JP2017070557A - Ophthalmologic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ophthalmologic apparatus capable of accurately determining a state of a subject's eye regardless of a type of an intraocular lens.SOLUTION: The ophthalmologic apparatus according to one embodiment includes a data acquisition section, a control section, and a determination section. The data acquisition section acquires data of a subject's eye using optical interference measurement. The control section controls the data acquisition section to acquire a signal corresponding to an object located between a cornea and a retina of the subject's eye. The determination section determines whether the subject's eye is a phakic eye or an intraocular lens implant eye on the basis of the intensity of the signal acquired by the control by the control section.SELECTED DRAWING: Figure 8

Description

  The present invention relates to an ophthalmic apparatus.

  Cataract is an eye disease in which visual acuity gradually decreases due to cloudiness of the lens that serves as a lens. In general, cataract surgery is performed on an eye to be examined in which cataract has progressed. For example, in cataract surgery, a turbid lens is removed and an intraocular lens (hereinafter referred to as IOL) is inserted instead. There are IOLs that have only sphericity, toric IOLs that can correct astigmatism, and multifocal IOLs that can focus both far and near. Prior to the cataract surgery, eyeball information (eg, axial length) representing the structure of the eye to be examined is measured, and the frequency of the IOL is determined from the obtained eyeball information.

  Patent Document 1 discloses an apparatus that can determine whether a subject's eye is a phakic eye, an aphakic eye, or an IOL transplanted eye in order to obtain a measurement value corresponding to the state of the crystalline lens of the subject's eye. . This apparatus detects reflection information from the anterior segment, extracts a reflection signal corresponding to a reflection object existing between the posterior capsule and the cornea based on the reflection information, and based on the extraction result, the eye to be examined Is configured to determine whether it is a phakic eye or an IOL transplanted eye. This determination process is performed by comparing the measurement result of the distance between the cornea and the lens front surface and the measurement result of the lens thickness with a threshold value.

Japanese Patent No. 5410954

  In recent years, there have been an increasing number of cases employing surgery (Phakik IOL surgery) in which an IOL is added to the phakic eye. There are anterior chamber type and posterior chamber type in the fake kick IOL (the crystalline lens IOL). The anterior chamber type fake kick IOL is fixed between the cornea and the iris, and the posterior chamber type fake kick IOL is fixed between the iris and the lens.

  When the eye to be examined is a fake kick IOL transplanted eye, in the invention described in Patent Document 1, not only the reflected signal corresponding to the cornea and the crystalline lens but also the reflected signal corresponding to the fake kick IOL is detected. It is difficult to accurately determine this.

  An object of the present invention is to provide an ophthalmologic apparatus that can accurately determine the state of a subject's eye (a phakic eye, an IOL transplanted eye, etc.) regardless of the type of IOL.

  The ophthalmologic apparatus according to the embodiment includes a data acquisition unit, a control unit, and a determination unit. The data acquisition unit acquires data of the eye to be examined using optical interference measurement. The control unit controls the data acquisition unit so that a signal corresponding to an object located between the cornea of the eye to be examined and the retina is acquired. The determination unit determines whether the eye to be examined is a phakic eye or an intraocular lens transplanted eye based on the intensity of the signal acquired by control by the control unit.

  According to the embodiment, it is possible to accurately determine the state of the eye to be examined (the phakic eye, the IOL transplanted eye, etc.) regardless of the type of the IOL.

It is the schematic which shows the structural example of the ophthalmologic apparatus which concerns on embodiment. It is the schematic which shows the structural example of the ophthalmologic apparatus which concerns on embodiment. It is the schematic which shows the operation example of the ophthalmologic apparatus which concerns on embodiment. It is the schematic which shows the operation example of the ophthalmologic apparatus which concerns on embodiment. It is the schematic which shows the operation example of the ophthalmologic apparatus which concerns on embodiment. It is the schematic which shows the operation example of the ophthalmologic apparatus which concerns on embodiment. It is the schematic which shows the structural example of the ophthalmologic apparatus which concerns on embodiment. It is the schematic which shows the structural example of the ophthalmologic apparatus which concerns on embodiment. It is the schematic which shows the operation example of the ophthalmologic apparatus which concerns on embodiment. It is a flowchart which shows the operation example of the ophthalmologic apparatus which concerns on embodiment.

  The ophthalmologic apparatus according to the embodiment can perform any ophthalmic measurement. Ophthalmic measurement includes objective measurement and subjective examination. The objective measurement is a measurement technique for acquiring information about the eye to be examined mainly using a physical technique without referring to a response from the subject. The objective measurement includes measurement for obtaining the characteristics of the eye to be examined and photographing for obtaining an image of the eye to be examined. Typical examples include objective refraction measurement, corneal shape measurement, intraocular pressure measurement, fundus imaging, and optical interference measurement. Optical interference measurement is to measure an eye to be examined using light interference, and one example is optical coherence tomography (OCT). A subjective test is a measurement technique that acquires information using a response from a subject. Typical examples include visual inspection such as distance inspection, near inspection, contrast inspection, and glare inspection, and visual field inspection.

  The ophthalmologic apparatus according to the embodiment is capable of executing at least optical interference measurement, and may be capable of executing at least one of arbitrary subjective examination and arbitrary objective measurement. Optical interference measurement is used to acquire eyeball information representing the structure of the eye to be examined, such as the axial length, corneal thickness, anterior chamber depth, and lens thickness. Moreover, in order to acquire the image and analysis data of the eye to be examined, optical interference measurement such as OCT can be used.

