JP7205137B2 - Ophthalmic laser therapy device - Google Patents

Description

TECHNICAL FIELD The present disclosure relates to an ophthalmic laser treatment apparatus that performs treatment by irradiating a patient's eye with laser light.

2. Description of the Related Art An ophthalmic laser treatment apparatus has been put into practical use, which treats a patient's eye by concentrating a laser beam in the transparent tissue of the patient's eye to generate plasma, thereby causing photodisruption in the transparent tissue. In such an ophthalmic laser treatment apparatus, for example, a flash lamp-excited Nd:YAG laser is used as a light source.

This type of laser treatment apparatus is used, for example, as described in Patent Document 1, for treatment of secondary cataract occurring in the posterior capsule of the lens, treatment of glaucoma by perforation or incision of the iris or angle, and the like. In the posterior capsulorhexis for the treatment of secondary cataract, the therapeutic laser beam is irradiated with the focal position of the therapeutic laser beam shifted. That is, in the posterior capsulotomy, the distance between the posterior capsule surface of the lens and the position of plasma generation is adjusted by shifting the focal position of the treatment laser beam in order to reduce the impact of the treatment laser beam on the intraocular lens. are doing. On the other hand, in iridotomy for glaucoma treatment, treatment laser light is emitted without shifting the focal position of the treatment laser light.

JP 2016-154790 A

However, in the above-described ophthalmic laser treatment apparatus, the spot size of the treatment laser light is generally suitable for posterior capsulorhexis, which is frequently used. In other words, the spot size of the treatment laser beam was fixed (constant), and the spot size in the irisotomy was the same as in the case of the posterior capsulotomy (for example, about 8 μm). Therefore, the spot size is likely to be insufficient for the aqueous humor to flow through the iris incision, and it is desired that the iris incision can be performed with a treatment laser beam having a larger spot size.

Here, in the above-described ophthalmic laser treatment apparatus, it is possible to increase the spot size of the treatment laser beam, but as the spot size increases, the laser energy per unit area decreases in inverse proportion. When the energy of the therapeutic laser beam becomes small, plasma may not be generated and incision may not be possible. In particular, a spot size of at least 150 μm is desirable for iridotomy, but if the spot size of the treatment laser beam is increased to 150 μm in the above ophthalmic laser treatment apparatus, the laser energy per unit area becomes very small. As a result, it becomes difficult to generate plasma, and iridotomy may not be possible. If a laser light source capable of emitting high-power therapeutic laser light is used, iridotomy may be possible even if the spot size is increased.

Therefore, in order to solve the above-described problems, the present disclosure aims to provide an ophthalmic laser treatment apparatus that can generate plasma at the irradiation site even if the spot size of the treatment laser beam is increased. .

One aspect of the present disclosure made to solve the above problems is
An ophthalmic laser therapy apparatus capable of treating the transparent tissue of a patient's eye by condensing a laser beam into the transparent tissue to generate plasma,
A laser medium that is excited by excitation light, a first reflector and a second reflector that serve as optical resonators that resonate emitted light from the laser medium, and a saturable absorber that emits the emitted light as pulsed laser light. a solid-state laser device comprising
an excitation light source for injecting the excitation light into the solid-state laser element;
a zoom optical system that changes the beam size of the excitation light;
a motor for moving the zoom optical system;
an irradiation optical system that converges laser light emitted from the solid-state laser element onto a three-dimensional target position within the transparent tissue;
a control unit that controls the entire device ,
The control unit controls the motor to move the zoom optical system to change the beam size of the excitation light incident on the solid-state laser element, thereby obtaining a first zoom lens having a different spot size from the solid-state laser element. It is characterized in that the treatment laser beam and the second treatment laser beam are switched and emitted .

According to the ophthalmic laser treatment apparatus of the present disclosure, plasma can be generated at the irradiation site even if the spot size of the treatment laser beam is increased.

