JPH01238819A - Perimeter - Google Patents

Abstract

PURPOSE:To allow a measuring person to perform a correct test in response to the condition of a person under test by reading out programs of the screening test, three-zone test, and threshold value test, controlling an LED driving means according to the programs, and storing and displaying test results. CONSTITUTION:For the screening test, targets are presented in sequence according to the selected presentation time and presentation interval at measurement points of light emitting diodes 52 on a screen. When a person under test can observe the target, he responds by pushing a response switch. The response results are all stored in a data memory, the presence of a dark point for each target is printed out. For the three-zone test, a target is presented with the highest intensity for the dark point found, the point where the target of the dark point section can not be observed is set to an absolute dark point, the point where it can be observed is set to a comparative dark point, they are distinguished with different marks for display. The intensity of the targets of the comparative dark points is increased in steps of 2dB, after the visual test is performed on all comparative dark points, the threshold value of each comparative dark point is displayed. The threshold value is printed out in the numerical display.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a perimeter, and more particularly to an automatic perimeter that can perform any selection from a screening test to a detailed test.

(Prior Art) Perimetry is widely used in ophthalmology as a device that can effectively detect visual field abnormalities as well as eye diseases such as glaucoma, and various devices have been provided heretofore.

This visual field meter fixes the subject's eye at a fixed position, presents an optotype on the facing viewing surface, and tests the visual field by checking whether the optotype can be seen at each position on the viewing surface. It is something to do.

Conventional perimeters can be divided into two types based on the shape of the screen: those with a dome-shaped screen and those with a flat screen.

In addition, the display format of optotypes also varies, for example, dome-shaped ones that use a reflector to project an image in a spot shape on the inner surface of the dome, or light-emitting diodes (LEDs) on the viewing surface.
There is a method in which a large number of light emitting diodes are built in and displayed by emitting light.

The number of visual targets provided on these visual recognition surfaces ranges from a few tens of measurement points to a few hundred measurement points, and usually the visual targets are automatically presented according to a predetermined program and the test subject The device is configured to perform a visual field test by checking whether the visual target can be visually recognized.

Conventional perimeter perimeter meters have various programs prepared depending on the content of the test, and the measurer selects an appropriate program depending on the subject to be examined to proceed with the test.

(Problems to be Solved by the Invention) With a perimeter, the more visual targets presented on the viewing surface, the more precise measurements can be made. There are problems such as long inspection time, and depending on the object to be measured, it may be difficult to handle.

On the other hand, a perimeter meter with fewer visual targets has the advantage of having a simple device, easy operation, short inspection time, and low price, but has the problem of lower inspection accuracy. There is a point.

In addition, as mentioned above, conventional inspection programs are available in a variety of types depending on the inspection target, so selecting a program can be rather troublesome, and once an inspection has started, it is difficult to proceed according to a predetermined program. There were problems such as it was difficult to understand the tester's intention to perform the test by just using the method.

Therefore, the present invention has been made to solve the above-mentioned problems, and its purpose is to provide a simple screening test that allows the operator to conduct an accurate test according to the condition of the subject. The aim is to provide an easy-to-operate perimeter that enables more precise inspections.

(Means for solving problems) The present invention has the following configuration to achieve the above object.

That is, an LED driving means for presenting an optotype by energizing light emitting diodes provided in a predetermined arrangement on a viewing surface, a screening test program for detecting dark spots,
A program storage means for storing a three-zone test program for distinguishing between a comparative scotoma and an absolute scotoma, and a threshold test program for measuring a threshold value of the comparative scotoma, and data for storing test result data. A storage means, a display means for displaying the test results, a control switch including a selection switch for switching the screening test, the three-zone test, and the threshold test to be performed in this order continuously or individually, and an input signal to the control switch. A predetermined program is read from the program storage means, and according to the program, test result data of the LEDyjA operating means is stored in the data storage means.

The apparatus is characterized by comprising a control means such as a CPU for controlling display of the test result data on the display means.

(Embodiments) Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[Perimeter body]

FIG. 1 is a front view showing an embodiment of a perimeter according to the present invention, and FIG. 2 is a side view. First, the configuration of the perimeter body will be described below.

In the figure, reference numeral 10 denotes a body portion of the perimeter, and the body portion 10 is formed in the shape of a closed hollow box. 12 is a light-shielding panel provided on the front surface of the body portion 10, and this light-shielding panel 12
A viewing window 14 for viewing the screen is provided in the center with a circular opening. Note that the viewing window 14 is set to have as small a diameter as possible in order to reduce the influence of external light.

