JP2015037473A - Ophthalmic laser surgery device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ophthalmic laser surgery device in which convergence position of a pulse laser beam can be adequately scanned in a simpler structure.SOLUTION: An ophthalmic laser surgery device 1 condenses a pulse laser beam on a tissue of a patient eye E to treat the patient eye E. The ophthalmic laser surgery device 1 comprises: an XY scan unit 25; an objective lens 35; and a Z scan unit 44. The XY scan unit 25 scans the pulse laser beam emitted from a laser source 10 in an XY direction. The objective lens 35 condenses the pulse laser beam via the XY scan unit 25. The Z scan unit 44 moves at least one part of the XY scan unit 25 along an optical axis so that convergence position of the pulse laser beam is scanned in a Z direction along the optical axis.

Description

  The present invention relates to an ophthalmic laser surgical apparatus for treating a patient's eye by condensing pulsed laser light onto a patient's eye tissue.

  Conventionally, various techniques have been proposed to focus pulse laser light on a three-dimensional target position in a patient's eye. For example, an ophthalmic laser surgical apparatus disclosed in Patent Document 1 includes an XY scanning unit and an expander. The XY scanning unit scans the laser beam condensing position (laser spot) on an XY plane orthogonal to the optical axis. The expander is disposed on the upstream side of the XY scanning unit, and moves the condensing position of the laser light along the Z direction.

JP 2013-78399 A

  In order to perform a precise treatment, it is desirable for an ophthalmic laser surgical apparatus to perform a three-dimensional scanning with high accuracy on a focused position of pulsed laser light. However, there are various restrictions in order to improve the scanning capability of the condensing position while simplifying the configuration of the ophthalmic laser surgical apparatus. In the conventional ophthalmic laser surgical apparatus, it is difficult to appropriately scan the condensing position of the pulse laser beam with a simpler configuration.

  It is a typical object of the present invention to provide an ophthalmic laser surgical apparatus capable of appropriately scanning the condensing position of pulse laser light with a simpler configuration.

  An ophthalmic laser surgical apparatus of the present invention is an ophthalmic laser surgical apparatus for treating a patient's eye by condensing a pulsed laser beam in a tissue of a patient's eye, wherein the pulsed laser beam emitted from a laser light source is An XY scanning unit that scans in a direction that intersects the optical axis, and an objective lens that is arranged on the downstream side of the optical path of the pulsed laser light with respect to the XY scanning unit and collects the pulsed laser light that has passed through the XY scanning unit, A Z-scanning unit that scans the condensing position of the pulsed laser light in the Z direction along the optical axis by moving at least a part of the XY scanning unit along the optical axis.

  The ophthalmic laser surgical apparatus of the present invention can appropriately scan the condensing position of the pulse laser beam with a simpler configuration.

It is a figure which shows the structure of the ophthalmic laser surgery apparatus 1 of 1st embodiment. It is a figure which shows the structure of the XY scanning part 25 in 1st embodiment. It is explanatory drawing for demonstrating the structure of the Y scanning part 27 and upstream relay optical element 31 in 1st embodiment. It is a figure which shows the structure of the ophthalmic laser surgery apparatus 2 of 2nd embodiment.

<First embodiment>
Hereinafter, a first embodiment which is one of typical embodiments of the present invention will be described with reference to FIGS. 1 to 3. In this embodiment, an ophthalmic laser surgical apparatus 1 capable of treating both the cornea and the lens of the patient's eye E is illustrated. “Treatment” indicates that the tissue of the patient's eye E is cut or broken. Hereinafter, for each configuration of the ophthalmic laser surgical apparatus 1 according to the first embodiment, from the laser light source 10 side (that is, the upstream side of the optical path of the pulse laser beam) to the patient eye E side (that is, downstream of the optical path of the pulse laser beam). Side).

  The laser light source 10 emits pulsed laser light. In the present embodiment, when the pulsed laser light emitted from the laser light source 10 is condensed in the tissue of the patient's eye E, plasma is generated at the condensing position, and the tissue is cut and fractured. The above phenomenon is sometimes referred to as photodisruption. As the laser light source 10, for example, a device that emits pulsed laser light having a pulse width on the order of femtoseconds to picoseconds can be used. Hereinafter, the direction along the optical axis of the pulsed laser light emitted from the laser light source 10 is defined as the Z direction. One of the directions intersecting the Z direction (vertically intersecting in the present embodiment) is defined as the X direction. A direction that intersects both the Z direction and the X direction (vertically intersects in this embodiment) is defined as a Y direction. The X, Y, and Z directions may be set as appropriate. For example, when the direction is defined based on the patient's up / down / left / right direction, the X direction may be the patient's left / right direction, the Y direction may be the patient's up / down direction, It is good.

  The aiming light source 11 emits aiming light indicating a position to which the pulse laser light is irradiated. In the present embodiment, a light source that emits visible laser light is used as the aiming light source 11. The aiming light source 11 may be omitted.

  The dichroic mirror 12 is provided between a laser light source 10 and a zoom expander 13 (described later) in an optical path of pulsed laser light (hereinafter sometimes simply referred to as “optical path”). The dichroic mirror 12 combines the laser light emitted from the laser light source 10 and the aiming light emitted from the aiming light source 11. Specifically, the dichroic mirror 12 according to the present embodiment transmits most of the laser light emitted from the laser light source 10 and reflects most of the aiming light emitted from the aiming light source 11, thereby 2 Two lights are combined.

  The zoom expander 13 is provided between the laser light source 10 and the XY scanning unit 25 (described later) in the optical path. Specifically, in this embodiment, a beam expander 13 is provided between the laser light source 10 and the high-speed Z scanning unit 15 (described later). The zoom expander 13 can change the beam diameter of the pulsed laser light emitted from the laser light source 10. The control unit (not shown) of the ophthalmic laser surgical apparatus 1 drives the zoom expander 13 to change the beam diameter of the pulsed laser light, so that the objective lens 35 (described later) is directed toward the patient's eye E. The numerical aperture NA of the emitted pulsed laser beam can be adjusted. The numerical aperture NA increases as the beam diameter increases, and the numerical aperture NA decreases as the beam diameter decreases.