It is a perspective view which shows the external appearance of an ophthalmic laser treatment apparatus. It is a figure which shows schematic structure of the optical system and control system of an ophthalmic laser treatment apparatus. 1 is a perspective view of a microchip laser; FIG. 1 is a cross-sectional view of a microchip laser; FIG. FIG. 4 is a diagram showing a schematic configuration of a zoom optical system (low magnification state); FIG. 4 is a diagram showing a schematic configuration of a zoom optical system (high magnification state); FIG. 4 is a diagram showing the relationship between the amount of energy per pulse of therapeutic laser light emitted from a microchip laser; 1 is a diagram showing a schematic configuration of an optical system and a control system of an ophthalmic laser treatment apparatus when scanning irradiation is performed; FIG. It is a perspective view of a laser light source provided with a plurality of excitation light sources. It is a figure which shows the example of arrangement|positioning in the case of providing several excitation light sources. It is a figure which shows another example of arrangement|positioning in the case of providing several excitation light sources.

Hereinafter, typical embodiments of the present disclosure will be described in detail based on the drawings. First, the ophthalmic laser treatment apparatus of this embodiment will be described with reference to FIGS. 1 and 2. FIG. FIG. 1 is a perspective view showing the appearance of the ophthalmic laser treatment apparatus of this embodiment. FIG. 2 is a diagram showing a schematic configuration of an optical system and a control system of the laser treatment apparatus of this embodiment.

As shown in FIG. 1, the laser treatment apparatus 30 of this embodiment includes a main body 31, a pedestal 32, a control panel 33, a joystick 34, and a power supply 35. As shown in FIG. The body portion 31 is provided with a therapeutic laser light source, an aiming light source, a light guiding optical system, and the like. The mount 32 is vertically movable. The main body part 31 is mounted on the base 32 , and the main body part 31 moves up and down together with the base 32 .

The control panel 33 is an operation panel for setting laser irradiation conditions and the like, and can select a treatment mode from the operation panel. The joystick 34 moves the main body 31 forward, backward, leftward, and rightward on the table of the pedestal 32, and performs aiming for irradiating the affected area with the therapeutic laser light. By rotating a rotary knob provided on the joystick 34, the main body portion 31 is moved up and down to perform aiming in the vertical direction. A trigger switch 34a is provided on the head of the joystick 34, and the treatment laser beam is emitted (irradiated) toward the affected area by operating the trigger switch 34a.

A focus shift knob 36 and an excitation beam size change knob 37 are provided on the main body 31 . By operating the focus shift knob 36, a convex lens 49b, which will be described later, can be moved in the optical axis direction, and the focal position of the therapeutic laser beam can be shifted in the range of 0 to 500 μm toward the front side or the far side with respect to the focal position of the aiming light. It is possible. Further, by operating the excitation beam size changing knob 37, the beam size of the excitation light LB1 incident on the microchip laser 1, which will be described later, can be changed. The power supply unit 35 is provided with a power switch 35a. By operating the power switch 35a, the power of the laser treatment apparatus 30 is turned on/off.

Here, the optical system and control system provided in the main body 31 will be described with reference to FIG. As shown in FIG. 2, the laser treatment apparatus 30 includes a laser light source 41, a laser irradiation optical system 40 for irradiating a patient's eye E with a therapeutic laser beam emitted from the laser light source, and observing the patient's eye E. , a slit projection optical system 65 for projecting slit illumination onto the patient's eye E, and a controller 70 . The laser light source 41 of this embodiment is a light source that emits therapeutic laser light with a dominant wavelength of 1064 nm, and includes the microchip laser 1, a laser diode 42 that is an excitation light source, and a laser diode 42 between the microchip laser 1 and the laser diode 42. and a zoom optical system 10 arranged in the .

As shown in FIGS. 3 and 4, the microchip laser 1 of this embodiment includes a laser medium 2, a saturable absorber 3, a radiator 4, a first reflector 5, and a second reflector 6. , are integrated. This microchip laser 1 has, for example, a cylindrical shape having a central axis along the direction of the optical axis L. From the incident side of the excitation light LB1 (the left side in FIG. , the laser medium 2, the saturable absorber 3, and the second reflector 6 are arranged in the order of the optical axis L direction. In other words, the laser medium 2 and the saturable absorber 3 are arranged between the first reflecting section 5 and the second reflecting section 6 , and the first reflecting section 5 and the second reflecting section 6 allow the light from the laser medium 2 to It constitutes an optical resonator that resonates the emitted light. The shape of the microchip laser 1 is not limited to a columnar shape, and may be a polygonal columnar shape (for example, a rectangular parallelepiped shape).

