JP2017136212A - Ophthalmologic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To evaluate a type of a dry eye objectively.SOLUTION: An anterior eye part Ef of an eye E to be examined is irradiated with an illumination light from a light source 11 by an illumination optical system 10. A return light of the illumination light from the anterior eye part Ef is received by an image pickup device 25 by an observation optical system 20. Thereby, a front image of the eye E to be examined is obtained. By processing the plurality of front images continuously obtained by the observation optical system 20, a control part 51 detects at least one of a dry spot formation position and a direction that lacrimal fluid moves in the periphery of the dry spot, and a shape of the dry spot which is a region where a lacrimal fluid layer is destroyed in the cornea, and determines the symptom of a dry eye in the eye to be examined according to the detection result.SELECTED DRAWING: Figure 2

Description

  The present disclosure relates to an ophthalmologic apparatus for examining the state of a tear film of an eye to be examined.

  Conventionally, an ophthalmologic apparatus for inspecting dry eye based on a front image of an anterior segment is known. In this type of ophthalmologic apparatus, the temporal change of the tear film on the cornea is analyzed from the continuously acquired front images (see, for example, Patent Document 1). For example, when dry eye is progressing, with the passage of time after opening, a part of the tear film is crushed (breaks up) and the corneal surface appears as a dry spot.

JP 2001-309889 A

  Until now, examination and diagnosis by observing the shape of the dry spot and how it appears have been done based on the subjective judgment of the examiner. For this reason, the accuracy of the examination and diagnosis depended on the experience of each examiner.

  The present disclosure has been made in view of the above circumstances, and an object of the present disclosure is to provide an ophthalmologic apparatus that objectively evaluates the type of dry eye.

  An ophthalmologic apparatus according to the first aspect of the present disclosure receives an illumination optical system that irradiates illumination light from a light source on an anterior eye part of an eye to be examined, and a return light of the illumination light from the anterior eye part by an imaging device. An observation optical system that obtains a front image of the eye to be examined, and a plurality of the front images that are continuously obtained by the observation optical system, whereby tears are formed around the dry spot formation position and the dry spot. Detecting at least one of the directions in which the fluid moves, and the shape of the dry spot, which is a region where the tear film is destroyed in the cornea, and determining the symptoms of dry eye in the eye according to the detection result Analyzing means for determining.

As described above, according to the present disclosure, the type of dry eye can be objectively evaluated.

It is a schematic block diagram of the optical system and control system of the apparatus concerning the apparatus of this indication. It is a figure which shows the flowchart in a measurement. It is a figure which shows an interference fringe image and a measurement area setting screen. It is a figure for demonstrating the dry spot formed on a cornea in the type of dry eye with a damage | wound. It is a figure for demonstrating the dry spot formed on a cornea in the mucin reduction type dry eye. It is the table | surface which put together the determination result of the symptom of the dry eye in an Example.

  Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the drawings. FIG. 1 is a diagram illustrating a schematic configuration of an ophthalmologic apparatus 1 according to the present embodiment. The ophthalmologic apparatus 1 is used to inspect dry eyes based on a front image of the anterior segment.

<About optical system>
First, the optical system of the ophthalmologic apparatus 1 will be described. In the present embodiment, the ophthalmologic apparatus 1 mainly includes an illumination optical system 10 and an observation optical system 20. The illumination optical system 10 irradiates the anterior segment Ef of the eye E with illumination light from the light source 11. In addition, the observation optical system 20 acquires the front image of the anterior eye portion Ef by receiving the return light of the illumination light from the anterior eye portion Ef by the imaging element 25. The observation optical system 20 acquires an image representing at least the distribution of tears on the cornea as a front image. Such a front image may be, for example, an image based on interference of illumination light at the tear film, an image based on reflection of illumination light at the tear film, or a tear film. It may be an image based on fluorescence. In the case of an image based on fluorescence, for example, the cornea in a state in which a fluorescent agent such as fluorescein is instilled is irradiated with illumination light (as excitation light) from the illumination optical system 10, and as a result, fluorescence generated in the tear film is Light is received by the image sensor 25. In the optical system illustrated in FIG. 1, a front image based on interference and a front image based on fluorescence can be switched and photographed (details will be described later).