  The ophthalmic laser surgical apparatus 1 can improve the treatment capability when treating the patient's eye E by adjusting the numerical aperture NA. For example, the larger the numerical aperture NA, the smaller the spot size at the focused position of the pulse laser beam. In corneal surgery, it is often required to perform a precise treatment by increasing the accuracy of the focused position of pulsed laser light. On the other hand, in crystalline lens surgery, it may be required to increase the spot size to shorten the operation time. Therefore, the ophthalmic laser surgical apparatus 1 according to the present embodiment may increase the numerical aperture NA and reduce the spot size in the corneal surgery mode compared to the lens surgery mode. In the mode in which the lens operation is performed, the numerical aperture NA may be decreased to increase the spot size. In this case, the ophthalmic laser surgical apparatus 1 can perform more appropriate treatment according to the site of the patient's eye E. In addition, the adjustment method of numerical aperture NA can be changed suitably. For example, the ophthalmic laser surgical apparatus 1 may change the numerical aperture NA continuously or intermittently according to scanning in the Z direction of the condensing position. In this case, the ophthalmic laser surgical apparatus 1 can cause an appropriate optical destruction in the tissue in accordance with the depth of the condensing position in the Z direction.

  The high-speed Z scanning unit 15 (second Z scanning unit: an expander in the present embodiment) is disposed between the laser light source 10 and the XY scanning unit 25 in the optical path (specifically, the zoom expander 13 and the XY scanning in the first embodiment). Between the portions 25). The high-speed Z scanning unit 15 of this embodiment includes an optical element 16 having negative refractive power and a high-speed Z scanning drive unit 17 that moves the optical element 16 along the optical axis. A lens 21 is provided between the optical element 16 and the XY scanning unit 25. The lens 21 guides the laser light that has passed through the high-speed Z scanning unit 15 to the XY scanning unit 25.

  When the optical element 16 disposed on the optical path moves along the optical axis, the focused position of the pulsed laser light moves in the Z direction. Therefore, the control unit of the ophthalmic laser surgical apparatus 1 can scan the condensing position in the Z direction by driving and controlling the high-speed Z scanning driving unit 17 to move the optical element 16. In addition, the high-speed Z scanning unit 15 of the present embodiment can scan the condensing position in the Z direction at a higher speed than the Z scanning unit 44 (described later). Therefore, the control unit can finely adjust the light collection position in the Z direction by using the high-speed Z scanning unit 15. For example, the control unit may improve the light collection accuracy by driving the high-speed Z control unit 15 according to the inclination of the patient's eye E. Further, by driving the high-speed Z control unit 15 in accordance with the scanning in the XY direction by the XY scanning unit 25, an error in the condensing position in the Z direction caused by the scanning in the XY direction may be reduced. .

  The XY scanning unit 25 scans the pulse laser beam on the XY plane intersecting the optical axis. In the present embodiment, the XY scanning unit 25 includes an X scanning unit 26 and a Y scanning unit 27. The X scanning unit 26 scans the pulsed laser light emitted from the laser light source 10 in the X direction. The Y scanning unit 27 further scans the pulse laser beam scanned in the X direction by the X scanning unit 26 in the Y direction. In the present embodiment, galvanometer mirrors are employed for both the X scanning unit 26 and the Y scanning unit 27. However, other devices that scan light (for example, a polygon mirror, an acoustooptic device (AOM), etc.) may be employed in at least one of the X scanning unit 26 and the Y scanning unit 27.

  With reference to FIG. 2, the structure of the XY scanning part 25 in 1st embodiment is demonstrated in detail. In the first embodiment, as an example, an XY scanning unit 25 using three galvanometer mirrors is employed. Specifically, the X scanning unit 26 of the first embodiment includes a first X scanning unit 28 and a second X scanning unit 29. The first X scanning unit 28 scans the pulse laser beam incident from the upstream side of the optical path (lens 21 in the present embodiment) in the X direction. The rotation axis of the second X scanning unit 29 is parallel to the rotation axis of the first X scanning unit 28. The second X scanning unit 29 further scans the pulse laser beam scanned in the X direction by the first X scanning unit 28 in the X direction. As shown in FIG. 2, the control unit controls the scanning amount of the second X scanning unit 29 in accordance with the scanning amount of the first X scanning unit 28, so that a predetermined portion of the Y scanning unit 27 (in this embodiment, A pulse laser beam is made incident on the center of the scanning surface of the mirror. That is, the principal ray of the pulsed laser light is incident on a predetermined portion of the Y scanning unit 27 regardless of the scanning amount in the X direction. Therefore, the ophthalmic laser surgical apparatus 1 can eliminate various effects caused by changes in the incident position of the pulse laser beam in the Y scanning unit 27. In the first embodiment, the center of the scanning surface of the Y scanning unit 27 is a pivot point through which the principal rays of all the pulsed laser beams scanned by the XY scanning unit 25 pass.

  As shown in FIG. 1, the relay unit 30 is provided between the XY scanning unit 25 and the objective lens 35. The relay unit 30 of this embodiment is a Keplerian relay optical system. Even when the Kepler-type relay optical system is constituted by three or more optical members, the function can be expressed by two lenses. Therefore, in FIG. 1, the relay part 30 is shown by two lenses. The Kepler-type relay optical system described below is also illustrated with two lenses. The relay unit 30 includes a pivot point in the XY scanning unit 25 (in the first embodiment, a pivot point P at the center of the scanning surface in the Y scanning unit 27) by an upstream relay optical element 31 and a downstream relay optical element 32. An object side focal point of an objective lens 35 (described later) is connected in a conjugate relationship.