<Configuration>
A configuration example of a typical embodiment is shown in FIGS. The ophthalmologic apparatus 1000 is a Z alignment system 1, an XY alignment system 2, a kerato measurement system 3, a target projection system 4, an observation system 5, a reflex measurement projection system 6, a reflex system as optical systems for inspecting the eye E to be examined. A measurement light receiving system 7 and an intraocular distance measurement system 8 are included. The ophthalmologic apparatus 1000 includes a processing unit 9.

(Processing unit 9)
The processing unit 9 controls each unit of the ophthalmologic apparatus 1000. The processing unit 9 can execute various arithmetic processes. The processing unit 9 includes a processor. The processor is, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), a programmable logic device (for example, SPLD (Simple Programmable LD). (Field Programmable Gate Array)) or the like. The processing unit 9 realizes the function according to the embodiment by reading and executing a program stored in a storage circuit or a storage device, for example.

(Observation system 5)
The observation system 5 captures a moving image of the anterior segment of the eye E. Light (infrared light) from the anterior segment of the eye E to be examined passes through the objective lens 51, passes through the dichroic mirrors 52 and 53, passes through the aperture of the diaphragm 54, passes through the half mirror 55, and relay lens. The light passes through 56 and 57 and is imaged on the imaging surface of the imaging element 59 (area sensor) by the imaging lens 58. The imaging element 59 performs imaging and signal output at a predetermined rate. An output (video signal) of the image sensor 59 is input to the processing unit 9. The processing unit 9 displays the anterior segment image E ′ based on the video signal on the display screen 10 a of the display unit 10. The anterior segment image E ′ is, for example, an infrared moving image. The observation system 5 may include an illumination light source for illuminating the anterior segment.

(Z alignment system 1)
The Z alignment system 1 irradiates the eye E with light (infrared light) for alignment in the optical axis direction (front-rear direction, Z direction) of the observation system 5. The light output from the Z alignment light source 11 is applied to the cornea K of the eye E, reflected by the cornea K, and imaged on the line sensor 13 by the imaging lens 12. When the position of the corneal apex changes in the front-rear direction, the light projection position on the line sensor 13 changes. The processing unit 9 obtains the position of the corneal apex of the eye E based on the projection position of the light on the line sensor 13, and executes Z alignment based on this.

(XY alignment system 2)
The XY alignment system 2 irradiates the eye E with light (infrared light) for alignment in a direction (left-right direction (X direction), vertical direction (Y direction)) orthogonal to the optical axis of the observation system 5. . The XY alignment system 2 includes an XY alignment light source 21 provided in an optical path branched from the observation system 5 by a half mirror 55. The light output from the XY alignment light source 21 is reflected by the half mirror 55 and is applied to the eye E through the observation system 5. The reflected light of the light irradiated on the cornea K is guided to the image sensor 59 through the observation system 5.

  This reflected light image (bright spot image) is depicted in the anterior segment image E ′. As illustrated in FIG. 1, the processing unit 9 displays the anterior segment image E ′ including the bright spot image Br and the alignment mark AL on the display screen 10 a. When performing XY alignment manually, the user performs an operation of moving the optical system so as to guide the bright spot image Br in the alignment mark AL. When the alignment is performed automatically, the processing unit 9 obtains the displacement of the bright spot image Br with respect to the alignment mark AL, and controls the movement of the optical system so as to cancel this displacement.

(Kerato measurement system 3)
The kerato measurement system 3 projects a ring-shaped light beam (infrared light) for measuring the shape of the cornea K onto the cornea K. The kerato plate 31 is disposed between the objective lens 51 and the eye E. A kerato ring light source 32 is provided on the back side of the kerato plate 31 (objective lens 51 side). A ring-shaped light beam is projected onto the cornea K by illuminating the kerato plate 31 with light from the kerato ring light source 32. The reflected light (keratring image) of the ring-shaped light beam projected onto the cornea K is detected by the image sensor 59 together with the anterior segment image E ′. The processing unit 9 calculates a corneal shape parameter by performing a known calculation based on this keratoling image.

(Target projection system 4)
The target projection system 4 presents various targets such as a fixation target and a subjective test target to the eye E. Light (visible light) output from the light source 41 is applied to the target chart 42. The target chart 42 includes, for example, a turret plate or a transmissive liquid crystal panel provided with various target patterns, and presents a pattern representing the target. The light that has passed through the target chart 42 passes through the focusing lens 43 and the VCC lens 44, is reflected by the reflecting mirror 45, is reflected by the dichroic mirror 53, passes through the dichroic mirror 52, and passes through the objective lens 51. Projected onto the fundus oculi Ef. The light source 41 and the target chart 42 are integrally movable in the optical axis direction.

  When performing the subjective examination, the processing unit 9 controls the visual chart 42, the light source 41, and the VCC lens 44 based on the result of the objective measurement. The processing unit 9 displays the optotype selected by the examiner or the processing unit 9 on the optotype chart 42. Thereby, the selected optotype is presented to the subject. The subject responds to the target. Upon receiving the response content, the processing unit 9 performs further control and calculation of the subjective test value. For example, in the visual acuity measurement, the processing unit 9 selects and presents the next target based on the response to the Landolt ring or the like, and repeats this to determine the visual acuity value.

(Ref measurement projection system 6 and Reflex measurement light receiving system 7)
The reflex measurement projection system 6 and the reflex measurement light receiving system 7 are used for objective refraction measurement (ref measurement). The reflex measurement projection system 6 projects a ring-shaped light beam (infrared light) for objective measurement onto the fundus oculi Ef. The ref measurement light receiving system 7 receives the return light from the eye E of the ring-shaped light flux.

