JP2018102792A - Ophthalmic laser treatment apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ophthalmic laser treatment apparatus that detects a degree of solidification generated by therapeutic laser light and performs irradiation control of therapeutic laser light based on a detection result.SOLUTION: An ophthalmic laser treatment apparatus includes: a second irradiation optical system for irradiating a treatment part with measuring light; a light receiving optical system for receiving reflected light corresponding to measuring light reflected at the treatment part; and irradiation control means for detecting a degree of solidification of the treatment part irradiated with therapeutic laser light using phase change in reflected light and controlling radiation of therapeutic laser light based on the detection result.SELECTED DRAWING: Figure 3

Description

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

  Laser treatment systems that irradiate a treatment site of a patient's eye with a laser treatment beam are known. For example, the laser treatment system of U.S. Pat. No. 6,053,075 adjusts the power and duration of the laser treatment beam in response to a selected energy value to form a barely visible trauma (endpoint).

JP 2014-14486 A

  However, even in the laser treatment system of Patent Document 1, there is a case where test irradiation is performed before irradiation of a treatment site. That is, there are cases where a trial hit is made on a site other than the treatment site to confirm that a barely visible trauma is formed. Moreover, the judgment of the test irradiation result relied on the operator's visual observation. There were problems such as increase in treatment time due to test irradiation, ambiguity due to visual judgment of the operator, or non-quantitative.

  The present disclosure is to provide an ophthalmic laser treatment apparatus that detects the degree of coagulation generated by a treatment laser beam and performs irradiation control of the treatment laser beam based on the detection result.

In order to solve the above problems, the present invention is characterized by having the following configuration.
(1) An ophthalmic laser treatment apparatus that performs treatment by irradiating a treatment laser beam to a patient's eye includes a first irradiation optical system for irradiating a treatment laser beam to the treatment site of the patient's eye, and measurement light to the treatment site. A second irradiating optical system for irradiating light, a light receiving optical system for receiving reflected light corresponding to the measurement light reflected at the treatment site, and coagulation of the treatment site irradiated with the treatment laser beam Irradiation control means for detecting the degree using the phase change of the reflected light and controlling the irradiation of the treatment laser light based on the detection result.

  ADVANTAGE OF THE INVENTION According to this invention, the ophthalmic laser treatment apparatus which detects the degree of coagulation produced | generated with the treatment laser beam, and performs irradiation control of a treatment laser beam based on a detection result can be provided.

It is a schematic block diagram of the optical system of the ophthalmic laser treatment apparatus. It is a schematic block diagram of a control part. It is a figure explaining the relationship between a treatment laser beam and reflected light. It is a flowchart concerning the irradiation control of a control part.

  Hereinafter, exemplary embodiments of the present disclosure will be described. FIG. 1 is a schematic configuration diagram of an ophthalmic laser treatment apparatus 1 according to this embodiment. The ophthalmic laser treatment apparatus 1 of this embodiment irradiates a treatment laser beam to a treatment site (for example, macular region of the fundus) of the patient's eye Ep, and performs treatment of the treatment site (photocoagulation of the treatment site in this embodiment). Used for. The ophthalmic laser treatment apparatus 1 according to this embodiment receives an irradiation optical system 10 for irradiating a treatment laser beam or measurement light to a patient eye Ep, and measurement light reflected by the patient eye Ep (hereinafter referred to as reflected light). A light receiving optical system 20 for observing the patient's eye Ep and an observation optical system 30 for observing the patient's eye Ep. In addition, the measurement light of this embodiment is used also as aiming light for irradiating a treatment laser beam to a treatment site.

<Irradiation optics>
The irradiation optical system 10 of the present embodiment includes a first irradiation optical system 10A for irradiating the patient's eye Ep with treatment laser light (treatment light), and a second irradiation optical system for irradiating the patient's eye Ep with measurement light. 10B. The first irradiation optical system 10A includes an optical axis L1, and the second irradiation optical system 10B includes an optical axis L2. In the present embodiment, the treatment laser light source 11, the dichroic mirror 13, the optical fiber 14, the irradiation lens group 15, and the half mirror 16 are arranged in this order to form the first irradiation optical system 10A. In the present embodiment, the measurement light source 12, the dichroic mirror 13, the optical fiber 14, the irradiation lens group 15, and the half mirror 16 are arranged in this order to form the second irradiation optical system 10B.