  In addition, as shown in FIG. 3, the positional relationship between the upstream relay optical element 31 and the XY scanning unit 25 so that the object-side focal point of the upstream relay optical element 31 coincides with the pivot point P in the XY scanning unit 25. Is maintained. That is, the distance between the upstream relay optical element 31 and the pivot point P matches the focal length f31 of the upstream relay optical element 31. Therefore, the telecentric performance of the pulse laser beam emitted from the upstream relay optical element 31 is maintained.

  The objective lens 35 is disposed on the downstream side of the optical path from the downstream relay optical element 32 of the relay unit 30. In other words, the main plane of the objective lens 35 is located downstream of the main plane of the downstream relay optical element 32 in the optical path. The pulsed laser light that has passed through the objective lens 35 is focused on the tissue of the patient's eye E through the eyeball fixing interface 37. Although not shown in detail, the eyeball fixing interface 37 has a suction ring and a cup. A negative pressure is applied to the suction ring by a suction pump or the like. As a result, the anterior segment of the patient's eye E is sucked and fixed by the suction ring. The cup covers the anterior eye area. At the time of surgery, the cup is filled with a liquid having a refractive index comparable to that of the cornea. Therefore, the refraction of the pulse laser beam by the cornea or the like is weakened, and the accuracy of the condensing position is improved. Needless to say, the configuration of the eyeball fixing interface 37 may be changed as appropriate. A contact lens or the like may be attached to the patient's eye E. Surgery by the ophthalmic laser surgical apparatus 1 can be performed without using the eyeball fixing interface 37 or the like.

  A dichroic mirror 38 is provided between the objective lens 35 and the downstream relay optical element 32 in the optical path. In the present embodiment, the dichroic mirror 38 reflects most of the pulsed laser light from the laser light source 10 and the aiming light from the aiming light source 12, and large amounts of light from the observation unit 40 and the OCT unit 41 described later. Transparent part. As a result, the optical axes of the plurality of lights are coaxial. In addition, when making the optical axis of the light of the observation unit 40 and the OCT unit 41 coaxial with the optical axis of pulsed laser light, it is also possible to change the coaxial position.

  In the first embodiment, among the optical elements positioned on the upstream side of the objective lens 35 in the optical path, the optical element closest to the objective lens 35 and having a refractive power (hereinafter referred to as “upstream element of the objective lens 35”). ) Is a downstream relay optical element 32 of the relay unit 30. In the first embodiment, the distance between the main plane in the upstream element of the objective lens 35 and the main plane in the objective lens 35 is the focal length of the upstream element of the objective lens 35 and the focal length of the objective lens 35. Is equal to the sum of That is, the image side focal point of the downstream relay optical element 32 coincides with the object side focal point of the objective lens 35. In the present embodiment, the positions of the downstream relay optical element 32 and the objective lens 35 on the optical path are fixed.

  Further, as described above, in the first embodiment, the pivot point P in the XY scanning unit 25 and the object side focal point of the objective lens 35 are in a conjugate relationship by the relay unit 30. Accordingly, the principal rays of all the pulsed laser beams scanned by the XY scanning unit 25 pass through the object side focal point of the objective lens 35. In the present embodiment, the dichroic mirror 38 is provided at the object-side focal position of the objective lens 35 (that is, the image-side focal position of the downstream relay optical element 32).

  The focal length for defining the object side focal point of the objective lens 35 may be the focal length of only the objective lens 35, or the focal length of an optical element including the objective lens 35 and the eyeball fixing interface 37. It may be. The same applies to the case where the main plane of the objective lens 35 is considered. That is, the expression “objective lens” in the present invention may refer to an optical element including the eyeball fixing interface 37.

  The observation unit 40 acquires a front image of the patient's eye E. The observation unit 40 of the present embodiment can capture the patient's eye E illuminated by visible light or infrared light and display it on a monitor (not shown). The surgeon can observe the patient's eye E from the front by looking at the monitor.

  The OCT unit 41 acquires a tomographic image of the tissue of the patient eye E. As an example, the OCT unit 41 of the present embodiment includes a light source, a light splitter, a reference optical system, a scanning unit, and a detector. The light source emits light for acquiring a tomographic image. The light splitter divides the light emitted from the light source into reference light and measurement light. The reference light enters the reference optical system, and the measurement light enters the scanning unit. The reference optical system has a configuration that changes the optical path length difference between the measurement light and the reference light. The scanning unit scans the measurement light in a two-dimensional direction on the tissue. The detector detects an interference state between the measurement light reflected by the tissue and the reference light that has passed through the reference optical system. The ophthalmic laser surgical apparatus 1 scans the measurement light and detects the interference state between the reflected measurement light and the interference light to acquire information in the depth direction of the tissue. A tomographic image of the tissue is acquired based on the acquired information in the depth direction. The ophthalmic laser surgical apparatus 1 according to the present embodiment associates a target position on which pulsed laser light is collected with a tomographic image of the patient's eye E. As a result, the ophthalmic laser surgical apparatus 1 can create data for controlling the operation of irradiating and scanning the pulsed laser beam using the tomographic image. Various configurations can be used for the OCT unit 41. For example, any of SS-OCT, SD-OCT, TD-OCT, etc. may be adopted as the OCT unit 41. The ophthalmic laser surgical apparatus 1 may capture a tomographic image using a technique other than optical interference. When the target position can be determined without using the tomographic image (for example, when only the applanated cornea is treated), the OCT unit 41 may be omitted.

  The dichroic mirror 42 is coaxial with the optical axis of the observation unit 40 and the optical axis of the OCT unit 41. The light that has passed through the dichroic mirror 42 is made coaxial with the pulse laser light from the laser light source 10 by the dichroic mirror 38 described above.