The laser medium 2 contains a photoactive substance, and the photoactive substance is excited by the incidence of the excitation light LB1 emitted from the excitation light source (the laser diode 42 in this embodiment), and the photoactive substance emits light. is generated. As the laser medium 2, for example, one obtained by replacing yttrium (Y) in the YAG crystal as the base material with another rare earth element can be used. In this embodiment, an Nd:YAG crystal, for example, is used as the laser medium 2 . Therefore, the dominant wavelength of the excitation light LB1 is 808 nm, and the dominant wavelength of the emission light (laser light LB2) is 1064 nm. Note that the wavelength of the excitation light LB1 is not limited to 808 nm, and may be 885 nm, for example. Also, the laser medium 2 is not limited to the Nd:YAG crystal, and Yb:YAG crystal, for example, can also be used.

The saturable absorber 3 has a reduced light absorption rate due to saturation of light absorption, and operates as a passive Q switch in the optical resonator. That is, the saturable absorber 3 has a characteristic that when the light intensity is low, the light absorption rate is large, and when the light intensity exceeds a predetermined value, the light absorption is saturated and the light absorption rate suddenly decreases. This saturable absorber 3 is joined to the laser medium 2 . In this embodiment, a Cr:YAG crystal, for example, is used as the saturable absorber 3 .

The radiator 4 is a light transmissive material that transmits the excitation light LB1. The radiator 4 is joined to the first reflector 5 (laser medium 2) and radiates heat generated in the laser medium 2 to the outside. In this embodiment, for example, an undoped YAG crystal is used as the radiator 4 . The radiator 4 is not limited to non-doped YAG crystal, and may be made of sapphire, diamond, or the like.

The first reflector 5 acts as a total reflection mirror that transmits the excitation light LB<b>1 and reflects the emission light emitted from the laser medium 2 . The first reflector 5 is a dielectric multilayer film, and is formed on the end surface 2 a of the laser medium 2 opposite to the joint surface 23 with the saturable absorber 3 . In other words, the first reflector 5 is formed between the laser medium 2 and the radiator 4 . The second reflector 6 acts as a half mirror that transmits part of the emitted light from the laser medium 2 and reflects the rest. The second reflecting portion 6 is a dielectric multilayer film, and is formed on the end surface 3 b of the saturable absorber 3 opposite to the joint surface 23 with the laser medium 2 . Thus, the first reflecting portion 5 and the second reflecting portion 6 have the laser medium 2 and the saturable absorber 3 on the resonant optical path between them, and constitute an optical resonator that resonates the emitted light from the laser medium 2. do.

In such a microchip laser 1, a laser beam LB2 is emitted as follows. That is, emitted light generated from the laser medium 2 excited by the excitation light LB1 reaches the saturable absorber 3. As shown in FIG. At this time, while the power of the emitted light from the laser medium 2 is small, the light absorption rate of the saturable absorber 3 is large, and laser oscillation does not occur in the optical resonator. After that, the power of the emitted light from the laser medium 2 increases, and when the light intensity in the saturable absorber 3 exceeds a predetermined value, the light absorption of the saturable absorber 3 is saturated and the light absorbance sharply increases. Decrease. When the light absorption rate of the saturable absorber 3 decreases, the emitted light from the laser medium 2 passes through the saturable absorber 3 and makes a round trip between the first reflector 5 and the second reflector 6 . This causes stimulated emission in the laser medium 2 and laser oscillation in the optical resonator. As soon as such laser oscillation occurs, the power of the emitted light from the laser medium 2 decreases, the light absorption rate of the saturable absorber 3 increases, and the laser oscillation ends in the optical resonator. By repeating the above operations, the microchip laser 1 outputs a pulsed laser beam LB2.