  The illumination optical system 10 in the example of FIG. 1 includes a light source 11, a projection lens 12, a polarization beam splitter (an example of a light branching unit) 13, an objective lens 14, and a quarter wavelength plate 15. Further, the example of FIG. 1 includes an exciter filter 16 that can be inserted into and removed from the optical path of the illumination optical system 10.

  In the example of FIG. 1, a white light source such as a halogen lamp is used as the light source 11. The illumination light emitted from the light source 11 passes through the projection lens 12 and then enters the polarization beam splitter 13. Of the illumination light beam incident on the polarizing beam splitter 13, most of the s-polarized component in the visible range is reflected by the polarizing beam splitter 13. The reflected light passes through the objective lens 14 and enters the quarter-wave plate 15. The quarter wavelength plate 15 has a characteristic of converting linearly polarized light into circularly polarized light. For this reason, the illumination light beam of the s-polarized component incident on the quarter wavelength plate 15 is converted into, for example, clockwise circularly polarized light, and illuminates the tear film on the eye cornea to be examined. For example, the illumination position may be adjusted to the oil layer on the outermost layer of tears.

  The exciter filter 14 is inserted into the optical path of the illumination optical system 10 when fluorescence imaging is performed. In order to take a fluorescent image by fluorescein, for example, a blue filter may be used as the exciter filter 14.

  The observation optical system 20 in the example of FIG. 1 includes a quarter-wave plate 15, an objective lens 14, a polarizing beam splitter 13, an imaging lens 21, and an imaging element 25 arranged in this order from the eye E side. ing. In the example of FIG. 1, the quarter wavelength plate 15, the objective lens 14, and the polarization beam splitter 13 are shared with the illumination optical system 10. In the example of FIG. 1, an area sensor (for example, a color CCD) capable of color photographing is used as the image sensor 25.

  As a result of the illumination optical system 10 illuminating the tear film of the eye to be examined, the return light of the illumination light from the anterior segment Ef enters the observation optical system 20. Reflecting the clockwise circularly polarized light, the rotation direction of the circularly polarized light is reversed. Therefore, as return light, counterclockwise circularly polarized light whose rotation direction is inverted with respect to incident light (illumination light) is extracted as return light. The return light is converted into linearly polarized light by entering the quarter-wave plate 15. Since the rotation direction of deflection is reversed from clockwise to counterclockwise due to reflection at the tear film, the return light that has passed through the quarter-wave plate 15 becomes p-polarized light that is orthogonal to s-polarized light (illumination light). Converted. The return light converted to p-polarized light passes through the objective lens 14 and then enters the polarization beam splitter 13. Since the reflected light is converted into p-polarized light, most of the light passes through the polarization beam splitter 13 and further forms an image on the imaging surface of the imaging device 25 via the imaging lens 21. As a result, a front image (specifically, an anterior segment front image) of the eye E is imaged by the image sensor 25. Here, the illumination light is reflected by each layer of the tear film, whereby an interference pattern is formed on the corneal surface. The interference pattern is a pattern according to the thickness of the tear film (for example, the thickness of the oil layer) at each position on the cornea. The front image acquired from the image sensor 25 includes an interference fringe image Ic by a tear film (see FIG. 3).

  In the example of FIG. 1, the polarization beam splitter 13 is used as a branching portion that branches the optical path between the illumination optical system 10 and the observation optical system 20. Thereby, the flare based on the reflection of the illumination light on the rear surface (surface on the light source 11 side) of the objective lens 14 is suppressed.

<About control system>
Next, the control system will be described. The ophthalmologic apparatus 1 includes a calculation control unit 51 (hereinafter, abbreviated as a control unit) that performs control processing of the entire apparatus and various calculations. For example, the control unit 51 may include a CPU, a ROM, and a RAM. The CPU is a processing device (processor) for executing various processes related to the ophthalmologic apparatus 1. The ROM is a non-volatile storage device that stores a control program, fixed data, and the like. The RAM is a rewritable volatile storage device. For example, temporary data used for imaging and measurement of the eye E by the ophthalmologic apparatus 1 is stored in the RAM.