  The Z scanning unit 44 moves at least part or all of the XY scanning unit 25 along the optical axis. As a result, the focused position of the pulse laser beam is scanned in the Z direction along the optical axis. That is, the Z scanning unit 44 receives the pulse laser beam from the laser light source 10 and scans the condensing position of the received pulse laser beam in the Z direction. In the first embodiment, the Z scanning unit 44 includes an optical unit including the XY scanning unit 25 (the X scanning unit 26 and the Y scanning unit 27) and the upstream relay optical element 31 of the relay unit 30 along the optical axis. To move. More specifically, the Z scanning unit 44 of the first embodiment moves the high-speed Z scanning unit 15 and the lens 21 along the optical axis together with the XY scanning unit 25 and the upstream relay optical element 31.

  As described above, the ophthalmic laser surgical apparatus 1 according to the first embodiment moves the pulse laser by moving at least a part or all of the XY scanning unit 25 (all in the first embodiment) along the optical axis. The light condensing position is scanned in the Z direction. Specifically, the Z scanning unit 44 of the first embodiment includes at least part or all of the XY scanning unit 25 and an optical element having refractive power (the upstream relay optical element 31 in the first embodiment). Move along the optical axis. The optical element forms a laser beam waist image at a finite distance. In other words, the optical element forms a conjugate point of the condensing position formed by the objective lens 35. The ophthalmic laser surgical apparatus 1 according to the first embodiment can appropriately scan the condensing position of the pulse laser beam with a simpler configuration. Hereinafter, the details of the advantages when the optical system of the ophthalmic laser surgical apparatus 1 according to the present embodiment is employed will be described with several examples.

  For example, instead of using the Z scanning unit 44 in the first embodiment, by moving an optical member (for example, an expander on the upstream side of the XY scanning unit 25) in the optical axis direction, the light collection position is moved in the Z direction. It is also possible to scan. In this case, the amount of movement of the condensing position in the Z direction with respect to the amount of movement of the optical member is affected by the optical system arranged on the downstream side of the optical member to be moved. As a result, if the optical member is not moved greatly, there may be a case where a sufficient amount of movement of the condensing position cannot be ensured.

  The above problem will be described based on an example in which FIG. 1 is modified. In the first embodiment shown in FIG. 1, it is assumed that scanning in all Z directions is executed only by the high-speed Z scanning unit 15 without using the Z scanning unit 44. First, when the focal length of the upstream relay optical element 31 is f31 and the focal length of the downstream relay optical element 32 is f32, the lateral magnification of the relay unit 30 on the downstream side of the XY scanning unit 25 is “f32 / f31”. expressed. Here, in general, in order to set the numerical aperture NA of the pulsed laser light emitted from the objective lens 35 to an appropriate value and to keep the distance between the objective lens 35 and the patient's eye E at an appropriate distance, the objective lens 35 is used. It is necessary to increase the focal length to some extent. On the other hand, since the XY scanning unit 25 needs to be driven at high speed, the mirror diameter of the galvanometer mirror used in the XY scanning unit 25 is often very small compared to the entrance pupil diameter of the objective lens 35. As a result, the lateral magnification “f32 / f31” of the relay unit 30 tends to be a large value. When scanning in all Z directions is performed only by the high speed Z scanning unit 15, the amount of movement of the high speed Z scanning unit 15 required to move the focal position in the Z direction by a unit distance is the vertical magnification ( Proportional to the square of the lateral magnification). Therefore, it is difficult to reduce the amount of movement of the high-speed Z scanning unit 15 due to restrictions on the relay unit 30. Similarly, the restriction of the optical element upstream of the XY scanning unit 25 can also affect the reduction of the movement amount of the high-speed Z scanning unit 15.

  It is also conceivable to reduce the amount of movement of the optical member by moving the optical member downstream of the XY scanning unit 25 (for example, the downstream relay optical element 32 or the objective lens 35) along the optical axis. . However, in this case, the Z scanning unit needs to appropriately scan the pulse laser beam scanned off-axis by the XY scanning unit 25, and the design of the Z scanning unit may be complicated. Further, when the Z-direction scanning is performed by moving the objective lens 35 and the like, the aberration tends to increase with the Z-direction scanning. As a result, problems such as complicated design of the optical system may occur. Further, when the objective lens 35 is moved, it is necessary to design the eyeball fixing interface 37 so that the objective lens 35 can be moved.

  On the other hand, the ophthalmic laser surgical apparatus 1 according to the first embodiment moves at least a part or the whole (all in the first embodiment) of the XY scanning unit 25 along the optical axis, thereby The condensing position is scanned in the Z direction. Therefore, the influence of the optical system positioned downstream of the Z scanning unit 44 is reduced as compared with the case where scanning in the Z direction is performed upstream of the XY scanning unit 25. Compared to the case where scanning in the Z direction is performed upstream of the XY scanning unit 25, the size of the XY scanning unit 25 can be easily reduced. In addition, unlike the case of scanning in the Z direction downstream from the XY scanning unit 25, it is unlikely that a design for appropriately scanning the pulse laser beam scanned in the XY direction in the Z direction is likely to occur. . Therefore, the ophthalmic laser surgical apparatus 1 according to the first embodiment can appropriately scan the condensing position of the pulse laser beam with a simpler configuration.

