JP2015123207A - Ophthalmologic light stimulation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ophthalmologic light stimulation apparatus capable of favorably executing light stimulation to the retina.SOLUTION: An ophthalmologic light stimulation apparatus 1 applies light stimulation to the fundus oculi r of a subject eye Er to cause the fundus oculi to output an electrophysiological signal. The ophthalmologic light stimulation apparatus 1 includes a stimulation light projection optical system 2 for projecting pattern light exited by a projector 21, to the fundus oculi. Preferably, the ophthalmologic light stimulation apparatus 1 includes control means that has a two-dimensional pattern where a plurality of examination areas are aligned, and causes the projector to exit the pattern light that applies multilocal light stimulation to the fundus oculi by varying the light intensity for each examination area.

Description

  The present invention relates to an ophthalmic light stimulation apparatus that performs light stimulation on the fundus and outputs an electrophysiological signal from the fundus.

  2. Description of the Related Art Conventionally, a visual function test is known in which a light stimulus is applied to the fundus and an electrophysiological signal emitted from a living body is measured in response to the light stimulus. For example, there is an electroretinogram examination (ERG examination) that measures an electrophysiological signal generated in the retina based on light stimulation to the fundus. When local light stimulation is performed on a part of the retina, for example, an action potential at the stimulation site is obtained as an electrophysiological signal (local ERG examination: see, for example, Patent Document 1). In Patent Document 1, an opening that partially passes light from the stimulus light source to the eye side to be examined is disposed between the stimulus light source and the eye to be examined, and the opening is switched to one having a different size. Discloses a technique for changing the size of the pattern light applied to the fundus.

  In the multi-local electroretinogram examination (mfERG examination), electrophysiological signals for a plurality of sites (local areas) on the retina are simultaneously measured. In the mfERG test, the retina is photo-stimulated in a multi-regional manner by presenting a two-dimensional pattern in which a plurality of regions whose brightness varies randomly to the eye to be examined. Conventionally, photo-stimulation of the retina has been performed by causing the subject to fixate the monitor and performing a two-dimensional pattern variation display on the monitor (see, for example, Patent Document 2).

JP 2010-240177 A JP-A-6-38928

  However, with conventional devices, it has been difficult to achieve both local light stimulus intensity and flexibility. For example, in the inspection apparatus disclosed in Patent Document 1, since the size and pattern shape of the pattern light are determined in advance by the shape of the opening, it may be difficult to perform the light stimulation desired by the examiner.

  Further, in the apparatus disclosed in Patent Document 2, light output from the monitor is not collected on the eye, so that stimulation efficiency is low and the time required for light stimulation tends to be long. As a result, for example, there is a problem that the subject is likely to be burdened. Also, the longer the time of light stimulation, the more easily the measurement result is affected by the movement of the eye to be examined that occurred during the light stimulation, so the reliability of the measurement result tends to decrease.

  The present invention has been made in view of the above-described problems of the prior art, and an object thereof is to provide an ophthalmologic light stimulating apparatus capable of performing light stimulation to the retina more suitably.

  An ophthalmic photostimulation device according to a first aspect of the present invention is an ophthalmic photostimulation device that outputs electrophysiological signals related to vision by photostimulating the fundus of a subject's eye, and uses pattern light emitted by a projector on the fundus. A stimulus light projection optical system for projection is provided.

  According to the present invention, light stimulation to the retina can be performed better.

It is the schematic block diagram which showed the optical system of the ophthalmic optical stimulation apparatus. It is the figure which showed the two-dimensional pattern of pattern light. It is the block diagram which showed the control system of the ophthalmic optical stimulation apparatus. It is the flowchart which showed the process of CPU regarding a mfERG test | inspection. It is the flowchart which showed the fundus oculi stimulation process performed by CPU.

  Hereinafter, typical embodiments of the present invention will be described with reference to the drawings. First, with reference to FIG. 1, the schematic structure of the ophthalmic light stimulating apparatus 1 in this embodiment is demonstrated.

  In the present embodiment, the ophthalmologic light stimulating apparatus 1 mainly has a stimulating light projection optical system 2. Further, the ophthalmic light stimulating apparatus 1 of the present embodiment includes an imaging optical system 3 and an electrode 4.

  The stimulation light projection optical system 2 is used to project pattern light (stimulation light) onto the fundus. In the present embodiment, the stimulation light projection optical system 2 mainly includes a projector 21 and an optical member that guides light from the projector 21 to the eye E and collects the light on the eye Er. In the present embodiment, as an example of the optical member, the projection lens 22, the mirror 23, the dichroic mirror 24, and the concave mirror 40 are provided.

  The projector 21 is used as a light source that emits pattern light. In the present embodiment, DLP (registered trademark) is used as the projector 21. The DLP has, for example, a visible light source and a digital mirror device (both not shown). The DLP can be driven at a high speed and can form an image with a high contrast ratio in a free shape (pattern). For this reason, the projector 21 according to the present embodiment easily performs light stimulation of the fundus. In the present embodiment, for convenience of explanation, it is assumed that the color of light output from the projector 21 is white. White light stimulates each of the S cone, M cone, and L cone on average.