  In the present embodiment, the control unit 51 is connected to the light source 11, the image sensor 25, the monitor 55, the operation unit 53, the HDD (hard disk) 52, and the like.

  The HDD 52 is an example of a rewritable nonvolatile storage medium. In the present embodiment, in the present embodiment, the HDD 52 may store at least a program for causing the control unit 51 to execute various imaging processes, measurement processes, and the like. The HDD 52 may store a front image captured by the ophthalmologic apparatus 1.

  The imaging signal output from the imaging element 25 is processed by the control unit 51 and displayed on the monitor 55. Thereby, in this embodiment, the front image imaged at any time with the image sensor 25 is sequentially displayed on the monitor 55. Therefore, the examiner can observe the state of the tear film on the monitor 55.

  Further, the image pickup signal from the image pickup device 25 may be sequentially input to the HDD 52. The hue of the interference fringes input to the HDD 52 is analyzed, and information on the change over time is obtained. The analysis result obtained by the control unit 51 is displayed on the color monitor 22 via the graphic generation unit 23.

  The operation unit 53 is an input interface through which various operations by an examiner for giving instructions to the apparatus are input. The control unit 51 receives various instructions based on signals from the operation unit 53.

<Description of operation>
Next, the operation of the ophthalmologic apparatus 1 will be described with reference to the flowchart of FIG. The measurement operation of the ophthalmologic apparatus 1 (for example, acquisition of a front image including interference fringes and derivation of an analysis result) may be started based on an operation on the operation unit 53, for example. Further, for example, the measurement operation may be automatically started by detecting an open state using an anterior eye front image or the like and detecting the open state. Here, a case where the measurement operation is automatically started is illustrated.

  First, the control unit 51 starts irradiating illumination light to the eye E (S1). Further, the front image is continuously acquired (captured) based on the signal from the image sensor 25, and the display of the captured front image is started (S2).

  Next, the examiner performs alignment so that the interference fringe image Ic shown in FIG. 3 is observed at the center of the monitor 55 and is in focus (S3). For example, the examiner adjusts the positional relationship between the eye E and the optical system by driving an alignment mechanism (not shown).

  In the present embodiment, the control unit 51 sets the measurement area 101a on the cornea Ec in the front image (S4). The measurement area 101a is an area that is analyzed in order to obtain information on dry eye symptoms and progress. The range in which the measurement area 101a is set may be determined in advance with reference to the cornea (more specifically, the cornea center). It may be set in a region designated by the examiner via the operation unit or the like on the front image.

  As an example, reference numeral 101a in FIG. 3 indicates a measurement area for analysis (however, the measurement area is inside a rectangle indicated by reference numeral 101a). The range and shape of the measurement area 101a are not limited to those shown in FIG. 3, and may be changed as appropriate. For example, when the examiner operates the operation unit 53, the shape of the measurement area 101a may be switched from a rectangle to a circle, or the size may be changed.

  After completing the alignment and measurement area setting, the examiner operates the operation unit 53 to start detection of opening. The examiner instructs the subject to close the bag once and have it open again. The control unit 51 detects the opening of the eyelid from the signal in the measurement area 101a output from the image sensor 25, and automatically starts measurement (S5: Yes). In addition, a known technique (Japanese Patent Laid-Open No. 9-149884) may be used to detect the open state. Since the eye to be examined may blink several times, in this case, when the eyelid continues for a certain time or longer by time measurement, the opening start time is set as the measurement start timing.

  After the measurement is started, the control unit 51 sequentially stores the front image captured by the image sensor 25 in the HDD 52 at a predetermined sampling interval (S6). Thereafter, when the preset measurement time has passed, the examiner is notified of the end of the measurement by sound or a display on the monitor 55. As the sampling interval and the measurement time, desired values are set by operating the operation unit 53. For example, if the sampling interval is set to 0.1 and the measurement time is set to 5 seconds, 50 front images (interference fringe images) are stored in the HDD 52. In this way, the HDD 52 stores a plurality of front images continuously obtained by the observation optical system 20.

