Abstract: A method is disclosed for photodisrupting a surface in the stroma of an eye at a substantially constant distance from the anterior surface of the eye. A frame of reference is established for the eye that includes an axis of rotation. Next, the focal point of a laser beam is positioned in the stroma at a radial distance from the axis. At least one laser pulse is delivered to the stromal tissue at the focal point, photodisrupting the tissue there and creating a photodisruption bubble having a diameter “d”. The focal point is then rotated about the axis through an arc length substantially equal to “d” and the photodisruption step is repeated. During rotation, the distance between the focal point and the axis is decreased at a rate substantially equal to the distance “d” per revolution. The method can be used to create a flap for a LASIK type procedure.

Abstract: A method and device for photoablation is disclosed wherein photoablation occurs along the interface between a material having a lower energy ablation threshold and a material having a higher energy ablation threshold. The method and device utilize a laser beam having a beam energy density which is less than the higher energy ablation threshold and greater than or equal to the lower energy ablation threshold. By directing such a laser beam to the interface, the material having the lower energy threshold is photoablated while the material having the higher energy threshold is largely unaffected.

Abstract: A system and method for dissecting a transparent material utilizes pre-dissection diagnostic information about the transparent material. Specifically, in the system and method, a prototypic dissection path is planned to achieve a desired result. Then, the topology of the transparent material is defined and analyzed to calculate a predicted result of a dissection along the prototypic dissection path. After comparing the desired result and the predicted result, a refined dissection path is established in which any difference between the predicted result of a dissection along the refined dissection path and the desired result is minimized. As a result, dissection of the transparent material along the refined dissection path achieves the desired result.

Abstract: A device for establishing a desired alignment between a patient's eye and a laser system to facilitate an engagement therebetween includes a light source to illuminate the eye. A moveable platform is provided to move the patient relative to the laser system. To establish alignment between the eye and the laser system, a reference marker is based on the laser system. An image of the marker, along with reflections from the illuminated eye, is then transmitted to the system controller. There, the image and reflections are processed to determine a measured alignment that is then compared to the desired alignment. An error signal that is indicative of an alignment difference is then generated and used to incrementally move the platform, or the patient, in an appropriate direction.

Abstract: A method for photodisrupting a preselected subsurface volume of corneal tissue to alter a cornea's refractive properties is disclosed. Specifically, at least one stromal volume having a substantially conical shaped surface is photodisrupted. For this purpose, a laser device having a laser source, laser scanner and one or more optical elements is typically used. In one embodiment, a plurality of stromal volumes, with each stromal volume having a substantially conical shaped surface, is sequentially photodisrupted to form a contiguous stromal cavity. In a particular implementation, each conical shaped surface defines a cone axis that is aligned to be co-linear with a reference axis that passes through the anterior surface of the eye and may be aligned orthogonally to the anterior surface of the eye.

Abstract: A system and method for performing laser induced optical breakdown (LIOB) in corneal tissue of an eye requires calculating a pattern of focal spots. LIOB is then induced at a first focal spot, and is continued at a plurality of interim focal spots within a time period ?. Each focal spot has a diameter “d1” and generates a temporal cavitation bubble of diameter “d2”. It then collapses within time “?” to a substantially stationary diameter “d3”, with (d1?d3?d2). Importantly, each focal spot is located more than “d2” from every other interim focal spot within the time period of “?”. At the time “?”, a second focal spot in the pattern can be generated at a distance “d3” from the first focal spot. This process is then continued with another plurality of interim focal spots being generated within another time period “?”.

Abstract: A system for performing a corneal transplantation includes a laser source for generating a laser beam and a chair for positioning a patient relative to the laser source. A stabilizing element, engageable with the laser source, is fixated on the anterior surface of the patient's cornea to hold the cornea in alignment with the laser source. The laser source is then used to remove diseased tissue from the cornea of the patient, thereby creating a corneal cavity of known dimensions. In a subsequent step, a donor graft that was previously photoaltered to have substantially the same dimensions as the corneal cavity, is transplanted into the corneal cavity.

Abstract: A method is disclosed for photodisrupting a surface in the stroma of an eye at a substantially constant distance from the anterior surface of the eye. A frame of reference is established for the eye that includes an axis of rotation. Next, the focal point of a laser beam is positioned in the stroma at a radial distance from the axis. At least one laser pulse is delivered to the stromal tissue at the focal point, photodisrupting the tissue there and creating a photodisruption bubble having a diameter “d”. The focal point is then rotated about the axis through an arc length substantially equal to “d” and the photodisruption step is repeated. During rotation, the distance between the focal point and the axis is decreased at a rate substantially equal to the distance “d” per revolution. The method can be used to create a flap for a LASIK type procedure.

Abstract: A device and method for steering a laser beam to a focal point in target tissue requires generating a laser beam. Diversions of the laser beam from a central beam path are minimized by a sequential arrangement of optical steering components. In order, the beam is first directed to the center of a z-scanning apparatus which will move the focal point in the medium in a z-direction. The beam is then passed to the center of a first galvanometric mirror which introduces focal point movements in the x-direction. A second galvanometric mirror then compensates for the x-direction movement by redirecting the beam to the center of a third galvanometric mirror where focal point movements in the y-direction are introduced.