  Here, the digital mirror device is a semiconductor chip in which a number of micromirrors are two-dimensionally arranged. In the present embodiment, each pixel of a projected image (for example, a two-dimensional pattern image) is formed by each micromirror. The micromirror is driven into two states, on and off, by tilting the mirror surface around the torsion axis. The light reflected by the mirror in the on state goes to the projection lens 22 along the optical axis L1. As a result, white pixels are formed. On the other hand, the mirror in the off state reflects light from the light source to an absorber (not shown). As a result, the reflected light of the mirror in the off state is discarded without entering the projection lens 22. As a result, black pixels are formed. In the present embodiment, the two-dimensional pattern of pattern light used for multipolar stimulation of the retina is formed by individually driving each micromirror.

  Here, an example of a two-dimensional pattern is shown with reference to FIG. As shown in FIG. 2, a plurality of inspection areas h are arranged to form a two-dimensional pattern. In the present embodiment, either white (bright) or black (dark) is individually set for each inspection region h. Light stimulation to the retina is performed by the white inspection region h and not by the black inspection region h. In the present embodiment, a plurality of two-dimensional patterns having different arrangements of white areas and black areas are prepared in advance. As the two-dimensional pattern is sequentially switched to a different one, the color (brightness) of each inspection region h is changed (inverted) independently. In the present embodiment, light stimulation to the retina of the eye E is performed universally and multipolarly by switching a plurality of two-dimensional patterns.

  In FIG. 2, the shape of the inspection region h is shown as a hexagon, but is not necessarily limited to this shape. The inspection region h may be a polygon (triangle, square, etc.) or a shape having a curve in part or in whole. Also, the size and shape may be different in each inspection region h. For example, as shown in FIG. 2, the size of the inspection region h arranged on the outer side may be set larger. The response density of the electrophysiological signal from the retina is considered to correspond to the density of the cone. That is, the response density of the electrophysiological signal becomes smaller as the site is farther from the macula. Therefore, when the pattern light has a two-dimensional pattern as shown in FIG. 2, it is preferable to perform stimulation so that the center of the pattern and the macula overlap. In this case, if each part on the retina where each examination area h is located is normal, the same electrophysiological signal is extracted from each examination area h, and the retinal function in each part is well understood. It becomes easy.

  Stimulation conditions such as the number density of the inspection area h included in the two-dimensional pattern, the amount of light in the white and black inspection areas h, and the shape of the inspection area h are appropriately determined by a stimulation condition setting unit (for example, the control unit 100). It may be set. At this time, for example, a stimulation condition may be selected from a plurality of stimulation conditions prepared in advance. For example, the stimulation condition instructed by the examiner via the operation unit 70 described later may be set.

  Note that the fixation of the eye E to be examined when optical stimulation is performed on the retina and when a fundus image is captured through the imaging optical system 2 may be guided by the stimulation light projection optical system 2. . For example, a fixation target (fixation pattern) may be projected from the projector 21 onto the fundus along with the two-dimensional pattern. Of course, the ophthalmologic light stimulating apparatus 1 may be provided with a fixation target presenting optical system for fixing the eye to be examined separately from the stimulating light projection optical system 2 and the imaging optical system 3.

  Pattern light output from the projector 21 is projected onto the fundus Er of the eye E through the projection lens 22, mirror 23, dichroic mirror 24, and concave mirror 40. That is, the pattern light emitted from the projector 21 is condensed by the projection lens 22 to the concave mirror 40 and guided to the fundus Er. Therefore, in the present embodiment, the light stimulation of the fundus Er is performed by the condensed light, so that the fundus light stimulation is performed efficiently.

  In the present embodiment, the position of the projection lens 22 in the direction of the optical axis L1 can be adjusted by the drive mechanism 22a (see FIG. 3). By displacing the projection lens 22, the diopter of the stimulus light projection optical system 2 can be adjusted according to the refractive power of the eye E to be examined. The diopter of the stimulus light projection optical system 2 can be adjusted by other methods. For example, diopter correction may be performed by adjusting the position of the projector 21. In this case, for example, a drive mechanism that moves the projector 21 to adjust the diopter may be provided. Of course, the diopter adjustment may be performed by moving both the projection lens 22 and the projector 21.

  The dichroic mirror 24 reflects visible wavelength light and transmits infrared wavelength light. Note that the configuration of the dichroic mirror 24 is not limited as long as the pattern light can be combined with infrared light from the light source 31 (to be described later) and coaxial (combined) on the optical axis L1. For example, a half mirror may be used instead of the dichroic mirror 24.

  The imaging optical system 3 will be described. The imaging optical system 3 is used for imaging and observing the fundus. In the present embodiment, the imaging optical system 3 uses a scanning laser ophthalmoscope (SLO) optical system. The imaging optical system 3 is not limited to the configuration of the scanning laser ophthalmoscope, and may be any that can be used for imaging and observing the fundus. For example, a fundus camera optical system may be used as the imaging optical system 3.

  As shown in FIG. 1, the imaging optical system 3 of the present embodiment includes a light projecting optical system (illumination optical system) 3a and an observation optical system (light receiving optical system) 3b. The light projecting optical system 3a is an optical system that projects illumination light to each position of the fundus Er. The projection optical system 3a of the present embodiment includes a laser beam emitting unit 31, a perforated mirror 32, a lens 33, a diopter correction unit 34, a concave mirror 36, a polygon mirror 37, a concave mirror 38, a galvano mirror 39, and a concave surface. A mirror 40.

  In the present embodiment, the laser beam emitting unit 31 is used as a light source for imaging the fundus. In the present embodiment, the laser light emitting unit 31 emits laser light in the infrared region near the wavelength of 790 nm.

