the capability of following the features, identifying a new location of those features and re-presenting images of those features to the surgeon/user in a time period less than the frame rate of the video display means.

12. The instrument and system of claim 10, wherein the tracking means includes electromagnetically driven turning mirror means along an optical path of both the three dimensional mapping means and the laser beam, for shifting the aim of the three dimensional mapping means and a laser beam in response to the recognized to the recognized shift in position of the features of the eye.

13. The instrument and system of claim 10, wherein the display means comprises a video monitor which as a frame rate and the tracking means includes fast tracking means and backup slow tracking means with the backup slow tracking means including means for following the features at the surgical site, identifying a new location of said features and re-presenting images of said features to the surgeon/user in a time period at least as fast as the video frame rate, and the fast tracking means being capable of tracking movement of the tissue at much faster closed loop response times; and the backup slow tracking means having means for analyzing tissue position based on the three-dimensional topography of the tissue as determined, and for searching and finding, using the microprocessor means, a feature of the tissue when that feature is not found by the fast tracking means and for moving to the new position of the subject tissue feature and enabling the fast tracking means tore-commence fast tracking.

14. The instrument and system of claim 5, wherein the display means comprises a video display monitor, and further including surgical microscope means on a common optical path with the laser beam, for obtaining a greatly enlarged image of a small region of the eye at which the laser beam is directed and for generating a video image of that small region for presentation on the display means.

15. The instrument and system of claim 14, wherein the surgical microscope means includes intensified video camera means for imaging at low light levels at high magnification while remaining within safe illumination levels for human clinical procedures.

16. The instrument and system of claim 14, wherein the display means comprises a video screen divided to show the image from the surgical microscope means as well as topography information obtained from the three dimensional mapping means and generated by said microprocessor means.

17. The instrument and system of claim 14, further including eye illumination means also along the common optical path with the laser beam, the surgical microscope and the three dimensional mapping means.

18. The instrument and system of claim 14, further including optical zooming mean associated with the surgical microscope means, for forming an image of adjustable magnification range of not less than tenfold increased magnification, of said small region of the eye with optical elements located a considerable and comfortable distance from the patient.

19. The instrument and system of claim 18, wherein the optical path includes a final focusing lens at the exterior of the instrument, with the final focusing lens positioned at least 100 mm from the patient's eye.

20. A system for facilitating precisely controlled surgery using a focused laser beam, comprising,

user interface means for presenting information to a surgeon/user and for enabling control of the surgical procedure by the surgeon/user, including video display means for presenting precise information to the surgeon/user relating to the location in a patient's tissue at which the system is targeted, and the three-dimensional topography and contours of features of the subject tissue and including means for displaying images of cross sections of portions of the patient's tissue, and including means in the control of the surgeon/user for scanning across the tissue to change the information on the video display means as desired by the surgeon/user and for enabling control of the firing of a surgical laser beam by the surgeon/user,

an imaging system connected to the video display means, including three-dimensional mapping means for generating, reading, and interpreting data to obtain information regarding the location in three dimensions of significant features of the tissue to be operated upon, and including microprocessor means for interpreting the data and presenting the data to the video display means in a format useful to the surgeon/user,

a short pulse visible light laser power source for generating a laser beam capable of effecting the desired laser surgery in the patient's tissue, including within transparent tissue of the patient,

optical path means for receiving the laser beam and redirecting the laser beam and focusing it as appropriate toward a desired target in the tissue to be operated upon,

surgical microscope means positioned to intercept and to be coaxial with the optical path means, for taking surgical microscopic images of said target along the optical path means and for feeding video image information to the video display means, and

tracking means in the optical path means and associated with the microprocessor means, for tracking movements of the subject tissue at which the system is targeted without damaging the subject tissue before the next pulse of the laser is fired and shifting the optical path means accordingly before the next pulse of the laser is fired, such that information and images generated by the three dimensional mapping mans and by the surgical microscope means, as well as the aiming and position of the laser beam, follow changes in position of the tissue.

