JP2016083318A - Ophthalmologic apparatus, and method to control ophthalmologic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ophthalmologic apparatus which reduces a burden on a subject in ophthalmography, and a method to control the ophthalmologic apparatus.SOLUTION: The ophthalmologic apparatus comprising an imaging system focus lens disposed in an imaging optical system for acquiring an image of a subject eye and a fixation lamp focus lens disposed in a fixation lamp system for accelerating fixation of the subject eye further comprises control means which executes focal adjustment of the imaging system focus lens and thereafter executes focal adjustment of the fixation lamp focus lens.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an ophthalmic apparatus used for ophthalmic medical care and the like and a control method thereof.

  2. Description of the Related Art In recent years, an optical image measurement technique that forms an image of the surface or inside of an object to be measured using light attracts attention. Since the optical image measurement technique uses light that does not have invasiveness to the human body, such as conventional X-ray CT, application development is expected especially in the medical field. Above all, the application in the field of ophthalmology has made remarkable progress.

  As a typical technique of optical image measurement technology, there is a technique called optical coherence tomography (OCT: Optical Coherence Tomography: hereinafter referred to as an OCT apparatus). According to this method, since an interferometer is used, measurement with high resolution and high sensitivity is possible. In addition, since weak broadband light is used as illumination light, there is also an advantage that safety to the subject is high.

  On the other hand, the OCT device has a long measurement time among ophthalmic devices and superimposes images for noise removal, so it is important to minimize physical movement of the eye to be examined (stabilization of fixation). It is. For this reason, the OCT apparatus preferably has a fixation lamp projection system that presents a fixation target that is easily visible to the eye to be examined. For this reason, a conventional fixation lamp projection system generally has a focus lens drive mechanism. For example, in the apparatus disclosed in Patent Document 1, the fixation lamp projection system has a focus lens that is common to the fundus camera imaging system, and is configured to be adjustable in focus.

JP 2010-181172 A

  Here, examples of the fundus oculi observation system used for observing the fundus of the eye to be examined include an OCT imaging system, an SLO (confocal laser scanning ophthalmoscope) imaging system, and a fundus camera. The focusing configuration of the fundus observation optical system and the configuration for fixing the fixation lamp are simultaneously moved, and conventionally, the fixation lamp focus position is determined simultaneously according to the focus position of the fundus observation system.

  However, when the configuration for focusing on the fundus oculi observation system and the configuration for fixation lamp focus are moved simultaneously, the eye to be inspected adjusts the diopter following the fixation lamp focus. For this reason, eye fatigue due to diopter adjustment is given to the eye to be examined. Furthermore, since the focus position of the fundus observation system is moved under the influence of diopter adjustment of the eye to be examined, it takes time to determine the focus position. As a result, the subject is burdened by taking the measurement posture for a long time.

  When determining the fixation lamp focus position, the fixation lamp focus needs not to be moved in order not to adjust the diopter of the eye to be examined. First, the fundus observation system focus is moved to find a focus position, and the fixation lamp focus is moved later in accordance with the determined fundus observation system focus focus position. As a result, the focus position of the fundus observation system focus and the fixation lamp focus can be uniquely determined after eliminating the diopter adjustment of the eye to be examined.

  In view of the above points, an object of the present invention is to provide an ophthalmologic apparatus that reduces the time required for focusing, reduces the measurement time, and reduces the burden on the subject, and a control method thereof.

In order to solve the above problems, an ophthalmologic apparatus according to the present invention includes an imaging system focus lens disposed in an imaging optical system that acquires an image of an eye to be examined;
When arranged in a fixation lamp system that promotes fixation of the eye to be examined, a fixation lamp focus lens;
Control means for executing the focus adjustment of the fixation lamp focus lens after executing the focus adjustment of the photographing system focus lens.

  According to the present invention, it is possible to shorten the time required to focus the eye to be examined, and to reduce the burden on the subject.