  Laser light emitted from the laser light emitting unit 31 passes through the opening of the perforated mirror 32, passes through the lens 33, is reflected by the diopter correction unit 34, and the concave mirror 36, and travels toward the polygon mirror 37. The light beam reflected by the polygon mirror 37 is reflected by the concave mirror 38, the galvano mirror 39, and the concave mirror 40, and then collected by the fundus Er of the eye E to be examined.

  The diopter correction unit 34 is a mechanism for performing diopter correction. The diopter correction unit 34 includes two mirrors 34a and 34b and a drive unit (not shown). The drive unit moves the two mirrors 34a and 34b in the direction of the arrow s while maintaining the positional relationship between the two mirrors 34a and 34b. As a result, the optical path lengths of the light projecting optical system 3a and the light receiving optical system 3b described later are changed. Thereby, diopter correction of the imaging optical system 3 is performed.

  In the present embodiment, the scanning unit that two-dimensionally scans the fundus Er with the laser light is configured by a pair of reflection mirrors (polygon mirror 37 and galvano mirror 39). By rotating the polygon mirror 37 by a motor 37a (see FIG. 3), the irradiation position (scan position) of the laser light on the fundus Er moves in the horizontal direction (that is, the X direction) of the fundus Er. Further, by rotating the galvanometer mirror 39 by the motor 39a (see FIG. 3), the irradiation position of the laser light on the fundus Er moves in the vertical direction (that is, the Y direction) on the fundus. Thus, in the present embodiment, the laser light is scanned two-dimensionally on the fundus Er by driving the polygon mirror 37 and the galvanometer mirror 39. As the scanning unit, for example, as described above, a reflection mirror such as a polygon mirror or a galvanometer mirror may be used. As another reflection mirror, for example, a resonant mirror may be used.

  Light is emitted from the fundus Er by irradiating the fundus Er with laser light from the laser beam emitting unit 31. For example, when the laser beam is reflected by the fundus Er, the fundus reflection light of the laser beam is emitted from the pupil.

  Next, the light receiving optical system 3b will be described. In the light receiving optical system 3b, the light receiving element 45 receives light from the fundus Er accompanying the laser light from the light projecting optical system 3a. In the present embodiment, the photographing optical system 3 shares the members arranged from the perforated mirror 32 to the concave mirror 40 on the optical path L1 of the light projecting optical system 2 with the light projecting optical system 3a. In addition, the light receiving optical system 3 b of the present embodiment includes a lens 41, a stimulation light filter 42, a pinhole plate 43, a lens 44, and a light receiving element 45.

  The fundus reflection light of the laser light emitted from the pupil is guided on the optical axis L2 by following the projection optical system 3a as described above and being reflected by the perforated mirror 32. Thereafter, the fundus reflection light is focused on the pinhole of the pinhole plate 43 through the lens 41 and the stimulation light filter 42. The light from the focused fundus Er is received by the light receiving element 45 through the lens 44. In the present embodiment, a case where a light receiving element 45 having sensitivity in the visible region and the infrared region (for example, an avalanche photodiode: APD) will be described. As described above, in the light receiving optical system 3b of the present embodiment, the observation surface of the fundus Er and the pinhole of the pinhole plate 43 are conjugate points. The light receiving element 45 can receive light well. Therefore, based on the light reception signal from the light receiving element 45, an image in which the fundus oculi Er is depicted in detail can be constructed.

  The stimulation light filter 42 blocks light (mainly visible light) projected from the projector 21 and reflected from the fundus Er, and outputs light output from the laser light emitting unit 31 and reflected from the fundus Er. It has the property of transmitting. For example, the stimulation light filter 42 at least blocks the wavelength band where the wavelength band of the pattern light projected from the projector 21 overlaps the wavelength band where the light receiving element 45 has sensitivity. Since the fundus reflection light of the light from the projector 21 that can be noise in obtaining the fundus image is blocked, a good fundus image is constructed via the imaging optical system 3.

  The electrode 4 is used to detect an electrophysiological signal (for example, retinal potential; ERG) induced by light stimulation to the retina. In the present embodiment, a contact electrode that transmits light from the projector 21 and the laser light emitting unit 31 and derives an electrophysiological signal from the cornea is used as the electrode 4. In the present embodiment, the output from the electrode 4 is guided to the control unit 100 described later via a conducting wire. The electrode 4 is not limited to the contact electrode as long as an electrophysiological signal from the retina can be obtained. For example, it may be a skin electrode attached to the lower eyelid and the corner of the eye.

  When the electrode 4 is mounted on the eye E, the eye E is preliminarily subjected to mydriatic eye drops for examination (for example, Midrin P) and ophthalmic surface anesthetic (for example, 0.4% solution of Benoxeal). Are preferred. The electrode 4 may be mounted in a state where a cornea mounting aid (for example, scopisol) is applied.

  Next, a control system of the ophthalmologic light stimulation apparatus 1 according to the present embodiment will be described. FIG. 3 is a block diagram showing a control system of the ophthalmic light stimulating apparatus 1 in the present embodiment. The main control of the ophthalmic light stimulation apparatus 1 is performed by the control unit 100. In the present embodiment, the control unit 100 is a processing apparatus having an electronic circuit that performs control processing of the entire apparatus, signal processing of signals input from various devices, calculation processing of measurement results, and the like.