  The treatment laser light (for example, wavelength 577 nm (yellow)) emitted from the treatment laser light source 11 passes through the dichroic mirror 13 and then enters the incident end of the optical fiber 14. The treatment laser light emitted from the emission end of the optical fiber 14 passes through the irradiation lens group 15. The treatment laser light transmitted through the irradiation lens group 15 is deflected by the half mirror 16 toward the patient's eye Ep. The treatment laser light deflected by the half mirror 16 passes through the contact lens 41 and then forms a spot on the treatment site of the patient's eye Ep. In the present embodiment, the operator holds the contact lens 41. The treatment laser light source 11 may emit treatment laser light of 532 nm (green), 640 nm (red), or the like.

  Measurement light (for example, laser light having a wavelength of 635 nm (red)) emitted from the measurement light source 12 is reflected by the dichroic mirror 13 and travels toward the incident end of the optical fiber 14. The measurement light incident on the incident end of the optical fiber 14 travels in the order of the irradiation lens group 15, the half mirror 16, and the contact lens 41 in the same manner as the treatment laser light, and then strikes the treatment site of the patient's eye Ep. The dichroic mirror 13 of this embodiment makes the optical axis L1 of treatment laser light and the optical axis L2 of measurement light coaxial. Further, the half mirror 16 of the present embodiment makes the optical axis L2 of the second irradiation optical system 10B and the optical axis L3 of the light receiving optical system 20 coaxial.

<Light receiving optical system>
In the present embodiment, the light receiving optical system 20 is formed by arranging members in the order of the objective lens 21, the dichroic mirror 22, the band pass filter 23, and the light receiving element 24. The light receiving optical system 20 of this embodiment has an optical axis L3. The dichroic mirror 22 of the present embodiment has a characteristic of transmitting observation light and reflecting reflected light (measurement light reflected by the patient's eye Ep). Reflected light emitted from the patient's eye Ep (in other words, measurement light reflected by the treatment site of the patient's eye Ep) is reflected by the dichroic mirror 22 after passing through the half mirror 16 and the objective lens 21. The reflected light reflected by the dichroic mirror 22 is condensed on the light receiving element 24 after passing through the band pass filter 23.

<Observation optics>
The observation optical system 30 of the present embodiment shares the objective lens 21 and the dichroic mirror 22 with the light receiving optical system 20. The observation optical system 30 of this embodiment includes an operator protection filter 31 and an eyepiece lens group 32. The ophthalmic laser treatment apparatus 1 of this embodiment can illuminate the patient's eye Ep with observation illumination light (not shown). The observation illumination light (observation light) reflected by the patient's eye Ep passes through the half mirror 16, the objective lens 21, the dichroic mirror 22, the operator protection filter 31, and the eyepiece group 32 in this order, and then the fundus of the operator's eye Eo. It is focused on.

  The ophthalmic laser treatment apparatus 1 according to this embodiment includes a laser light source unit 17, a delivery unit 18, and a microscope unit 27. The laser light source unit 17 includes a treatment laser light source 11, a measurement light source 12, and a dichroic mirror 13. The delivery unit 18 includes an optical fiber 14, an irradiation lens group 15, and a half mirror 16. The microscope unit 27 includes an objective lens 21, a dichroic mirror 22, a band pass filter 23, a light receiving element 24, an operator protection filter 31, and an eyepiece group 32. In addition, the laser light source part 17 and the delivery part 18 of this embodiment are couple | bonded by the coupling mechanism (not shown). In addition, the irradiation optical system 10 or the light receiving optical system 20 of this embodiment is only an example. For example, the delivery unit 18 may include the light receiving optical system 20.