It is a figure which shows typically the structure of the whole apparatus which concerns on one Embodiment of this invention. It is the schematic which shows the structure of the measurement optical system which concerns on the 1st Embodiment of this invention. It is a flowchart which shows the imaging | photography procedure which concerns on the 1st Embodiment of this invention. It is a brightness | luminance graph of an SLO image at the time of focus adjustment in a SLO imaging system. It is the schematic which shows the structure of the measurement optical system which concerns on the 2nd Embodiment of this invention. It is a flowchart which shows the imaging | photography procedure which concerns on the 2nd Embodiment of this invention. It is a flowchart which shows the imaging | photography procedure which concerns on the 3rd Embodiment of this invention. It is the schematic which shows the structure of the measurement optical system which concerns on the 4th Embodiment of this invention.

  Hereinafter, the best embodiment of the present invention will be described. In this embodiment, an optical tomography apparatus (OCT apparatus) is taken as an example of an ophthalmologic apparatus. However, the ophthalmologic apparatus to which the present invention can be applied is not limited to the OCT apparatus, and can be applied to general ophthalmologic photographing apparatuses having an internal fixation lamp such as an SLO apparatus and a fundus camera.

[First Embodiment]
An optical tomographic imaging apparatus to which the present invention is applied, which is a first embodiment of an ophthalmic apparatus according to the present invention, will be described below.

(Schematic configuration of the device)
A schematic configuration of the optical tomographic imaging apparatus according to the present embodiment will be described with reference to FIG.

  FIG. 1 is a side view of an optical tomographic imaging apparatus according to an embodiment of the present invention. The optical tomographic imaging apparatus 200 includes an optical head 900, a stage unit 950, a base unit 951, and a chin rest 323, and includes a personal computer 825, a monitor 928, and an input unit 929 as components for controlling these components.

  The optical head 900 is a measurement optical system for capturing a two-dimensional image and a tomographic image of the fundus of the eye to be examined. The stage unit 950 functions as a moving unit that can move the optical head 900 in the xyz direction in the drawing using a motor (not shown). The base unit 951 supports the stage unit 950 and incorporates a spectrometer described later.

  The personal computer 925 also serves as a control unit of the optical tomographic imaging apparatus 200, and performs the configuration of the tomographic image and the like along with the control of the optical tomographic imaging apparatus 200. The personal computer 925 includes a hard disk 926 that stores a program for tomographic imaging. The personal computer 925 gives instructions to the monitor 928 as a display unit and the personal computer, and is specifically connected to an input unit 929 including a keyboard and a mouse. The chin rest 323 promotes fixation of the subject's eyes (examined eye) by fixing the subject's chin and forehead. In the present embodiment, the control unit 925, the hard disk 926, and the display unit 928 are provided outside the optical tomographic imaging apparatus 200, but may be configured to be built in the optical tomographic imaging apparatus 200.

(Configuration of measurement optical system and spectrometer)
Next, the configuration of the measurement optical system and the spectroscope according to the first embodiment of the present invention will be described with reference to FIG.

  First, optical elements and the like arranged inside the optical head 900 will be described. In the optical head 900 according to the present embodiment, an OCT optical system disposed on the optical path L1, an internal fixation lamp and an SLO imaging system disposed on the optical path L2, and an optical path L3 are disposed according to the application. An anterior ocular segment observation optical system is housed.

  In the optical head 900, the objective lens 101-1 is disposed facing the eye 100, and the dichroic mirror 102 and the dichroic mirror 103 are disposed on the optical axis thereof. By these dichroic mirrors, the optical path from the eye to be examined is branched into the above-described optical path L1, optical path L2, and optical path L3 for each wavelength band.

A dichroic mirror 106 is further disposed on the optical path L2. The dichroic mirror 106 causes the optical path L2 to travel to the optical path to the internal fixation lamp 112 and to the optical path to the SLO imaging system that reaches the SLO light source 109 and the photodetector 110. Branch off.

  A lens 101-2, an X scanner 104-1, a Y scanner 104-2, a lens 105, the dichroic mirror 106, the lens 107, and the mirror 108 are arranged in this order from the dichroic mirror 103 on the optical path L 2 leading to the SLO imaging system. Be placed. The mirror 108 transmits the light emitted from the light source 109, is reflected by the eye to be examined 100, and guides the measurement light that has passed through the lens 107 to the photodetector 110. Further, the lens 11 and the internal fixation lamp 112 are arranged in order from the dichroic mirror 106 in the optical path on the internal fixation lamp side.