  In the present embodiment, the control unit 100 includes the electrode 4, the projector 21, the drive mechanism 22a, the laser light emitting unit 31, the diopter correction unit 34, the polygon mirror driving motor 37a, the galvano mirror driving motor 39a, the light receiving element 45, It is connected to the image processing IC 50, the operation unit 70, the HDD (hard disk) 104, and the like. The control unit 100 is connected to the monitor 60 via the image processing IC 50. The monitor 60 is a display device for displaying an image of the eye E to be inspected taken by the ophthalmologic apparatus 1 and various measurement results.

  The control unit 100 includes a CPU 101, a ROM 102, and a RAM 103. The CPU 101 is a processor for executing various processes related to the ophthalmic light stimulation apparatus 1. The ROM 102 is a non-volatile storage device that stores a control program and fixed data. The RAM 103 is a rewritable volatile storage device. The RAM 103 temporarily stores, for example, image data obtained via the imaging optical system 3 and data related to signals obtained from the electrodes 4.

  The HDD 104 is a rewritable nonvolatile storage device. In the present embodiment, the HDD 104 stores a program for causing the ophthalmic light stimulation apparatus 1 to perform an mfERG examination. In addition, image data, inspection results of mfERG inspection, and the like may be stored.

  The image processing IC 50 is a processing device for forming a fundus image of the eye E based on a signal output from the light receiving element 45. The image processing IC 50 constructs (generates) image data of a fundus image for one frame based on the light reception signal sequentially output from the light receiving element 45 and outputs the image data to the monitor 60. In the present embodiment, the generation and output of the fundus image by the image processing IC 50 is repeated for each scan of one frame by the polygon mirror 37 and the galvano mirror 39, so that a live image of the fundus is displayed on the screen of the monitor 60. Observable. Hereinafter, unless otherwise specified, the description will be made assuming that a live image of the fundus is generated and displayed on the monitor 60 during the operation of the apparatus related to the mfERG examination.

  The operation unit 70 receives an operation for the examiner to input an instruction to the control unit 100. The operation unit may be, for example, a joystick, a mouse, a keyboard, various switches, and the like.

  Next, the operation of the ophthalmic light stimulation apparatus 1 having the above configuration will be described.

  Here, an example of the operation of the apparatus relating to the mfERG inspection will be described with reference to the flowchart of FIG. In the present embodiment, first, diopter correction processing is performed by the CPU 101 (S1). In the diopter correction process (S1), the diopter correction unit (for example, the projection lens 22 and the projector 21) of the stimulus light projection optical system 2 is driven to correct the diopter of the stimulus light projection optical system 2. For example, in the present embodiment, the position of the projection lens 22 is adjusted so that a two-dimensional pattern based on the pattern light from the projector 21 is clearly imaged on the fundus Er. Further, in the diopter correction process (S1) of the present embodiment, the diopter correction unit 34 is driven to correct the diopter of the photographing optical system 3. For example, the position of the diopter correction unit 34 is adjusted so that the fundus image displayed on the monitor 60 can be clearly seen. At this time, the diopter correction of the stimulus light projection optical system 2 and the imaging optical system 3 may be performed based on the refractive power of the eye E measured in advance. For example, a measurement result by an eye refractive power measurement device or the like may be used. The diopter correction may be performed manually by the examiner. For example, the diopter correction of the stimulus light projection optical system 2 is performed by the examiner operating the operation unit 70 and displacing the projection lens 22 based on the response of the subject whose pattern light is projected onto the eye E. It may be done. Further, for example, the diopter correction of the imaging optical system 3 is performed by the examiner operating the operation unit 70 while displacing the diopter correction unit 34 while confirming the fundus image (live image) displayed on the monitor 60. It may be done. Further, the projection lens 22 and the like are displaced in conjunction with the displacement of the diopter correction unit 34 at this time, so that the diopter correction of the stimulus light projection optical system 2 and the imaging optical system 3 is performed at the same time. It may be done.

  Furthermore, the CPU 101 performs alignment processing (S2). In the alignment process (S2) of the present embodiment, for example, the photographing position of the fundus oculi Er is adjusted based on the operation of the operation unit (for example, joystick) by the examiner. At this time, the stimulation position of the pattern light may be moved together with the photographing position of the fundus image. The adjustment of the imaging position may be performed, for example, by changing the fixation position and changing the line-of-sight direction of the eye E. At this time, the stimulation position of the pattern light is also moved in accordance with the adjustment of the photographing position.

  Next, the CPU 101 sets an inspection target range (S3). The inspection target range in this embodiment is a region where light stimulation is performed. The process of S3 may be, for example, a process of setting a part of the range instructed by the examiner as the examination target range within the fundus range displayed on the monitor 60. An instruction from the examiner regarding the inspection target range is input to the control unit 100 via the operation unit 70, for example. More specifically, for example, the examination target range may be set in an area surrounded by dragging the cursor of the pointing device on the fundus image of the monitor 60. In addition, instead of dragging, the examiner may specify a plurality of points on the image, and an inspection target range including these points may be set. For example, the shape and / or size of the inspection target range may be selected by the examiner from predetermined ones. In this case, the position where the examination target range is set on the fundus image may be further indicated by a pointing device or the like.

  For example, the process of S3 may be a process of automatically setting the inspection target range. In this case, for example, image processing in which a region including a characteristic part such as a macula and an optic disc is set as a detection target region may be performed. After the setting, the position information of the inspection target range may be stored in the RAM 103, for example. Note that the setting of the inspection target range is not necessarily performed. In this case, the retinal potential is measured for a certain range on the fundus image (for example, the entire range of the fundus image).

