JP2017176777A - Ophthalmic laser surgery device and aberration correction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ophthalmic laser surgery device and an aberration correction method capable of appropriately suppressing an influence of an aberration.SOLUTION: An ophthalmic laser surgery device treats eyes of a patient by condensing a pulse laser beam inside a tissue of the eyes of the patient. The ophthalmic laser surgery device is equipped with a holding mechanism 40. The holding mechanism 40 holds any one of optical elements installed on a laser beam optical path in a state that it can be moved in a direction intersecting with an optical axis of the pulse laser beam. Since the optical element held by the holding mechanism 40 is moved in a direction intersecting with the optical axis, an aberration of the pulse laser beam is corrected.SELECTED DRAWING: Figure 2

Description

  The present disclosure relates to an ophthalmic laser surgical apparatus for treating a patient's eye by condensing pulsed laser light in a tissue of the patient's eye, and an aberration correction method in the ophthalmic laser surgical apparatus.

  2. Description of the Related Art Conventionally, an ophthalmic laser surgical apparatus that treats (for example, cuts or destroys) a tissue by condensing pulse laser light at each of a plurality of target positions in a patient's eye is known. For example, in the apparatus disclosed in Patent Document 1, pulsed laser light emitted from a laser light source is condensed into a tissue of a patient's eye via an XY scanning unit, a relay optical element, an objective lens, an interface, and the like.

JP 2015-37473 A

  In an ophthalmic laser surgical apparatus, aberration may occur in pulsed laser light due to various effects. For example, aberrations may occur due to manufacturing errors, interface mounting errors, mirror distortion, or deflection of the base supporting the optical element. When aberrations occur, the quality of surgery can be reduced.

  A typical object of the present disclosure is to provide an ophthalmic laser surgical apparatus and an aberration correction method capable of appropriately suppressing the influence of aberration.

  One aspect of the ophthalmic laser surgical apparatus according to the present disclosure is an ophthalmic laser surgical apparatus that treats a patient's eye by condensing pulsed laser light in a tissue of a patient's eye, and is on an optical path of the laser light. A holding mechanism that holds at least one of the installed optical elements in a state of being movable in a direction crossing the optical axis of the pulsed laser light, and the optical element held by the holding mechanism includes the light By moving in the direction intersecting the axis, the aberration of the pulse laser beam is corrected.

  One aspect of the ophthalmic laser surgical apparatus according to the present disclosure is an ophthalmic laser surgical apparatus that treats the patient's eye by condensing pulsed laser light in a tissue of the patient's eye, and the light of the pulsed laser light An aberration changing unit for changing the aberration of the pulsed laser light, and an optical path branched from an optical path extending from the light source of the pulsed laser light to the patient's eye. A measuring device for measuring, and the aberration changing unit is moved in accordance with a result measured by the measuring device, whereby the aberration of the pulse laser beam is corrected.

  One aspect of the ophthalmic laser surgical apparatus according to the present disclosure is an ophthalmic laser surgical apparatus that treats the patient's eye by condensing pulsed laser light in a tissue of the patient's eye, and the light of the pulsed laser light An aberration changing unit that changes the aberration of the pulsed laser light, and at least an interface interposed between the main body of the ophthalmic laser surgical apparatus and the patient's eye among the optical paths of the pulsed laser light. Imaging means for photographing a part, and the aberration changing unit is moved according to the state of the interface determined from the image photographed by the photographing means, whereby the aberration of the pulse laser beam is corrected. The

  One aspect of the aberration correction method in the present disclosure is an aberration correction method for correcting an aberration of an ophthalmic laser surgical apparatus that treats a patient's eye by condensing pulsed laser light in a tissue of the patient's eye, A correction step of correcting an aberration of the pulsed laser beam by moving at least one of the optical elements installed on the optical path of the pulsed laser beam in a direction intersecting the optical axis of the pulsed laser beam;

  According to the ophthalmic laser surgical apparatus and the aberration correction method according to the present disclosure, the influence of the aberration is appropriately suppressed.

It is a figure which shows the structure of the ophthalmic laser surgery apparatus 1 of 1st Embodiment. It is sectional drawing of the downstream LBE12 at the time of seeing in the cross section containing an optical axis. It is the figure which looked at the movable ring member 45, screw | thread 46A, 46B, guide part 47A, 47B, and the 4th lens 54 from the direction of the optical axis of a pulse laser beam. It is a figure which shows the structure of the ophthalmic laser surgery apparatus 1 of 2nd Embodiment. It is sectional drawing of downstream LBE12 of 2nd Embodiment. 6 is a schematic diagram illustrating an example of a state in which the IF lens is mounted. It is a figure which shows the structure of the ophthalmic laser surgery apparatus 1 of the modification example.

<Overview>
An ophthalmic laser surgical apparatus exemplified in the present disclosure includes a holding mechanism that holds at least one of optical elements installed on an optical path of pulsed laser light in a state of being movable in a direction crossing the optical axis of the pulsed laser light. Is provided. The aberration is corrected (that is, unnecessary aberrations are reduced) by moving the optical element held by the holding mechanism in a direction intersecting the optical axis. As a result, the influence of aberration is appropriately suppressed.

  The holding mechanism may hold a part of the plurality of lenses included in the beam expander in a state in which the lens can move in a direction intersecting the optical axis. In this case, the influence of the aberration is more easily suppressed as compared with the case where other optical elements such as the XY scanning unit are moved. However, it is also possible to correct the aberration by moving optical elements other than the lens of the beam expander. In addition, the aberration may be corrected by moving an optical element other than the lens in a direction intersecting the optical axis.