<Control unit>
The control unit 80 of this embodiment will be described with reference to FIG. The control unit 80 of the present embodiment includes a CPU 81, a ROM 82, a RAM 83, a nonvolatile memory 84 (flash memory), and the like. The CPU 81 controls each part of the ophthalmic laser treatment apparatus 1. The ROM 82 stores various programs, initial values, and the like. The RAM 83 temporarily stores various information. The nonvolatile memory 84 is a non-transitory storage medium that can retain stored contents even when power supply is interrupted. A treatment laser light source 11, a measurement light source 12, a light receiving element 24, a setting switch 85, a trigger switch 86, and the like are connected to the control unit 80 of the present embodiment. In the present embodiment, the setting switch 85 is used for various settings of the ophthalmic laser treatment apparatus 1. The trigger switch 86 is used when the surgeon starts irradiating treatment laser light. Note that the control unit 80 according to the present embodiment detects the degree of coagulation of the treatment site irradiated with the treatment laser beam using the phase change of the reflected light, and controls the irradiation of the treatment laser beam based on the detected result. Acts as a control means.

<Irradiation control of ophthalmic laser treatment device>
The usage method of the ophthalmic laser treatment apparatus 1 of this embodiment is demonstrated using FIG. 3 and FIG. In step S101, the control unit 80 turns on the measurement light. The operator can align the irradiation optical system 10 to the patient's eye Ep using the measurement light. In addition, the measurement light of this embodiment is irradiated (lit) as continuous light. Moreover, the measurement light of this embodiment is irradiated with a constant light amount. The control unit 80 of the present embodiment functions as measurement light irradiation control means. In step S102, the control unit 80 determines whether the trigger switch 86 has been pressed. When it is determined (detected) that the trigger switch 86 has been pressed, the control unit 80 proceeds to step S103, and when it is determined that the trigger switch 86 has not been pressed, the control unit 80 remains at step S102.

  In step S103, the control unit 80 irradiates treatment laser light. The ophthalmic laser treatment apparatus 1 according to this embodiment irradiates pulse light (rectangular wave) as treatment laser light. The treatment laser light of this embodiment is irradiated with a rectangular wave of less than 1 ms. The treatment laser light emitted from the ophthalmic laser treatment apparatus 1 forms a spot at the treatment site of the patient's eye Ep. The temperature of the treatment site where the spot is formed increases. In this way, the treatment site is more coagulated (photocoagulated) as the treatment site is irradiated with the treatment laser beam. The surgeon previously sets the pulse width of the treatment laser beam, the interval between pulses, the irradiation energy per pulse, the threshold value (limit value of the degree of coagulation), etc., using the setting switch 85. A threshold value based on statistical data (a limit value of the degree of coagulation) is stored in the nonvolatile memory 84, and may be automatically set by the control unit 80.

  Next, in step S104, the control unit 80 detects the degree of coagulation of the treatment site. Specifically, the ophthalmic laser treatment apparatus 1 of the present embodiment detects the degree of coagulation of the treatment site irradiated with the treatment laser light using the phase change of the reflected light. A method for detecting the degree of coagulation will be described in detail later. When the detection of the degree of coagulation is completed in step S104, the control unit 80 proceeds to step S105. In addition, irradiation of the treatment laser beam and detection of the degree of coagulation may be performed in parallel.

  In step S105, the control unit 80 determines whether or not the degree of coagulation detected in step S104 is equal to or less than a threshold value. When the degree of coagulation is less than or equal to the threshold, the control unit 80 returns to step S103 to irradiate the treatment laser light again. When the degree of coagulation exceeds the threshold, the control unit 80 returns to step S106 to end the treatment laser light irradiation sequence. move on. That is, until the degree of coagulation reaches the threshold value, irradiation with the treatment laser light and detection of the degree of coagulation are repeated. In other words, the ophthalmic laser treatment apparatus 1 of the present embodiment can detect the degree of coagulation of the treatment site in real time during the irradiation control of the treatment laser light. In step S106, the control unit 80 performs end processing. In the present embodiment, the treatment laser light irradiation (irradiation sequence) is completed at the time of step S104. Moreover, in this embodiment, irradiation of the measurement light to the patient's eye Ep is continued after step S106. As described above, irradiation control of the treatment laser light is performed so that the treatment site has a predetermined degree of coagulation. In addition, although the treatment laser beam of this embodiment is pulsed light, it may be continuous light. Continuous light may continue to be irradiated until a predetermined degree of solidification is reached.