  Next, the CPU 101 executes fundus stimulation processing (S4). In the fundus stimulation processing (S4) of the present embodiment, light projection to the retina is performed by controlling the projection of the pattern light by the projector 21. In addition, the retinal potential detected with the light stimulation by the pattern light is measured and stored.

  Here, with reference to FIG. 5, the fundus stimulation process (S4) of the present embodiment will be described in more detail. In the present embodiment, in the fundus stimulation process (S4), the processes from S11 to S14 are repeatedly executed. By the process of S11, the CPU 101 detects the movement of the eye E and obtains position correction information (S11). In the present embodiment, the movement of the eye E is detected using a live image of the fundus Er obtained via the imaging optical system 3. For example, the movement of the eye E when the template image is captured may be detected by image processing for obtaining a positional shift of the imaging range between the frame image captured most recently and the template image captured before that. The template image is taken at a timing such as when the alignment between the eye E to be examined and the optical system is completed (for example, when the process of S2 is completed) or when the fundus stimulation process (S4) starts. There may be. In this case, the positional deviation amount between the frame image and the template image is obtained as the position correction information.

  Next, the CPU 101 controls the projector device 21 to switch the two-dimensional pattern and adjust the stimulation position on the fundus Er (S12). The switching of the two-dimensional pattern may be performed every time the process of S12 is executed a certain number of times. Note that the order of switching the two-dimensional pattern may be a predetermined order or a random order.

  At this time, when the inspection target range is set by the process of S3, the CPU 101 projects the pattern light by the projector 21 so that the light intensity of the inspection region h is changed on the inspection target range. To control. For example, the CPU 101 causes the projector 21 to project pattern light based on a two-dimensional pattern for the inspection target range, and pattern light is projected from the projector 21 around (outside) the inspection target range. It may not be done. In this case, the projector 21 may not emit any light around the inspection target range (outside), but background light having a constant light intensity is projected from the projector 21. Also good. The electrophysiological activity of the retina can be activated by projecting background light around the area to be examined. As a result, the electrophysiological signal from the examination target range of the retina is easily output favorably. Background light projection is more effective when the inspection target range of the retina is narrow and the light stimulation by the pattern light is small. The background light is intermediate between the inspection region h that gives a light stimulus (white inspection region h in this embodiment) and the inspection region h that doesn't give a light stimulus (black inspection region h in this embodiment). It is preferable that the brightness is as high as possible. Appropriate background light brightness and range can be appropriately determined by experiments or the like.

  At this time, the examination region h may be set to have a size (and / or shape) according to the positional relationship with a characteristic part (for example, macula) on the fundus. For example, the projector 21 may be controlled by the CPU 101 so that pattern light that forms a larger examination region h is emitted toward a part of the fundus that is farther from the macula. More specifically, when pattern light having a two-dimensional pattern as shown in FIG. 2 is emitted, the projector 21 may be controlled so that the center of the two-dimensional pattern overlaps with the macula. As described above, in the two-dimensional pattern in FIG. 2, the size of each detection region h is set in accordance with the distribution of cones around the macula. Therefore, in this case, appropriate light stimulation is easily given to each part. In addition, when the inspection object range is set, a larger inspection region h may be set in a region farther from the macula on the range. Here, the characteristic part used as a setting reference for the examination region h may be detected by image processing on a fundus image (for example, a live image). Further, the position of the characteristic part may be designated by the examiner. For example, each examination region h may be set on the assumption that a characteristic part (for example, macular) exists at a position designated by overlapping the cursor of the pointing device on the fundus image of the monitor 60. In addition, although the macula was illustrated as a characteristic part, it is not restricted to this, For example, a nipple, a retinal blood vessel, its crossing part, etc. may be sufficient.

  In addition, the projector 21 may be controlled by the CPU 101 under preset imaging conditions (for example, the intensity of light in the inspection area h, the number density of the inspection area h, the shape of the inspection area, etc.).

  In the present embodiment, the pattern light irradiation range may be corrected by the process of S12 by controlling the projector 21 based on the position correction information obtained by the process of S11 immediately before. In the present embodiment, for example, the projection position of the pattern light can be made to follow the movement of the eye by correcting the driving amount of each micromirror that is controlled to be on in the digital mirror device according to the position correction information. Good. It is possible to suppress the positional relationship between each part of the fundus Er and each examination region h from being changed while switching a plurality of two-dimensional patterns. As a result, the ophthalmic light stimulating apparatus 1 can satisfactorily give multi-site light stimulation to the retina.

  Next, the CPU 101 acquires a retinal potential via the electrode 4, and stores the acquired potential in a storage device such as the RAM 103 (S13).

  In the present embodiment, after executing the processes of S11 to S13, the CPU 101 determines whether or not the light stimulus and the acquisition of the potential are completed (S14). For example, it may be determined that the light stimulation and the acquisition of the potential have been completed (S14: Yes) when at least one light stimulation with a two-dimensional pattern prepared in advance is performed. If the light stimulation has not been completed (S14: No), the process returns to S11, and the light stimulation and the acquisition of the potential by the plurality of two-dimensional patterns are continued. When the CPU 101 determines that the light stimulus and the acquisition of the potential are completed (S14: Yes), the process of the CPU 101 proceeds to the analysis process (S5, see FIG. 4).