  The lens 107 is used for focus adjustment with respect to the eye to be examined in the SLO imaging system, and the lens 111 is used for focus adjustment of the internal fixation lamp, and is driven by a motor (not shown). The measurement light emitted from the light source 109 has a center value near 780 nm, and the photodetector 110 is sensitive to light near 780 nm. On the other hand, the internal fixation lamp 112 generates visible light to promote fixation of the subject.

  Light emitted from the light source 109 and the internal fixation lamp 112 is scanned by the X scanner 104-1 and the Y scanner 104-2, respectively. Thereby, the whole region of interest in the fundus of the eye to be examined can be measured using SLO. In addition, the internal fixation lamp 112 can project various patterns such as a cross shape and an X shape on various positions of the eye to be inspected by controlling the lighting position in conjunction with the scanning of the measurement light by these scanners. It becomes possible. Accordingly, by directing the eye to be examined in various directions, a wide area in the fundus of the eye to be examined can be imaged.

  The optical path L1 constitutes an OCT optical system as described above, and obtains an interference signal for forming a tomographic image. In the optical path L1, a lens 101-3, a mirror 113, an X scanner 114-1, a Y scanner 114-2, a lens 115, and a lens 116 are arranged in this order from the dichroic mirror 103. The X scanner 114-1 and the Y scanner 114-2 are used for scanning the OCT measurement light on a measurement target part (fundus and anterior eye part) of the eye 100 to be examined. The lens 115 is driven by a motor (not shown) in order to adjust the focus of the light from the light source 118 emitted from the fiber 117-2 connected to the optical coupler 117 to the measurement target portion of the eye to be examined. By this focusing adjustment, the light from the measured part is simultaneously imaged in the form of a spot on the tip of the fiber 117-2 and is incident on the fiber 117-2.

  Next, the optical path from the light source 118, the reference optical system in the OCT optical system, and the configuration of the spectrometer will be described. The OCT imaging system includes a light source 118, a mirror 119, a dispersion compensation glass 120, the above-described optical coupler 117, optical fibers 117-1 to 117-4, and a lens 121 in addition to the configuration of the above-described OCT optical system. A spectroscope 180 is further added to these configurations, and in this embodiment, a Michelson interferometer is configured. The optical fibers 117-1 to 117-4 are single mode optical fibers that are connected to and integrated with an optical coupler.

  The light emitted from the light source 118 is split into measurement light on the optical fiber 117-2 side and reference light on the optical fiber 117-3 side through the optical coupler 117-1 through the optical coupler 117-1. The measurement light is irradiated on the fundus of the eye 100 to be inspected through the objective lens 101-1, through the optical path L1 of the OCT optical system. The irradiated measurement light returns through the same optical path due to reflection and scattering by the retina of the eye 100 and reaches the optical coupler 117.

  On the other hand, the reference light reaches the reference mirror 119 via the optical fiber 117-3, the lens 121, and the dispersion compensation glass 120, and is reflected. The dispersion compensation glass 120 is inserted on the optical path to match the dispersion of the measurement light and the reference light. The reference light reflected by the reference mirror 119 returns along the same optical path and reaches the optical coupler 117. The measurement light and the reference light are combined by the optical coupler 117 and become interference light. Here, interference occurs when the optical path length of the measurement light and the optical path length of the reference light satisfy a predetermined condition.

  The reference mirror 119 is held so as to be adjustable in the optical axis direction by a motor and a driving mechanism (not shown), and the optical path length of the reference light can be adjusted to the optical path length of the measuring light that varies depending on the part to be measured. The interference light is guided to the spectroscope 180 via the optical fiber 117-4.

  The spectroscope 180 includes a lens 181, a diffraction grating 182, a lens 183, and a line sensor 184. The interference light emitted from the optical fiber 117-4 becomes substantially parallel light via the lens 181, and then is dispersed by the diffraction grating 182 and imaged on the line sensor 184 by the lens 183. The licensor 184 is shown as an example of a light receiving element that receives interference light and generates and outputs an output signal corresponding to the interference light in the present invention.