  The reflex measurement light source 61 is movable in the optical axis direction and is disposed at a position optically conjugate with the fundus oculi Ef. The light output from the reflex measurement light source 61 passes through the condenser lens 62, is reflected by the reflecting mirror 63, passes through the conical prism 64A and the relay lens 64B, passes through the ring-shaped light transmitting portion of the ring stop 64C, and is ringed. It becomes a light beam. The ring-shaped light beam formed by the ring stop 64C is reflected by the reflecting surface of the perforated prism 65, passes through the rotary prism 66, and is guided to the quick return mirror 67.

  The rotary prism 66 is used to average the light amount distribution of the ring-shaped light flux with respect to the blood vessel and diseased part of the fundus oculi Ef. The quick return mirror 67 is used for switching between objective refraction measurement and ocular axial length measurement. When the objective refraction measurement is performed, the reflection surface of the quick return mirror 67 is arranged in an optical path (branching optical path) branched from the optical path of the observation system 5 by the dichroic mirror 52. Thereby, both the optical path of the reflex measurement projection system 6 and the optical path of the reflex measurement light receiving system 7 are coupled to the optical path of the observation system 5. On the other hand, when measuring the axial length, the quick return mirror 67 is retracted from the branch optical path. Thereby, the optical path of the intraocular distance measuring system 8 is coupled to the optical path of the observation system 5. When the wavelength used for objective refraction measurement is different from the wavelength used for axial length measurement, a dichroic mirror may be arranged instead of the quick return mirror 67. In this case, it is not necessary to drive the dichroic mirror.

  In objective refraction measurement, the ring-shaped light beam that has passed through the rotary prism 66 is reflected by the quick return mirror 67, is reflected by the dichroic mirror 52, passes through the objective lens 51, and is projected onto the fundus oculi Ef.

  The return light of the ring-shaped light beam projected on the fundus oculi Ef passes through the objective lens 51, is reflected by the dichroic mirror 52 and the quick return mirror 67, passes through the rotary prism 66, and passes through the hole of the perforated prism 65. Then, the light passes through the relay lens 71 and the focusing lens 72 and is imaged on the imaging surface of the imaging element 74 by the imaging lens 73. The output of the image sensor 74 is input to the processing unit 9. The processing unit 9 calculates the spherical power S, the astigmatism power C, and the astigmatism axis angle A of the eye E by performing a known calculation based on the output from the image sensor 74.

  Based on the calculated refraction value, the processing unit 9 moves the reflex measurement light source 61 and the focusing lens 72 in the optical axis direction to a position where the reflex measurement light source 61 and the fundus oculi Ef are conjugated. Further, the processing unit 9 moves the focusing lens 85 of the intraocular distance measurement system 8 in the optical axis direction in conjunction with the movement of the focusing lens 72 and the reflex measurement light source 61. The processing unit 9 can also move the reflex measurement light source 61, the focusing lens 72 and the focusing lens 85, the light source 41, and the target chart 42 integrally.

(Intraocular distance measurement system 8)
The intraocular distance measurement system 8 performs optical interference measurement for measuring intraocular distance as eyeball information. When the optical interference measurement is performed, the quick return mirror 67 is retracted from the branch optical path. Further, the reflex measurement is performed before the optical interference measurement, and the position of the focusing lens 85 is adjusted so that the end surface of the optical fiber 80a is conjugate with the fundus oculi Ef.

  As shown in FIG. 2, in the interferometer unit 80, the light (infrared light, broadband light) L0 output from the interferometer light source 81 is measured by the fiber coupler 82 guided through the optical fiber 80b and the measurement light LS and the reference light. It is divided into LR. The measurement light LS is guided to the collimator lens 84 through the optical fiber 80a. On the other hand, the reference light LR is guided to the optical path length changing unit 90 through the optical fiber 80c.

  The optical path length changing unit 90 changes the optical path length of the reference light LR. The reference light LR guided to the optical path length changing unit 90 is collimated by the collimator lens 91 and enters the beam splitter 92. A retinal shutter 93 and a retinal reference mirror unit 94 are provided in the transmission direction of the beam splitter 92, and a corneal shutter 95 and a corneal reference mirror unit 96 are provided in the reflection direction. The retina reference mirror unit 94 includes an imaging lens 94A and a reference mirror 94B. The cornea reference mirror unit 96 includes an imaging lens 96A and a reference mirror 96B.

  The reference light LR is split into two light beams (a retina light beam and a corneal light beam) by, for example, a 50:50 beam splitter 92. When the retina shutter 93 is retracted from the optical path, the retina light beam is imaged on the reflecting surface of the reference mirror 94B by the imaging lens 94A, reflected by the reference mirror 94B, and passes through the imaging lens 94A to be a beam. Return to splitter 92. When the corneal shutter 95 is retracted from the optical path, the corneal light beam is imaged on the reflecting surface of the reference mirror 96B by the imaging lens 96A, reflected by the reference mirror 96B, passes through the imaging lens 96A, and passes through the beam splitter. Return to 92. The light division ratio by the beam splitter 92 is not limited to equal division, and may be an asymmetric ratio such as 30:70 or 10:90, for example.

  On the other hand, the measurement light LS output from the interferometer unit 80 is converted into a parallel light beam by the collimator lens 84, deflected by the optical scanner 87b, passes through the focusing lens 85 and the relay lens 86, is reflected by the mirror 87a, and is reflected in the pupil. The light passes through the lens 88, is reflected by the dichroic mirror 52, passes through the objective lens 51, and is irradiated to the eye E. The return light of the measurement light LS from the eye E passes through the objective lens 51 and is guided to the interferometer unit 80 through the same path as the forward path. The optical scanner 87b includes, for example, one or more galvanometer mirrors, and changes the deflection direction of the measurement light LS under the control of the processing unit 9. The optical scanner 87b is disposed at a position optically conjugate with the fundus oculi Ef.