16 is a forehead rest provided near the upper edge of the viewing window 14, and 18 is a chin rest provided below the light shielding panel 12.

On the side of the body part 10 is an operation panel 2 for operating the perimeter.
4 is provided. On this operation panel 24 is an operation section 26.
A monitor section 30 is provided which displays the test results based on the optotype pattern.

Control switches 27 such as a start switch and a setting switch for setting optotype brightness are provided on the operation unit 26.
A display unit 28 for displaying threshold values and the like is provided.

In addition, the monitor section 30 is provided with light emitting bodies such as light emitting diodes in the same number as the number of visual targets on the back surface of the front plate so that the test results are displayed according to the visual target arrangement pattern arranged on the viewing surface. , the monitor unit 30 is configured so that the light from the light emitter can be seen through from the front side.

In FIG. 1, 40 is a response switch.

FIG. 3 is a sectional view showing the internal structure of the perimeter main body. Inside the body of the viewing window 14 is an introduction tube 42 formed concentrically with the viewing window 14 and having a short cylindrical shape with a larger diameter than the viewing window 14. A rectangular tube 44 is provided around the outer periphery of the introduction tube 42.

The opening end of the tube 44 on the viewing window 14 side contacts the outer peripheral surface of the introduction tube 42 via a wall surface 45, and the opening end facing the viewing window 14 is provided with a screen 46.

48 is an LED support plate joined to the back surface of this screen 46. A large number of light emitting diodes are embedded and fixed in this LED support plate 48 in a predetermined arrangement.

The light emitting diodes disposed on the LED support plate 48 are used to present optotypes on the screen 46 during a visual field test, and these light emitting diodes are connected to a control unit 50 that controls light emission timing, brightness, etc. Ru. 5
1 is a power supply section. FIG. 4 shows the L of the light emitting diode 52.
The mounting on the ED support plate 48 shows the state. In the embodiment, the side peripheral surface of the light emitting diode 52 is housed in the recess, and the diameter of the part where the top of the light emitting diode 52 comes into contact is reduced, so that the light from the light emitting diode 52 is The light is projected from this reduced diameter portion 53. The reduced diameter portion 53 has a diameter of 2.4 mm in the example.

54 is a light shielding material for shielding light leaking from the back side of the light emitting diode 52.

In the example, a yellow light emitting diode was used as the light emitting diode 52 for the optotype.

Furthermore, the screen 46 provided on the front surface of the LED support plate 48 is made of a scattering material that allows light emitted from the light emitting diodes 52 to pass through suitably and to be slightly diffused.

The surface of the screen 46 is preset to a predetermined brightness during inspection. In FIG. 3, 55 is a light bulb for internal illumination, and 56 is a lighting filter provided in front of the light bulb 55 for internal illumination. There are four internal lighting bulbs 55, one each in the vertical direction and one each in the horizontal direction.

The brightness of the screen 46 in the example is 3.15 asb.

[Optotype placement]

Next, the arrangement of optotypes presented on the screen 46 will be explained.

FIG. 5 shows an example of the arrangement of light emitting diodes 52 fixed on the LED support plate 48. In the figure, the light emitting diode 52 is indicated by a small circle.

As shown in the figure, the arrangement pattern of the light emitting diodes 52 in this embodiment is substantially concentric, and the visual field measurement range is limited to a visual field range with a radius of 25°.

Note that four small circles shown at equal intervals on a circumference with a radius of 7.5° are auxiliary fixation points 58 used to assist fixation. A red light emitting diode is used for this auxiliary fixation point 58 to distinguish it from the visual target.

A total of 85 light emitting diodes are provided on the LED support plate 48 as measurement points, excluding the auxiliary fixation point 58.

Actually 1. Since the ED support plate 48 is covered by the screen 46, the subject cannot see each light emitting diode on the LED support plate 48.

Note that a fixation point 60 for the subject to fixate is displayed at the center position of the screen 46. The fixation points 60 are displayed as small black dots on the surface of the screen 46, and are displayed at four positions surrounding the visual target of the fovea 70, as shown in FIG.

During the visual field test, the subject looks at the fixation point 60 displayed on the screen 46 and looks at it.

FIG. 6 shows an embodiment of the recording paper that is set on the monitor section 3o of the operation panel 24 to record test results, etc. As shown in FIG. 0 so that inspection results can be written in according to the marker placement pattern.
A mark 62 is printed. The arrangement of the light emitters provided on the monitor section 3o coincides with the arrangement position of the O mark 62 for writing.