  Next, the periphery of the light source 118 will be described. In the present embodiment, a super luminescent diode (SLD), which is a typical low coherent light source, is used as the light source 118. The center wavelength of the obtained measurement light is 855 nm, and the wavelength bandwidth is about 100 nm. Here, the bandwidth is an important parameter because it affects the resolution of the obtained tomographic image in the optical axis direction. Further, although the SLD is selected here as the type of light source, it is only necessary to emit low-coherent light, and ASE (Amplified Spontaneous Emission) or the like can also be used. In view of measuring the eye, the center wavelength is preferably near infrared light. Moreover, since the center wavelength affects the lateral resolution of the obtained tomographic image, it is desirable that the center wavelength be as short as possible. For both reasons, in this embodiment, measurement light having a center wavelength of 855 nm is used.

  In the present embodiment, a Michelson interferometer is used as an interferometer, but a Mach-Zehnder interferometer may be used. These are preferably selected according to the light amount difference between the measurement light and the reference light. If the light amount difference is large, use a Mach-Zehnder interferometer. If the light amount difference is relatively small, use a Michelson interferometer. Is desirable.

(Shooting flow)
A tomographic imaging flow in the first embodiment will be described with reference to FIG. First, when the subject places his / her jaw on the chin rest 323 and the position of the eye to be examined is fixed, measurement is started by aligning the optical head 900 with respect to the eye to be examined (S101). When the alignment is completed, first, the focus adjustment of the SLO imaging system is performed (S102). Specifically, the control unit 925 adjusts the position of the SLO focus lens 107 on the optical axis by a drive system (not shown) while calculating the luminance or contrast of the SLO image. Then, the position on the optical axis of the SLO focus lens 107 that maximizes the brightness or contrast of the SLO image is determined as the in-focus position at the time of imaging the SLO image. That is, the in-focus position of the SLO focus lens 107 of the photographing system is the signal intensity output from the photodetector 110 that is a light receiving element that receives measurement light from the eye to be examined via the focus lens 107, or the contrast of the image of the eye to be examined. To be determined.

  In order to adjust the focus of the SLO imaging system, an optical system that projects a focus target (for example, a split index) on the fundus of the eye to be examined may be separately provided. In this case, an index image (fundus reflection image) based on the fundus reflection light of the projection light is received by the two-dimensional image sensor, and the focus position information is acquired based on the light reception result output from the two-dimensional image sensor. good.

  Since the diopter of the eye to be examined is known by the focus adjustment of the SLO imaging system, in the subsequent S103, the focus adjustment of the internal fixation lamp is performed in accordance with the diopter. After completing the focus adjustment in S103, in S104, the focus adjustment of the OCT optical system is performed in accordance with the diopter of the eye to be examined. Since the in-focus positions on the optical axis of the focusing lenses of the internal fixation lamp and the OCT optical system are uniquely determined if the diopter of the eye to be examined is known, these adjustments can be performed at the same time.

  After the focus adjustment of the OCT optical system is completed, the optical path length of the reference light is adjusted in S105. At that time, the control unit 925 changes the reference optical path length using the OCT image as an index. Then, the reference optical path length is adjusted to determine the reference light optical path length so that the portion to be measured appears at the position where it can be best seen. Finally, the region is scanned with the measurement light over the entire region of interest of the eye to be examined, and a tomographic image of the region is captured (S106).

  Here, the focus adjustment of the SLO imaging system executed in S102 will be described more specifically. In the conventional shooting flow, the focus adjustment of the internal fixation lamp is performed simultaneously with the focus adjustment of the SLO shooting system. On the other hand, the human eye has diopter adjustment power, and adjusts the diopter following the focus adjustment of the internal fixation lamp. For this reason, the focus position of the SLO imaging system is not uniquely determined, and the SLO image is focused in the entire diopter adjustment range of the eye to be examined.

  On the other hand, in the first embodiment described above, the focus of the internal fixation lamp is fixed during the focus adjustment of the SLO imaging system. For this reason, the eye to be examined is in a unique diopter state in a natural state. That is, the focus position of the SLO imaging system is uniquely determined.

  FIG. 4 shows a luminance graph of an SLO image (possible as a contrast graph) during focus adjustment in the conventional and first embodiments. In order to find the in-focus position of the SLO imaging system, that is, the peak of the luminance of the SLO image, it is necessary to find a point where the luminance increases and decreases. As described above, in the conventional focus adjustment operation, the eye to be examined performs diopter adjustment following the focus adjustment of the SLO imaging system. Therefore, the in-focus position of the SLO imaging system cannot be found without moving the focusing lens from end to end with respect to the diopter adjustment range of the eye to be examined.