Here, in the present embodiment, the beam size of the excitation light LB1 emitted from the laser diode 42 is changed by the zoom optical system 10 so as to enter the microchip laser 1 . As shown in FIG. 5, the zoom optical system 10 includes lenses 11 and 14 fixedly arranged on the optical axis L3 of the excitation light LB1, and a zoom lens 12 movably arranged along the optical axis L3. , 13 and motors 77 , 78 for moving the zoom lenses 12 , 13 . The zoom lenses 12 and 13 have the role of changing the beam size, and are moved along the optical axis L3 by controlling the driving of the motors 77 and 78 based on commands from the control section 70 . The zoom lens 12 is a convex lens, and the zoom lens 13 is a concave lens. Here, the zoom lens 12 serves as a variator and the zoom lens 13 serves as a compensator.

In this embodiment, for example, when performing a posterior capsulotomy, the control unit 70 moves the zoom lenses 12 and 13 in the direction of the optical axis L3 as shown in FIG. 5 to reduce the beam size of the excitation light LB1. (low magnification). At this time, in this embodiment, the beam size of the excitation light LB1 is set to 1 mm. On the other hand, when performing iris incision, the control unit 70 moves the zoom lenses 12 and 13 in the direction of the optical axis L3 as shown in FIG. 6 to increase the beam size of the excitation light LB1 (high magnification). At this time, in this embodiment, the beam size of the excitation light LB1 is set to 2 mm. In this manner, the control unit 70 switches (changes) the beam size of the excitation light LB1 incident on the microchip laser 1 by controlling the zoom optical system 10 . In this embodiment, the beam size of the excitation light LB1 is switched between two stages of low magnification and high magnification. can also be changed to In this embodiment, an excitation beam size changing knob 37 (see FIG. 1) is provided as an operation means for changing the beam size of the excitation light LB1.

FIG. 7 shows the relationship between the beam size of the excitation light incident on the microchip laser 1 and the amount of energy per pulse of the treatment laser light emitted from the microchip laser 1 in this embodiment. In the microchip laser 1 of this embodiment, the amount of energy of the emitted therapeutic laser light changes according to the beam size of the excitation light LB1. That is, when the beam size of the excitation light LB1 increases, the energy amount of the treatment laser light increases, and when the beam size of the excitation light LB1 decreases, the energy amount of the treatment laser light decreases. If the pulse energy required for the iris incision is 5.0 mJ, if the beam size of the excitation light LB1 is increased (1.8 mm or more), the treatment laser beam with a pulse energy of 5.0 mJ or more can be microscopically irradiated. It can be emitted from the chip laser 1 . In other words, the zoom optical system 10 of this embodiment can be said to be first adjustment means for adjusting the energy amount of the therapeutic laser light emitted from the laser light source 41 .

In this embodiment, the spot size of the therapeutic laser light emitted from the microchip laser 1 is determined by the beam size of the excitation light LB1 incident on the microchip laser 1. FIG. That is, if the beam size of the excitation light LB1 is increased, the spot size of the treatment laser beam is increased, and if the beam size of the excitation light LB1 is decreased, the spot size of the treatment laser beam is decreased.

Therefore, by increasing the beam size of the excitation light LB1 with the zoom optical system 10 to increase the spot size of the therapeutic laser light emitted from the laser light source 41, the energy amount of the therapeutic laser light can be increased. That is, for example, when the spot size of the therapeutic laser light is increased as in the conventional device, the amount of energy per unit area of the therapeutic laser light does not decrease. Therefore, in the laser treatment apparatus 30 of the present embodiment, even if the spot size of the treatment laser beam is increased, it is easy to secure a sufficient amount of energy (5.0 mJ or more) to generate plasma. Therefore, according to the laser treatment apparatus 30 of the present embodiment, plasma can be stably generated at the irradiation site when the treatment laser beam is expanded to a spot size of 150 μm and irradiated to the affected area. Therefore, it is easy to perform iridotomy with treatment laser light having a large spot size (150 μm in this embodiment).