However, on this recording paper, the outer periphery is shown slightly compressed toward the center compared to the arrangement of the light emitting diodes 52 arranged on the LED support plate 48 for the purpose of space saving.

In addition, on this recording paper, in addition to the 0 mark 62 for writing, there are also an angle display showing the optotype position, a display showing the screening level,
It is structured so that you can fill in other necessary information.

A small circle at a radius of 7.5° indicates the position of the auxiliary fixation target 58.

[Control unit]

Next, a control unit that controls the presentation conditions of the optotype and the like will be explained.

This control section is configured so that the tester can proceed with the test step by step while selecting the test contents at any time.The external input section includes a control switch 27 operated by the tester and a control switch 27 operated by the subject. There is a response switch 40 that responds to the input signals, and these input signals are input to a central processing unit (CPU) via an input/output section.

Further, the output of the CPU is inputted to an LED driving section that drives a light emitting diode via an input/output section, and the LED driving section causes a predetermined light emitting diode (target) to emit light at a predetermined brightness based on the output signal of the CPU.

Further, the output signal of CP[J is inputted via the input/output section to a drive section for a light emitting body such as a light emitting diode for monitoring disposed in the monitor section 30, and is also input to a display section 28 that displays threshold values and the like. is input. The CPU also includes a data memory section for storing test results, a memory for storing a light emission order program of the optotype, and a clock section for presenting the optotype at predetermined time intervals.

Furthermore, the inspection data is output to an external printer via the input/output section.

The above-mentioned CPU controls the LED drive unit, etc. in accordance with the operator's operations to display optotypes, print out test results, etc. The operation of the control unit in this example will be explained below. This will be explained according to the functional flowcharts shown in FIGS. 7(G), 7(C).

First, the power switch is turned on and the chin rest 18 is adjusted so that the eye of the subject is positioned at a predetermined position in the viewing window 14.

Next, the presentation time of the optotype (0, 2, 0, 4, 0, 8 seconds)
, and the visual target presentation interval (l, 2.3 seconds) are selected and set. This setting is made so that the examinee can undergo the examination without difficulty.

Next, input whether the eye to be examined is the right eye or the left eye. The presentation time, presentation interval, and right/left distinction of the optotype are all stored in the memory.

Next, set the screening level.

This screening level set measures the sensitivity curve of the subject and sets the screening level. In the example, thresholds are set for one point at center g, 70, and four points at a radius of 1°. Sensitivity curves are set from the five threshold values obtained, and the second from the top of these sensitivity curves is defined as the sensitivity curve level of the subject.

When the screening level is automatically set, the screening level is automatically set to a sensitivity curve level that is 6 dB minus this sensitivity curve level. .

Manual correction of the screening level involves correcting the automatically set screening level, or manually setting the screening level to an appropriate value by operating a control switch without going through the automatic setting of the screening level.

Only after reaching this stage does the screening test proceed.

A major feature of the optotype arrangement of this embodiment is that the optotype is located at the fovea 70, and as described above, by measuring the fovea when setting the screening level, subsequent measurements can be made extremely efficiently. It has the characteristic that it can be done. That is, since the threshold value of the fovea 70 is displayed on the display unit 28 when setting the screening level, it is possible to check whether there is a scotoma in the fovea by comparing it with the screening level set as described above. Can be done.

If there is a scotoma in the fovea, the isotropy target 60 displayed at the center of the screen will not function effectively for the subject, so the auxiliary fixation point 58 (red light emitting diode) is turned on to provide this assistance. It is possible to prompt the user to direct his/her eyes to the center of the fixation point 58 and make the user fixate the gaze.

In this way, it is important to know in advance whether there is a central scotoma in order to perform subsequent examinations accurately.

In the perimeter of the embodiment, the brightness of the optotype is set so that the screening test is carried out according to the threshold-related method, and the screening test proceeds as follows according to a preset program.

First three times the foveal light emitting diode is 40asb (10
dB) to attract the examinee's attention and encourage them to look at the same eye so that the examinee's eye points toward the center.

Next, the optotypes are sequentially presented at the 84 measurement points on the screen 46 according to the presentation time and presentation interval. Note that one of the 85 light emitting diodes arranged on the L[ED support plate 48 corresponds to the position of a blind spot, so there are 84 measurement points. When the subject can visually recognize the visual target, the subject presses the response switch 40 to respond.