  On the other hand, as shown in FIG. 4, in the focus adjustment according to the first embodiment, since the eye to be examined is in a unique diopter state, the luminance peak of the SLO image is determined as one point. That is, when the focusing lens moves to the diopter in the diopter state, the focusing position of the SLO imaging system can be found.

  Further, since the focus position B in FIG. 4 determined by the focus adjustment of the first embodiment is in a natural diopter state of the eye to be examined, this is also a diopter state that is easy for the eye to be examined. Diopter is stable. On the other hand, according to the conventional focus adjustment, the focus position may be recognized as the focus position in the range of diopters A to B 'in FIG. The position indicated as the in-focus position A is the most near-sighted position in the diopter adjustment range.

  If the in-focus position has been determined at this point A, the diopter is not stable because the eye to be examined is in a state where the diopter is adjusted to the maximum extent, that is, in a state where the maximum force is applied to the crystalline lens. . For this reason, when the eye to be examined loosens the diopter adjustment during the subsequent OCT image capturing, the focused state for the OCT image is lost and the OCT image becomes blurred. Therefore, even in the conventional sequence, it is preferable to take an image on the far vision side (a state in which the power of the crystalline lens is lost and diopter adjustment is not working) as much as possible. That is, it is necessary to move the in-focus positions of the SLO optical system, the internal fixation lamp, and the OCT optical system to B 'on the far vision side again.

  As described above, the focus adjustment is easier in the focus adjustment operation in the first embodiment than in the conventional focus adjustment operation. Furthermore, since the eye fatigue due to the diopter adjustment of the eye to be examined is avoided, the burden on the eye to be examined can be reduced.

  In S103, it is preferable to start driving the focusing lens from the farthest side in the diopter adjustment range of the apparatus in focusing adjustment of the internal fixation lamp. From this state, it is preferable to adjust the focus of the internal fixation lamp by moving the focusing lens to the near vision side.

  For example, consider the case where the focus adjustment of the internal fixation lamp is started from a diopter of 0D (diopter). In this way, in the case of a hyperopic subject eye whose diopter can be adjusted to 0D, diopter adjustment is performed in step S102 in order to see the fixed visual acuity of 0D. For this reason, a load is applied to the eye to be examined, and the diopter adjustment of the eye to be examined during photographing is out of focus of the OCT image, resulting in a blurred image of the OCT image. As in this embodiment, it is preferable to start the focus adjustment after moving the fixation lamp focus lens to the far vision side so that the focus adjustment of the internal fixation lamp is started from the farthest side. With this configuration, it is possible to prevent the subject's eye from adjusting the diopter, and the focus adjustment of the internal fixation lamp can be adjusted to the natural diopter state of the subject's eye. As a result, the fixation lamp can be seen in a natural state for the eye to be inspected, and a stable fixation state can be obtained.

  As described above, in the present embodiment, the configuration arranged as the imaging system focus lens in the imaging optical system that acquires the image of the eye to be examined corresponds to the SLO focus lens 107. Further, the configuration arranged in the fixation lamp system that promotes fixation of the subject's eye as the fixation lamp focus lens corresponds to the lens 111 for adjusting the focus of the internal fixation lamp. Then, the focus adjustment of the photographing system focus lens is executed by the control unit 925 constituting the control means, and after it is determined that the in-focus state is once obtained, the focus adjustment of the fixation lamp focus lens is executed. . Further, when adjusting the focus of the fixation lamp focus lens, the determined focus position of the photographing system focus lens is fixed, and these two focus positions are uniquely determined. Note that the determination operation is also executed by the module that functions as the photographing system focus lens focusing determination unit in the control unit 925.

  By arranging the above configuration, a fixation lamp focus position determination process is established in which after the fundus observation system focus focus position is determined, the fixation lamp focus focus position is determined. As a result, the time required for focusing the eye to be examined can be shortened, and the burden on the subject can be reduced. Further, the fixation target focus position can be quickly determined by avoiding diopter adjustment.

