JP2016144549A - Perimeter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a perimeter which facilitates visual recognition of a target in a patient with a disease in a yellow spot and by which visual field information in a situation more based on a real life than before can be acquired.SOLUTION: A perimeter for examining a visual field of a subject is configured to include target presentation means for presenting a target to an eye to be examined. The target presentation means can present a black target in a white background.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a perimeter for inspecting a visual field of a subject.

  Conventionally, an ophthalmologic apparatus for inspecting the visual field of an eye to be examined has been developed. This type of ophthalmologic apparatus measures the visual field of the eye to be examined by presenting the eye test eye to the eye to be examined and making a visual response to the eye test eye. Patent Document 1 discloses a conventional technique related to this type of ophthalmic apparatus.

JP 2005-102946 A

  In the above-described prior art, the visual target is displayed with higher brightness than the background. However, since a patient with macular disease can be distinguished only by shading, there is a problem that it is difficult to visually recognize the target when a target with higher luminance is presented against a background with a certain luminance. It was. In daily life, there are many opportunities to acquire information represented by luminance lower than that of the background, such as looking at characters written in black on a white background. Therefore, only a display method in which the luminance of the target is higher than the luminance of the background does not sufficiently evaluate that an object is seen in real life.

  Furthermore, in the prior art, a symbol is used as a visual target. However, in the case of low vision, it is important whether characters can be identified, and an inspection using only the visual target of the symbol is insufficient.

  The present invention has been made to solve the above problem, and makes it easier to visually recognize a target even in a patient with a disease of the macula, and obtains visual field information in a situation that is more suitable for real life than before. An object is to provide a perimeter that can be used.

  In order to achieve the above object, according to a first aspect of the present invention, there is provided a perimeter for inspecting a visual field of a subject, including a visual target presenting means for presenting a visual target to an eye to be examined. The presenting means is characterized in that a black target can be presented on a white background.

  According to the perimeter configured in accordance with this aspect, the target can be presented so that the luminance of the target is lower than the luminance of the background. Easy to see. In addition, it is possible to acquire visual field information in a situation that is more suitable for real life than in the case of only the presentation method in which the luminance of the target is higher than the luminance of the background.

  According to a second aspect of the present invention, in the perimeter according to the first aspect, there is a luminance measuring means for measuring the luminance of the visual target and the background.

  According to a third aspect of the present invention, in the perimeter according to the second aspect, a luminance correction for correcting a luminance by calculating a contrast ratio between a visual target and a background based on a luminance value acquired by the luminance measuring means. Have means.

  According to a fourth aspect of the present invention, in the perimeter according to any one of the first to third aspects, the target presentation means can display a character as a target, and the character size or the number of characters or It is characterized in that at least one of the symbol shapes can be changed.

  According to the perimeter configured according to this aspect, in low vision, it is important not only whether or not the target can be visually recognized, but also whether or not the character can be identified. By enabling and changing at least one of the character size, the number of characters, or the shape of the symbol, it is possible to perform an effective examination in the low vision diagnosis.

  According to a fifth aspect of the present invention, in the perimeter according to any one of the first to fourth aspects, a DLP is used as the target presentation means.

According to the perimeter configured in accordance with this aspect, it is possible to obtain a high contrast ratio by using DLP as the target presentation means, and therefore, it is easy to visually recognize the target in a patient with a disease in the macula. Will improve.

  As described above, according to the perimeter according to the present invention, the target can be presented so that the luminance of the target is lower than the luminance of the background. Can be easily viewed, and it is possible to acquire visual field information in a situation more suited to real life. In addition, by making it possible to display characters as targets, it is possible to perform an effective examination in low vision diagnosis.

It is a schematic block diagram of the optical system of the perimeter based on a present Example. It is a block diagram of the control system of the perimeter based on a present Example. It is a figure which shows the example of the display screen of the monitor of the target presentation position setting of the perimeter based on a present Example. It is explanatory drawing of the state of the target presentation of the perimeter based on a present Example, and the tracking method of a presentation position.

  Hereinafter, a perimeter according to an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the perimeter of the present embodiment includes a fundus image acquisition optical system 10 (Scanning Laser Optoscope: SLO) that acquires a fundus image by scanning a laser beam on the fundus of an eye E, and a DLP. A (registered trademark) (Digital Light Processing) system projector has a target optical system 20 that presents a target, a background, and a fixation lamp to the fundus of the eye E. In addition, the perimeter includes an observation optical system for observing the anterior segment of the eye E and an alignment optical system for aligning the ophthalmologic apparatus in a predetermined positional relationship with the eye E (not shown). ).