  The ophthalmic laser surgical apparatus may include an actuator that moves the optical element held by the holding mechanism in a direction crossing the optical axis. The driving of the actuator may be controlled by the control unit. In this case, the optical element can be moved more easily and with higher accuracy than when the service person manually moves the optical element.

  The ophthalmic laser surgical apparatus may include a measuring instrument that measures the characteristics of the pulsed laser light. The control unit may control the driving of the actuator according to the result measured by the measuring instrument. In this case, the aberration is corrected more appropriately according to the characteristics of the pulse laser beam. Although not essential, the control unit can also move the optical element in real time while monitoring the characteristics of the pulse laser beam.

  The ophthalmic laser surgical apparatus may include imaging means for imaging at least a part of an interface interposed between the main body and the patient's eyes. The control unit may detect the state of the attached interface from the image photographed by the photographing unit, and may control driving of the actuator according to the detected state. In this case, the ophthalmic laser surgical apparatus can more appropriately correct aberrations caused by at least one of an interface installation error and a manufacturing error of the interface itself. Note that the “state of the installed interface” is, for example, at least one of the amount of eccentricity of the interface with respect to the optical axis of the pulsed laser beam, the inclination of the interface with respect to the optical axis, or the manufacturing error (crossing) of the interface. May be.

  An ophthalmic laser surgical apparatus exemplified in the present disclosure includes an aberration changing unit and a measuring instrument. The aberration changing unit is installed on the optical path of the pulse laser beam and changes the aberration of the pulse laser beam. The measuring device is provided on an optical path branched from the optical path extending from the light source of the pulsed laser light to the patient's eye, and measures the characteristics of the pulsed laser light. The aberration changing unit is moved according to the result measured by the measuring instrument, so that the aberration of the pulse laser beam is corrected. Therefore, according to the technique in the present disclosure, the aberration is appropriately corrected according to the characteristics of the pulse laser beam. In this case, the configuration of the aberration changing unit can be changed as appropriate. For example, the aberration changing unit may change the aberration by moving at least a part of the optical element in a direction intersecting the optical axis. The aberration changing unit may change the aberration by moving at least a part of the optical element in the optical axis direction. The aberration changing unit may change the aberration by changing the angle of the plate that transmits the pulse laser beam.

  An ophthalmic laser surgical apparatus exemplified in the present disclosure includes an aberration changing unit and an imaging unit. An imaging | photography means image | photographs at least one part of the interface interposed between the main body of an ophthalmic laser surgery apparatus and a patient's eye among the optical paths of pulsed laser light. The aberration of the pulsed laser beam is corrected by moving the aberration changing unit in accordance with the state of the interface determined from the image photographed by the photographing means. Therefore, according to the technique in the present disclosure, the aberration is appropriately corrected according to the state of the interface. Also in this case, the configuration of the aberration changing unit can be changed as appropriate. For example, the aberration correction unit may move at least a part of the optical element in the optical axis direction, or may change the angle of the plate that transmits the pulse laser beam.

  In the aberration correction method exemplified in the present disclosure, the aberration is corrected by moving at least one of the optical elements installed on the optical path of the pulsed laser light in a direction intersecting the optical axis. Therefore, the influence of aberration is appropriately suppressed. Note that the method of moving the optical element may be a method of automatically moving the optical element by an actuator, or a method of moving it manually by a serviceman or a factory worker. In the case of manual movement, since it is not necessary to provide an actuator in the ophthalmic laser surgical apparatus, the apparatus configuration is simplified.

  The optical element may be moved according to the measured characteristics of the pulsed laser beam. In this case, the aberration is corrected more appropriately according to the characteristics of the pulse laser beam.

  A null lens that generates an aberration that approximates the aberration of the patient's eye may be installed in the optical path of the pulsed laser beam. The characteristics of the pulsed laser beam may be measured with a null lens installed. In this case, without actually irradiating the patient's eye with pulsed laser light, the aberration in the entire optical path from the laser light source to the condensing position is measured and the optical element is moved. Accordingly, the aberration is easily corrected.

<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. The ophthalmic laser surgical apparatus 1 exemplified in this embodiment can treat tissue (cornea, lens, etc.) of a patient's eye. “Treatment” refers to cutting, crushing, or the like of the tissue of the patient's eye. Hereinafter, for each configuration of the ophthalmic laser surgical apparatus 1 according to the first embodiment, from the laser light source 2 side (that is, the upstream side of the optical path of the pulse laser beam) to the interface 17 side (that is, the downstream side of the optical path of the pulse laser beam). ) In order.

  The laser light source 2 emits pulsed laser light. In the present embodiment, when the pulsed laser light emitted from the laser light source 2 is condensed in the tissue of the patient's eye, plasma is generated at the condensing position (spot), and the tissue is cut and fractured. . The above phenomenon is sometimes referred to as photodisruption. For the laser light source 2, 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 2 is defined as the Z direction. One of the directions perpendicular to the Z direction is defined as the X direction. A direction perpendicular to both the Z direction and the X direction is defined as a Y direction.