[Second Embodiment]
In the first embodiment, the SLO imaging system is used as the fundus observation system, but a fundus camera may be used as the fundus observation system. However, in the second embodiment, an imaging flow in the OCT imaging system in an ophthalmologic apparatus that does not include an optical system dedicated to fundus front imaging, such as an SLO imaging system or a fundus camera, will be described.

  FIG. 5 schematically shows a schematic configuration of the measurement optical system in the second embodiment. It differs in the optical element arrange | positioned in the optical path L2 with respect to 1st Embodiment. However, the optical elements arranged on the optical path L1 of the OCT optical system and the optical path L3 of the anterior ocular segment observation system have the same configuration.

  In the present embodiment, the optical path L2 is the optical path of the internal fixation lamp. A lens 101-2, a focus lens 122, and a light source 123 are disposed on the optical path L2. The light source 123 is a two-dimensionally arranged light source, and by controlling the lighting position of the light source, various patterns can be projected as various internal fixation lamps at various positions on the eye to be examined. However, the configuration of the internal fixation lamp may be a scanning and lighting control method using a scanner, as in the first embodiment. The focus lens 122 is driven along the optical path L2 by a motor (not shown), and thereby adjusts the focus of the internal fixation lamp 123 on the eye 100 to be examined.

  FIG. 6 shows an imaging flow when capturing a tomographic image in the second embodiment. Since the optical system used in the second embodiment does not have an optical system dedicated to photographing the front of the fundus, first, in order to measure the diopter of the eye to be examined, focus adjustment is performed with the OCT optical system (S202). When performing the focus adjustment in the OCT optical system, the focus adjustment method shown as an example of the SLO imaging system in the first embodiment can be applied as it is. That is, the control unit 925 drives the focus lens 122 while measuring the brightness of the OCT image (or the intensity of the OCT signal at a certain point). Then, the position on the optical path L1 of the focus lens 115 that maximizes the measured luminance, that is, the in-focus position is found.

  In subsequent S203, the focus lens 122 is driven on the optical path L2 to adjust the focus of the internal fixation lamp so as to match the diopter of the eye to be inspected, which is clarified by the focus adjustment of the OCT optical system. . After the focus adjustment of the internal fixation lamp is completed, the reference light path length is adjusted in S204, and a tomographic image is taken in subsequent S205.

  In the present embodiment, the configuration arranged in the imaging optical system that acquires the image of the eye to be inspected as the imaging system focus lens corresponds to the focus lens 115.

  According to the second embodiment described above, even in an OCT apparatus that is not equipped with an optical system dedicated to fundus frontal imaging, a natural fixation state for the eye to be examined can be quickly created and tomographic imaging can be performed.

[Third Embodiment]
In the first and second embodiments, the diopter adjustment of the eye to be examined is always natural at the time of focusing adjustment by the first fundus observation system (for example, the OCT optical system, the SLO imaging system, and the fundus camera). Assume that you are in a state. In the third embodiment, if the diopter state of the eye to be examined is unstable (for example, when the lens is powered and the diopter is adjusted to the nearsighted side), It is possible to return the degree state to a natural state.

  FIG. 7 shows an imaging flow when capturing a tomographic image in the third embodiment. In the present embodiment, a step of measuring diopter stability shown in S304 to S306 is added to the photographing flow in the first embodiment. The other steps S301 to S303 correspond to the steps S101 to S103, respectively, and the steps S307 to S310 correspond to the steps S104 to S107, respectively. Since the contents performed in the corresponding steps are the same, detailed description is omitted here.

  In S303, after the focus adjustment of the fixation lamp is completed, in S304, the temporal change of the in-focus state of the SLO imaging system is measured, thereby evaluating the stability of the diopter. Specifically, a change in luminance value or contrast with time of the SLO image is measured. In S305, it is determined from the measurement result in S304 whether there is a temporal change in the in-focus state. If it is determined that there is no change with time (it can be determined that the diopter state is stable. For this reason, the flow proceeds to S307 as it is, the focus adjustment of the OCT optical system, and the reference light path length in S308. Adjustment and tomography in S309 are executed.