  The ophthalmic laser surgical apparatus 1 according to the first embodiment includes an output optical element (upstream relay optical element 31 in the first embodiment) that emits pulsed laser light to the outside of the Z scanning unit 44, at least in the XY scanning unit 25. Move along the optical axis together with a part. That is, in the first embodiment, the positional relationship between the XY scanning unit 25 and the upstream relay optical element 31 is fixed even when scanning in the Z direction is performed at least while the tissue is irradiated with the pulse laser beam. Has been. Therefore, the scanning control of the condensing position is easy. Further, the object side focal point of the output optical element coincides with the pivot point in the XY scanning unit 25. In this case, even if the focal position is scanned in the Z direction by the Z scanning unit 44, the telecentric performance of the pulse laser beam emitted from the emission optical element of the Z scanning unit 44 is maintained. Furthermore, in the first embodiment, the position of the objective lens 35 and the like on the optical path is fixed. As a result, the emission angle of the pulsed laser light from the objective lens 35 is constant regardless of scanning in the Z direction. Therefore, the scanning control of the condensing position is further facilitated. For example, the control when the pulse laser beam is scanned off-axis becomes easy. Control of the irradiation position of pulsed laser light based on the OCT image (for example, creation of control data for controlling the XY scanning unit 25 and the Z scanning unit 44) is also facilitated.

  Furthermore, in the first embodiment, the principal rays of all the pulsed laser beams scanned by the XY scanning unit 25 pass through the object side focal point of the objective lens 35. In this case, the image-side telecentric performance of the objective lens 35 is maintained even when the condensing position is scanned in the Z direction. In other words, the emission angle of the pulse laser beam emitted from the objective lens 35 toward the patient's eye E is kept parallel. Therefore, the scanning control of the condensing position is further facilitated.

  In the first embodiment, the distance between the main plane of the downstream relay optical element 32 and the main plane of the objective lens 35 in the relay unit 30 is equal to the sum of the focal lengths. In this case, the numerical aperture NA of the pulsed laser light emitted from the objective lens 35 is maintained regardless of the Z scanning performed by the Z scanning unit 44. Therefore, the scanning control of the condensing position is further facilitated. For example, ignoring the influence of aberration, by making the numerical aperture NA constant, the spot size becomes constant regardless of the scanning amount in the Z direction.

  The ophthalmic laser surgical apparatus 1 according to the first embodiment moves an optical unit including the XY scanning unit 25 and the upstream relay optical element 31 in the relay unit 30 along the optical axis. In this case, the XY scanning unit 25 can be realized without providing a relay unit between the X scanning unit 26 and the Y scanning unit 27. If a relay unit is not provided between the X scanning unit 26 and the Y scanning unit 27, the configuration is simplified and the influence of aberration is reduced as compared with the case where a relay unit is provided.

  In the first embodiment, the XY scanning unit 25 includes a first X scanning unit 28, a second X scanning unit 29, and a Y scanning unit 27. The pulse laser beam scanned in the X direction by the first X scanning unit 28 and the second X scanning unit 29 enters a predetermined portion of the Y scanning unit 27. In this case, scanning in the Y direction is performed at a predetermined position of the Y scanning unit 27 regardless of the scanning amount in the X direction. Therefore, the scanning accuracy of the condensing position is further improved.

  In the first embodiment, a high-speed Z scanning unit (second Z scanning unit) 15 is provided between the laser light source 10 and the XY scanning unit 25 in the optical path. By providing a plurality of Z scanning units, the accuracy of treatment is improved. As an example, the high-speed Z scanning unit 15 of the present embodiment scans the focused position of the pulse laser light in the Z direction at a higher speed than the Z scanning unit 44. In this case, the ophthalmic laser surgical apparatus 1 performs various elements (for example, at least one of inclination of the eyeball, curvature of field due to scanning in the XY directions, and the like) while the treatment with the pulse laser beam is performed. Accordingly, the condensing position can be scanned in the Z direction at high speed.

  In the first embodiment, the zoom expander 13 is provided between the laser light source 10 and the XY scanning unit 25 in the optical path. The zoom expander 13 changes the beam diameter of the pulse laser beam. In this case, the ophthalmic laser surgical apparatus 1 can adjust the numerical aperture NA of the pulsed laser light emitted from the objective lens 35 by changing the beam diameter with the zoom expander 13. Since the zoom expander 13 of this embodiment is disposed upstream of the XY scanning unit 25, it is not necessary to deal with pulsed laser light scanned off-axis.

<Second embodiment>
A second embodiment which is one of typical embodiments different from the first embodiment will be described with reference to FIG. In the second embodiment, the configurations of the XY scanning unit 55 and the Z scanning unit 66 are different from those of the first embodiment, but there are also configurations that are common to the first embodiment. Therefore, in the following, the same configurations as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and description thereof is omitted or simplified. Similarly to the first embodiment, the second embodiment exemplifies an ophthalmic laser surgical apparatus 2 that can treat both the cornea and the crystalline lens of the patient's eye E.

  The ophthalmic laser surgical apparatus 2 according to the second embodiment includes a laser light source 10, an aiming light source 11, a dichroic mirror 12, a zoom expander 13, a high-speed Z scanning unit 15, and a lens 21. The configuration exemplified in the first embodiment can be adopted as the configuration from the laser light source 10 to the lens 21 described above.

  The XY scanning unit 55 of the second embodiment includes an X scanning unit 56, a Y scanning unit 57, and an XY relay unit 60. The X scanning unit 56 scans the pulse laser beam incident from the lens 21 in the X direction. The Y scanning unit 57 scans the pulse laser beam incident from the X scanning unit 56 in the Y direction. As an example, in the second embodiment, each of the X scanning unit 56 and the Y scanning unit 57 is one galvanometer mirror. However, other devices that scan light may be employed. A plurality of devices (for example, two galvanometer mirrors) may be employed in at least one of the X scanning unit 56 and the Y scanning unit 57.