  Returning to FIG. 4, the description will be continued. In the analysis process (S5) of the present embodiment, for example, the CPU 101 uses the retinal potential for each two-dimensional pattern stored by the fundus stimulation process (S4) to use the retinal potential (for each examination region h) in a plurality of regions of the retina. Retinal potential). At this time, the analysis of the output waveform of the signal for each part may be performed. For a specific derivation method, see, for example, Patent Document 2 described above.

  After completion of the analysis process (S5), the CPU 101 outputs an analysis result (S6). The analysis result may be output to a printer, HDD 104, etc. (not shown) in addition to the monitor 60. For example, when output to the monitor 60, the analysis result may be shown using a two-dimensional pattern graphic. The retinal potential measured in each inspection region h may be indicated by the color density, the degree of deformation, etc. of each inspection region h in the two-dimensional pattern graphic. Moreover, you may display the output waveform of the bioelectric signal for every site | part (every test area | region h). Further, the output waveform and the graphic of each inspection area h of the two-dimensional pattern may be superimposed and displayed. In addition, graphics such as a two-dimensional pattern and an output waveform may be displayed superimposed on the fundus image. After the process of S6, the process ends.

  As described above, according to the ophthalmic light stimulation apparatus 1 of the present embodiment, the pattern light emitted from the projector 21 is directly projected onto the fundus Er by the stimulation light projection optical system 2. Thereby, the light stimulation to a retina can be performed efficiently. As a result, for example, the retinal potential can be obtained better. Moreover, since the projector is used as the light source of the pattern light, the ophthalmic light stimulation apparatus 1 can easily perform light stimulation with a high degree of freedom.

  In addition, when the examination target range is detected by the process of S3, the ophthalmic light stimulation apparatus 1 according to the present embodiment performs projection of pattern light in which the light intensity of the examination region h is changed in the examination target range. Thus, the projector 21 is controlled (S4). Therefore, multi-site light stimulation can be performed on a specific part that is an examination target range. As a result, in this embodiment, the functional test for each part of the retina can be performed satisfactorily.

  In the ophthalmic light stimulating apparatus 1 according to the present embodiment, an optical system of a scanning laser ophthalmoscope is used as the imaging optical system 3. In particular, in this embodiment, since the observation surface of the fundus Er and the pinhole of the pinhole plate 24 are optically conjugate, there is little noise input to the light receiving element 45 and a detailed fundus image can be obtained. For this reason, for example, by comparing the fundus image with the obtained potential analysis result, the examiner can easily confirm the abnormal portion of the fundus Er correctly. As a result, it is possible to satisfactorily measure the retinal function at a stage where visual confirmation cannot be made by an ophthalmoscopic examination or the like performed under general visible light (direct viewing), or at a stage where no chief complaint has been made at the non-illness stage.

  In addition, while the plurality of two-dimensional patterns are switched and the light stimulation of the retina is performed, there may be a case where the eye to be inspected is moved due to microscopic fixation or the like. The ophthalmic light stimulating apparatus 1 according to the present embodiment corrects the irradiation range of the pattern light projected from the projector 21 based on position correction information obtained by detecting the movement of the eye to be examined from the live image of the fundus. In this embodiment, the irradiation range is made to follow the movement of the eye. As a result, the displacement of the pattern light irradiation range on the retina is suppressed while the light stimulation is performed. Therefore, in the ophthalmic light stimulating apparatus 1 according to the present embodiment, even if the eye E moves due to a slight eye movement or the like, the light stimulation is performed while the correspondence between each part of the retina and each examination region h is maintained. Is easy to be done.

  Here, the limit of the follow-up speed of the irradiation range is roughly determined by the total value of the live image capturing speed by the imaging optical system 3 and the display speed of the two-dimensional pattern by the projector device 21. In the present embodiment, a DLP is used as the projector device 21. The DLP can operate at a sufficiently high speed (for example, about 120 Hz) as compared with the generation period (about 10 Hz) of fixation fine movement of the eye to be examined. For this reason, it is easy to make the irradiation range of the pattern light follow the movement of the eye favorably. When the imaging speed of the live image by the imaging optical system 3 is about 30 Hz, for example, the tracking speed of the irradiation range is (1/120 + 1/30) ≈1 / 24 (that is, 24 Hz). For this reason, it is possible to suitably follow the irradiation range of the pattern light with respect to fixation fine movement (about 10 Hz).

  Further, a stimulus light filter 42 that blocks fundus reflected light due to light from the projector 21 is disposed in front of the light receiving element 45 of the imaging optical system 3 (in the imaging optical system 3). Thereby, the ophthalmologic light stimulating apparatus 1 constructs a good fundus image based on the light reception signal from the light receiving element 45. Here, in the present embodiment, a live image of the eye to be examined obtained based on the light reception signal from the light receiving element 45 is used to adjust the irradiation position of the pattern light. Therefore, in this embodiment, the stimulation light filter 42 contributes to increasing the adjustment accuracy of the irradiation position of the pattern light. The stimulation light filter 42 may be provided on the optical path of the stimulation light projection optical system 2 (for example, on the optical axis L1). However, the stimulation light filter 42 is arranged closer to the light receiving element 45 than the dichroic mirror 24, as compared with the case where it is arranged in the stimulation light projection optical system 2, the irradiation intensity of the pattern light irradiated to the retina is ensured. Since it is easy to be done, it is more preferable.