  In addition, the control unit 51 analyzes the plurality of front images stored in the HDD 52, and outputs information on the dry eye symptom and progress of the eye E (S7, S8).

  In the present embodiment, the shape of the dry spot in the cornea and the position of the dry spot are detected from a plurality of front images obtained continuously. Further, a change with time in the distribution of tears in the cornea is detected by the control unit 51 from a plurality of front images. The detected temporal change may be a temporal change after opening. In the present embodiment, the movement direction of tears around the dry spot is detected based on the change over time. In the present embodiment, the control unit 51 determines dry eye symptoms in the eye E based on these detection results. Furthermore, in this embodiment, the formation position of the dry spot in the cornea is detected from the front image.

  Here, the dry spot is a region where the corneal surface is exposed, and interference with tears cannot be obtained. Therefore, it appears as a low luminance region in the front image. For this reason, for example, the control unit 51 may detect the dry spot and its shape based on the luminance information of the front image. The control unit 51 may detect, for example, an area having a luminance value lower than the threshold value as a dry spot in the front image. At this time, for example, the gradient of the brightness in the front image is obtained, and the position where the brightness rapidly decreases (for example, the inflection point) is used as the contour position to detect the shape of the dry spot and the position where the dry spot is formed in the cornea. May be. The shape and the formation position of the dry spot may be detected from at least one front image including the dry spot among the plurality of front images. Of course, it may be detected by a method other than the above.

  Note that a plurality of dry spots may be formed on the cornea at the same time or at different timings. In the case of dry eye due to multiple causes, characteristics with different symptoms may appear in each dry spot. Moreover, in one dry spot, there may be a case where characteristics of a plurality of types of symptoms appear in combination. The control unit 51 may determine at least one symptom as an analysis result when analyzing a front image related to dry eye caused by multiple causes.

  In the present embodiment, the change with time in the distribution of tears is indicated, for example, as a change in interference color in the front image. For example, since the normal tear film has a thin and uniform uppermost oil layer, the interference color in the tear film is a color close to white. On the other hand, as dry eye progresses, the tears show a red or yellow interference fringe pattern. When the change with time at the time of opening is followed, the tear film of the interference fringe portion is crushed (breakup), and the corneal surface may be exposed as a dry spot. At that time, the color of the interference fringe portion changes with time. For example, taking a red component as an example, when breakup occurs, red gradually increases with time. By following this change over time with various colors such as a spectrum as well as red, it becomes possible to objectively grasp the change in tear distribution.

  In the present embodiment, for example, the evaporation amount of tears and the movement direction of tears can be quantitatively detected from the change in interference color over time in the front image.

  Here, with reference to FIG. 3 to FIG. 6, a method for determining symptoms of dry eye by the ophthalmologic apparatus 1 will be described.

  For example, in the case where a decrease in tears (reduction of at least one of water and oil) occurs, after the tear film is completely formed on the cornea, the tear film is destroyed and a dry spot appears. The dry spots at this time tend to be formed in a similar circle shape (in other words, a rounded shape close to a circle) as indicated by reference numerals D1 and D2 in FIG. Therefore, for example, when a dry spot formed in a similar circle shape is included in the front image as a result of detection of the dry spot from a plurality of front images, the control unit 51 determines the “tears reduction type”. It may be determined that this is a symptom. Whether the shape is similar or not may be determined based on, for example, the ratio of the length in the lengthwise direction to the widthwise direction (longitudinal direction / widthwise direction) in the dry spot. For example, when the ratio (longitudinal direction / short direction) is a value close to 1, the dry spot may be a similar circle, and the symptom may be determined to be “tear reduction type”. Here, “a value close to 1” means that a range up to a predetermined value of 1 or more (hereinafter referred to as a first threshold) is allowed. That is, for example, when the ratio (longitudinal direction / short side direction) is 1 or more and less than the first threshold value (for example, 1.5), it is determined that the symptom is “tear reduction type”.