21. The laser surgical system of claim 1, further including first control interlock means for preventing firing of the surgical laser beam except when the tracking means is properly tracking movements of the subject tissue at which the system is targeted, by preventing the laser from firing a next pulse of energy unless the tracking means has tracked the subject tissue.

22. The laser surgical system of claim 1, further including means for superimposing program templates over images created by the imaging system, for automatically effecting a pre-selected pattern of laser surgery.

23. The laser surgical system of claim 1, wherein the imaging system includes scattered light detection means for detecting scattered light from the features of the tissue, with means for filtering out substantially all specularly-reflected light for the scattered light detection means.

24. The laser surgical system of claim 1, wherein the surgical microscope means includes an intensified video camera means for imaging at low light levels at high magnification while remaining within safe illumination levels for human clinical procedures.

25. The laser surgical system of claim 1, wherein the optical path means includes a final focussing lens with means for focussing the laser beam, the three dimensional mapping means and the surgical microscope means an appreciable and comfortable distance from the final focussing lens with respect to the patient, a distance of not less than about 50 mm.

26. The laser surgical system of claim 25, including an objective lens assembly of which the final focussing lens comprises a front element, and wherein the tracking means includes a turning mirror under automatic control of the microprocessor means, with the turning mirror positioned within the objective lens assembly and movable with respect to the final focussing lens.

27. The laser surgery system of claim 1, including tracking and profilometer camera means associated with the three dimensional mapping means and with the tracking means, also intercepting and directed along said optical path means and having an angle of view, for obtaining data from the patient's tissue along said optical path means and for sending data to the microprocessor means of the imaging system, for generation of topographical information to the presented on the video display means.

28. The laser surgery system of claim 27, wherein the tracking means includes a electromagnetically driven turning mirror which affects the angle of view of the tracking and profilometer camera means and also the aim of the surgical microscope means and the laser beam, the electromagnetically driven mirror being under the control of signals generated by the microprocessor means of the imaging system to follow recognized features of the patient's tissues after movement of that tissue.

29. The laser surgery of claim 1, wherein the tracking means includes fast tracking means for tracking movements of the tissue at tracking closed loop response times of one millisecond or less.

30. The laser surgery system of claim 29, wherein the tracking means further includes backup slow tracking means for analyzing tissue position based on the three-dimensional topography of the tissue as determined, and for searching and finding, using the microprocessor means, a feature of the tissue when that feature is not found by the fast tracking means within a predetermined time and for shifting the optical path means to reposition the optical path means on the tissue feature.

31. The laser surgery system of claim 30, wherein the backup slow tracking means includes a video camera having a frame rate, and wherein the slow tracking means operates at tracking closed loop response times equal to the video camera frame rate.

32. A system for use in ophthalmic laser surgery, comprising,

a laser source for producing a pulsed visible light laser beam having a power capable of effecting a desired type of surgery at targeted tissue at a selected surgical site in the ocular tissues,

optical path means for delivering the laser beam, including beam directing means for controlling aim and depth of focus of the laser beam,

three dimensional mapping means for sensing locations, shapes and features on and in a patient's eye in three dimensions, and for generating data and signals representing such locations, shapes and features,

display means receiving signals from the three dimensional mapping means, for presenting to a surgeon user images representative of said locations, shapes and features of the eye including at depths in the eye selectable by the surgeon,

position analysis means associated with and receiving signals from the three dimensional mapping means, for recognizing the occurrence of changes of position of features of targeted tissue of the eye,

target tracking means associated with the position analysis means, for searching for a feature of targeted tissue and finding the feature's new position after such a change of position, and for generating a signal indicative of the new position of the targeted feature tissue, and

tracking positioning means for receiving said signal from the target tracking mean and for executing a change in the aim of the three dimensional mapping means to the new position of a targeted tissue feature to thereby follow the feature and stabilize the images on the display means, and for simultaneously and accordingly adjusting the aim of the laser beam to be directed at a new position of the targeted feature.