  The fiber coupler 82 causes the reference light that has passed through the optical path length changing unit 90 to interfere with the return light of the measurement light LS. The interference light LC generated thereby is guided to the spectroscope 83 by the optical fiber 80d. The spectrometer 83 spatially separates the interference light LC and detects these wavelength components with a line sensor. The processing unit 9 extracts information in the depth direction by performing known signal processing such as FFT (Fast Fourier Transform: FFT) on the signal output from the spectroscope 83.

  In this example, the spectral domain OCT is applied, but other types of OCT may be applied. For example, when the swept source OCT is applied, a wavelength swept light source (wavelength variable light source) is provided as the interferometer light source 81 instead of the low coherence light source, and a photodetector such as a balanced photodiode is used instead of the spectroscope 83. Is provided.

  The processing unit 9 moves the retina reference mirror unit 94 and the cornea reference mirror unit 96 so that the interference signal (peak) is arranged at a predetermined position in the depth direction. An example of the distribution of the intensity of the interference signal obtained by FFT in the depth direction is shown in FIG. When the interference signal SC0 indicated by the dotted line is obtained, the reference mirror unit 94 for retina is brought close to the beam splitter 92 as shown in FIG. 3 (that is, the position indicated by the dotted line of the imaging lens 94A and the reference mirror 94B). 4), the interference signal SC0 (corresponding to the retina) can be moved within the predetermined range shown in FIG.

  By using the position of the corneal apex detected using the Z alignment system 1, the distance (working distance) of the objective lens 51 with respect to the eye E can be kept constant. When the corneal shutter 95 is retracted from the optical path, an interference signal corresponding to the cornea K is also simultaneously detected by the spectroscope 83. The reference mirror 96B is arranged at a position away from the position corresponding to the cornea K by a predetermined distance d so as not to overlap the interference signal SC1 corresponding to the retina (FIG. 5). Thereby, as shown in FIG. 6, both the interference signal SC1 corresponding to the retina and the interference signal SC2 corresponding to the cornea can be simultaneously acquired in the measurement range R in the depth direction.

  As shown in FIG. 6, when the signal sensitivity SC changes in the measurement range R, the interference signal SC1 having a relatively weak signal is detected in the measurement range R1 having a relatively high sensitivity, and the interference signal SC2 having a relatively strong signal is relatively detected. Detection is possible in the low-sensitivity measurement range R2. Thereby, the detection sensitivity of the two interference signals SC1 and SC2 can be optimized.

(Information processing system configuration)
The information processing system of the ophthalmologic apparatus 1000 will be described. An example of the functional configuration of the information processing system of the ophthalmologic apparatus 1000 is shown in FIGS. In FIG. 8, components related to operations described later according to the present embodiment are particularly presented. The processing unit 9 includes a control unit 110 and an arithmetic processing unit 120. The reflex measurement projection system 6 and the reflex measurement light receiving system 7 used for objective refraction measurement are collectively referred to as a reflex measurement system 130. Furthermore, the ophthalmologic apparatus 1000 includes a display unit 170, an operation unit 180, and a communication unit 190.

(Control unit 110)
The control unit 110 includes a processor and controls each unit of the ophthalmologic apparatus 1000. The control unit 110 includes a storage circuit and a storage device.

(Operation processing unit 120)
The arithmetic processing unit 120 calculates, for example, eye refractive power, intraocular distance (eye axis length, anterior chamber depth, lens thickness, corneal thickness, etc.), IOL power calculation, and optical interference measurement image (OCT image). Various calculations such as generation and analysis of optical interference measurement images are performed. As illustrated in FIG. 8, the arithmetic processing unit 120 according to the present embodiment includes an objective value calculation unit 121 and a determination unit 122.

  In the calculation of the eye refractive power, the objective value calculator 121 analyzes the shape of the output (ring image) from the reflex measurement light receiving system 7. For example, the objective value calculation unit 121 obtains the center of gravity position of the ring image from the luminance distribution in the obtained image, obtains the luminance distribution along a plurality of scanning directions extending radially from the center of gravity position, and uses the ring distribution from the luminance distribution. An image is specified, an approximate ellipse of the specified ring image is obtained, and the spherical power S, the astigmatism power C, and the astigmatism axis angle A are obtained by substituting the major axis and the minor axis of the approximate ellipse into known equations. Alternatively, the objective value calculation unit 121 can determine the eye refractive power parameter based on the deformation and displacement of the ring image with respect to the reference pattern.

  At least the spherical power can be obtained from the result of optical interference measurement using the intraocular distance measurement system 8. For example, the processing unit 9 identifies the peak position of the detection signal of the interference light LC by moving the reference mirror unit (for example, the retina reference mirror unit 94), and the displacement of the reference mirror unit with respect to the reference position corresponding to 0D And the equivalent spherical power can be obtained based on the displacement of the specified peak position with respect to the reference position.

  The arithmetic processing unit 120 calculates the corneal refractive power, the corneal astigmatism, and the corneal astigmatism axis angle based on the keratoling image acquired by the observation system 5. For example, the arithmetic processing unit 120 calculates the corneal curvature radius of the strong main meridian and the weak main meridian on the front surface of the cornea by analyzing the keratling image, and calculates the parameter based on the corneal curvature radius.

  In the measurement of the axial length, the arithmetic processing unit 120 calculates the axial length of the eye E based on the interval between the peaks (FIG. 6) of the two interference signals acquired using the intraocular distance measurement system 8. Similarly, measurement of other intraocular distances can be performed based on the interval between two interference signals corresponding to both ends of the intraocular distance.