  The length in the longitudinal direction and the length in the short direction of the dry spot may be obtained, for example, by obtaining the length of each dry spot detected in advance in the meridian direction, and obtaining the maximum value and the minimum value thereof. . The image used for the determination may be, for example, an image in which the dry spot is most widened among a plurality of front images. Alternatively, an image in an intermediate size from the start of the formation of the dry spot to the maximum spread may be used.

  In addition, dry eye of “a type with a wound (mainly a line wound)” in the cornea is known. As a result of the progress of the dry eye, the cornea may be damaged, or the dry eye may have progressed due to the damage. Both of them are included in the “type with scratches” mentioned here. In the case of “scratched type” dry eyes, dry spots are likely to be formed along the scratches. For this reason, in general, a dry spot having a shape extending on a line along the flaw (that is, an elongated shape) as indicated by reference numerals D3 and D4 in FIG. 4 tends to be observed on the front image.

  Therefore, for example, when the control unit 51 includes a dry spot formed in a linear shape as a result of detection of the dry spot from a plurality of front images, the control unit 51 determines that the “scratch type” May be determined (see FIG. 6). Whether or not the shape is linear may be determined based on, for example, a ratio of lengths in the respective directions of the long direction and the short direction in the dry spot (longitudinal direction / short direction). For example, when the ratio (longitudinal direction / short side direction) is relatively large with respect to 1 (for example, a large value with respect to the first threshold), the dry spot is linear, It may be determined that the symptom is “type”.

  Further, for example, it is conceivable that the action of retaining tears on the cornea is reduced due to a disorder such as a membrane type mucin and a decrease in secretory type mucin. In this case, a similar dry spot (for example, see the dry spot indicated by the symbol D5 in FIG. 5) is observed (for example, immediately after opening), or in the vertical direction mainly below the cornea (lower half). An extending linear dry spot (for example, refer to the dry spots indicated by D6 and D7 in FIG. 5) may be formed. For this reason, this symptom (referred to as “mucin-reducing type” for convenience) is difficult to distinguish from the “tear-reduced type” symptom and the “scratched type” symptom, focusing only on the shape of the dry spot. Can be considered.

Therefore, in the present embodiment, the control unit 51 further determines the symptom in consideration of the tear flow around the dry spot. In this embodiment, the tear flow is detected from the change in interference color in the front image with time. In the “mucin reduction type”, tear fluid flows from the top to the bottom in the dry spot and its surroundings. On the other hand, in the symptom of “tear reduction type” and the symptom with “scratch type”, the dry spot is formed by the movement of tears in each direction and the overall evaporation of tears on the cornea, And disappear. For this reason, the flow of tears from top to bottom is not necessarily dominant around the dry spot. Therefore, for example, the control unit 51 can distinguish and determine each symptom by considering the movement direction of the tears in the dry spot and the surrounding area. In other words, the control unit 51, when the tear liquid at the dry spot formation position and its periphery flows from top to bottom (for example, when red or brown components spread downward) It is determined that the symptom is “mucin decreased type” (see FIG. 6).

  Note that the symptom determined as “mucin-decreasing type” may be further subdivided and determined. For example, a case where an elliptical dry spot is observed and a case where a linear dry spot is observed below the cornea may be determined as different symptoms. For example, when a linear dry spot is observed below the cornea, there is a further suspicion that the amount of water in the tears is reduced. Therefore, for example, a case where a linear dry spot is observed below the cornea is determined as a symptom of “mucin reduction / moisture content reduction type”, and a similar dry spot is observed. Alternatively, it may be determined that the symptom is simply “mucin-decreasing type” (see FIG. 6).

  In addition, the control part 51 may derive | lead-out the determination result that the to-be-tested eye corresponds to several symptom simultaneously as a result of having analyzed the several front image.