33. The system of claim 32, further including pre-programmed surgery execution means for automatically controlling timing of laser firing in conjunction with automatically controlling the beam directing means as to laser aim and depth of focal point in accordance with a preselected surgical path in three dimensions, to fully automatically execute a selected surgical procedure on the eye, and including tracking feedback means associated with the target tracking means and the surgery execution means, for sending signals to the pre-programmed surgery execution means to confirm that a feature's new position has been found, and to discontinue laser firing if such a confirming signal is not received by the surgery execution means within a preselected period of time.

34. The system of claim 32, wherein the display means is a video display monitor, and further including surgical microscope means positioned to intercept and to be coaxial with the optical path means, for taking video microscopic images of target areas of the ocular tissue and for feeding video image information to the video display monitor to cause such video microscopic images to be displayed, assisting the surgeon in the laser surgery.

35. The system of claim 32, further including surgeon control means connected to the beam directing means for enabling a surgeon user to control the aim and depth of focus of the laser beam.

36. A method for conducting laser surgery, comprising,

providing a system for imaging a patient's tissue in three dimensions, displaying images is selected formats on a display screen in front of a surgeon, delivering a visible light laser beam at the patient's tissue and firing the laser in accordance with a surgical path in three dimensions as selected by the surgeon directing the laser and for tracking the patient's tissue so as to stabilize images presented on the display screen and to essentially immobilize the subject target tissue on the display screen in spite of actual movements of the tissue,

placing a patient adjacent to the system,

under control of the surgeon, reviewing the patient's tissue at different locations and along different cross-sections by selection of desired images on the display screen,

under control of the surgeon, selecting a surgical path in three dimensions for surgery on the subject tissue and comprising a series of locations for targeting the focal point of and firing the laser beam to effect the surgery, and entering the precise surgical path as selected by the surgeon into a computer and memory of the system,

under control of the surgeon, initiating the firing of the laser along the programmed surgical path selected by the surgeon, and

automatically interrupting the surgery along the programmed surgical path whenever the tracking device of the system has failed to relocate a moved tissue feature within a pre-selected period of time.

37. The method of claim 36, further including the surgeon's surveying video microscopic images of the subject ocular tissue along with the other images displayed on the screen, as a guide to the surgeon in controlling the laser surgery, using a surgical microscope which views the patient's eye tissue at substantially the same region viewed by the three dimensional imaging system, with the system having means for presenting a video microscopic image of the subject targeted tissue on the display screen.

38. A method for conducting ophthalmic laser surgery using an imaging system which displays for the surgeon precise information as the location and configuration of features of the patient's eye and as to the aim and depth of focal point of a surgical laser beam, comprising,

generating with a laser source a visible light laser beam having a power capable of effecting a desired type of surgery in the eye,

delivering the laser beam along an optical path,

controlling aim and depth of focus of the laser beam with a beam directing means associated with the laser optical path,

sensing locations, shapes and features on and in a patient's eye in three dimensions with a three dimensional mapping means, and generating data and signals representing such locations, shapes and features,

presenting to a surgeon user images representative of said locations, shapes and features of the eye at the target site, on a display mans which receives signals from the three dimensional mapping means including images of cross sections of portions of the eye,

recognizing the occurrence of changes of position of features of the at the targeted site, with a position analysis means associated with and receiving signals from the three dimensional mapping means,

searching for a target site feature and finding the target site feature's new position after such a change of position ,and generating a signal indicative of the new position, with a target tracking means associated with the position analysis means, and

automatically executing a change in the aim of the three dimensional mapping means to the new position of the feature with a tracking positioning means receiving said signal from the target tracking means, to thereby follow the target site feature and stabilize the images on the display means, and simultaneously and accordingly adjusting automatically the aim and depth of the focus of the laser beam to be directed at the new position of a feature targeted.

39. The method of claim 38, further including the step of reviewing by the surgeon different cross-sections of the ocular tissues by manually selecting different formats to be presented on the display means.

