JPS5912320A - Visual field meter - Google Patents

Abstract

PURPOSE:To shorten the measuring time of a visual field meter without utilizing the reaction of a person to be checked, by judging that the person to be checked has acknowledged a display light, based on the signal indicating that the moving direction of the eye of the person to be checked is detected. CONSTITUTION:A central gazed light 3, indicated the center of a visual field. Peripheral gazed lights 4, 5, 6, and 7 are provided for attracting the attention of the person to be checked on arbitrary points around the central gazed light 3. A driving means is provided to drive the central gazed light and the peripheral gazed lights. A position detecting sensor 9 detects the moving direction of the eye of the person to be checked. A judging means judges whether the person to be checked has acknowledged the driven peripheral gazed lights 4, 5, 6, and 7. After the central gazed light 3 is turned OFF, the arbitrary peripheral gazed light is lighted. When the eye to be checked 1 has turned to the direction of said gazed light within a specified time, it is judged that the lighted gazed light could have been acknowledged by the eye to be checked.

Description

[Detailed description of the invention] The present invention relates to a perimeter for measuring the visual field of the eye.

In the conventional perimetry 1, the subject's visual field was measured based on reactions from the subject, such as when the subject confirmed an optotype and pressed a button. For this reason, conventional perimeter perimeters require the examiner to press a pushbutton or other action to notify the examiner that the visual target has been confirmed, which is troublesome for the examinee and takes time to measure. was there.

An object of the present invention is to provide a perimeter that does not require a reaction from the subject and can shorten the measurement time.

In order to achieve the above object, the present invention.

A driving means for driving a central fixation lamp that indicates the center of the visual field, a peripheral fixation lamp that allows the examinee to gaze at an arbitrary point around the central fixation lamp, and a movement direction of the examinee's eyes. and a determining means for determining whether or not the subject has confirmed the driven indicator light based on the output signal of the detecting means.

The present invention will be described below based on embodiments shown in the drawings.

FIG. 1 shows an embodiment of the present invention. 1 is the eye to be examined, 2 is the center of rotation of the eye to be examined, and 3.4.5.6.7 is a fixation lamp on which the eye 1 to be examined fixates.

A sufficient number of fixation lights is required to measure the visual field of the eye to be examined 1, and they are generally arranged on a spherical surface centered on the rotation center 2, but all are shown for convenience of explanation. Since things only get complicated, I have only shown the points necessary for explanation.

Reference numeral 8 denotes a light source that emits light such as infrared rays that cannot be detected by the IK of the subject's eye, and is disposed on the focal plane of the lens L1. 9
is a position detection sensor such as a two-dimensional position sensor placed on the focal plane of lens L, and the optical system is formed by lens L+, the corneal surface of subject 1-1-, and lens L. The image position of the light source 8 is detected.

The actual actuator Jl'f in the device C7 configured in this way will be explained.

First, the central fixation lamp 3 is turned on. The infrared light source 8 is always turned on, and the light from the infrared light source enters the eye 1 to be examined as a substantially parallel light beam due to the lens (Ll). A reflected image 8' reflected by the cornea of the eye 1 to be examined passes through the lens L3 and forms an image on the light receiving element 9, and the position of this reflected image is constantly measured by the position detection sensor 9.

The fixation lamp 3 is a reference light source located approximately at the center of the visual field of the eye 1 to be examined, and when the eye 1 to be examined is fixating on the fixation lamp 3, the reflected image of the light source 8 is approximately at the center of the visual field of the eye 1 to be examined. Initial settings are made so that the image is centered. That is, the reflected image of the light source 80 is the position detection tJ3-t! If the eye is at the center of the sensor 9 at t1, it means that the subject's eye IVi is fixating on the central fixation lamp 3. If this can be confirmed by the output signal of the position detection sensor 9, the central fixation light 3 goes out and the peripheral fixation light 4.5.6.1
etc. will light up. If the examinee's eye 1 is instructed in advance to gaze at the lit fixation lamp, the examinee's eye 1, which is gazing at the central fixation lamp 3, will be directed to one of the other fixation lamps 4, 5, 6, and T. Fix your gaze in that direction by checking that it is lit. At this time, the eye 1 to be examined rotates around the rotation center 2.

Therefore, since the direction of reflection of the light from the light source 8 on the eye 1 to be examined changes, the reflected image on the position detection sensor 9 moves. If the moving direction of this reflected image matches the lighting direction of the fixation lamp, it is inferred that the subject 11t1 was able to confirm the lit fixation lamp.

On the position detection sensor 9, assuming that the inside of the paper is the X direction and the direction perpendicular to the paper is the y direction, the amount of deviation of the reflected image from the center of the position detection sensor 9 in the X direction and the y direction is hx, h
y), hx=Rdnψx−1lH+9 fists---(
1) h7. =R output ψy-1-r picture i...
It is expressed as (2).

Here, ψX: amount of rotation of the eye 1 to be examined in the X direction ψy: amount of rotation of the eye 1 to be examined in the y direction 0; lens Ll and lens 11. angle R of the optical axis; distance r from the center of rotation of the eyeball to the center of corneal curvature; radius of curvature of the cornea.