  The zoom expander 3 is provided between the laser light source 2 and the XY scanning units 8 and 9 (described later) in the optical path (specifically, between the laser light source 2 and the high-speed Z scanning unit 4 (described later) in the present embodiment). Is provided. The zoom expander 3 can change the beam diameter of the pulsed laser light emitted from the laser light source 2. The control unit 30 (described later) drives the zoom expander 3 to change the beam diameter of the pulse laser beam, thereby opening the pulse laser beam emitted from the objective lens 15 (described later) toward the patient's eye. The number NA 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 high-speed Z scanning unit 4 (expander in the present embodiment) is disposed between the laser light source 2 and the XY scanning units 8 and 9 in the optical path (specifically, in the present embodiment, the zoom expander 3 and the XY scanning units 8 and 9). Between). As an example, the high-speed Z scanning unit 4 of the present embodiment includes an optical element (a lens in the present embodiment) 5 having negative refractive power, and a high-speed Z scanning drive unit 6 that moves the optical element 5 along the optical axis. Is provided. A lens 7 is provided between the optical element 5 and the XY scanning units 8 and 9. The lens 7 guides the laser light that has passed through the high-speed Z scanning unit 4 to the XY scanning units 8 and 9.

  When the optical element 5 moves along the optical axis, the focused position of the pulse laser beam moves in the Z direction. Therefore, the control unit 30 can scan the condensing position in the Z direction by driving and controlling the high-speed Z scanning driving unit 6 to move the optical element 5. Further, the high-speed Z scanning unit 4 of the present embodiment is provided on the upstream side of the optical path from the XY scanning units 8 and 9. In this case, laser light that has not been scanned in the XY directions is incident on the optical element 5. Therefore, compared with the case where the high-speed Z scanning unit 4 is provided on the downstream side of the optical path from the XY scanning units 8 and 9, the optical element 5 can be easily downsized. Therefore, the high-speed Z scanning unit 4 of the present embodiment can scan the condensing position in the Z direction at a higher speed than the Z scanning unit 25 (described later).

  The XY scanning units 8 and 9 scan the pulse laser beam on the XY plane intersecting the optical axis. In the present embodiment, the XY scanning units 8 and 9 include an X scanning unit 8 and a Y scanning unit 9. The X scanning unit 8 scans the pulsed laser light emitted from the laser light source 2 in the X direction. The Y scanning unit 9 further scans the pulse laser beam scanned in the X direction by the X scanning unit 8 in the Y direction. In this embodiment, galvanometer mirrors are employed for both the X scanning unit 8 and the Y scanning unit 9. However, another device that scans light (for example, a scanner such as a polygon mirror or an acousto-optic element (AOM)) may be employed in at least one of the X scanning unit 8 and the Y scanning unit 9. Further, at least one of the X scanning unit 8 and the Y scanning unit 9 may include a plurality of scanners. As an example, the ophthalmic laser surgical apparatus 1 according to the present embodiment is configured so that the X scanning unit 8 is configured by two galvanometer mirrors, so that the principal ray of the pulsed laser light is converted into the Y scanning unit regardless of the scanning amount in the X direction. 9 is incident on a predetermined location. As a result, the predetermined portion of the Y scanning unit 9 becomes a pivot point through which the principal rays of all the pulse laser beams scanned by the XY scanning units 8 and 9 pass.

  A large beam expander (hereinafter also referred to as “LBE”) 10 is provided between the XY scanning units 8 and 9 and the objective lens 15. The LBE 10 of this embodiment expands the beam diameter of the pulsed laser light that has passed through the XY scanning units 8 and 9. In addition, the LBE 10 of the present embodiment includes a pivot point in the XY scanning units 8 and 9 (in this embodiment, a predetermined portion of the scanning surface in the Y scanning unit 9) and an objective lens 15 by the upstream LBE11 and the downstream LBE12. The object side focal point is connected in a conjugate relationship. Further, the positional relationship between the upstream LBE 11 and the XY scanning units 8 and 9 is maintained so that the object side focal point of the upstream LBE 11 coincides with the pivot point in the XY scanning units 8 and 9. Therefore, the telecentric performance of the pulse laser beam emitted from the upstream side LBE 11 is maintained. In FIG. 1, the upstream LBE 11 is represented by one lens, but the upstream LBE 11 may be composed of a plurality of optical elements. Other optical elements may also be configured by a number of optical elements different from the number of optical elements shown in the figure.

  The objective lens 15 is disposed on the downstream side of the optical path from the downstream side LBE12 of the LBE10. The pulsed laser light that has passed through the objective lens 15 is condensed on the tissue of the patient eye E through the interface 17.

  The interface 17 is interposed between the main body of the ophthalmic laser surgical apparatus 1 and the patient's eye in the optical path of the pulsed laser light, and is coupled to the patient's eye. In the present embodiment, the user can selectively use a plurality of types of interfaces 17 according to the region to be operated, the surgical procedure, and the like. As an example, the plurality of types of interfaces 17 in the present embodiment include an immersion interface and an applanation interface.

  The immersion interface includes an immersion lens and an eye fixing part (in this embodiment, a suction ring). When the eye fixing part comes into contact with the patient's eye, a sealed space is formed between the surface of the patient's eye and the eye fixing part. By discharging the gas in the sealed space, the eye fixing part is sucked and fixed to the patient's eye. When the eye fixing part is fixed to the patient's eye, the immersion lens is arranged in a state of being separated from the surface (cornea) of the patient's eye. A substance (for example, a liquid such as water or a viscoelastic substance, or an elastic body) whose refractive index difference between the transparent tissue of the patient's eye (eg, cornea) is smaller than that of air is not between the immersion lens and the patient's eye. Injected into the space. As a result, the influence of the refractive index difference between the transparent tissue of the patient's eye and air (for example, the occurrence of aberrations) is suppressed.

  The applanation interface includes a contact lens and an eye fixing part. When the eye fixing part is fixed to the patient's eye by suction, the contact lens comes into contact with the surface of the patient's eye (including the cornea). That is, the cornea of the patient's eye is applanated. As a result, the shape of the surface of the cornea is deformed to the shape of the rear surface of the contact lens (the surface on the patient's eye side). Therefore, the irradiation position of the pulse laser beam is set appropriately. Further, as compared with the case where air is interposed between the contact lens and the cornea, adverse effects due to light refraction (for example, occurrence of aberrations in the cornea) are suppressed.