40. The method of claim 38, further including monitoring the patient's tissue with a surgical microscope, and sending signals from the surgical microscope to the display means to present video display of greatly magnified images of the eye tissue, with the surgical microscope sharing a common optical path with the laser beam, including a final focussing lens, such that the video microscopic images displayed comprise a microscopic region at the same location and focal depth that the laser beam is directed.

41. The method of claim 40, including illuminating the patient's eye tissue at a low light level within a safe illumination level for human clinical procedures for said monitoring of the patient's tissue on the video display, the surgical microscope including an intensified video camera for imaging at low light levels at high magnification.

42. The method of claim 38, further including performing laser ophthalmic surgery automatically, in accordance with pre-programmed surgical paths in three dimensions, by selecting a software-based surgical path and initiating the program to automatically aim, focus and fire the laser sequentially at the preselected points establishing the surgical path.

43. The method of claim 42, further including automatically interrupting the aiming and firing of the laser along the pre-programmed path whenever the target tracking means fails to relocate a moved feature within a preselected period of time, thereby interrupting the execution of the pre-programmed surgery immediately when the ocular features subjected to the surgery become transposed an unsafe distance from the intended focal point of the laser beam.

44. The method of claim 42, wherein the system includes surgeon-controlled means for writing and editing pre-programmed surgical path templates, and the method including the surgeon's writing a pre-programmed surgical template before initiating the automatic execution of the surgery along the pre-programmed path.

Method and apparatus for precision laser surgery

Abstract

A system for effecting precision laser surgery includes an intensified surgical video microscope directed at the tissue to be operated upon and having zoom capability. The surgical microscope presents a microscopic image on a video screen in front of the surgeon. Preferably, the video screen is divided into multiple separate sections, with the microscopic video image in one section and precise cross sectional and plan views indicating location presented in the other sections of the screen. These additional views may be generated using Moire interferometry by projecting a Ronchi ruling on the surface of the tissue, in viewing the projection with a camera to obtain all necessary information for contour tracking of the subject surface. Interior elements and interfaces of, for example, the eye are also sensed by a light beam and precisely located and mapped by a computer forming a part of the device. The imaging system of the invention enables the surgeon to have before him abundant...

Patent number: 5098426
Filing date: Feb 6, 1989
Issue date: Mar 24, 1992
Inventors: H. Alfred Sklar, Alan M. Frank, Olga M. Ferrer, Charles F. McMillan, Stewart A. Brown, Fred Rienecker, Paul Harriss, Steven Schiffer
Assignee: Phoenix Laser Systems, Inc.

download



What is claimed is:

1. A system for use in ophthalmic diagnosis and analysis and for support of ophthalmic surgery, comprising,

three dimensional mapping means for sensing locations, shapes and features on and in a patient's eye in three dimensions, and for generating data and signals representing such locations, shapes and features,

display means receiving signals from the three dimensional mapping means, for presenting to a user images representative of said locations, shapes and features of the eye, at targeted locations including display control means for enabling a user to select the target location and to display a cross section of portions of the eye,

position analysis means associated with and receiving signals from the three dimensional mapping means, for recognizing the occurrence of changes of position of features of the eye,

target tracking means associated with the position analysis means, for searching for a feature of target tissue and finding said features new position after such a change of position, and for generating a signal indicative of the new position, and

tracking positioning means for receiving said signal from the target tracking means and for executing a change in the aim of the three dimensional mapping means to the new position of said feature of the target tissue, to thereby follow the feature and stabilize the images on the display means.

2. The system of claim 1, wherein the display means is a video display, and further including surgical microscope means directed at the patient's eye, for taking video microscopic images of target areas of the ocular tissue and for feeding video image information to the video display means to cause such video microscopic images to be displayed, assisting the user in diagnosis and analysis.

3. The system of claim 1, further including display control means for enabling the user to cause to be displayed on the display means different cross sections of the patient's tissue, as selected by the user.