  The XY relay unit 60 is provided between the X scanning unit 56 and the Y scanning unit 57. The XY relay unit 60 includes an upstream XY relay optical element 61 and a downstream XY relay optical element 62 provided on the downstream side of the upstream XY relay optical element 61. The XY relay unit 60 is a Keplerian relay optical system, and relays the X scanning unit 56 to the Y scanning unit 57. That is, the scanning center of the X scanning unit 56 and the scanning center of the Y scanning unit 57 are in a conjugate relationship by the XY relay unit 60. The positional relationship between the upstream XY relay optical element 61 and the X scanning unit 56 is maintained so that the object side (front) focal point of the upstream XY relay optical element 61 coincides with the scanning center in the X scanning unit 56. . Therefore, the telecentric performance of the pulse laser beam emitted from the upstream XY relay optical element 61 is maintained. In the second embodiment, the positional relationship between the downstream XY relay optical element 62 and the Y scanning unit 57 is fixed. Specifically, the positional relationship between the downstream XY relay optical element 62 and the Y scanning unit 57 so that the image side (rear) focal point of the downstream XY relay optical element 62 coincides with the scanning center in the Y scanning unit 57. Is maintained.

  A relay unit 30, a dichroic mirror 38, and an objective lens 35 are provided in this order on the downstream side of the optical path from the XY scanning unit 55. For the relay unit 30, the dichroic mirror 38, and the objective lens 35, the same configuration as that exemplified in the first embodiment can be adopted. Specifically, also in the second embodiment, the positional relationship between the upstream relay optical element 31 and the Y scanning unit 57 so that the object-side focal point of the upstream relay optical element 31 coincides with the pivot point in the Y scanning unit 57. Is maintained. The distance on the optical path between the main plane of the upstream element of the objective lens 35 (the downstream relay optical element 32 in the second embodiment) and the main plane of the objective lens 35 is the upstream element of the objective lens 35. Is equal to the sum of the focal length of the objective lens 35 and the focal length of the objective lens 35. Further, the principal rays of all the pulsed laser beams scanned by the XY scanning unit 55 pass through the object side focal point of the objective lens 35. However, in the second embodiment, unlike the first embodiment, the upstream relay optical system 31 in the relay unit 30 does not move along the optical axis (details will be described later).

  In the second embodiment, the distance on the optical path between the main plane of the upstream relay optical element 31 and the main plane of the downstream relay optical element 32 in the relay unit 30 is the focal length of the upstream relay optical element 31. , Equal to the sum of the focal lengths of the downstream relay optical elements 32. The distance on the optical path between the main plane of the upstream relay optical element 31 and the main plane of the downstream XY relay optical element 62 is the focal length of the upstream relay optical element 31 and the downstream XY relay optical element. Equal to the sum of 62 focal lengths. In this case, the numerical aperture NA of the pulsed laser light emitted from the objective lens 35 is maintained even when scanning by a Z scanning unit 66 described later is performed.

  In the second embodiment, the observation unit 40 and the OCT unit 41 may be mounted. The configuration of the observation unit 40, the OCT unit 41, the dichroic mirrors 38 and 42, etc. may be the same as or different from the first embodiment.

  Similar to the first embodiment, the Z scanning unit 66 moves the condensed position of the pulsed laser light in the Z direction by moving at least a part of the XY scanning unit 55 along the optical axis. However, unlike the first embodiment, the Z scanning unit 66 of the second embodiment includes an optical unit including an X scanning unit 56 and an upstream XY relay optical element 61 of the XY relay unit 60 along the optical axis. To move. In the second embodiment, the downstream XY relay optical element 62, the Y scanning unit 57, and the relay unit 30 are not moved by the Z scanning unit 66. The Z scanning unit 66 of the second embodiment moves the high-speed Z scanning unit 15 and the lens 21 along the optical axis together with the X scanning unit 56 and the upstream XY relay optical element 61.

  On the optical path of the Z scanning unit 66 in the second embodiment, the optical element located on the most downstream side among the optical elements having refractive power is the upstream XY relay optical element 61. Accordingly, the upstream XY relay optical element 61 functions as an emission optical element that emits pulsed laser light to the outside of the Z scanning unit 66. The object-side focal point of the upstream XY relay optical element 61 coincides with the pivot point in the X scanning unit 56.

  As described above, the ophthalmic laser surgical apparatus 2 according to the second embodiment moves at least a part of the XY scanning unit 66 along the optical axis in the same manner as the ophthalmic laser surgical apparatus 1 according to the first embodiment. Thus, the focused position of the pulse laser beam is scanned in the Z direction. Specifically, the Z scanning unit 66 of the second embodiment transmits at least a part of the XY scanning unit 55 and an optical element having refractive power (the upstream XY relay optical element 61 in the second embodiment) to the light. Move along the axis. Therefore, the ophthalmic laser surgical apparatus 2 can appropriately scan the condensing position of the pulse laser beam with a simpler configuration.

  Specifically, the Z scanning unit 66 according to the second embodiment moves the optical unit including the X scanning unit 56 and the upstream XY relay optical element 61 along the optical axis, thereby moving the light collection position in the Z direction. Move to. In this case, the ophthalmic laser surgical apparatus 2 can perform scanning in the Z direction without moving the Y scanning unit 57. Further, the focal length of the lens 21 positioned immediately before the X scanning unit 56 may be the distance to the X scanning unit 56. Therefore, it is easy to shorten the focal length of the lens 21. Furthermore, a part of the configuration of the ophthalmic laser surgical apparatus 2 in the second embodiment is common to the part of the configuration of the ophthalmic laser surgical apparatus 1 in the first embodiment. Therefore, at least a part of the effects in the first embodiment described above can be similarly achieved in the second embodiment.

  Of course, the present invention is not limited to the above-described embodiments, and various modifications are possible. First, in FIG. 1 to FIG. 4, each optical element (for example, 16, 21, 31, 32, 35, 61, 62) is illustrated by one optical member (for example, a lens or the like). However, as a matter of course, each optical element may be constituted by one optical member or a plurality of optical members. In the description of the above embodiment, the expression “the optical element A is positioned downstream of the optical element B” means that the main plane of the optical element A is positioned downstream of the main plane of the optical element B. Indicates. Therefore, in the above example, a part of the optical member constituting the optical element A may be located upstream from at least a part of the optical member constituting the optical element B.