  The fundus image acquisition optical system 10 uses a line laser light source 40 that emits light on a line. The light on the line emitted from the line laser light source 40 is reflected by the mirror 42, passes through a hole in the center of the hall mirror 44, and irradiates the scanner 46. In this embodiment, the scanner 46 is a galvanometer and is deflected in a predetermined direction by a mirror (galvanometer mirror) 48 attached to the galvanometer. Then, the light passes through the lenses 50 and 52 and is irradiated on the fundus of the eye E through the dichroic mirror 54 and the lens 56. The reflected light from the fundus of the eye E is reflected by the Hall mirror 44 and reflected by the ring mirror through the lens 56, the dichroic mirror 54, the lenses 50 and 52, and the scanner 46. Then, the light passes through the lens 58 and is detected by the line sensor 60. The light intensity information detected by the line sensor 60 is converted into a digital signal and input to the control device 80.

  The target optical system 20 uses the DLP projector 70 as a light source in order to present (project) a predetermined target at a predetermined position on the fundus of the eye E. The DLP projector 70 creates a presentation pattern by variably controlling the angles of micron-sized micromirrors spread in a matrix. That is, the inclination angle of each micromirror is turned on / off. When the micromirror is turned on, light is projected through the lens, and when it is off, the light is absorbed by the light absorption plate. Therefore, by controlling on / off the inclination angle of each micromirror, it is possible to form and present a visual target having an arbitrary shape and size at an arbitrary position of the fundus. The target to be presented can form not only symbols but also characters, and the number of characters can be freely changed. In addition to the visual target, the DLP projector 70 can also project a fixation lamp and a background for causing the subject to gaze for the purpose of fixing the eye to be examined. Furthermore, since the DLP projector 70 can change the brightness by changing the ratio of the on / off time of each micromirror, it is possible to present a black target on a white background.

  The light emitted from the DLP projector 70 passes through the lens 72, is reflected by the mirror 74, is reflected by the dichroic mirror 54 through the lens 76, and is irradiated on the fundus oculi of the eye E to be examined.

  Next, the configuration of the control system of the perimeter of the present embodiment will be described. As shown in FIG. 2, the perimeter is controlled by a control device 80. The control device 80 is configured by a microcomputer (microprocessor) including a CPU, a ROM, a RAM, and the like. Connected to the control device 80 are a DLP projector 70, a scanner 46, a line sensor 60, a monitor 84 of a touch panel 82, a memory 86, and a luminance measuring unit 88.

  The control device 80 scans the line-shaped light on the fundus of the eye E by controlling the driving of the scanner 46. That is, in the present embodiment, the light output from the line laser light source 40 extends in a line shape in the X direction, so the control device 80 moves the scanner 46 in the Y direction (a direction orthogonal to the paper surface of FIG. 1). Drive control and scan light. Further, the control device 80 receives an electrical signal corresponding to the intensity of the reflected light detected line by line by the line sensor 60, and generates a two-dimensional fundus image 100 of the eye E from a plurality of lines of electrical signals. The generated fundus image 100 is displayed on the monitor 84. Further, the control device 80 receives the luminance information of the target and the background acquired by the luminance measuring unit 88, calculates the contrast ratio of the target and the background based on the acquired luminance information, and corrects the luminance. To do.

  Next, an operation in the case of measuring the visual field of a patient's eye using a perimeter having the above configuration will be described.

  The examiner operates an operation member such as a joystick (not shown) to align the eye E with the apparatus. When the alignment is completed, the luminous flux of the line laser light source 40 is irradiated on the fundus of the eye E, the control device 80 drives the scanner 46, and the acquisition of the fundus image 100 is started. In this embodiment, the fundus image 100 of the eye E is continuously acquired by the line sensor 60 and displayed on the monitor 84 as a real-time moving image.

  When the fundus image 100 is displayed on the monitor 84, the examiner sets a presentation position 110 for projecting the visual target 130 onto the fundus image 100. In the present embodiment, as described above, the monitor 84 is a touch panel type, and the setting of the presentation position 110 can be performed by the examiner touching the touch panel 82 on the screen of the monitor 84. It has become. That is, the touch panel 82 functions as a designation unit. As described above, the presenting position 110 may be set by operating the mouse if there is a mouse function.