  In calculating the IOL frequency, the arithmetic processing unit 120 substitutes the calculation result of the kerato measurement and the calculation result of the axial length into a known calculation formula. It is also possible to obtain the IOL frequency in consideration of corneal thickness, anterior chamber depth, lens thickness, and the like.

  The determination unit 122 will be described. As a premise, the control unit 110 performs optical interference measurement so that a signal (target signal) corresponding to an object (target object) positioned between the cornea K of the eye to be examined and the retina (surface of the fundus oculi Ef) is acquired. Execute the control regarding. The target object is an object having a refraction function such as a crystalline lens or an IOL.

  The control for acquiring the target signal includes, for example, processing for changing the optical path length (reference arm length) of the reference light LR. In the present embodiment, the retina reference mirror unit 94 is moved. As a specific example, the storage unit 112 stores a reference mirror position set in advance with respect to the target object. When the target object is a crystalline lens or an IOL, a reference mirror position corresponding to a standard position of the crystalline lens or a standard installation position of the IOL is stored in the storage unit 112. Alternatively, when the position of the target object in the eye E is obtained in advance, the reference mirror position obtained based on the position can be stored in the storage unit 112. The main control unit 111 reads the reference mirror position from the storage unit 112, and moves the retina reference mirror unit 94 based thereon.

  Note that the target signal of this example is an interference signal obtained by performing FFT or the like on data obtained by optical interference measurement performed with the retina reference mirror unit 94 placed at a predetermined reference mirror position. Identified as a peak. However, when an eye to be examined in which the target object is arranged at a position greatly deviating from the standard position is to be examined, no peak is obtained even if the retina reference mirror unit 94 is arranged at a predetermined reference mirror position. There is a case. In this case, the processing unit 9 can search for a peak while moving the retina reference mirror unit 94. Alternatively, the interference signal or information based on the interference signal (such as an optical interference measurement image) may be displayed on the display unit 170 by the main control unit 111 and the user may manually move the retina reference mirror unit 94 to search for a peak. Good.

  In this embodiment, the reference arm is changed. However, a configuration in which the optical path length (measurement arm length) of the measurement light LS is changed and a configuration in which both the reference arm length and the measurement arm length can be changed are applied. Is also possible.

  The accuracy of the process of changing the reference arm length (measurement arm length) in order to acquire the target signal is arbitrary. As a first example, the reference arm length can be changed so that the target signal is included in the interference signal obtained by the optical interference measurement, that is, the target signal appears in the measurement range by the optical interference measurement. As a second example, the target signal is arranged at a predetermined depth position (or the vicinity thereof) in the measurement range by the optical interference measurement so that the target signal is arranged at the predetermined position (or the vicinity thereof) of the interference signal. As can be seen, the reference arm length can be changed. The predetermined depth position is, for example, a position where the measurement sensitivity is maximized. Note that after the target signal is detected according to the first example, control can be performed so that the target signal is arranged at a predetermined position according to the second example.

  In addition to the process of changing the reference arm length (measurement arm length), the control for acquiring the target signal may include focus adjustment of the measurement light LS. The focus adjustment of the measurement light LS is executed by the main control unit 111 controlling the drive mechanism 85A (see FIG. 8) that moves the focusing lens 85 along the optical path of the measurement light LS. The focus adjustment is executed after changing the reference arm length, for example. As a specific example, the control unit 110 adjusts the focus so that the intensity of the target signal is maximized after changing the reference arm length so that the target signal is included in the data (interference signal) acquired by the optical interference measurement. (Control of the drive mechanism 85A) can be performed. Alternatively, the control unit 110 changes the reference arm length so that the target signal included in the data (interference signal) acquired by the optical interference measurement is arranged at or near the predetermined position, and then the intensity of the target signal is increased. Focus adjustment (control of the drive mechanism 85A) can be performed so as to be maximized.

  The control for acquiring the target signal is not limited to the change of the reference arm length (measurement arm length) or the focus adjustment of the measurement light LS. For example, a configuration in which a lens or a lens system having a positive refractive power can be arranged in the optical path of the measurement light LS can be applied. This lens (or lens system) is inserted at an arbitrary position in the optical path of the measurement light LS, and discontinuously changes the focal position of the measurement light LS. That is, this lens (or lens system) acts to bring the measuring light LS closer to the focal point by a distance corresponding to its refractive power. Note that a variable refractive power lens such as an Alvarez lens may be applied as this lens (or lens system). The position where this lens (or lens system) is inserted may be a position adjacent to the focusing lens 85, for example. Hereinafter, this lens (or lens system) may be referred to as an auxiliary lens.

  For example, the refractive power of the auxiliary lens is set to a positive refractive power corresponding to a standard distance between the retina surface and the lens front surface. In another example, an auxiliary lens having a negative refractive power corresponding to a standard distance between the corneal surface and the front surface of the crystalline lens is applied, and a corneal reference mirror unit 96 (preferably movable) is used. It is possible to perform optical interference measurement. In the present specification, the standard value of the structural or functional value of the eye may be a value in a model eye or a statistical value obtained clinically.

  When an interference signal including the target signal is obtained, the determination unit 122 determines whether the eye E is a phakic eye or an IOL transplanted eye based on the intensity of the target signal. This determination process is executed by the intensity detector 1222 and the intensity comparator 1223 shown in FIG.

  The intensity detector 1222 detects the intensity of the target signal (peak) included in the interference signal by analyzing the interference signal. This process is, for example, a process of searching for the maximum intensity value in the interference signal expressed as an intensity distribution in the depth direction. Note that intensity detection may be performed after removing or reducing noise.