  Moreover, in FIG. 1 to FIG. 4, a simplified configuration than the actual configuration is shown in order to simplify the description. Accordingly, an optical member (not shown) (for example, an optical member for bending the optical path) may be included in the configuration. In addition, various optical members such as a convex lens, a concave lens, a concave mirror, and a plane mirror and combinations thereof can be adopted as the optical element.

  In the first and second embodiments, the Z scanning units 44 and 66 replace the optical elements having the positive refractive power (the upstream relay optical element 31 or the upstream XY relay optical element 61) with the XY scanning units 25 and 55, respectively. Along with the optical axis. However, the Z scanning units 44 and 66 may move the optical element having negative refractive power together with at least a part of the XY scanning units 25 and 55. Further, the position of the optical element that is moved together with at least a part of the XY scanning units 25 and 55 is not limited to the position exemplified in the first and second embodiments. For example, the Z scanning unit may move the optical element disposed upstream of the XY scanning units 25 and 55 together with at least a part of the XY scanning units 25 and 55.

  It is also possible to change the configuration of the relay unit 30 and the like. For example, in the second embodiment shown in FIG. 4, the upstream relay optical element 31 and the downstream relay optical element 32 are provided between the Y scanning unit 57 and the objective lens 35. However, in the second embodiment, for example, by adjusting the focal length of the downstream XY relay optical element 62 or the like, the pulse laser beam emitted from the Y scanning unit 57 is made non-parallel light, and the upstream relay of the relay unit 30 The optical element 31 can be omitted. In this case, specifically, the object side focal point of the upstream XY relay optical element 61 coincides with the scanning center of the X scanning unit 56. The image side focal point of the downstream XY relay optical element 62 is made to coincide with the scanning center of the Y scanning unit 57. Further, the scanning center of the Y scanning unit 57 and the object side focal point of the objective lens 35 are conjugate. Even in this case, the condensing position is determined similarly to the above embodiment. Similarly, the upstream relay optical element 31 in the first embodiment and the upstream XY relay optical element 61 in the second embodiment can be omitted. The downstream relay optical element 32 and the downstream XY relay optical element 62 may be omitted.

  In the first and second embodiments, various configurations including the laser light source 10 and the optical system for irradiating the patient's eye E with the laser are integrally incorporated in the ophthalmic laser surgical apparatuses 1 and 2. Exemplified the case. However, the configuration including the optical system can be modularized and incorporated into the ophthalmic laser surgical apparatuses 1 and 2. In this case, the modularized optical system can be expressed as follows, for example. An optical system used in an ophthalmic laser surgical apparatus for treating a patient's eye by condensing pulsed laser light in a tissue of a patient's eye, wherein the pulsed laser light emitted from a laser light source is used as an optical axis. An XY scanning unit that scans in an intersecting direction; an objective lens that is arranged downstream of the optical path of the pulsed laser light from the XY scanning unit and collects the pulsed laser light that has passed through the XY scanning unit; and at least the XY scanning An optical system comprising: a Z scanning section that moves a part of the section along the optical axis to scan the focused position of the pulsed laser light in the Z direction along the optical axis. .

  In the first and second embodiments, the ophthalmic laser surgical apparatuses 1 and 2 capable of treating both the cornea and the crystalline lens are exemplified. However, the configuration exemplified in the above embodiment can also be applied to an ophthalmic laser surgical apparatus that treats a specific part of the patient's eye E (for example, only the cornea or only the lens). Note that it is necessary to increase the scanning amount in the Z direction when treating the crystalline lens, compared with when treating only the cornea. Furthermore, it is necessary to increase the scanning amount in the Z direction when treating both the cornea and the crystalline lens, compared to treating only the crystalline lens. It is more difficult to perform appropriate Z-direction scanning with a simple configuration as the amount of scanning in the Z-direction increases. However, by using the techniques exemplified in the first and second embodiments, scanning in the Z direction can be performed appropriately. Therefore, the techniques exemplified in the first and second embodiments exhibit a greater advantage when treating the lens and when treating both the lens and the cornea. In the ophthalmic laser surgical apparatuses 1 and 2, even when both the crystalline lens and the cornea are treated, a configuration for switching the optical path for corneal treatment and the optical path for crystalline lens treatment is not essential.

  The ophthalmic laser surgical apparatuses 1 and 2 according to the first and second embodiments include the relay unit 30 on the upstream side of the objective lens 35. Therefore, the ophthalmic laser surgical apparatuses 1 and 2 can appropriately focus the laser beam on the target position. In addition, the optical axes of the observation unit 40 and the OCT unit 41 can be easily combined with the optical axis of the pulse laser beam in the relay unit 30. However, the configuration can be simplified by omitting the relay unit 30.

  In the first embodiment, the Z scanning unit 44 moves the high-speed Z scanning unit 15, the lens 21, the XY scanning unit 25, and the upstream relay optical element 31 in the optical axis direction. In the second embodiment, the Z scanning unit 66 moves the high-speed Z scanning unit 15, the lens 21, the X scanning unit 56, and the upstream XY relay optical element 61 in the optical axis direction. However, the configuration moved by the Z scanning units 44 and 66 can be changed. For example, in the first and second embodiments, the high speed Z scanning unit 15 and the lens 21 can be excluded from the configuration moved by the Z scanning units 44 and 46. The Z scanning units 44 and 46 may also move other members such as the zoom expander 13 in the Z direction.