  The dichroic mirror 14 is provided between the objective lens 15 and the downstream LBE 12 in the optical path. The dichroic mirror 14 of the present embodiment reflects most of the pulsed laser light from the laser light source 2 and transmits most of light from the tomographic image capturing unit 21 and the front image capturing unit 22 described later. As a result, the optical axes of the plurality of lights are coaxial.

  The tomographic image capturing unit 21 can capture a tomographic image of at least a part of the tissue of the patient's eye and the interface 17. In the present embodiment, an OCT unit that captures a tomographic image using the optical interference technique is used as the tomographic image capturing unit 21. The tomographic image capturing unit 21 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 the two-dimensional direction on the imaging target. The detector detects an interference state between the measurement light reflected by the subject 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 reference light, thereby acquiring information in the depth direction of the imaging target. A tomographic image to be imaged is acquired based on the acquired depth direction information. Various configurations can be used for the OCT unit. For example, any of SS-OCT, SD-OCT, TD-OCT, etc. may be adopted as the OCT unit. The ophthalmic laser surgical apparatus 1 may capture a tomographic image using a technique other than optical interference.

  The front image capturing unit 22 can capture front images of the patient's eyes and at least a part of the interface 17. The front image capturing unit 22 of the present embodiment can capture a patient's eye illuminated with visible light or infrared light and display it on a monitor (not shown). The surgeon can observe the patient's eyes from the front by looking at the monitor.

  The dichroic mirror 23 is coaxial with the optical axis of the tomographic image capturing unit 21 and the optical axis of the front image capturing unit 22. The light passing through the dichroic mirror 23 is made coaxial with the pulse laser light emitted from the laser light source 2 by the dichroic mirror 14 described above.

  The Z scanning unit 25 scans the focused position (spot) of the pulse laser beam in the Z direction. As an example, the Z scanning unit 25 of the present embodiment moves an optical unit including the XY scanning units 8 and 9 and the upstream LBE 11 along the optical axis, so that the space between the upstream LBE 11 and the objective lens 15 is increased. Change the optical path length. As a result, the spot is scanned in the Z direction. The configuration of the Z scanning unit 25 can be changed as appropriate. For example, the ophthalmic laser surgical apparatus 1 has at least one of optical elements (for example, the upstream LBE 11, the downstream LBE 12, and the objective lens 15) positioned downstream of the XY scanning units 8 and 9 in the optical axis direction. The spot may be scanned in the Z direction by moving it. It is also possible to scan the spot in the Z direction using only the high-speed Z scanning unit 4.

  The measuring device 26 can measure the characteristics of the pulsed laser beam. For the measuring device 26, for example, a wavefront sensor that measures the wavefront of the pulsed laser light or a beam profiler that measures the spatial intensity distribution of the pulsed laser light can be used.

  The measuring device 26 is provided on an optical path branched from the optical path of pulsed laser light extending from the laser light source 2 to the patient's eye. As an example, in the first embodiment, a branch mirror 27 is installed on the optical path between the laser light source 2 and the zoom expander 3. The measuring device 26 is installed on the optical path branched by the branch mirror 27. That is, in the first embodiment, the optical path between the laser light source 2 and the optical element closest to the laser light source 2 (in this embodiment, the zoom expander 3) is branched, and the measuring device 26 is provided on the branched optical path. It is done. In the present embodiment, the pulse laser beam that is once irradiated from the objective lens 15 to the outside and then returns to the same optical path as before the irradiation is measured by the measuring device 26. However, the position where the measuring device 26 is installed can be changed as appropriate.

  Note that the aberration correction method exemplified in the first embodiment can be performed, for example, at the time of manufacturing the ophthalmic laser surgical apparatus 1 and during maintenance. The worker who performs the aberration correction work performs the work after installing the measuring instrument 26 when performing the work. Further, when the work is completed, the measuring instrument 26 is removed. Since the branch mirror 27 remains installed, the optical path branched by the branch mirror 27 is prevented from being shifted. However, the branch mirror 27 may also be provided detachably.

  The control unit 30 controls various operations of the ophthalmic laser surgical apparatus 1 (for example, the operation of the laser light source 2, the operations of the scanning units 8, 9, 25, etc.). The control unit 30 includes a CPU 31, a ROM 32, a RAM 33, and the like. The CPU 31 manages various processes. The ROM 32 stores various programs and initial values for controlling the operation of the ophthalmic laser surgical apparatus 1. The RAM 33 temporarily stores various information.

  With reference to FIGS. 2 and 3, the holding mechanism 40 of the present embodiment will be described. The holding mechanism 40 moves at least one of the optical elements installed on the optical path of the pulsed laser light in a direction intersecting the optical axis of the pulsed laser light (in this embodiment, a direction perpendicular to the optical axis). Hold as possible.

  As an example, the holding mechanism 40 of this embodiment is provided in a beam expander that expands the beam diameter of pulsed laser light. In this case, the influence of the aberration can be more easily suppressed as compared with the case where other optical elements such as the XY scanning units 8 and 9 are moved. Specifically, in the present embodiment, the holding mechanism 40 is provided in the LBE 10 on the downstream side LBE 12 that does not move in the optical axis direction even when the spot is scanned in the Z direction. Therefore, in this embodiment, since it is not necessary to provide a mechanism for moving the optical element in both the direction intersecting the optical axis and the direction along the optical axis, the apparatus configuration is simplified. However, it is possible to change the optical element to be moved in the direction intersecting the optical axis. For example, the aberration may be corrected by moving the optical element of the zoom expander 3 in a direction intersecting the optical axis. You may move at least one part of the objective lens 15 comprised by a some lens in the direction which cross | intersects an optical axis.