4. The system of claim 1, wherein the tracking positioning means includes a turning mirror under automatic control, and the system including an objective lens assembly associated with the mapping means and having a final focussing lens, with the turning mirror positioned within the objective lens assembly and movable with respect to the final focussing lens.

5. An instrument and system for high precision ophthalmic laser surgery at a surgical site, comprising,

a laser pulsed source for producing a visible light laser beam having a power capable of effecting a desired type of surgery in an eye,

laser firing control means for enabling a surgeon/user to control the aim, depth, and timing of the firing of the laser to effect the desired surgery,

three dimensional mapping means directed at a patient's eye, for obtaining data representing the location and shapes of features on and inside the eye,

microprocessor means for receiving data from the three dimensional mapping means and for converting the data to a format presentable on a screen and useful to the surgeon/user in precisely locating features of the eye and the aim and depth of the laser beam within those features, and

display means for displaying microprocessor-generated images representing the topography of the eye and the aim and depth of the laser beam before the next pulse of the laser is fired to the surgeon/user in preparation for and during surgery, with display control means for enabling the surgeon/user to select areas of the eye for display, including images of cross sections of portions of the eye.

6. The instrument and system of claim 5, wherein the display means comprises a single video screen divided into multiple displays.

7. The instrument and system of claim 5, wherein the three dimensional mapping means, the microprocessor means, and the display means include means for presenting images to the surgeon/user indicating precise current location of laser aim and depth in computer generated views which comprise generally a plan view and selected cross sectional views of the eye representing features of the eye at different depths.

8. The instrument and system of claim 5, including an optical path with a focusing lens capable of controlling the focus of the laser beam on the eye tissue, and thus the depth at which the laser beam is effective, within about 5 microns, with depth control means for the surgeon to vary the focus of said lens to control the depth at which the laser beam is effective.

9. The instrument and system of claim 8, including system program means enabling the surgeon/user to pre-program a pattern of lesions in the ocular tissue along three axes in three dimensions and to activate the laser to follow the preselected pre-programmed path of surgery automatically.

10. The instrument and system of claim 5, further including tracking means for following movements of the eye during surgery and for following the movement of features at the surgical site of the eye with the three dimensional mapping means and with the laser, including means associated with the microprocessor for recognizing features at the surgical site after said features have moved and redirecting the three dimensional mapping system and the laser to the new location of said features.

11. The instrument and system of claim 10, wherein the display means includes a video monitor which has a frame rate and wherein the tracking means has the capability of following the features, identifying a new location of those features and re-presenting images of those features to the surgeon/user in a time period less than the frame rate of the video display means.

12. The instrument and system of claim 10, wherein the tracking means includes electromagnetically driven turning mirror means along an optical path of both the three dimensional mapping means and the laser beam, for shifting the aim of the three dimensional mapping means and a laser beam in response to the recognized to the recognized shift in position of the features of the eye.

13. The instrument and system of claim 10, wherein the display means comprises a video monitor which as a frame rate and the tracking means includes fast tracking means and backup slow tracking means with the backup slow tracking means including means for following the features at the surgical site, identifying a new location of said features and re-presenting images of said features to the surgeon/user in a time period at least as fast as the video frame rate, and the fast tracking means being capable of tracking movement of the tissue at much faster closed loop response times; and the backup slow tracking means having means for analyzing tissue position based on the three-dimensional topography of the tissue as determined, and for searching and finding, using the microprocessor means, a feature of the tissue when that feature is not found by the fast tracking means and for moving to the new position of the subject tissue feature and enabling the fast tracking means tore-commence fast tracking.

14. The instrument and system of claim 5, wherein the display means comprises a video display monitor, and further including surgical microscope means on a common optical path with the laser beam, for obtaining a greatly enlarged image of a small region of the eye at which the laser beam is directed and for generating a video image of that small region for presentation on the display means.

15. The instrument and system of claim 14, wherein the surgical microscope means includes intensified video camera means for imaging at low light levels at high magnification while remaining within safe illumination levels for human clinical procedures.