  If it is determined in S305 that the in-focus state of the SLO imaging system has changed with time, it can be determined that the diopter state of the eye to be examined is unstable. That is, there is a possibility that the subject has excessively adjusted the diopter with the eye 100 to be examined. For this reason, the SLO imaging system and the focus lens of the internal fixation lamp are moved to the far vision side so that the subject can relax the eye by removing the power of the crystalline lens. In S306, a position immediately before the luminance value or contrast of the SLO image starts to decrease is obtained, and the position of the focus lens on the optical axis is determined as the in-focus position of the SLO photographing system and the internal fixation lamp.

  After determining the in-focus position, the flow passes through S304 to S305, and it is confirmed again whether or not the temporal change in the in-focus state has been eliminated. If it is determined that there is no change over time, the flow proceeds to S307, S308, and S309. Steps S304 to S306 are repeated until the change with time reaches a certain level or less.

  The measurement of the temporal change of the intensity of the signal emitted from the light receiving element or the contrast of the eye image to be examined described above is executed by the module functioning as the imaging system focus temporal change measurement unit that measures the temporal change in the control unit 925. The The control unit 925 adjusts the focus of the photographing system focus lens and performs fixation when the photographing system focus temporal change measurement unit detects that the in-focus state has changed over time after the focus position of the fixation lamp focus lens is determined. The focus adjustment of the lamp focus lens is executed again. According to the third embodiment described above, tomographic imaging of the eye to be examined is possible after the diopter state of the eye to be examined is reliably stabilized.

[Fourth Embodiment]
In the first to third embodiments, the internal fixation lamp is in a defocused state during focus adjustment by the fundus observation system (for example, the OCT optical system, the SLO imaging system, and the fundus camera). When the diopter of the eye to be examined and the internal fixation light are greatly different, the fixation light is completely invisible to the eye to be examined, and fixation cannot be determined. Therefore, in the fourth embodiment, a configuration capable of supporting fixation of the eye to be examined is also provided during focus adjustment by the fundus observation system.

  FIG. 8 is a schematic diagram illustrating the configuration of an optical system according to the fourth embodiment. In the optical system, another fixation lamp path is added to the fixation lamp optical path in the optical system according to the first embodiment. The fixation lamp path includes a dichroic mirror 125, a lens 126, and a light source 127. The fixation lamp path is configured to have a greater depth of focus than the fixation lamp by the light source 112.

  Here, the fixation lamp by the light source 112 is a first fixation lamp system, and the fixation lamp by the light source 127 is a second fixation lamp system. The fixation target provided by the second fixation lamp system is visible to the eye to be examined even when the diopter of the eye to be examined and the internal fixation lamp are greatly different because of the deep focal depth. At this time, the eye 100 does not need to be in focus with respect to the fixation target provided by the second fixation lamp system. It is sufficient that the point light source is visible.

  In the present embodiment, the light source 127 of the second fixation lamp system is turned on until the focus of the internal fixation lamp is adjusted, and the eye to be examined is fixed by the second fixation lamp system. When adjusting the focus of the internal fixation lamp, the fixation lamp to be used is switched from the second fixation lamp light source 127, which is another fixation lamp, to the first fixation lamp light source 112. . As a result, the diopter can be accurately fixed together with the fixation. Note that when the subject's eye is fixed while using the second fixation lamp system, since the fixation target provided by the second fixation lamp system that promotes fixation has a deep focal depth, OCT It should be noted that the diopter of the eye to be inspected is not fixed during imaging and the OCT image may be blurred.

  As described above, by using different fixation lamp systems with different fixation depths before and after focusing adjustment of the internal fixation lamp, the fixation state of the eye to be examined is maintained, and the fundus observation system and It is possible to adjust the focus of the internal fixation lamp.

  In the embodiment shown in FIG. 6, another fixation lamp having a different depth of focus is provided. However, only one fixation lamp is used, a diaphragm is arranged on the fixation lamp optical path, and the focal depth of the fixation lamp is changed by changing the diameter of the diaphragm before and after adjusting the focus of the internal fixation lamp. It is also good. In this case, a stop with a variable aperture diameter is arranged on the fixation lamp, the aperture diameter is reduced before the focus position of the fixation lamp focus lens is determined, and the aperture diameter is determined after the focus position of the fixation lamp focus lens is determined. Should be larger.