  The ophthalmic laser surgical apparatuses 1 and 2 according to the first and second embodiments can cause the condensing position to be scanned in the Z direction at high speed according to various elements by the high-speed Z scanning unit 15. However, the high-speed Z scanning unit 15 can be omitted. In contrast to the first and second embodiments, the scanning speed of the Z scanning units 44 and 66 can be made higher than the scanning speed of the Z scanning unit 15. Even in this case, the accuracy of treatment can be easily improved as compared with the case of using one Z scanning unit. Further, the ophthalmic laser surgical apparatuses 1 and 2 according to the first and second embodiments can adjust the numerical aperture NA of the pulsed laser light by changing the beam diameter with the zoom expander 13. However, the zoom expander 13 can be omitted. Further, the positions of the high-speed Z scanning unit 15 and the zoom expander 13 may be interchanged.

  In the first and second embodiments, the emission angle of the pulse laser beam from the objective lens 35 is fixed (specifically, telecentric performance is maintained). Therefore, the ophthalmic laser surgical apparatuses 1 and 2 can easily perform high-precision scanning of the condensing position. However, the emission angle may vary. In this case, the condensing position may be scanned with high accuracy by driving control of the XY scanning units 25 and 55 or the like.

  In the first and second embodiments, the numerical aperture NA of the pulsed laser light emitted from the objective lens 35 is maintained regardless of scanning in the Z direction. However, the numerical aperture NA may change according to scanning in the Z direction. Further, the numerical aperture NA may be changed by driving the beam expander 13 or the like in accordance with various parameters (for example, the condensing position of the pulsed laser beam in the Z direction).

  In addition to the configuration of the above-described embodiment, it is possible to provide a configuration for correcting aberration that occurs due to scanning of pulsed laser light. For example, the aberration may be corrected by providing a device for changing the wavefront of the pulsed laser light upstream of the XY scanning units 25 and 55.

DESCRIPTION OF SYMBOLS 1, 2 Ophthalmic laser surgery apparatus 10 Laser light source 13 Zoom expander 15 High-speed Z scanning part 25, 55 XY scanning part 26, 56 X scanning part 27, 57 Y scanning part 28 First X scanning part 29 Second X scanning part 30 relay section 31 upstream relay optical element 32 downstream relay optical element 35 objective lens 44, 66 Z scanning section 60 XY relay section 61 upstream XY relay optical element 62 downstream XY relay optical element

Claims (9)

An ophthalmic laser surgical apparatus for treating a patient's eye by condensing pulsed laser light in a tissue of the patient's eye,
An XY scanning unit that scans a pulse laser beam emitted from a laser light source in a direction intersecting the optical axis;
An objective lens that is arranged on the downstream side of the optical path of the pulsed laser light with respect to the XY scanning unit and collects the pulsed laser light that has passed through the XY scanning unit;
A Z-scanning unit that scans the condensing position of the pulsed laser light in the Z direction along the optical axis by moving at least a part of the XY scanning unit along the optical axis. Ophthalmic laser surgery device. The ophthalmic laser surgical apparatus according to claim 1,
The Z scanning unit is
An emission optical element that emits pulsed laser light to the outside of the Z scanning unit is moved along the optical axis together with at least a part of the XY scanning unit,
An ophthalmic laser surgery characterized in that an object-side focal point of the output optical element coincides with a pivot point through which chief rays of all pulsed laser beams scanned by at least a part of the XY scanning unit pass. apparatus. The ophthalmic laser surgical apparatus according to claim 2,
An ophthalmic laser surgical apparatus, wherein chief rays of all pulsed laser beams scanned by the XY scanning unit pass through an object side focal point of the objective lens. An ophthalmic laser surgical apparatus according to any one of claims 1 to 3,
Of the optical elements located upstream of the objective lens in the optical path, the distance between the principal plane of the optical element closest to the objective lens and having a refractive power and the principal plane of the objective lens is the focal point of each other. The ophthalmic laser surgical apparatus according to claim 1, wherein the apparatus is equal to a sum of distances. An ophthalmic laser surgical apparatus according to any one of claims 1 to 4,
An upstream relay optical element positioned downstream of the XY scanning unit, and a relay unit having a downstream relay optical element positioned between the upstream relay optical element and the objective lens,
The Z scanning unit is
An ophthalmic laser surgical apparatus, wherein an optical unit including the XY scanning unit and the upstream relay optical element in the relay unit is moved along the optical axis. The ophthalmic laser surgical apparatus according to claim 5,
The XY scanning unit includes a first X scanning unit, a second X scanning unit, and a Y scanning unit,
The first X scanning unit scans a pulse laser beam in the X direction intersecting the optical axis,
The second X scanning unit scans the pulse laser beam scanned by the first X scanning unit in the X direction, and enters the Y scanning unit at a predetermined position,
The Y scanning unit scans the pulsed laser light incident from the second scanning unit in a Y direction that intersects both the optical axis and the X direction. An ophthalmic laser surgical apparatus according to any one of claims 1 to 4,
The XY scanning unit
An X scanning unit that scans a pulse laser beam in the X direction intersecting the optical axis;
A Y scanning unit that scans the pulse laser beam scanned by the X scanning unit in a Y direction that intersects both the optical axis and the X direction;
An upstream XY relay optical element disposed in the optical path between the X scanning unit and the Y scanning unit, and a downstream XY relay optical element positioned downstream of the upstream XY relay optical element. An XY relay unit that relays the X scanning unit to the Y scanning unit,
The Z scanning unit is
An ophthalmic laser surgical apparatus, wherein an optical unit including the X scanning unit and an upstream XY relay optical element in the XY relay unit is moved along the optical axis. An ophthalmic laser surgical apparatus according to any one of claims 1 to 7,
An ophthalmic laser surgery characterized by further comprising a second Z scanning unit that is disposed between the laser light source and the XY scanning unit in the optical path, and scans the focused position of the pulsed laser light in the Z direction. apparatus. An ophthalmic laser surgical apparatus according to any one of claims 1 to 8,
An ophthalmic laser surgical apparatus further comprising a beam diameter changing unit that is arranged between the laser light source and the XY scanning unit in the optical path and changes a beam diameter of pulsed laser light.