Returning to FIG. 2, the laser irradiation optical system 40 of this embodiment includes a half-wave plate 45, a polarizing plate 46, a beam splitter 47, a safety shutter 48, a concave lens 49a and a convex lens 49b, a dichroic mirror 50, and an expander lens. 51 , a dichroic mirror 52 , an objective lens 53 and a contact lens 54 . These optical elements are arranged on the optical axis L1 in the above order from the laser light source 41 side.

The half-wave plate 45 rotates the polarization direction of therapeutic laser light emitted from the laser light source 41 . The polarizing plate 46 is arranged at Brewster's angle. The half-wave plate 45 is rotated by a command from the control unit 70, and adjusts the energy amount of the therapeutic laser light irradiated to the affected area of the patient's eye E in combination with the polarizing plate 46. FIG. In other words, in this embodiment, the polarizing plate 46 and the half-wave plate 45 constitute a second adjusting means for adjusting the energy amount of the therapeutic laser beam emitted from the laser light source 41 . The laser treatment apparatus 30 of this embodiment can emit treatment laser light whose energy amount is adjusted by the first adjustment means and the second adjustment means. Since the laser treatment apparatus 30 includes the first adjusting means, for example, it is easy to treat the affected area with a large spot size and a large amount of energy. In addition, since the laser treatment apparatus 30 includes the second adjustment means, for example, the amount of energy can be easily attenuated while maintaining the beam characteristics (quality) of the treatment laser light emitted from the laser light source 41 . Note that the laser treatment device 30 may not have the second adjustment means. In this case, for example, the configuration of the laser treatment apparatus 30 can be simplified more easily.

The beam splitter 47 reflects part of the therapeutic laser light that has passed through the polarizing plate 46 . The therapeutic laser light reflected by the beam splitter 47 is detected by the photodetector 55 . The safety shutter 48 shuts off the therapeutic laser light in predetermined cases such as test oscillation or when an abnormality occurs. After passing through the safety shutter 48, the beam of therapeutic laser light is expanded and arranged by the concave lens 49a and the convex lens 49b, and then made coaxial with the aiming light (dominant wavelength 633 nm) from the visible light semiconductor laser 60 by the dichroic mirror 50. be. Aiming light emitted from a visible light semiconductor laser 60 passes through a lens 61 to be converted into a parallel beam, and then separated into two beams by an aperture 62 having two openings provided symmetrically with respect to the optical axis L2. be.

The expander lens 51 expands the therapeutic laser beam and the aiming beam. The dichroic mirror 52 reflects part of the aiming light and the therapeutic laser light and transmits the observation light. Also, the dichroic mirror 52 makes the optical axis L1 (L2) coaxial with the optical axis of the objective lens 53 . The therapeutic laser beam reflected by the dichroic mirror 52 is focused on the affected area of the patient's eye E via the objective lens 53 and the contact lens 54 .

Also, the aiming light separated into two beams is reflected by the dichroic mirror 52 and then condensed by the objective lens 53 and the contact lens 54 at the reference condensing position of the therapeutic laser light. The condensing position of the therapeutic laser beam is shifted with respect to the condensing position of the aiming light by moving the convex lens 49b installed in the lens moving mechanism 59 in the direction of the optical axis L1. A light beam from the slit projection optical system 65 illuminates the patient's eye E through the contact lens 54 .

The control unit 70 controls the entire device. The control unit 70 is connected to the laser light source 41, and controls the laser diode 42 and the zoom optical system 10 (motors 77, 78) based on commands from the control unit 70 to control the laser light source 41 (microchip laser 1) to change the spot size of the therapeutic laser light emitted from. A detection circuit 71 for detecting and processing a signal from the photodetector 55 is connected to the control section 70 , and the signal processed by the detection circuit 71 is input to the control section 70 . A position detection potentiometer 72 for detecting the rotational position of the half-wave plate 45 is also connected to the controller 70 . Adjustment of the output of the therapeutic laser light irradiated to the patient's eye E is determined by the rotational position of the half-wave plate 45 . Therefore, by detecting the rotational position of the half-wave plate 45 with the position detection potentiometer 72, the control unit 70 can calculate the planned irradiation output of the therapeutic laser light. The calculation result is displayed on the control panel 33 and can be confirmed by the operator. Further, the controller 70 is also connected to a motor 73 that drives the safety shutter 48 to open and close, and the motor 73 is controlled by control signals from the controller 70 .