  In addition, even if the diopter of the subject's eye and the internal fixation lamp is greatly different, the brightness of the internal fixation lamp is increased so that the internal fixation lamp defocused on the subject's eye can be seen. Also good. However, in this case, when the internal fixation lamp is focused, there is a possibility that the amount of light is too strong for the eye to be examined. It is conceivable that the eye to be examined contracts by irradiating the eye to be examined with such strong visible light and falls below the minimum imageable pupil diameter of the OCT apparatus. For this reason, it is preferable to reduce the luminance or the amount of light when adjusting the focus of the internal fixation lamp.

(Other examples)
The present invention can also be realized by executing the following processing. That is, software (program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU, or the like) of the system or apparatus reads the program. It is a process to be executed.

107: SLO focus lens 110: Photo detector 111, 122: Fixation lamp focus lens 112: Internal fixation lamp 115: OCT focus lens 126: Fixation lamp focus lens 127: Internal fixation lamp 184: Line sensor, 925: control unit

Claims (12)

An imaging system focus lens arranged in an imaging optical system for acquiring an image of the eye to be examined;
When arranged in a fixation lamp system that promotes fixation of the eye to be examined, a fixation lamp focus lens;
An ophthalmologic apparatus comprising: a control unit configured to execute focus adjustment of the fixation lamp focus lens after executing focus adjustment of the photographing system focus lens.   The control means corresponds to a focus position of the shooting system focus lens obtained by executing the focus adjustment, and fixes the focus position of the obtained shooting system focus lens to fix the fixation lamp focus. The ophthalmologic apparatus according to claim 1, wherein a focus position of the fixation lamp focus lens is determined by adjusting a focus of the lens.   The in-focus position of the imaging system focus lens is determined based on the signal intensity of a light receiving element that receives the measurement light from the eye to be examined via the imaging system focus lens or the acquired contrast of the image of the eye to be examined. The ophthalmic apparatus according to claim 1, wherein the ophthalmic apparatus is provided.   An imaging system focus temporal change measurement unit for measuring a temporal change in signal intensity of a light receiving element that receives measurement light from the eye to be examined through the imaging system focus lens or an acquired contrast of the image of the eye to be examined; The ophthalmologic apparatus according to claim 1, wherein the ophthalmologic apparatus is provided.   The control means determines the focusing position of the fixation lamp focus lens, and when the imaging system focus temporal change measurement unit detects the signal intensity or the contrast temporal change, The ophthalmologic photographing apparatus according to claim 4, wherein focus adjustment and focus adjustment of the fixation lamp focus lens are executed again.   When the focus adjustment of the photographing system focus lens and the fixation adjustment of the fixation lamp focus lens are performed again, the control means moves the photographing system focus lens and the fixation lamp focus lens to the far vision side. The ophthalmic apparatus according to claim 5.   When the control unit moves the imaging system focus lens and the fixation lamp focus lens to the far vision side, the control unit determines the position immediately before the signal intensity or the contrast is lowered and the focusing position of the imaging system focus lens and the The ophthalmologic apparatus according to claim 6, wherein the ophthalmologic apparatus is determined as an in-focus position of the fixation lamp focus lens.   The ophthalmologic according to any one of claims 1 to 7, wherein the fixation lamp has a variable brightness, and the brightness is lowered after determining a focus position of the fixation lamp focus lens. apparatus.   The fixation lamp has an aperture with a variable aperture diameter, the aperture diameter is reduced before the focus position of the fixation lamp focus lens is determined, and the focus position of the fixation lamp focus lens is determined after the focus position is determined. The ophthalmologic apparatus according to claim 1, wherein a diaphragm diameter is increased.   Having another fixation lamp having a deeper focal depth than the fixation lamp, and using the other fixation lamp for fixation of the eye to be inspected before determining the in-focus position of the fixation lamp focus lens, The ophthalmologic apparatus according to any one of claims 1 to 7, wherein the fixation lamp is used for fixation of the eye to be examined after the focus position of the fixation lamp focus lens is determined. Adjust the focus of the photographic focus lens placed in the photographic optical system that acquires the image of the eye to be examined,
A method of controlling an ophthalmologic apparatus, comprising: adjusting a focus of a fixation lamp focus lens when arranged in a fixation lamp system that promotes fixation of the eye to be inspected after the focus adjustment of the photographing system focus lens .   A program for causing a computer to execute each step of the method for controlling an ophthalmologic apparatus according to claim 11.

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