  As shown in FIG. 2, the downstream LBE 12 of this embodiment has five optical elements (a first lens 51, a second lens 52, a third lens 53, a fourth lens 54, and a fifth lens 55 in order from the upstream side). ). The holding mechanism 40 of the present embodiment holds the fourth lens 54 so as to be movable. Specifically, the downstream LBE 12 includes a lens barrel 41. The lens barrel 41 has a substantially cylindrical shape, and holds the five lenses 51 to 55 inside. The four lenses other than the fourth lens 54 are fixed to the lens barrel 41 and do not move. However, it goes without saying that the number of optical elements, the shape of each optical element, and the like can be changed.

  An annular movable ring member 45 is provided inside the lens barrel 41. The movable ring member 45 fixes the fourth lens 54 inside. The fourth lens 54 of the present embodiment is designed so that the coma aberration changes by moving in the direction intersecting the optical axis. On the outer peripheral surface of the movable ring member 45, there are formed a recess with which a later-described screw 46A contacts and a recess with which a screw 46B (see FIG. 3) contacts. Further, a columnar guide portion 47A and a guide portion 47B (see FIG. 3) are provided on the outer peripheral surface of the movable ring member 45 so as to protrude outward.

  The lens barrel 41 is formed with a screw hole 42A into which a screw 46A is inserted. Although not shown, the lens barrel 41 is also formed with a screw hole into which the screw 46B is inserted. The lens barrel 41 is formed with a guide hole 43A through which the guide portion 47A is inserted. Although not shown, the lens barrel 41 is also formed with a guide hole through which the guide portion 47B is inserted.

  As shown in FIG. 3, in a state where the screw 46A is fitted in the screw hole 42A, the straight line P connecting the screw 46A and the guide portion 47A passes through the center of the fourth lens 54. The movable ring member 45 is biased in a direction from the guide portion 47A toward the screw 46A by an unillustrated biasing member (for example, a spring or the like). Further, in a state where the screw 46B is fitted in the screw hole, the straight line Q connecting the screw 46B and the guide portion 47B also passes through the center of the fourth lens 54. The movable ring member 45 is biased in a direction from the guide portion 47B toward the screw 46B by an unillustrated biasing member (for example, a spring or the like).

  When the screw 46A rotates, the movable ring member 45 and the fourth lens 54 move along the straight line P. When the screw 46B rotates, the movable ring member 45 and the fourth lens 54 move along the straight line Q. The straight line P and the straight line Q intersect. Therefore, when the screw 46A and the screw 46B are rotated, the fourth lens 54 moves along a plane perpendicular to the optical axis (that is, a plane including both the straight line P and the straight line Q).

  The aberration correction method in the first embodiment will be described. In the first embodiment, an operator (for example, a worker in a factory that manufactures the ophthalmic laser surgical apparatus 1 or a service person who performs maintenance of the ophthalmic laser surgical apparatus 1) manually corrects aberrations. That is, the aberration correction method exemplified in the present embodiment is performed in order to perform maintenance and adjustment of the ophthalmic laser surgical apparatus 1 while not in operation.

  First, the operator installs the measuring device 26 on the optical path branched from the optical path extending from the laser light source 2 toward the condensing position. In the present embodiment, the operator installs the branch mirror 27 between the laser light source 2 and the zoom expander 3 to branch the optical path, and installs the measuring device 26 on the branched optical path.

  Next, the operator installs a null lens 36 that generates an aberration that approximates the aberration of the patient's eye in the optical path of the pulsed laser light (specifically, downstream of the interface 17). Further, the worker installs the reflection mirror 37 on the downstream side of the optical path from the null lens 36.

  Next, the worker emits laser light from the laser light source 2. The pulse laser beam emitted from the laser light source 2 passes through all optical elements on the optical path in the apparatus main body, passes through the interface 17 and the null lens 36, and is reflected by the reflection mirror 36. The reflected pulse laser light passes through all optical elements that have passed before being reflected in the reverse direction, and then enters the measuring device 26. The laser beam incident on the measuring device 26 may be a continuous wave instead of a pulsed laser beam. This is because the characteristics of the laser beam are measured even when the continuum is incident as in the case where the pulsed laser beam is incident.

  The operator measures the characteristics of the laser beam with the measuring device 26. The operator moves the fourth lens 54 in a direction intersecting the optical axis by rotating the screws 46A and 46B according to the measured characteristics of the laser light. As a result, aberration (coma aberration in the present embodiment) is corrected (reduced). For example, the operator may use a wavefront sensor as the measuring instrument 26 and move the fourth lens 54 while looking at the measurement result of the wavefront sensor so that the coma measured by the wavefront sensor is reduced. The operator may use a beam profiler as the measuring device 26 and move the fourth lens 54 so that the shape of the focused spot of the beam measured by the beam profiler approaches a perfect circle. When a beam profiler is used, a condenser lens is installed upstream of the beam profiler in the optical path. Further, the correspondence relationship between the moving distance of the optical element (the fourth lens 54 in the present embodiment) and the amount of change in aberration may be defined in advance by a calculation formula, a table, a manual, or the like. In this case, the operator may move the optical element so that the movement distance of the optical element is a distance that is previously associated with the magnitude of the aberration to be corrected.