The controller 70 is also connected to a motor 74 that moves the convex lens 49b in the direction of the optical axis L1, and the motor 74 is controlled by a control signal from the controller 70. FIG. A rotating shaft of the motor 74 is connected to a rotating shaft of the focus shift knob 36 . The movement amount detection potentiometer 75 detects the movement amount of the convex lens 49b by detecting the rotation of the motor 74 . The movement detection potentiometer 75 is connected to the control section 70 . Then, the control unit 70 controls the driving amount of the motor 74 so that the focus position of the therapeutic laser light is the focus shift position set by the operator or according to the treatment mode, and the convex lens 49b is moved to the optical axis. Move in the direction of L2. The controller 70 is connected to a memory 76 that stores set values (such as the beam size and focus position of the excitation light LB1) set for each treatment mode.

A procedure for treating (treating) the patient's eye E using this laser treatment apparatus 30 will be described. First, the operator turns on the power of the main body 31 by operating the power switch 35a. When the power is turned on, the control unit 70 performs an initialization operation such as confirmation of driving of the safety shutter 48 . After completion of this initialization operation, the operator operates the switches and various setting knobs of the control panel 33 to set the laser irradiation conditions such as the laser irradiation output and the number of irradiation pulses according to the treatment purpose of the patient's eye E. In addition to setting, the focus shift position is adjusted as necessary. In this embodiment, by selecting one mode from a plurality of treatment modes on the control panel 33, various setting values suitable for the selected treatment are set. As the treatment mode, for example, a posterior capsulotomy mode (first treatment mode) for performing posterior capsulotomy for cataract treatment, an iridotomy mode (second treatment mode) for performing irisotomy for glaucoma treatment, and the like are set.

After such advance preparations are completed, the patient's eye E is placed at a predetermined position. The operator operates the joystick 34 to perform general alignment with the patient's eye E. FIG. Then, after the therapeutic laser beam can be irradiated, the joystick 34 is operated to perform further aiming so that the aiming beam split into two beams overlaps the affected area at one point. When aiming with the aiming light is completed, the operator presses the trigger switch 34a to irradiate the therapeutic laser light.

Here, when the posterior capsulotomy mode (first treatment mode) is selected, the zoom lenses 12 and 13 in the zoom optical system 10 are moved in the direction of the optical axis L3 as shown in FIG. The beam size of LB1 is reduced and enters the microchip laser 1 . As a result, a treatment laser beam (first treatment laser beam) having a spot size of 8 μm is emitted from the microchip laser 1 . The therapeutic laser light emitted from the microchip laser 1 is guided to the laser irradiation optical system 40, and condensed at a position shifted by the amount set by moving the convex lens 49b with respect to the focus position of the aiming light. and irradiated. Then, the therapeutic laser beam irradiated to the patient's eye E generates plasma at the irradiation site, causing photodisruption, thereby performing posterior capsulorhexis.

On the other hand, when the iris incision mode (second treatment mode) is selected, the zoom lenses 12 and 13 of the zoom optical system 10 are moved in the direction of the optical axis L3 as shown in FIG. The beam size is made larger than in the posterior capsulotomy mode and enters the microchip laser 1 . As a result, the microchip laser 1 emits therapeutic laser light (second therapeutic laser light) having a spot size of 150 μm. The therapeutic laser light emitted from the microchip laser 1 is guided to the laser irradiation optical system 40, and irradiated so that the therapeutic laser light is condensed with respect to the focus position of the aiming light. As described above, the microchip laser 1 can stably generate plasma at the irradiation site even if the spot size of the laser beam is increased. Therefore, even if the patient's eye E is irradiated with therapeutic laser light having a spot size of 150 μm, plasma is generated at the irradiation site and photodisruption occurs, so that iridotomy can be easily performed. As a result, the iris incision can be performed efficiently in a short period of time, thereby reducing the burden on the operator and the patient. In the above description, the control unit 70 detects the treatment mode selected by the operator, and automatically moves the zoom lenses 12 and 13 based on the detection result. However, in this embodiment, the operator can change the beam size to any desired size by operating the excitation beam size changing knob 37 regardless of the treatment mode. As a result, for example, treatment can be easily performed with a more suitable spot size according to the condition of the affected area.