16. The instrument and system of claim 14, wherein the display means comprises a video screen divided to show the image from the surgical microscope means as well as topography information obtained from the three dimensional mapping means and generated by said microprocessor means.

17. The instrument and system of claim 14, further including eye illumination means also along the common optical path with the laser beam, the surgical microscope and the three dimensional mapping means.

18. The instrument and system of claim 14, further including optical zooming mean associated with the surgical microscope means, for forming an image of adjustable magnification range of not less than tenfold increased magnification, of said small region of the eye with optical elements located a considerable and comfortable distance from the patient.

19. The instrument and system of claim 18, wherein the optical path includes a final focusing lens at the exterior of the instrument, with the final focusing lens positioned at least 100 mm from the patient's eye.

20. A system for facilitating precisely controlled surgery using a focused laser beam, comprising,

user interface means for presenting information to a surgeon/user and for enabling control of the surgical procedure by the surgeon/user, including video display means for presenting precise information to the surgeon/user relating to the location in a patient's tissue at which the system is targeted, and the three-dimensional topography and contours of features of the subject tissue and including means for displaying images of cross sections of portions of the patient's tissue, and including means in the control of the surgeon/user for scanning across the tissue to change the information on the video display means as desired by the surgeon/user and for enabling control of the firing of a surgical laser beam by the surgeon/user,

an imaging system connected to the video display means, including three-dimensional mapping means for generating, reading, and interpreting data to obtain information regarding the location in three dimensions of significant features of the tissue to be operated upon, and including microprocessor means for interpreting the data and presenting the data to the video display means in a format useful to the surgeon/user,

a short pulse visible light laser power source for generating a laser beam capable of effecting the desired laser surgery in the patient's tissue, including within transparent tissue of the patient,

optical path means for receiving the laser beam and redirecting the laser beam and focusing it as appropriate toward a desired target in the tissue to be operated upon,

surgical microscope means positioned to intercept and to be coaxial with the optical path means, for taking surgical microscopic images of said target along the optical path means and for feeding video image information to the video display means, and

tracking means in the optical path means and associated with the microprocessor means, for tracking movements of the subject tissue at which the system is targeted without damaging the subject tissue before the next pulse of the laser is fired and shifting the optical path means accordingly before the next pulse of the laser is fired, such that information and images generated by the three dimensional mapping mans and by the surgical microscope means, as well as the aiming and position of the laser beam, follow changes in position of the tissue.

21. The laser surgical system of claim 1, further including first control interlock means for preventing firing of the surgical laser beam except when the tracking means is properly tracking movements of the subject tissue at which the system is targeted, by preventing the laser from firing a next pulse of energy unless the tracking means has tracked the subject tissue.

22. The laser surgical system of claim 1, further including means for superimposing program templates over images created by the imaging system, for automatically effecting a pre-selected pattern of laser surgery.

23. The laser surgical system of claim 1, wherein the imaging system includes scattered light detection means for detecting scattered light from the features of the tissue, with means for filtering out substantially all specularly-reflected light for the scattered light detection means.

24. The laser surgical system of claim 1, wherein the surgical microscope means includes an intensified video camera means for imaging at low light levels at high magnification while remaining within safe illumination levels for human clinical procedures.

25. The laser surgical system of claim 1, wherein the optical path means includes a final focussing lens with means for focussing the laser beam, the three dimensional mapping means and the surgical microscope means an appreciable and comfortable distance from the final focussing lens with respect to the patient, a distance of not less than about 50 mm.

26. The laser surgical system of claim 25, including an objective lens assembly of which the final focussing lens comprises a front element, and wherein the tracking means includes a turning mirror under automatic control of the microprocessor means, with the turning mirror positioned within the objective lens assembly and movable with respect to the final focussing lens.