Abstract: A system for positioning the eye of a patient, relative to a stationary surgical laser unit, includes a chair for moving the patient. An eye stabilizing element is held against the eye, with a tapered receptacle extending outwardly therefrom. Also, an alignment device with a tapered tip is mounted on the surgical laser unit. In operation, the patient is moved to engage the receptacle of the eye stabilizing element with the tip of the alignment device, to thereby align the patient's eye with the surgical laser unit for laser surgery.

Abstract: A system for accurately guiding a laser focal point along a predetermined path within the stroma of a cornea includes a contact lens for conforming the anterior surface of the cornea to a radius of curvature, Rlens, that is approximately 8.3 mm. Conforming the cornea to the lens causes minimal discomfort to the patient and does not upset the three-dimensional architecture of the corneal lamellae. As the focal point is advanced along a path within the cornea, the laser source is selectively translated parallel to the optical axis of the cornea to control the depth of the laser focal point. The movement includes three components: a first component, z1 that is dependent upon the shape of the contact lens, a second component, z2 that compensates for refraction at the surfaces of the contact lens, and a third component, z3, that compensates for refraction caused by the anatomical configuration of the cornea.

Abstract: A system for accurately guiding a laser focal point along a predetermined path within the stroma of a cornea includes a contact lens for conforming the anterior surface of the cornea to a radius of curvature, Rlens, that is approximately 8.3 mm. Conforming the cornea to the lens causes minimal discomfort to the patient and does not upset the three-dimensional architecture of the corneal lamellae. As the focal point is advanced along a path within the cornea, the laser source is selectively translated parallel to the optical axis of the cornea to control the depth of the laser focal point. The movement includes three components: a first component, z1 that is dependent upon the shape of the contact lens, a second component, z2 that compensates for refraction at the surfaces of the contact lens, and a third component, z3, that compensates for refraction caused by the anatomical configuration of the cornea.

Abstract: A device and method for increasing the accuracy of an ocular laser procedure by detecting and compensating for small eye movements includes the establishment of a corneal reference plane. To create the corneal reference plane, a laser beam is first used to photoablate stromal tissue at three different locations in the cornea. Bubbles that are created upon photoablation define the plane and can be imaged to determine the position of the plane as the eye moves. A pair of cameras and a processor are provided to image the cornea and triangulate the position of the reference plane. The updated position of the corneal reference plane is then used to guide the path of the laser beam during the course of the ocular procedure.

Abstract: A device and method for increasing the accuracy of an ocular laser procedure by detecting and compensating for small eye movements includes the establishment of a corneal reference plane. To create the corneal reference plane, a laser beam is first used to photoablate stromal tissue at three different locations in the cornea. Bubbles that are created upon photoablation define the plane and can be imaged to determine the position of the plane as the eye moves. A pair of cameras and a processor are provided to image the cornea and triangulate the position of the reference plane. The updated position of the corneal reference plane is then used to guide the path of the laser beam during the course of the ocular procedure.

Abstract: A device and method for establishing an aberration-free delivery system for use in evaluating an optical specimen includes a light source for directing light through the system and along a beam path toward the specimen. A first beam splitter is positioned on the beam path to direct light radiated from the system toward a detector for creation of a first wavefront, and for generation of a signal. In turn, the signal is used to program an active mirror that is also positioned on the beam path, to thereafter establish an aberration-free wavefront for light incident on the optical specimen. Further, a second beam splitter is positioned on the beam path for directing light reflected from the specimen toward the detector for the creation of a second wavefront having characteristics of optical aberrations in the specimen. The second wavefront is then used to further program the active mirror for analysis and evaluation of the optical specimen.

Abstract: A system for precompensating the refractive properties of an eye includes optical components for directing a beam of light through the eye for reflection from the retina. The reflected beam, which includes the refractive aberrations caused by the eye, is then separated into a plurality of individual beams by a lenslet. The plurality of individual beams are then collectively analyzed by a computer to establish an acuity map for the eye. Next, the acuity map is reversed by the computer to generate a negative acuity map, and this negative acuity map is then used to electronically configure the reflective surface of an active mirror in accordance with the negative acuity map. Subsequently, incoming light from a stimulus is reflected from the active mirror, and is thereby precompensated before reaching the eye as an undistorted light beam. It is contemplated by the present invention that a time history of the various active mirror configurations that are required by an eye can be used for diagnostic purposes.

Abstract: A system, and its method, for measuring the optical properties of an eye employs optical components for detecting both the reflection of a first light beam from the anterior surface of the eye, and the reflection of a second light beam from the retina of the eye. Sensors are included to receive and separate each of these reflected light beams into a plurality of individual beams, each having its own specific optical path length. The optical path lengths of individual beams reflected from the cornea are collectively used to create a topographical map of the cornea's anterior surface and the optical path lengths of individual beams reflected from the retina are collectively used to create an acuity map of the entire eye. Further, there are additional optical components which respectively determine the position of the eye, a length for the eye and an aberration for the relaxed lens of the eye.