Further, according to the laser treatment apparatus 30 of the present embodiment, since the microchip laser 1 is used as the laser light source 41, the patient's eye E can be easily irradiated with laser light having the same pulse shape at all times. Therefore, for example, plasma of a certain size can be stably generated with lower pulse energy than the conventional laser treatment apparatus, and highly accurate treatment (improved incision accuracy) can be performed in a short time. This makes it possible to reduce the influence of the laser light on areas other than the affected area (intraocular lens and other normal ocular tissues). Therefore, according to the laser therapy device 30, minimally invasive (highly efficient) treatment is possible.

Moreover, in the laser treatment apparatus 30 of this embodiment, the patient's eye E can be irradiated with the treatment laser beam at a repetition frequency of 50 Hz or more. The laser treatment apparatus 30 can always irradiate the patient's eye E with laser light having the same pulse shape. As a result, according to the laser therapy apparatus 30, treatment by scanning irradiation (continuous irradiation) of therapeutic laser light becomes possible. can. As a result, the treatment time can be shortened and the operation can be simplified, so that the burden on the operator and the patient can be reduced.

When performing such scanning irradiation of the therapeutic laser beam, for example, in the laser irradiation optical system 40, as shown in FIG. should be provided. The scanning unit 80 is a unit having an optical scanner that changes the traveling direction of the therapeutic laser beam from the laser light source 41 (microchip laser 1) (deflects the laser beam). For example, the scanning unit 80 can be composed of a resonant scanner 81 and a galvanomirror 82 , and their operations are controlled by the control unit 70 . Then, for example, the resonant scanner 81 performs main scanning of the therapeutic laser beam, and the galvanomirror 82 performs sub-scanning of the therapeutic laser beam. As the optical scanner of the scanning unit 80, for example, an acoustooptic device (AOM) that changes the traveling (deflecting) direction of light may be used in addition to a reflecting mirror (galvanomirror, polygon mirror, resonant scanner).

Here, in the laser treatment apparatus 30 described above, the laser light source 41 having one laser diode 42 as an excitation light source is exemplified. However, as the laser light source 41, a plurality of laser diodes 42, which are excitation light sources, can be provided. Thereby, it is possible to emit a plurality of therapeutic laser beams from the microchip laser 1 . For example, as shown in FIG. 9, three laser diodes 42a, 42b, 43c may be provided. Of course, the number of laser diodes arranged as excitation light sources is not limited to three, and may be two or four or more.

When a plurality of laser diodes 42 are provided in this way, the control section 70 controls the emission timing of each of the laser diodes 42a, 42b, and 43c. For example, by causing the laser diodes 42a, 42b, and 43c to simultaneously emit excitation light beams LB1a, LB1b, and LB1c by the control unit 70, a plurality of therapeutic laser beams LB2a, LB2b, and LB2c are emitted from the microchip laser 1. . Then, the plurality of therapeutic laser beams LB2a, LB2b, and LB2c are combined and condensed by the laser irradiation optical system 40 to finally become one laser beam LB2, and the affected part of the patient's eye E is irradiated with the laser beam LB2. Therefore, it is possible to irradiate the patient's eye E with the treatment laser beam LB2 having a higher energy than in the case of 1-pulse irradiation. This eliminates the need to use a high-power laser diode as an excitation light source. In addition, the output of the pumping light incident on the microchip laser 1 is reduced, and the pumping light is incident on the laser medium 2 at a plurality of locations. Therefore, heat generation in the microchip laser 1 is suppressed and heat dissipation efficiency is improved. As a result, the output of the microchip laser 1 can be increased.