  The intensity comparison unit 1223 compares the intensity of the target signal detected by the intensity detection unit 1222 with a predetermined threshold value. Thereby, it is determined whether the eye E is a phakic eye (an eye having a crystalline lens that is a living tissue) or an IOL transplanted eye (an eye in which an IOL is transplanted instead of or in addition to the crystalline lens). To do.

  The principle of this determination process will be described. The refractive index of aqueous humor filling the eyeball is generally about 1.336, and the refractive index near the surface of the lens is generally about 1.386. Therefore, the reflectance at the front surface of the crystalline lens is about 0.03%. On the other hand, IOL includes polymethyl methacrylate resin (PMMA), silicon resin, and the like as materials. A typical IOL has a refractive index on the order of 1.594, and the reflectance when it is placed in the eye is about 0.3 percent. Thus, the reflection intensity by the IOL is generally larger than that by the lens. The determination process according to the embodiment uses such a phenomenon.

  In this embodiment, a threshold value is set so that a difference in reflection intensity according to the type of object in the eye E can be identified. In particular, the intensity of the target signal in a state where the target signal included in the interference signal is arranged at or near a predetermined position in the depth direction is used. For example, in FIG. 9, the horizontal axis indicates the measurement range R in the depth direction, and the vertical axis indicates the intensity of the interference signal. Symbol R0 indicates a predetermined position in the depth direction, symbol P1 indicates a peak corresponding to the front surface of the crystalline lens, and symbol P2 indicates a peak corresponding to the front surface of the IOL. Further, the symbol TH indicates a threshold level set to identify the standard intensity of the peak P1 corresponding to the lens front surface and the standard intensity of the peak P2 corresponding to the IOL front surface. Note that by comparing the intensity of the target signal (peak) arranged at or near the predetermined position in the depth direction with a threshold value, the comparison can be performed with high accuracy and high accuracy.

  The determination unit 122 is further provided with an objective value comparison unit 1221. The objective value comparison unit 1221 is based on the refractive power (objective value) of the eye E calculated by the objective value calculation unit 121, and determines whether the eye E is an aphakic eye (an eye in which neither a crystalline lens nor an IOL exists). Judge whether or not. Note that, for example, based on whether the target signal is included in the interference signal, or based on whether the strength of the target signal included in the interference signal is less than a predetermined threshold (less than the above threshold). It is also possible to determine whether the eye is a crystalline lens.

  The limitation of the determination process by the objective value comparison unit 1221 will be described. When the eye E is an aphakic eye, both the refractive power by the lens and the refractive power by the IOL are lost, so that the objective value exhibits a strong hyperopia. The objective value comparison unit 1221 compares the threshold value (threshold indicating the degree of hyperopia) set in advance for this determination with the refractive power value calculated by the objective value calculation unit 121. When the degree of hyperopia of the eye E is equal to or greater than the threshold value, the eye E is determined to be an aphakic eye. On the other hand, when the degree of hyperopia of the eye E is less than the threshold, it is determined that the eye E is not an aphakic eye.

(Display unit 170, operation unit 180)
The display unit 170 displays information under the control of the control unit 110. The display unit 170 includes the display unit 10. The operation unit 180 is used to operate the ophthalmologic apparatus 1000 and input information. The operation unit 180 includes various hardware keys (joysticks, buttons, switches, etc.) and / or various software keys (buttons, icons, menus, etc.) presented on the display unit 170.

(Communication unit 190)
The communication unit 190 has a function of communicating with an external device. The communication unit 190 includes a communication interface corresponding to a connection form with an external device. As an example of the external device, there is a spectacle lens measurement device for measuring optical characteristics of a lens. The spectacle lens measurement device measures the power of the spectacle lens worn by the subject and inputs this measurement data to the ophthalmologic apparatus 1000. The external device may be an arbitrary ophthalmic device, a device that reads information from a recording medium (reader), a device that writes information to a recording medium (writer), or the like. Further, the external device may be a hospital information system (HIS) server, a DICOM server, a doctor terminal, a mobile terminal, a personal terminal, a cloud server, or the like.

<Operation example>
An operation of the ophthalmologic apparatus 1000 according to the embodiment will be described. An example of the operation of the ophthalmologic apparatus 1000 is shown in FIG.

(S1: Ref measurement)
First, the reflex measurement is performed using the reflex measurement system 130 and the objective value calculation unit 121. The refractive power value (especially spherical power) of the eye E obtained by the objective value calculation unit 121 is sent to the objective value comparison unit 1221 of the determination unit 122.

(S2: Are you farsighted beyond the threshold?)
The objective value comparison unit 1221 compares the spherical power acquired in step S1 with a threshold value. Here, it is determined whether the spherical power of the eye E corresponds to hyperopia with a threshold value or more.

(S3: Determined as aphakic eye)
When it is determined in step S2 that the spherical power of the eye E is equivalent to hyperopia with a threshold value or more (S2: Yes), the determination unit 122 determines that the eye E is an aphakic eye. The process proceeds to step S13.

(S4: Interferometer light source turned on)
On the other hand, when it is determined in step S2 that the spherical power of the eye E does not correspond to hyperopia with a threshold value or more (S2: No), the main control unit 111 turns on the interferometer light source 81.

(S5: Insertion of corneal shutter)
The main control unit 111 inserts a corneal shutter 95 in the optical path in the reflection direction of the beam splitter 92.

(S6: Auxiliary lens insertion)
The main control unit 111 inserts an auxiliary lens (not shown) in the optical path of the measurement light LS. In addition, the timing which performs three processes in step S4-step S6 is arbitrary. For example, these can be executed simultaneously or in an order different from this example. It is also possible to additionally execute operations other than these.