  As described above, the description has been given based on the embodiment, but the present invention is not limited to the above-described embodiment, and various modifications are possible.

  For example, in the above embodiment, the imaging optical system 3 includes the pinhole plate 44 and passes through a pinhole having a confocal (conjugate) positional relationship with the condensing point of the laser light from the light projecting optical system 3a on the fundus. The case where the received light is received by the light receiving element 45 has been described. Instead of the pinhole plate 44, it is arranged at a position conjugate with or near the condensing point on the fundus so that a part of the scattered light scattered before and after the condensing point is transmitted toward the light receiving element 45. In addition, a light flux limiting member that limits (or partially opens) the passage region of the scattered light may be disposed. In this case, a deeper layer of the retina can be observed by an image obtained based on the light reception signal from the light receiving element 45. For example, since the cell sheet transplanted under the retina can be confirmed, it is easy to confirm the established state (or engraftment status) of the transplanted cells using the measurement result of the mfERG test. As the light beam limiting member, for example, a ring aperture having a light shielding portion at a position conjugate with the condensing point of the laser light from the light projecting optical system 3a can be used. Of course, the ophthalmic light stimulating apparatus 1 may be provided with a switching mechanism that switches between the pinhole plate 44 and a light flux limiting member (ring aperture or the like) and arranges one of them on the optical axis L3. In the above embodiment, the case where the inspection target range is automatically set with respect to the range including the characteristic part such as the macula and the optic disc is exemplified. However, the inspection target is determined relative to the range including the transplanted cells under the retina. The range may be set automatically.

  In the above embodiment, the projector 21 has been described as outputting white light. However, by causing the projector 21 to output visible light having a specific wavelength, any one of the S cone, the M cone, and the L cone is output. However, it may be selectively stimulated. For example, at least one color of red (wavelength of about 670 nm), green (wavelength of about 530 nm), and blue (wavelength of about 470 nm) may be selectively output from the projector 21. The short wavelength cone (S cone), medium wavelength cone (M cone), and long wavelength cone (L cone) each have at least blue, green, and red sensitivities. For this reason, according to the color of the light output from the projector 21, the function of a different cone can be test | inspected. In this case, since cells having individual sensitivity to short-wavelength, medium-wavelength, and long-wavelength light can be individually or simultaneously stimulated, the retinal function can be measured in more detail. Note that light of a color instructed by the examiner via the operation unit 70 may be output from the projector 21.

  In the above-described embodiment, when the pattern light projection position is displaced with the movement of the eye E, the position of the pattern light irradiation is moved by following the movement of the eye E. The case where the deviation is suppressed has been described. However, for example, when the movement of the eye E is large, it may be difficult to make the pattern light irradiation range follow the eye E. Therefore, for example, when the positional deviation amount is larger than the threshold value, the retinal potential measured at that time may be excluded from the analysis target. At this time, the projector 21 may be controlled by the CPU 101 so that the switching of the two-dimensional pattern is interrupted, and the projector 21 is controlled so that the pattern excluded from the analysis target is output again later. Also good.

  Further, when a skin electrode is used as the electrode 4, an open state during light stimulation may be detected. For example, using the live image obtained from the imaging optical system 3, the output of the electrode 4, and the like, the control unit 100 can detect the open state. When it is detected that the eyelid is closed, the retinal potential measured at that time may be excluded from the analysis target.

  In the above-described embodiment, the case where the irradiation position of the pattern light is adjusted during the light stimulation using the fundus live image captured through the imaging optical system 3 has been described. However, the adjustment of the irradiation position of the pattern light may be performed using a live image of the eye E, and is not limited to the case where a live image of the fundus is used. For example, the movement of the eye to be examined may be detected using a live image of the anterior segment, and the pattern light irradiation position may be adjusted.

  Moreover, although the case where DLP was used as the projector 21 was demonstrated in the said embodiment, it is not necessarily restricted to this. For example, a CRT projector, an LCD projector, an LCOS projector, a GLV projector, or the like may be used.

  In the ophthalmologic light stimulating apparatus 1 of the above embodiment, the case where a fundus image such as a live image is captured using the fundus reflected light of the infrared light emitted from the illumination optical system 3a has been described. Is not something For example, a fundus image may be captured via the imaging optical system 3 using fluorescence emitted from a fluorescent contrast agent injected into the fundus or a self-fluorescent substance present in the fundus. In this case, for example, excitation light for causing the fluorescent material to emit light is projected onto the eye E from the illumination optical system 3a. In this case, the observation optical system 3b may be provided with a barrier filter according to the light emitted from the light source 31 and the wavelength of the generated fluorescence. In this case, for example, it becomes easy to compare and compare the characteristic part in the fluorescence image and the measurement result of mfERG.

  In the above embodiment, the case where the stimulation light filter 42 is arranged in the observation optical system 3b has been described. However, when the stimulation light filter 42 is disposed, it becomes difficult to observe the two-dimensional pattern formed on the fundus by the pattern light on the live image. Therefore, for example, the CPU 101 may display on the monitor 60 a virtual two-dimensional pattern superimposed on a live image by image processing. The virtual two-dimensional pattern may be displayed, for example, only in a portion where light stimulation is performed (more specifically, a portion on the range when the inspection target range is set in the process of S3). , The whole may always be displayed.