In other words, in the direction of connecting the center of rotation of the eye 1 to be examined (this coincides with the center of the spherical surface on which the fixation light is arranged) and the central fixation light, connect the center of rotation and any fixation light. Since the angle ii formed by the direction is known in advance, it is possible to know whether or not the eye 1 to be examined has been able to confirm the fixation lamp based on the position information from the position detection sensor 9, as described above.

If we can assume that the structure of the eyeball is the same for each person, then
The proportionality constant R of equations (1) and c2) can be found uniquely, but
In reality, such an assumption is not accurate, so the central fixation light 3 is turned off, an arbitrary fixation light is turned on 9 seconds later, and the direction of this fixation light is set so that the eye 1 to be examined turns within a predetermined time. Based on this, it may be determined that the eye 1 to be examined has confirmed the lit fixation lamp.

After turning on any fixation lamp for a certain period of time, the central fixation lamp 3 is turned on again, and the subject's eye 1 is directed toward the central fixation lamp 3. Furthermore, the above-mentioned measurements were repeated by turning on the arbitrary fixation lamps and the central fixation lamp 3 alternately.

The Nb operation as described above can be accomplished, for example, by a device as shown in the block diagram of FIG.

That is, the operating device 10 having an operation panel has operation buttons corresponding to fixation lights (fixation lights 3.4.5.6,
It has buttons 3', 4', 5', 6', and T' corresponding to TK (signs are attached to them), and a fixation lamp corresponding to the button turned on is turned on by a line (not shown). In this case, it is preferable to use buttons 3', 4', 5', 6', and 7' such that when any button is turned on, other buttons that were turned on automatically return to normal. Operating device 10
From there, a signal corresponding to the angle of the fixation lamp that is turned on is input to the comparator 12. The coordinate signals from the position detection sensor 9 correspond to hx and bylc in equations (1) and (2). Performance) The γ device 111 determines the direction in which the eye to be examined 1 is facing from the coordinate signal from the position detection sensor 9, adjusts the dimension to the signal corresponding to the angle from the operating device 10, and uses the comparison device 12
Output to. Comparison device i? 7.121, operating device 10
If the direction of the 3V device 11 almost matches the angle from
A display signal is output to the display device 13. The examiner knows that the subject has confirmed the fixation lamp by the display 13 (1).In this way, the examiner can check the display on the display 13 and operate the operation panel as described above. If you operate it,
The visual field of the eye 1 to be examined can be measured.

The configuration shown in Figure 2 is convenient because it allows the examiner to take measurements while observing the patient's condition. 3 and any other fixation light alternately,
Automatic measurement becomes possible by recording whether or not the subject has confirmed the fixation light each time.

In this case, if the fixation lamp is not confirmed, it is preferable to use a structure that alerts the examiner by sounding a buzzer, etc., so that re-measurement can be performed in that direction.

Further, if the operation panel of FIG. 2 is made into a polar coordinate type operation panel as shown in FIG. 3, corresponding to the position of each fixation lamp, operability will be improved.

Furthermore, in the above explanation, an example was given in which the central fixation lamp 3 and peripheral fixation lamps 4, 5, 6, T, etc. are selectively turned on, but the central fixation lamp 3 is turned on during measurement. Of course, you can leave it without it. At this time, the central fixation lamp 3 and the peripheral fixation lamps may be the same, but they may also be of different colors or the peripheral fixation lamps may be blinked to draw attention. In this case as well, the measurement can be carried out in the same manner as described above by simply reminding the subject to turn in that direction after confirming that the peripheral fixation lamp is lit.

And in this case buttons 3', 4', 5', 6', T
', only button 3' is the same as other buttons 4', 5',
6', T' may be turned on and off independently of buttons 4', 5'N, 6' and T', and the other buttons 4', 5'N, 6' and T' may be automatically reset buttons as described above.

In the present invention, since the visual field is measured based on the movement of the subject's eye, a response by the subject trap is not required.

Furthermore, since only the movement of the eyes is detected, the measurement time can be shortened.

[Brief explanation of the drawing]

Figure #11 shows an embodiment of the present invention, Figure 2 is a block diagram of a measuring device used in the embodiment of the present invention, and Figure 3 shows a polar coordinate type operation panel. (Explanation of codes for main parts 8A) 3 Central fixation lights 4 to 1 Peripheral fixation lights 9 Position detection sensor 10 Operation device f 11 Performance 7a device 12 Comparison device 13 Display device Applicant: Nippon Kogaku Kogyo Co., Ltd. 2 figures 3 figures 5'

Claims (1)

[Claims] A driving means for driving a central fixation lamp that indicates the center of the visual field, a peripheral fixation lamp that allows the subject to gaze at an arbitrary point around the nucleus-centered fixation lamp, and a direction in which the subject's eye moves. and a determining means for determining whether or not the subject has confirmed the driven indicator light based on the output signal of the nuclear detection means. Total.