<Detection of coagulation degree>
A method of detecting the degree of coagulation in this embodiment will be described with reference to FIG. In FIG. 3, the horizontal axis indicates time, and the vertical axis indicates the energy of the treatment laser beam or the amount of reflected light received. In FIG. 3, the characteristic of the treatment laser beam is indicated by a solid line, and the characteristic of the reflected light is indicated by a dotted line. In the state of FIG. 3, the patient's eye Ep is irradiated with measurement light with a constant light amount. When the temperature of the treatment site changes with irradiation of the treatment laser beam, the reflectance of the measurement light at the treatment site changes. In FIG. 3, the amount of reflected light decreases as the treatment laser beam is irradiated (that is, the reflectance decreases).

  Further, when the temperature of the treatment site changes with the irradiation of the treatment laser light, the phase of the reflected light changes. If it demonstrates using FIG. 3, the space | interval (code | symbol t1, t2, t3) of irradiation start timing (code | symbol a1, a2, a3 location) of treatment laser light and the light quantity change timing (code | symbol b1, b2, b3 location) of reflected light. ) Has changed. In FIG. 3, the intervals (reference numerals t1, t2, t3) are shortened as the treatment laser light is irradiated. In other words, in this embodiment, the thermal penetration rate of the treatment site is calculated using a thermoreflectance method (also called a light heating thermoreflectance method or a laser heat reflection method), and the calculation result is used to detect the progress of coagulation in the treatment site. Use. The thermoreflectance method is a method for measuring thermophysical properties from the phase of changes in heating light and reflected light from an object. In this embodiment, the treatment laser light is used as the heating light, the reflection of the measurement light is used as the reflected light, and the interval between the treatment laser light and the reflected light (reference numerals t1, t2, t3) is used as the phase.

  Thus, in the present embodiment, the degree of coagulation is quantified by detecting the thermal penetration rate of the treatment site irradiated with the treatment laser beam. Whether the control unit 80 of the present embodiment detects the coagulation state of the treatment site based on the phase of the reflected light and continues the irradiation of the treatment laser light while the treatment laser light irradiation is paused (pulse light pause section). Decide whether or not. The control unit 80 continues (restarts) irradiation of the treatment laser beam when the treatment site does not reach the desired coagulation state, and ends the irradiation of the treatment laser beam when the treatment site reaches the desired coagulation state. In this embodiment, the coagulation state of a treatment site can be detected quantitatively. Thereby, in this embodiment, it is easy to be freed from the problem which arises by the increase in the treatment time by test irradiation, and the ambiguity / non-quantitative by an operator's visual judgment.

<Action and effect>
As described above, the ophthalmic laser treatment apparatus 1 according to the present embodiment irradiates the treatment site with the first irradiation optical system 10A for irradiating the treatment site of the patient's eye Ep with the treatment laser beam. The second irradiation optical system 10B, the light receiving optical system 20 for receiving the reflected light corresponding to the measurement light reflected by the treatment site, and the degree of coagulation of the treatment site irradiated with the treatment laser beam Irradiation control means for detecting using the change and controlling the irradiation of the treatment laser beam based on the detection result. This eliminates the need for test irradiation, for example. In addition, the degree of coagulation can be quantified. Even an inexperienced operator can easily coagulate, and the burden on the patient can be reduced.

  In addition, the measurement light of the ophthalmic laser treatment apparatus 1 of the present embodiment is also used as aiming light for irradiating the treatment laser light to the treatment site. Thereby, for example, the degree of coagulation can be detected with a simple configuration. As another aspect of the ophthalmic laser treatment apparatus 1, the ophthalmic laser treatment apparatus 1 is reflected at the treatment site by the first irradiation optical system 10A for irradiating the treatment site of the patient's eye Ep with the treatment laser beam. A light receiving optical system 20 for receiving reflected light corresponding to the treatment laser light and the degree of coagulation of the treatment site irradiated with the treatment laser light using the phase change of the reflected light, and based on the detected result You may provide the irradiation control means which controls irradiation of a treatment laser beam. Thereby, for example, the configuration of the ophthalmic laser treatment apparatus 1 can be further simplified, test irradiation is not required, and the degree of coagulation can be quantified. Even an inexperienced operator can easily coagulate, and the burden on the patient can be reduced.