Further, for example, by causing the laser diodes 42a, 42b, and 43c to emit excitation light beams LB1a, LB1b, and LB1c at different timings by the control unit 70, the therapeutic laser beams LB2a, LB2b, and LB2c are emitted from the microchip laser 1. Illuminated continuously at different timings. Thereby, in the laser treatment apparatus 30, parallel pulse irradiation can be performed by irradiating the affected part of the patient's eye E with the treatment laser beams LB2a, LB2b, and LB2c at different timings. The irradiation interval of the therapeutic laser light may be determined according to the characteristics of the tissue of the affected area to be treated.

By performing such parallel pulse irradiation, even if the pulse energy of the second and subsequent therapeutic laser beams LB2b and LB2c is reduced, the affected area can be appropriately treated. Therefore, the pulse energy of the therapeutic laser required for the treatment can be made smaller than before, so that the surgical scar on the affected area can be kept clean, and treatment with little influence on the surroundings of the affected area can be realized. In addition, even if the energy of the therapeutic laser beam irradiated to the patient's eye E is made smaller than in the conventional method, the same treatment as in the conventional method can be performed. Furthermore, since the output of the therapeutic laser light can be suppressed, the cost and size of the laser therapy device 30 can be reduced.

Furthermore, when a plurality of laser diodes 42 are provided, they can be arranged in the irradiation pattern shape of the therapeutic laser light that is generally (many) performed in the treatment of the patient's eye E. For example, as shown in FIG. 10, the laser diodes 42a-42i can be arranged in a cross shape, or as shown in FIG. 11, the laser diodes 42a-42l can be arranged in a circular shape. By causing the controller 70 to simultaneously emit excitation light from the laser diodes 42a, 42b, 43c, . Therefore, the operability of the laser treatment apparatus 30 can be improved and the treatment time can be greatly shortened. As a result, the burden on the operator and the patient can be greatly reduced.

It should be noted that the above-described embodiment is merely an example and does not limit the present disclosure in any way, and of course various improvements and modifications are possible without departing from the gist of the present disclosure. For example, a microchip laser mounted in a laser therapy device of the present disclosure includes a saturable absorber to act as a passive Q-switch. However, the technique of the present disclosure can also be applied to a laser treatment apparatus equipped with a microchip laser that does not have a passive Q-switch in its resonator.

1 microchip laser 2 laser medium 3 saturable absorber 5 first reflector 6 second reflector 10 zoom optical system 30 laser treatment device 40 laser irradiation optical system 41 laser light source 42 laser diode 70 controller E patient's eye LB1 excitation light LB2 laser light

Claims (2)

An ophthalmic laser therapy apparatus capable of treating the transparent tissue of a patient's eye by condensing a laser beam into the transparent tissue to generate plasma,
A laser medium that is excited by excitation light, a first reflector and a second reflector that serve as optical resonators that resonate emitted light from the laser medium, and a saturable absorber that emits the emitted light as pulsed laser light. a solid-state laser device comprising
an excitation light source for injecting the excitation light into the solid-state laser element;
a zoom optical system that changes the beam size of the excitation light;
a motor for moving the zoom optical system;
an irradiation optical system that converges laser light emitted from the solid-state laser element onto a three-dimensional target position within the transparent tissue;
a control unit that controls the entire device ,
The control unit controls the motor to move the zoom optical system to change the beam size of the excitation light incident on the solid-state laser element, thereby obtaining a first zoom lens having a different spot size from the solid-state laser element. Switching between the treatment laser beam and the second treatment laser beam for emission
An ophthalmic laser treatment device characterized by: In the ophthalmic laser treatment device according to claim 1 ,
The control unit
when a first treatment mode for performing posterior capsulotomy of the patient's eye is selected, emitting the first treatment laser light from the solid-state laser element;
An ophthalmology clinic characterized in that, when a second treatment mode for performing iridotomy on a patient's eye is selected, the second treatment laser beam having a spot size larger than that of the first treatment laser beam is emitted from the solid-state laser element. for laser therapy.

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