  Further, the operator may move the optical element according to the measurement result of the photo destruction. For example, an operator focuses pulse laser light in a test material for trial hitting and observes whether or not photodestruction occurs. Next, the worker irradiates the test substance with the pulsed laser light a plurality of times while appropriately moving the optical element so that the optical destruction is caused with the lowest possible laser energy. Even in this case, the aberration is appropriately corrected.

Second Embodiment
A second embodiment, which is one of typical embodiments different from the first embodiment, will be described with reference to FIGS. 4 and 5. In the second embodiment, the aberration is automatically corrected while actually irradiating the patient's eye with pulsed laser light. In the following description of the second embodiment, 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.

  As shown in FIG. 4, the ophthalmic laser surgical apparatus 1 according to the second embodiment does not measure the characteristics of the reflected light of the pulsed laser light emitted from the interface 17 toward the outside of the apparatus, but the laser light source 2. The pulse laser beam emitted from the outside to the outside of the apparatus is branched on the way and measured by the measuring device 26. As an example, the measuring device 26 of the second embodiment measures pulsed laser light that has passed through the dichroic mirror 14. Since the beam diameter of the pulse laser beam that passes through the dichroic mirror 14 is enlarged, a reduction optical system may be provided upstream of the measuring device 26 in the optical path in the second embodiment. The ophthalmic laser surgical apparatus 1 according to the second embodiment does not use the null lens 36 and the reflection mirror 37 (see FIG. 1), and actually irradiates the patient's eye E with pulsed laser light, while upstream of the interface 17. The aberration generated by the optical element is measured by the measuring device 26 in real time. It is also possible to change the installation position of the measuring instrument 26. For example, the measuring device 26 may be installed by branching the optical path between the objective lens 15 and the interface 17.

  As shown in FIG. 5, the ophthalmic laser surgical apparatus 1 according to the second embodiment moves the optical element (the fourth lens 54 in the present embodiment) held by the holding mechanism 40 in a direction intersecting the optical axis. An actuator 60 is provided. The actuator 60 of the second embodiment is a motor that rotates the screws 46A and 46B (in FIG. 5, the actuator that rotates the screw 46B is omitted). However, it goes without saying that actuators other than motors may be used. The control unit 30 can adjust the amount of movement of the fourth lens 54 by controlling the amount of rotation of the actuator 60 that is a motor.

  In the second embodiment, the control unit 30 controls the driving of the actuator 60 according to the specification of the pulse laser beam measured by the measuring device 26. For example, the control unit 30 may control the driving of the actuator 60 so that the coma measured by the wavefront sensor is reduced. Further, the control unit 30 may control the drive of the actuator 60 so that the shape of the beam measured by the beam profiler approaches a perfect circle. Further, the correspondence relationship between the moving distance of the optical element (the fourth lens 54 in the present embodiment) and the amount of change in aberration may be defined in advance by a calculation formula or a table. In this case, the control unit 30 may control the driving of the actuator 60 so that the moving distance of the optical element is a distance that is previously associated with the magnitude of the aberration to be corrected.

<Third Embodiment>
A third embodiment, which is one of the typical embodiments, will be described with reference to FIG. The ophthalmic laser surgical apparatus 1 according to the second embodiment detects the state of the interface 17 attached to the apparatus main body from the image captured by the imaging unit. The ophthalmic laser surgical apparatus 1 reduces the aberration by moving the optical element (the fourth lens 54 in the present embodiment) in a direction crossing the optical axis in accordance with the detected state of the interface 17. The same configuration as that of the second embodiment can be adopted as the configuration of the ophthalmic laser surgical apparatus 1 in the following third embodiment (however, the measuring device 26 is not essential in the third embodiment). Therefore, the description of the device configuration in the third embodiment is omitted.

  An example of a method for detecting the state of the attached interface 17 will be described with reference to FIG. In the third embodiment, as an example, the state of the interface 17 is detected from a tomographic image captured by the tomographic image capturing unit 21 (see FIG. 4). When the interface 17 is mounted at an appropriate position and at an appropriate angle with respect to the apparatus main body, the influence of aberration is reduced.

  FIG. 6 shows an example of a mounting state of the IF lens 70 included in the interface 17 (for example, an immersion lens included in the immersion interface or a contact lens included in the applanation interface) with respect to the apparatus main body. In the example shown in FIG. 6, the center 73 of the front surface 71 of the IF lens 70 (that is, the surface of the two lens surfaces of the IF lens 70 positioned on the upstream side of the laser light) is the reference axis S (for example, the apparatus body) The optical axis of the pulse laser beam. However, in FIG. 6, the angle of the IF lens 70 with respect to the apparatus main body is shifted (tilted) with respect to the optimum angle. In this case, the angle of the front surface 71 with respect to the reference axis S is not perpendicular at the intersection of the reference axis S and the front surface 71 of the IF lens 70. As a result, the aberration generated in the pulse laser beam by the front surface 71 increases. Even if the angle of the IF lens 70 with respect to the apparatus main body is optimal, the aberration increases if the center 73 of the IF lens 70 is deviated (decentered) from the reference axis S.

  As described above, the rear surface 72 of the IF lens 70 of the present embodiment is in contact with a substance whose refractive index difference with the transparent tissue of the patient's eye is smaller than that of air or directly on the patient's eye. Contact. Therefore, the influence of the aberration due to the rear surface 72 of the IF lens 70 is small. Therefore, in the third embodiment, a tomographic image including the front surface 71 of the IF lens 70 is captured by the tomographic image capturing unit 21. The control unit 30 detects the state of the front surface 71 with respect to the apparatus main body from the tomographic image including the front surface 71 of the IF lens 70. As a result, the state of the eccentricity and tilt of the IF lens 70 with respect to the apparatus main body is appropriately detected.