27. The laser surgery system of claim 1, including tracking and profilometer camera means associated with the three dimensional mapping means and with the tracking means, also intercepting and directed along said optical path means and having an angle of view, for obtaining data from the patient's tissue along said optical path means and for sending data to the microprocessor means of the imaging system, for generation of topographical information to the presented on the video display means.

28. The laser surgery system of claim 27, wherein the tracking means includes a electromagnetically driven turning mirror which affects the angle of view of the tracking and profilometer camera means and also the aim of the surgical microscope means and the laser beam, the electromagnetically driven mirror being under the control of signals generated by the microprocessor means of the imaging system to follow recognized features of the patient's tissues after movement of that tissue.

29. The laser surgery of claim 1, wherein the tracking means includes fast tracking means for tracking movements of the tissue at tracking closed loop response times of one millisecond or less.

30. The laser surgery system of claim 29, wherein the tracking means further includes backup slow tracking means for analyzing tissue position based on the three-dimensional topography of the tissue as determined, and for searching and finding, using the microprocessor means, a feature of the tissue when that feature is not found by the fast tracking means within a predetermined time and for shifting the optical path means to reposition the optical path means on the tissue feature.

31. The laser surgery system of claim 30, wherein the backup slow tracking means includes a video camera having a frame rate, and wherein the slow tracking means operates at tracking closed loop response times equal to the video camera frame rate.

32. A system for use in ophthalmic laser surgery, comprising,

a laser source for producing a pulsed visible light laser beam having a power capable of effecting a desired type of surgery at targeted tissue at a selected surgical site in the ocular tissues,

optical path means for delivering the laser beam, including beam directing means for controlling aim and depth of focus of the laser beam,

three dimensional mapping means for sensing locations, shapes and features on and in a patient's eye in three dimensions, and for generating data and signals representing such locations, shapes and features,

display means receiving signals from the three dimensional mapping means, for presenting to a surgeon user images representative of said locations, shapes and features of the eye including at depths in the eye selectable by the surgeon,

position analysis means associated with and receiving signals from the three dimensional mapping means, for recognizing the occurrence of changes of position of features of targeted tissue of the eye,

target tracking means associated with the position analysis means, for searching for a feature of targeted tissue and finding the feature's new position after such a change of position, and for generating a signal indicative of the new position of the targeted feature tissue, and

tracking positioning means for receiving said signal from the target tracking mean and for executing a change in the aim of the three dimensional mapping means to the new position of a targeted tissue feature to thereby follow the feature and stabilize the images on the display means, and for simultaneously and accordingly adjusting the aim of the laser beam to be directed at a new position of the targeted feature.

33. The system of claim 32, further including pre-programmed surgery execution means for automatically controlling timing of laser firing in conjunction with automatically controlling the beam directing means as to laser aim and depth of focal point in accordance with a preselected surgical path in three dimensions, to fully automatically execute a selected surgical procedure on the eye, and including tracking feedback means associated with the target tracking means and the surgery execution means, for sending signals to the pre-programmed surgery execution means to confirm that a feature's new position has been found, and to discontinue laser firing if such a confirming signal is not received by the surgery execution means within a preselected period of time.

34. The system of claim 32, wherein the display means is a video display monitor, and further including surgical microscope means positioned to intercept and to be coaxial with the optical path means, for taking video microscopic images of target areas of the ocular tissue and for feeding video image information to the video display monitor to cause such video microscopic images to be displayed, assisting the surgeon in the laser surgery.

35. The system of claim 32, further including surgeon control means connected to the beam directing means for enabling a surgeon user to control the aim and depth of focus of the laser beam.