  The control part 51 may obtain | require the information which shows the progress degree of dry eye with such a determination result from the several front image (image used for determination of the symptom) obtained continuously. Then, information indicating the degree of progress may be displayed on the monitor 55 together with the determination result about the symptom. For example, when the symptom is determined using the change in the interference color over time in the front image as in the present embodiment, information indicating the degree of progress is further derived based on the change over time in the interference color. May be. For example, the information indicating the degree of progress may be derived based on at least one of a change in the area of each color component and the number of stripes in each color component (that is, the number of interference fringes). Furthermore, information indicating the degree of progress may be derived in consideration of a change in signal intensity in each color component. As the dry eye progresses, various interference colors appear in the break-up process, and the intensity change in each color becomes stronger. For this reason, for example, information (for example, information by numerical values) that objectively indicates the degree of progress of the dry eye based on any one of the number of stripes, the area ratio, the intensity change for each color component, and the like. (For details, refer to Japanese Patent Application Laid-Open Nos. 2001-309889, 2005-211173, etc. by the present applicant).

  Note that information indicating the degree of progress of dry eye in the entire measurement area 101a may be acquired by analyzing the entire measurement area 101a in the front image, and the dry spot and the surrounding area are analyzed in the front image. By doing so, information indicating the degree of local dry eye progression in each dry spot may be acquired. Note that the numerical information is not necessarily limited to information calculated based on a change with time of the interference color. For example, the numerical information may be, for example, breakup time or other numerical information. In general, it is considered that dry eye progresses as the breakup time is shorter. In this case, the control unit 51 may detect a breakup time (a time from opening until a dry spot is detected) from a front image sequentially acquired after opening.

  As a specific example, here, the interference color in the measurement area 101a is extracted for each color by the control unit 51, and the ratio (relative area) of the occupied area in the measurement area of each extracted color is obtained. By performing this process on each front image, the change in interference color over time can be obtained. The extracted color component may be a component in a predetermined band such as 16 colors or 256 colors. The control unit 51 acquires information indicating the degree of progress of dry eye based on the detection result of the change in tears over time in the entire cornea.

  In addition, the change in the state of the tear film can be objectively and quantitatively confirmed from the change in interference color over time. For example, the amount of tears in the entire cornea (for example, the amount of each layer of the oil layer and the water layer), changes thereof, and the like can be grasped.

Therefore, for example, the control unit 51 further
・ There is a suspicion of quantitative and qualitative abnormality of the oil reservoir, and the degree of abnormality,
The degree of water loss in the tear film,
Whether there is any suspicion about increased evaporation of water and the extent of the increase,
Of these, determination on at least one of them may be performed based on the detection result of the tear change with time, and this determination result may be displayed on the monitor 55 together with the above-described dry eye determination result. This determination result may be taken into consideration in the above-described dry eye determination result. Here, “considered in the determination result of dry eye” means, for example, a more detailed classification than the classifications such as “tear reduction type”, “mucin reduction type”, and “scratch type” exemplified above. Giving may be performed. Moreover, information for specifying the cause of dry eye or the layer in which the symptom appears in the tear film may be acquired. Further, BUT (time until breakup occurs after opening) may be further considered in the dry eye determination result.

  The determination result regarding the dry eye symptom thus obtained may be displayed on the monitor 55, for example. Further, the determination result may be stored in the HDD 53. Thus, in this embodiment, the apparatus determines the symptoms of dry eye in the eye to be examined by analyzing a plurality of front images in which changes in tear distribution with time are expressed. As a result, the examiner can satisfactorily confirm the symptoms of dry eye in the eye to be examined. Since dry eye has different eye drops to be selected depending on the symptom, prescription of the eye drops can be performed well by showing the symptom determination result as in the above embodiment. Note that the information displayed as the dry eye determination result need not be information that clearly indicates any type of dry eye, and may be information indicating the degree of each symptom.

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

  For example, in the above-described embodiment, the case where the symptoms of dry eye are determined by processing the interference fringe image as the front image has been described. However, it is not necessarily limited to this. For example, dry eye symptoms may be determined as a result of processing front images other than interference fringe images. Such a front image may be an image based on fluorescence at the tear film or an image based on reflection of illumination light at the tear film. In the case of an image based on fluorescence, for example, a dry spot can be detected and a tear fluid distribution in the cornea can be detected based on the luminance distribution in each front image.