  However, the method for detecting the mounting state of the interface 17 can be changed as appropriate. For example, the control unit 30 may detect both the state of the front surface 71 and the state of the rear surface 72 of the IF lens 70 from the tomographic image. Further, the state of the interface 17 may be detected from the front image captured by the front image capturing unit 22. For example, the control unit 30 may detect only the amount of eccentricity of the interface 17 with respect to the apparatus main body from a front image including at least a part of the interface 17 (for example, an edge of the interface 17). Even in this case, the influence of aberration is reduced. Further, the front image capturing unit 22 may capture a front image including a bright spot reflected by the IF lens 70 or the patient's eye. In this case, the control unit 30 may detect the mounting state of the interface 17 based on the position of the bright spot. The ophthalmic laser surgical apparatus 1 may detect the state of the interface 17 using a sensor (for example, a magnetic sensor) that detects at least one of the position and the angle of the attached interface 17. Further, the control unit 30 may detect a manufacturing error of the interface 17 (for example, a manufacturing error of the front surface 71 of the IF lens 70) using a tomographic image or the like. Further, the control unit 30 may detect the state of the interface 17 based on a Shine peak image, an SLO image, or the like.

  An example of a method for controlling the driving of the actuator 60 based on the state of the attached interface 17 will be described. In the third embodiment, an algorithm for estimating the Zernike change amount with respect to the shift amount of the IF lens 70 is constructed. For example, in the example shown in FIG. 6, the front surface 71 of the IF lens 70 has a shape along a spherical surface. Therefore, if the intersection 74 between the front surface 71 and the straight line T passing through the center O of the spherical surface and parallel to the reference axis S coincides with the reference axis S, the influence of aberration is reduced. As an example, in the third embodiment, an aberration change amount (eg, Zernike change amount) is associated with an amount of deviation between the intersection 74 and the reference axis S by an algorithm. The algorithm may be a calculation formula, table data, or the like.

  In the third embodiment, an algorithm for estimating the amount of change in aberration with respect to the amount of movement of the optical element (in this embodiment, the fourth lens 54) moved in the direction intersecting the optical axis is constructed. The control unit 30 detects the amount of deviation between the intersection 74 and the reference axis S and the direction of deviation from the image, and estimates the generated aberration from the detected amount of deviation based on an algorithm. The control unit 30 estimates the amount of movement of the fourth lens 54 for correcting the estimated aberration based on an algorithm. The control unit 30 controls the driving of the actuator 60 according to the estimated movement amount and the direction of deviation. As a result, the influence of aberration is appropriately suppressed.

  The technology disclosed in the above embodiment is merely an example. Therefore, it is possible to change the technique exemplified in the above embodiment. For example, in the above embodiment, the coma aberration is mainly corrected by moving the optical element in the direction intersecting the optical axis. However, different aberrations may be corrected together with or separately from coma aberration. For example, astigmatism may be corrected by moving the optical element in a direction intersecting the optical axis. Moreover, both astigmatism and coma may be corrected. For example, the ophthalmic laser surgical apparatus 1 includes a lens in which both coma and astigmatism change by moving in a direction crossing the optical axis, and coma and astigmatism by moving in a direction crossing the optical axis. A lens that changes one of the aberrations may be provided. In this case, coma and astigmatism are corrected with higher accuracy.

  The ophthalmic laser surgical apparatus 1 (see FIG. 4) of the second embodiment measures the characteristics of the pulsed laser light transmitted through the dichroic mirror 14 in real time while irradiating the patient's eye E with the pulsed laser light. The aberration is corrected according to the measurement result. However, the configuration for measuring the characteristics of the pulsed laser beam in real time while irradiating the patient's eye E with the pulsed laser beam is not limited to the configuration illustrated in FIG. In the modification example described below, the same number is assigned to the same configuration as the above embodiment, and the description is omitted or simplified.

  The ophthalmic laser surgical apparatus 1 of the modification example shown in FIG. 7 includes a reflection plate 81 that reflects a part of the pulse laser beam in the middle of the optical path. In the example shown in FIG. 7, a reflecting plate 81 is provided on the optical path between the downstream LBE 12 and the dichroic mirror 14. The reflecting surface of the reflecting plate 81 is provided perpendicular to the optical axis. However, the position of the reflecting plate 81 may be changed. For example, a reflecting plate 81 may be provided on the optical path between the objective lens 15 and the interface 17. In the example shown in FIG. 7, a λ / 4 wavelength plate is used as the reflecting plate 81.

  In the example shown in FIG. 7, most of the pulsed laser light that has passed through the LBE 10 toward the patient's eye E is transmitted through the reflecting plate 81, but a part is reflected by the reflecting plate 81. When the pulse laser beam is reflected by the reflection plate (λ / 4 wavelength plate) 81, the polarization direction of the pulse laser beam changes.

  In the example shown in FIG. 7, a polarization beam splitter 82 is provided in the optical path between the laser light source 2 and the zoom expander 3. The polarization beam splitter 82 substantially transmits the pulsed laser light that travels downstream from the laser light source 2, and substantially reflects the pulsed laser light that has been reflected by the reflecting plate 81 and whose polarization direction has changed. The measuring device 26 is arranged at a position where the return light reflected by the polarizing beam splitter 82 is incident. The ophthalmic laser surgical apparatus 1 illustrated in FIG. 7 can measure the characteristics of the return light that returns the optical path toward the upstream side by the reflection plate 81 by the measuring device 26 while irradiating the patient's eye E with pulsed laser light. it can. Therefore, the ophthalmic laser surgical apparatus 1 illustrated in FIG. 7 can measure the aberration of the pulsed laser light in real time while irradiating the patient's eye E with the pulsed laser light.