  Normally, by the processing so far, a signal (target signal, peak) corresponding to the front surface of the crystalline lens or the IOL appears in the measurement range R of the interference signal (see FIG. 9). When the target signal does not exist in the measurement range R, the target signal can be searched automatically or manually as described above.

(S7: Adjustment of reference arm length)
The main control unit 111 performs movement control of the retina reference mirror unit 94 so that the target signal is arranged at a predetermined position R0 within the measurement range R. As a result, the target signal is arranged at or near the predetermined position R0.

(S8: Focus adjustment of measurement light)
The main control unit 111 performs focus adjustment (movement control of the focusing lens 85) so that the intensity of the target signal is maximized. As a result, the intensity of the target signal arranged at or near the predetermined position R0 is optimized.

(S9: Detection of intensity of target signal)
The intensity detector 1222 detects the intensity of the target signal that is arranged at or near the predetermined position R0 and whose intensity is optimized.

(S10: Is the intensity greater than or equal to the threshold?)
The intensity comparison unit 1223 compares the intensity of the target signal detected in step S9 with a threshold value. If the intensity is greater than or equal to the threshold (S10: Yes), the process proceeds to step S11. If the intensity is less than the threshold (S10: No), the process proceeds to step S12.

(S11: IOL transplanted eye determined)
When it is determined as “Yes” in Step S <b> 10, the determination unit 122 determines that the eye E is an IOL transplanted eye. The process proceeds to step S13.

(S12: Determined as phakic eye)
When it is determined “No” in step S10, the determination unit 122 determines that the eye E is a phakic eye. The process proceeds to step S13.

  Note that when the eye E is a fake kick IOL, since both the crystalline lens and the IOL exist, one or more target signals (peaks) corresponding to these are detected one by one. Then, the intensity of any one of the target signals is equal to or greater than the threshold, and the intensity of any other target signal is equal to or less than the threshold. As a result, the eye E is determined to be an IOL transplanted eye and a phakic eye (ie, a fake kick IOL transplanted eye).

(S13: Display of determination result)
The main control unit 111 causes the display unit 170 to display information indicating the determination result (the state of the eye E) obtained in step S3, S11, or S12.

  Here, an operation mode to be applied in subsequent processing can be set. The operation mode is set manually or automatically. The manual setting of the operation mode is performed using, for example, a graphical user interface (GUI) displayed on the display unit 170. On the other hand, manual setting of the operation mode is executed by the main control unit 111, for example.

  The operation mode information may include a type of inspection to be performed, a parameter value applied in the inspection, and the like. Furthermore, the operation mode information may include information on operations executed as preparation for measurement, such as an alignment mode and a focusing mode.

  As a specific example, when it is determined that the eye E is a phakic eye or an aphakic eye, known processing including calculation of the frequency of an IOL to be implanted in the eye E can be performed. Further, parameter values and calculation formulas applied to the frequency calculation of the IOL may be included in the operation mode information. Further, information indicating that the normal alignment mode is applied may be included in the operation mode information.

  When it is determined that the eye E is an IOL transplanted eye, it is possible to execute known processes including estimation of the frequency of the IOL, determination of suitability, calculation of the frequency of the IOL to be newly transplanted, and the like. It is. The parameter values are the same as described above. In addition, for the alignment, information indicating that the IOL alignment mode in consideration of the reflection image by the IOL is applied may be included in the operation mode information.

(S14: Measurement / analysis)
The ophthalmologic apparatus 1000 performs measurement (eye length measurement or the like) or analysis (IOL frequency calculation or the like) based on the operation mode set in step S13. This is the end of the description of this operation example.

[Action / Effect]
The operation and effect of the ophthalmologic apparatus according to the embodiment will be described.

  The ophthalmologic apparatus according to the embodiment includes a data acquisition unit, a control unit, and a determination unit.

  The data acquisition unit acquires data of the eye to be examined using optical interference measurement. In the above-described embodiment, the data acquisition unit includes the intraocular distance measurement system 8 and an optical element group that forms the optical path of the measurement light LS.

  The control unit controls the data acquisition unit so that a signal (target signal) corresponding to an object located between the cornea of the eye to be examined and the retina is acquired. In the above embodiment, the control unit includes at least the control unit 110 of the processing unit 9.

  The determination unit determines whether the eye to be examined is a phakic eye or an intraocular lens transplanted eye based on the intensity of the target signal acquired by control by the control unit. For example, when the intensity of the target signal is less than a predetermined threshold, the determination unit determines that the eye to be examined is a phakic eye, and when the intensity of the target signal is greater than or equal to the predetermined threshold, the eye to be examined is an intraocular lens. Determined to be a transplanted eye. In the embodiment described above, the determination unit includes the determination unit 122 (particularly, the intensity calculation unit 1222 and the intensity comparison unit 1223).

  When the eye to be examined is a fake kick IOL (phakic IOL) transplanted eye, the conventional technique detects not only the reflected signal corresponding to the cornea and the lens but also the reflected signal corresponding to the fake kick IOL. It was difficult to accurately determine the state (phakic eye, IOL transplanted eye, etc.). However, according to the ophthalmologic apparatus according to the embodiment, since the determination is performed based on the intensity of the optical interference signal (target signal) corresponding to the object existing between the cornea and the retina, it is possible to identify the fake kick IOL. It is.