36. A method for conducting laser surgery, comprising,

providing a system for imaging a patient's tissue in three dimensions, displaying images is selected formats on a display screen in front of a surgeon, delivering a visible light laser beam at the patient's tissue and firing the laser in accordance with a surgical path in three dimensions as selected by the surgeon directing the laser and for tracking the patient's tissue so as to stabilize images presented on the display screen and to essentially immobilize the subject target tissue on the display screen in spite of actual movements of the tissue,

placing a patient adjacent to the system,

under control of the surgeon, reviewing the patient's tissue at different locations and along different cross-sections by selection of desired images on the display screen,

under control of the surgeon, selecting a surgical path in three dimensions for surgery on the subject tissue and comprising a series of locations for targeting the focal point of and firing the laser beam to effect the surgery, and entering the precise surgical path as selected by the surgeon into a computer and memory of the system,

under control of the surgeon, initiating the firing of the laser along the programmed surgical path selected by the surgeon, and

automatically interrupting the surgery along the programmed surgical path whenever the tracking device of the system has failed to relocate a moved tissue feature within a pre-selected period of time.

37. The method of claim 36, further including the surgeon's surveying video microscopic images of the subject ocular tissue along with the other images displayed on the screen, as a guide to the surgeon in controlling the laser surgery, using a surgical microscope which views the patient's eye tissue at substantially the same region viewed by the three dimensional imaging system, with the system having means for presenting a video microscopic image of the subject targeted tissue on the display screen.

38. A method for conducting ophthalmic laser surgery using an imaging system which displays for the surgeon precise information as the location and configuration of features of the patient's eye and as to the aim and depth of focal point of a surgical laser beam, comprising,

generating with a laser source a visible light laser beam having a power capable of effecting a desired type of surgery in the eye,

delivering the laser beam along an optical path,

controlling aim and depth of focus of the laser beam with a beam directing means associated with the laser optical path,

sensing locations, shapes and features on and in a patient's eye in three dimensions with a three dimensional mapping means, and generating data and signals representing such locations, shapes and features,

presenting to a surgeon user images representative of said locations, shapes and features of the eye at the target site, on a display mans which receives signals from the three dimensional mapping means including images of cross sections of portions of the eye,

recognizing the occurrence of changes of position of features of the at the targeted site, with a position analysis means associated with and receiving signals from the three dimensional mapping means,

searching for a target site feature and finding the target site feature's new position after such a change of position ,and generating a signal indicative of the new position, with a target tracking means associated with the position analysis means, and

automatically executing a change in the aim of the three dimensional mapping means to the new position of the feature with a tracking positioning means receiving said signal from the target tracking means, to thereby follow the target site feature and stabilize the images on the display means, and simultaneously and accordingly adjusting automatically the aim and depth of the focus of the laser beam to be directed at the new position of a feature targeted.

39. The method of claim 38, further including the step of reviewing by the surgeon different cross-sections of the ocular tissues by manually selecting different formats to be presented on the display means.

40. The method of claim 38, further including monitoring the patient's tissue with a surgical microscope, and sending signals from the surgical microscope to the display means to present video display of greatly magnified images of the eye tissue, with the surgical microscope sharing a common optical path with the laser beam, including a final focussing lens, such that the video microscopic images displayed comprise a microscopic region at the same location and focal depth that the laser beam is directed.

41. The method of claim 40, including illuminating the patient's eye tissue at a low light level within a safe illumination level for human clinical procedures for said monitoring of the patient's tissue on the video display, the surgical microscope including an intensified video camera for imaging at low light levels at high magnification.

42. The method of claim 38, further including performing laser ophthalmic surgery automatically, in accordance with pre-programmed surgical paths in three dimensions, by selecting a software-based surgical path and initiating the program to automatically aim, focus and fire the laser sequentially at the preselected points establishing the surgical path.

43. The method of claim 42, further including automatically interrupting the aiming and firing of the laser along the pre-programmed path whenever the target tracking means fails to relocate a moved feature within a preselected period of time, thereby interrupting the execution of the pre-programmed surgery immediately when the ocular features subjected to the surgery become transposed an unsafe distance from the intended focal point of the laser beam.

44. The method of claim 42, wherein the system includes surgeon-controlled means for writing and editing pre-programmed surgical path templates, and the method including the surgeon's writing a pre-programmed surgical template before initiating the automatic execution of the surgery along the pre-programmed path.