  In the second embodiment and the third embodiment, the control unit 30 controls the operation of the actuator 60 so that the fourth lens 54 is automatically moved. However, also in the second embodiment and the third embodiment, the operator may manually move the fourth lens 54. In this case, for example, in the third embodiment, the control unit 30 may present the moving distance and moving direction of the fourth lens 54 to the operator based on the detection result of the mounting state of the interface 17. The control unit 30 does not need to be incorporated in the ophthalmic laser surgical apparatus 1. For example, the control unit of the personal computer may perform the same process as the process of the control unit 30 exemplified in the above embodiment.

  In the above embodiment, the “direction intersecting the optical axis of the pulse laser beam” is a direction perpendicular to the optical axis. However, the direction in which the optical element held by the holding mechanism 40 can move is not limited to the direction perpendicular to the optical axis.

  In the above embodiment, the aberration is changed by moving the optical element in the direction intersecting the optical axis of the pulse laser beam. That is, the holding mechanism 40 functions as an aberration changing unit. However, even if the configuration of the aberration changing unit is changed, the aberration of the pulse laser beam can be corrected. For example, the aberration changing unit may change the aberration by moving at least a part of the optical element in the optical axis direction. The aberration changing unit may change the aberration by changing the angle of the plate that transmits the pulse laser beam. A plurality of aberration changing units may be used.

1 Ophthalmic Laser Surgery Device 2 Laser Light Source 10 LBE
12 Downstream LBE
15 Objective Lens 17 Interface 21 Tomographic Image Capture Unit 22 Front Image Capture Unit 26 Measuring Device 27 Branch Mirror 30 Control Unit 31 CPU
36 Null lens 37 Reflecting mirror 40 Holding mechanism 60 Actuator

Claims (10)

An ophthalmic laser surgical apparatus for treating a patient's eye by condensing pulsed laser light in a tissue of the patient's eye,
A holding mechanism for holding at least one of the optical elements installed on the optical path of the laser light in a state movable in a direction intersecting the optical axis of the pulsed laser light;
An ophthalmic laser surgical apparatus, wherein the optical element held by the holding mechanism is moved in a direction crossing the optical axis, whereby the aberration of the pulse laser beam is corrected. The ophthalmic laser surgical apparatus according to claim 1,
The holding mechanism is
An ophthalmic laser surgical apparatus characterized in that a part of a plurality of lenses provided in a beam expander for expanding the beam diameter of the pulsed laser light is held in a movable state in a direction intersecting the optical axis. The ophthalmic laser surgical apparatus according to claim 1 or 2,
An actuator for moving the optical element held by the holding mechanism in a direction intersecting the optical axis;
A control unit for controlling the driving of the actuator;
An ophthalmic laser surgical apparatus, further comprising: The ophthalmic laser surgical apparatus according to claim 3,
A measuring instrument provided on an optical path branched from an optical path extending from the light source of the pulsed laser light to the patient's eye, and measuring a characteristic of the pulsed laser light;
The ophthalmic laser surgical apparatus, wherein the controller controls driving of the actuator according to a result measured by the measuring instrument. An ophthalmic laser surgical apparatus according to any one of claims 1 to 3,
An imaging means for imaging at least a part of an interface interposed between a main body of the ophthalmic laser surgical apparatus and the patient's eye in the optical path of the pulsed laser light;
The controller is configured to detect a state of the attached interface from an image photographed by the photographing unit, and to control driving of the actuator according to the detected state of the interface. Laser surgical device. 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 aberration changing unit that is installed on the optical path of the pulsed laser light and changes the aberration of the pulsed laser light;
A measuring instrument provided on an optical path branched from an optical path extending from the light source of the pulsed laser light to the patient's eye, and measuring the characteristics of the pulsed laser light;
With
The ophthalmic laser surgical apparatus is characterized in that the aberration of the pulsed laser beam is corrected by moving the aberration changing unit according to the result measured by the measuring instrument. 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 aberration changing unit that is installed on the optical path of the pulsed laser light and changes the aberration of the pulsed laser light;
Imaging means for imaging at least a part of an interface interposed between the main body of the ophthalmic laser surgical apparatus and the patient's eye in the optical path of the pulsed laser light,
With
An ophthalmic laser surgical apparatus characterized in that the aberration of the pulsed laser beam is corrected by moving the aberration changing unit in accordance with the state of the interface determined from an image photographed by the photographing means. An aberration correction method for correcting an aberration of an ophthalmic laser surgical apparatus for treating a patient's eye by condensing pulsed laser light in a tissue of a patient's eye,
A correction step of correcting the aberration of the pulsed laser beam by moving at least one of the optical elements installed on the optical path of the pulsed laser beam in a direction intersecting the optical axis of the pulsed laser beam. An aberration correction method characterized by the above. The aberration correction method according to claim 8, comprising:
A measurement step of measuring characteristics of the pulsed laser light by a measuring device provided on an optical path branched from an optical path extending from the light source of the pulsed laser light to the patient's eye;
In the correction step, the optical element is moved in accordance with the specification of the pulse laser beam measured in the measurement step. The aberration correction method according to claim 9, comprising:
Further comprising an installation step of installing a null lens that generates an aberration that approximates the aberration of the patient's eye in the optical path of the pulsed laser light;
In the measuring step, the characteristic of the pulse laser beam is measured in a state where the null lens is installed in the optical path of the pulse laser beam.