  In addition, the perimeter of the present embodiment has an auto-tracking function that moves the presentation position 110 in accordance with the temporal movement of the eye E to be inspected due to fixation fine movement or the like. In order to perform auto-tracking, first, the examiner designates two feature parts in the fundus image 100 displayed on the monitor 84. For example, the examiner specifies two points of the nipple and blood vessel in the fundus image 100 by touching the touch panel. Then, the control device 80 sequentially analyzes frames obtained by moving image shooting, detects the shift amount (movement amount) of each coordinate position of the two designated feature parts, and presents the position 110 based on the detected shift amount. And the DLP projector 70 is controlled.

  Specifically, as shown in FIG. 4, in the frame image designated by the examiner (referred to as the initial frame image), the coordinates of the nipple are (Xa, Ya), the coordinates of the blood vessel are (Xb, Yb), and the presentation position 110 Is set to (Xc, Yc) (see FIG. 4A). Assuming that the coordinates of the nipple in the next frame image are (Xa ′, Ya ′) and the coordinates of the blood vessel are (Xb ′, Yb ′), the center coordinates (Xc ′, Yc ′) of the presentation position 110 are obtained from the frame initial image. (Xc ′, Yc ′) = (Xc +) from the amount of deviation of the coordinate position of the nipple (Xa′−Xa, Ya′−Ya) and the amount of deviation of the coordinate position of the blood vessel (Xb′−Xb, Yb′−Yb) ((Xa′−Xa) + (Xb′−Xb)) / 2, Yc + ((Ya′−Ya) + (Yb′−Yb)) / 2) (see FIG. 4B). Then, the DLP projector is controlled so that the presentation position 110 comes to the calculated center coordinates (Xc ′, Yc ′). By performing this operation for each frame obtained by moving image shooting, it is possible to follow the presentation position 110 in accordance with the temporal movement of the eye E to be examined.

  When the various condition settings for the visual field inspection are completed, the examiner presses an optotype presenting switch (not shown). When the optotype presenting switch is pressed, the control device 80 turns on the light source of the DLP projector 70 and presents the optotype 130 set for a predetermined time with respect to the set presentation position 110. Further, the fundus of the eye E is irradiated at the same time as the optotype is presented. A method for confirming whether or not the patient can visually recognize the target may be a method in which the patient presses a response switch (not shown) or a method in which the patient is verbally notified to the examiner. In the present embodiment, the above-described auto-tracking of the presentation position is performed when the target is presented. As a result, even if there is a slight eye movement of the eye E during the presentation of the visual target, the presentation position 110 of the visual target 130 by the DLP projector 70 is corrected at any time based on the deviation amount of the characteristic part as described above. Therefore, the target 130 can be presented without shifting to the preset presentation position 110.

  As mentioned above, although the Example of this invention was described in detail, this is an illustration to the last, Comprising: A claim is not limited, A various change can be added in the range which does not deviate from the meaning of this invention. It is.

  In the above embodiment, a line SLO using a line laser light source is employed in the fundus image acquisition optical system. However, the fundus image acquisition unit is not limited to this, and may be an SLO that scans with a point or a fundus. You may employ | adopt the optical system of a camera. Further, although the configuration is complicated, fundus OCT using optical interference may be employed.

10 .... Fundus image acquisition optical system, 20 .... Target presentation optical system, 46 ... Scanner, 60 ... Line sensor, 70 ... DLP projector, 80 ... Control device, 84 ... Monitor, 88 ... Brightness Measurement unit

Claims (5)

In a perimeter that examines the field of view of a subject,
A perimeter which has a target presentation means for presenting a target to the eye to be examined, and which allows the target presentation means to present a black target on a white background. The perimeter according to claim 1, further comprising luminance measuring means for measuring luminance of the target and the background. The perimeter according to claim 2, further comprising a luminance correction unit that calculates a contrast ratio between the target and the background based on the luminance value acquired by the luminance measurement unit and corrects the luminance. The said optotype presenting means can display a character as an optotype, and can change at least any one of the character size, the number of characters, or the shape of the symbol. The perimeter according to claim 1. The perimeter according to any one of claims 1 to 4, wherein a DLP is used as the optotype presenting means.