  Moreover, in the said embodiment, the illumination optical system 10 demonstrated as what irradiates illumination light so that a cornea is illuminated uniformly (entirely). However, the present invention is not necessarily limited to this. For example, the illumination optical system 10 may be configured to project illumination light partially on the cornea by projecting a ring light beam. The ring light beam may be formed by two or more rings arranged concentrically. Each ring light beam may have an intermittent ring shape or a continuous ring shape with respect to the circumferential direction. Further, such a ring light beam may be used for obtaining information on the corneal curvature, such as topo ring and platid ring. The ring light beam may be projected with white light, for example. In this case, as a result of irradiation, interference fringes are formed in the irradiation region of the ring light beam in the front image. Data for obtaining the shape of the dry spot and the distribution of tears in the cornea (eg, interference fringe color information, luminance information, etc.) can be detected directly from the irradiation area of the ring light beam in the front image. . On the other hand, a region that is not irradiated with illumination light may be supplemented or estimated based on data obtained in a region where illumination light is projected. That is, based on the information on the ring irradiation area in the front image, the control unit 51 estimates the shape of the dry spot and the distribution of tears in each area of the cornea including the area not irradiated with the ring light flux. The And the symptom of a dry spot may be determined based on the estimation result with respect to the front image obtained sequentially.

  When an optical system that projects a ring light beam onto the cornea of the eye to be examined is applied to the illumination optical system 10, for example, the control unit 51 is based on a front image obtained by the observation optical system 20. Information regarding the corneal curvature of the optometry E and / or corneal curvature other than the corneal curvature may be analyzed.

DESCRIPTION OF SYMBOLS 1 Ophthalmology apparatus 10 Illumination optical system 11 Light source 20 Observation optical system 25 Image pick-up element 51 Control part E Eye to be examined Ef Anterior eye part

Claims (8)

An illumination optical system that irradiates the anterior segment of the eye to be examined with illumination light from a light source;
An observation optical system for obtaining a front image of the eye to be examined by receiving a return light of the illumination light from the anterior eye portion with an imaging device;
By processing the plurality of front images continuously obtained by the observation optical system, at least one of the dry spot formation position and the direction in which tear fluid moves around the dry spot, and tears in the cornea An ophthalmologic apparatus comprising: an analysis unit that detects a shape of a dry spot, which is an area where a liquid layer is destroyed, and determines a symptom of dry eye in the eye to be examined according to the detection result.   2. The analysis unit according to claim 1, wherein when the dry-spot extended linearly is detected, the analysis unit determines that the symptom is one of a symptom with a wound type and a reduced mucin type. Ophthalmic equipment.   The ophthalmic apparatus according to claim 2, wherein the analysis unit determines that the symptom is a type with a wound when the linear dry spot whose longitudinal direction is inclined with respect to the vertical direction is detected. The analysis means, when the lacrimal fluid in the vicinity of the formation position of the dry spot extending linearly and its periphery flows from top to bottom, it is determined that it is a mucin-decreasing type symptom,
The ophthalmologic apparatus according to claim 2 or 3, wherein when the tear is flowing in each direction at the position where the dry spot is formed and in the vicinity thereof, it is determined that the symptom is accompanied by a wound.   5. The analysis unit according to claim 1, wherein, when a similar dry spot is detected, the analysis unit determines that the symptom is one of a symptom of reduced tears and a reduced mucin. 5. An ophthalmic apparatus according to any one of the above.   The analysis means determines that the dry spot formation position and the dry spot formation position when tear fluid in the vicinity of the dry spot flows from top to bottom is a mucin-reducing symptom. The ophthalmologic apparatus according to claim 5, wherein when the lacrimal fluid flows in each direction in and around it, the symptom is determined to be a tear-reducing symptom. The illumination optical system irradiates the anterior eye part with a concentric ring light beam as the illumination light,
Based on the information on the ring irradiation area that is the area irradiated with the ring light beam in the front image, the analysis means includes the shape of the dry spot in each region of the cornea including the area not irradiated with the ring light beam. The ophthalmologic apparatus according to claim 1, wherein a tear distribution is estimated and the temporal change is detected based on the estimation result. The ophthalmologic apparatus according to claim 7, further comprising a second analysis unit that obtains information related to a corneal curvature of the eye to be inspected based on a front image obtained by the observation optical system.