  Further, the stimulation light filter 42 may be configured to be retractable from the optical axis L3. For example, a drive mechanism that moves the stimulation light filter 42 in a direction that intersects the optical axis L3 may be provided. For example, the two-dimensional pattern formed on the fundus by the pattern light can be observed on the live image by retracting the stimulation light filter 42 while the pattern light is irradiated on the eye to be examined. In the above embodiment, for example, when the inspection target range is set by the examiner, the CPU 101 controls the apparatus so that the stimulation light filter 42 is in the retracted state and pattern light is output from the projector 21. Also good. This makes it easier for the examiner to confirm the actual pattern light irradiation state.

  In the above-described embodiment, the case where the mfERG inspection is performed using the stimulus light projection optical system 2 that condenses the light from the projector 21 on the fundus is described, but the present invention is not necessarily limited thereto. For example, the stimulus light projection optical system 2 can be used for other examinations in which an electrophysiological signal is output from the fundus in association with light stimulus to the fundus. For example, it may be used for other ERG examinations such as local ERG examinations. It may also be used for VEP inspection.

DESCRIPTION OF SYMBOLS 1 Ophthalmic light stimulator 2 Stimulation light projection optical system 3 Imaging optical system 3a Light projection optical system (illumination optical system)
3b Observation optical system (light receiving optical system)
21 Projector 37 Polygon mirror 39 Galvano mirror 42 Stimulating light filter 100 Control unit 101 CPU
h Inspection area

Claims (11)

An ophthalmic light stimulating device that outputs an electrophysiological signal related to the state of the fundus from the fundus by light stimulating the fundus of the eye to be examined,
An ophthalmologic light stimulation apparatus comprising a stimulation light projection optical system for projecting pattern light emitted by a projector onto a fundus.   Control means for emitting from the projector the pattern light that has a two-dimensional pattern in which a plurality of examination regions are arranged and the light intensity is varied for each examination region to perform multi-local light stimulation on the fundus The ophthalmic light stimulation apparatus according to claim 1, wherein the ophthalmic light stimulation apparatus is provided. Fundus image acquisition means for acquiring a fundus image;
An examination target range setting means for setting an examination target range on the fundus on the fundus image acquired by the fundus image acquisition means;
Pattern projection control means for controlling the projector so that projection of pattern light in which the intensity of light in the inspection area is varied is performed at least in the inspection target range set by the inspection target range setting means;
The ophthalmic light stimulation apparatus according to claim 2, comprising:   The ophthalmic light stimulating apparatus according to claim 3, wherein the pattern projection control unit controls the projector so that background light is irradiated on a background of the inspection target range.   An inspection area for controlling the projector so that pattern light having an inspection area having a size corresponding to the positional relationship between a characteristic part on the fundus and a stimulation part where light stimulation is performed is performed on the stimulation part. The ophthalmic light stimulating apparatus according to claim 2, further comprising a size control unit.   Number density adjusting means capable of switching at least between a first mode in which the number density of the inspection region included in the two-dimensional pattern is a first density and a second mode in which the first density is also larger than the density. The ophthalmic light stimulating apparatus according to claim 2, wherein the ophthalmic light stimulating apparatus is provided.   7. The ophthalmic light stimulus according to claim 1, wherein the stimulus light projection optical system is a projector that selectively projects light from a light source onto an eye to be examined by driving a digital mirror device. apparatus. Live image acquisition means for acquiring a live image of the eye to be examined;
Position correction information acquisition means for detecting movement of the subject's eye using the live image acquired by the live image acquisition means and obtaining position correction information for suppressing displacement of the irradiation range of the pattern light on the fundus;
An irradiation range correction unit that corrects the irradiation range of the pattern light by controlling the output of the projector based on the position correction information obtained by the position correction information acquisition unit. Item 8. The ophthalmic light stimulator according to any one of Items 1 to 7. An imaging optical system that projects light onto the eye to be inspected, and receives the fundus reflection light of the light by a light receiving element;
A filter for blocking light in a wavelength region in which at least the light receiving element has sensitivity among the pattern light output from the projector is disposed in at least one of the stimulation light projection optical system and the imaging optical system. The ophthalmic light stimulator according to any one of claims 1 to 8, An illumination optical system having an optical member that condenses laser light on the fundus of the eye to be examined, and a scanning unit that two-dimensionally scans the fundus with the laser light, and the fundus of light from the light projecting optical system A light receiving optical system that collects the reflected light and receives it by the light receiving element;
A first light flux limiting unit that is disposed at a position conjugate with a condensing point of the observation surface of the fundus in the optical path of the light receiving optical system, and that limits the reflected light from the fundus;
The ophthalmic light stimulating apparatus according to claim 1, further comprising display means for displaying a fundus image formed based on a light reception signal from the light receiving optical system. An illumination optical system having an optical member that condenses laser light on the fundus of the eye to be examined, and a scanning unit that two-dimensionally scans the fundus with the laser light, and the fundus of light from the light projecting optical system A light receiving optical system that collects the reflected light and receives it by the light receiving element;
A part of the scattered light scattered before and after the condensing point is directed to the light receiving element at a position conjugate to or near the condensing point of the observation surface of the fundus in the optical path of the light receiving optical system. Second light flux limiting means for limiting a passage area of the scattered light so as to pass through,
The ophthalmic light stimulating apparatus according to claim 1, further comprising display means for displaying a fundus image formed based on a light reception signal from the light receiving optical system.