  Moreover, the irradiation control means of the ophthalmic laser treatment apparatus 1 of the present embodiment detects the degree of coagulation of the treatment site using the thermoreflectance method. Thereby, for example, the degree of coagulation can be detected with a simple configuration in which the treatment site is irradiated with the measurement light and the reflected light is received. The irradiation control means of the ophthalmic laser treatment apparatus 1 according to the present embodiment measures the change in reflectance of the treatment site from the change in the amount of reflected light, and detects the degree of coagulation of the treatment site based on the measurement result. Thereby, for example, by combining with the thermoreflectance method, it becomes possible to detect the degree of coagulation with higher accuracy. Note that the ophthalmic laser treatment apparatus 1 may detect the degree of coagulation only by estimating the change in reflectance based on the change in the amount of reflected light. Moreover, the irradiation control means of the ophthalmic laser treatment apparatus 1 of the present embodiment detects the degree of coagulation of the treatment site during irradiation of the treatment laser light. Thereby, for example, it is easy to quantify the degree of coagulation. Moreover, it is easy to suppress excessive coagulation. For example, solidification can be gradually advanced.

  In this embodiment, the coagulation state of the treatment site is detected by irradiating the measurement light, but the coagulation state of the treatment site may be detected only by the treatment laser beam. That is, treatment laser light may be used as measurement light. Thereby, for example, the ophthalmic laser treatment apparatus 1 can have a simpler configuration. In the present embodiment, the measurement light receives light reflected from the treatment site (reflected light), and detects the degree of coagulation at the treatment site. However, the treatment laser beam may receive light reflected from the treatment site and detect the degree of coagulation at the treatment site. In this method, there is no need to provide measurement light separately. In this embodiment, a rectangular wave pulse is irradiated as the treatment laser beam, but the treatment laser beam may be a sine wave. By using a sine wave, it is considered that the degree of coagulation can be detected more accurately. In addition, it is easy to simplify the treatment laser light source 11 because the treatment laser light is a rectangular wave pulse.

  It should be thought that embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1: Ophthalmic laser treatment apparatus 10A: first irradiation optical system 10B: second irradiation optical system 20: light receiving optical system 80: control unit

Claims (6)

A first irradiation optical system for irradiating the treatment site of the patient's eye with a treatment laser beam;
A second irradiation optical system for irradiating the treatment site with measurement light;
A light receiving optical system for receiving reflected light corresponding to the measurement light reflected by the treatment site;
An irradiation control means for detecting the degree of coagulation of the treatment site irradiated with the treatment laser light using a phase change of the reflected light, and controlling the irradiation of the treatment laser light based on the detected result;
An ophthalmic laser treatment apparatus comprising: The ophthalmic laser treatment device according to claim 1,
The ophthalmic laser treatment apparatus characterized in that the measurement light is also used as aiming light for irradiating the treatment site with the treatment laser light. A first irradiation optical system for irradiating the treatment site of the patient's eye with a treatment laser beam;
A light receiving optical system for receiving reflected light corresponding to the treatment laser light reflected at the treatment site;
An irradiation control means for detecting the degree of coagulation of the treatment site irradiated with the treatment laser light using a phase change of the reflected light, and controlling the irradiation of the treatment laser light based on the detected result;
An ophthalmic laser treatment apparatus comprising: The ophthalmic laser treatment apparatus according to any one of claims 1 to 3,
The irradiation control means detects the degree of coagulation of the treatment site using a thermoreflectance method,
An ophthalmic laser treatment apparatus characterized by the above. The ophthalmic laser treatment apparatus according to any one of claims 1 to 4,
The irradiation control means further measures the change in reflectance of the treatment site from the change in the amount of reflected light, and detects the degree of coagulation of the treatment site based on the measurement result.
An ophthalmic laser treatment apparatus characterized by the above. An ophthalmic laser treatment apparatus according to any one of claims 1 to 5,
The ophthalmic laser treatment apparatus, wherein the irradiation control means detects the degree of coagulation of the treatment site during the irradiation of the treatment laser light.