  In the embodiment, the data acquisition unit may include an interference optical system, a photodetector, and an optical path length changing unit. The interference optical system divides the light from the light source (interferometer light source 81) into measurement light and reference light, irradiates the measurement eye with the measurement light, and interferes with the return light of the measurement light from the inspection eye and the reference light. Let In the above embodiment, the interference optical system includes an interferometer light source 81, a fiber coupler 82, an optical element group that forms a measurement arm, and an optical element group that forms a reference arm. The photodetector detects the interference light generated by the interference optical system. In the above embodiment, the photodetector includes the spectroscope 83 (or a balanced photodiode or the like). The optical path length changing unit changes at least one of the optical path length of the measurement light and the optical path length of the reference light. In the above embodiment, the optical path length changing unit includes the retina reference mirror unit 94. Further, the optical path length changing unit may include an auxiliary lens and a driving mechanism for inserting the auxiliary lens into the optical path. The control unit may be configured to control the optical path length changing unit in order to acquire the target signal.

  According to this configuration, since the target signal can be acquired by controlling at least one of the optical path length of the measurement light and the optical path length of the reference light, the process of acquiring the target signal can be facilitated.

  Furthermore, in the embodiment, the data acquisition unit may include a focusing lens arranged in the optical path of the measurement light and a driving mechanism that moves the focusing lens along the optical path of the measurement light. In the above embodiment, the focusing lens includes the focusing lens 85, and the driving mechanism includes the driving mechanism 85A. The focusing lens may include an auxiliary lens, and the drive mechanism may include a mechanism for inserting the auxiliary lens into the optical path. The control unit can control the drive mechanism to acquire the target signal.

  In addition, in the embodiment, the control unit is driven so that the intensity of the target signal is maximized after controlling the optical path length changing unit so that the data acquired by the data acquisition unit includes the target signal. The mechanism can be controlled. At this time, the control unit can control the optical path length changing unit so that the target signal is arranged at or near the predetermined position in the data acquired by the data acquiring unit.

  According to such a configuration, it is possible to maximize the intensity of the target signal by adjusting the focus of the measurement light. Thereby, the state of the eye to be examined can be determined with high accuracy and high accuracy based on the intensity of the target signal.

  The ophthalmologic apparatus of the embodiment may further include an objective refraction measurement unit. The objective refraction measurement unit projects pattern light onto the retina, detects the return light, and analyzes the detection result to obtain the refractive power of the eye to be examined. In the above embodiment, the objective refraction measurement unit includes the reflex measurement system 130 and the objective value calculation unit 1221. The determination unit can determine whether the eye to be examined is an aphakic eye based on the refractive power obtained by the objective refraction measurement unit.

  According to this configuration, it is possible to easily determine whether or not the subject's eye is an aphakic eye based on the result of objective refraction measurement.

  In the embodiment, the control unit can selectively apply the operation mode according to the determination result by the determination unit. In the embodiment, at least one of the states of the eye that can be determined by the embodiment, such as a normal mode applied to a phakic eye, an IOL mode applied to an IOL transplanted eye, and an aphasic mode applied to an aphakic eye An operation mode corresponding to is provided. Each operation mode is executed by a macro configured to include a type of inspection to be performed, a parameter value applied in the inspection, a calculation formula, and the like.

  According to this configuration, since the operation mode according to the determination result of the state of the eye to be examined is automatically set, the examination can be speeded up. In addition, there is an advantage that an operation mode selection error can be prevented.

  The embodiment described above is merely an example of a configuration for carrying out the present invention. A person who intends to implement the present invention can make arbitrary modifications, omissions, additions, substitutions and the like within the scope of the present invention.

1000 Ophthalmological apparatus 8 Intraocular distance measurement system 110 Control unit 122 Determination unit

Claims (8)

A data acquisition unit for acquiring data of the eye to be examined using optical interference measurement;
A control unit that controls the data acquisition unit so that a signal corresponding to an object located between the cornea and the retina of the eye to be examined is acquired;
An ophthalmologic apparatus comprising: a determination unit that determines whether the eye to be examined is a phakic eye or an intraocular lens transplanted eye based on the intensity of the signal acquired by control by the control unit. The data acquisition unit
An interference optical system that divides light from a light source into measurement light and reference light, irradiates the measurement light on the eye to be examined, and causes interference between the return light of the measurement light from the eye to be examined and the reference light;
A photodetector for detecting the interference light generated by the interference optical system;
An optical path length changing unit that changes at least one of the optical path length of the measurement light and the optical path length of the reference light,
The ophthalmologic apparatus according to claim 1, wherein the control unit controls the optical path length changing unit to acquire the signal. The data acquisition unit
A focusing lens disposed in the optical path of the measurement light;
A drive mechanism for moving the focusing lens along the optical path of the measurement light,
The ophthalmologic apparatus according to claim 2, wherein the control unit controls the drive mechanism to acquire the signal. The control unit controls the drive mechanism so that the intensity of the signal is maximized after controlling the optical path length changing unit so that the data is included in the data acquired by the data acquisition unit. The ophthalmic apparatus according to claim 3, wherein the ophthalmic apparatus is performed. The ophthalmologic according to claim 4, wherein the control unit controls the optical path length changing unit so that the signal is arranged at or near a predetermined position in data acquired by the data acquisition unit. apparatus. The determination unit determines that the eye to be examined is a phakic eye when the intensity of the signal is less than a predetermined threshold, and the eye to be examined is an eye when the intensity of the signal is equal to or greater than the predetermined threshold. The ophthalmologic apparatus according to claim 1, wherein the ophthalmologic apparatus is determined to be an inner lens transplanted eye. Projecting pattern light on the retina, detecting the return light, and comprising an objective refraction measurement unit for determining the refractive power of the eye by analyzing the detection result,
The said determination part determines whether the said to-be-tested eye is an aphakic eye based on the said refractive power calculated | required by the said objective refraction measurement part. The any one of Claims 1-6 characterized by the above-mentioned. An ophthalmic device according to claim 1. The ophthalmologic apparatus according to any one of claims 1 to 7, wherein the control unit selectively applies an operation mode according to a determination result by the determination unit.