The presentation type of the optotype in this embodiment is based on the ■ character sequence method, and as shown in Figure 0, which shows the presentation type of the optotype for the right eye in Fig. 8, the optotype is the previously presented optotype. The program is such that visual targets located at symmetrical positions are sequentially presented. This type of visual target presentation is done in such a way that it passes through the center from the center to the outside or from the outside to the inside, so it has the characteristic of not biasing the line of sight in a certain direction, and has the effect of helping to maintain same vision. have Note that the left eye moves symmetrically with the right eye.

In this way, all responses by the subject are stored in the data memory, and after the test is completed, the presence or absence of a scotoma for each visual target is printed out.

Note that during the test, points that did not receive a response are displayed as lit on the monitor unit 30, and these lit points are displayed as dark spots. Therefore, when recording test results on recording paper, the recording paper is set on the top surface of the monitor section 30, and dark spots can be easily recorded from the illuminated position.

Further, the operation unit 26 is provided with an LED that displays the timing when the optotype is presented and the timing when the subject responds.
The measurer can check whether the subject's response is correct in response to the visual target presentation.

Further, in this embodiment, simultaneous viewing monitoring is performed using the Heysy-Krakow method. This method lights up the optotype in the blind spot while presenting the optotype and monitors whether there is a response from the subject.
The light emitting diode in the blind spot is turned on at ASB (OdB), and the presence or absence of a response from the subject is recorded. This result can be used as a reference for the reliability of the test.

In addition, the test subject is set to be able to put the device into a hold state by holding down the response switch, which allows the test to be temporarily stopped when the test is difficult to keep up with the visual target presentation speed. be able to.

In addition, when performing the screening test again, the screening start state is set by operating the control switch. At this time, it is possible to choose between re-screening only the scotoma detected in the previous screening test, or re-screening all the visual targets.

After the screening test, you can proceed to the three-zone test. This three-zone test measures whether the scotomas found during the screening test are absolute scotomas or comparative scotomas. In this three-zone test, the optotypes of the previous scotoma areas are presented at a maximum brightness of 400 asb, and the points where the optotypes of these scotoma areas cannot be visually recognized are defined as absolute scotomas, and the points where they are visible are defined as comparative scotomas.

The results of this three-zone test can also be printed out, and on this printout, the absolute scotoma and comparative scotoma are distinguished and displayed using different marks, as will be described later.

At this time, on the monitor unit 30, the absolute scotoma is displayed by continuous lighting, and the comparison scotoma is displayed by blinking lighting.

Following this three-zone test, a threshold test is also available. In this threshold test, the threshold value is measured for each comparison scotoma that has been previously determined as a comparison scotoma.

The perimeter of this example has a maximum brightness of 2d up to 400asb.
The brightness is set so that it can change in 17 steps at intervals of B, and when measuring the threshold of the comparison scotoma, the brightness of the optotype is set to 2.
Increase the amount in dB increments and decide based on the response from the subject.

Specifically, after the luminance of the optotype is gradually changed and a visual inspection is performed on all comparison scotomas, the threshold value of each comparison scotoma is displayed.

The threshold value of the comparison scotoma is displayed numerically in the printout as described later, but when it is displayed on the monitor unit 30, it is recorded on recording paper, so the measurement result must be read out manually after the measurement is completed. There is. That is, the numerical values displayed on the display section 28 are sequentially changed by operating the control switch, and the position of the comparison scotoma is determined based on the illuminated spot that appears on the monitor section 3o.
The threshold value for the comparison point is determined from the numerical value displayed in . According to this method, the numerical value (threshold value) of 1 display part
Since the position of the comparative scotoma (map of the comparative scotoma) can be obtained for each comparison point, three-dimensional information such as the position of the comparative scotoma and the extent of its depression can be obtained.

As is clear from the flowcharts shown in Figures 7(a) and 7(C), the perimeter of this example can
The three-zone test and the threshold test can be arbitrarily selected and performed, and operations such as re-testing depending on the measurement situation can be performed very easily.

This allows the patient to freely choose not to perform all the tests consecutively, for example, to perform only the screening test and finish it, or to proceed to the next three-zone test only when a scotoma is found in the screening test.

FIG. 9, FIG. 10, and FIG. 11 show printout examples of test results at each stage from the screening test to the threshold test.

Figure 9 shows the results of the snail cleaning test for the right eye, where the 0 mark indicates the point where the optotype was visible, the X mark indicates the point where the optotype was not visible, that is, the landing point. The mark indicates the location of the blind spot.

FIG. 10 shows the results of the three-zone test, where the 0 mark indicates an absolute scotoma and the S mark indicates a comparative scotoma.

FIG. 11 shows the threshold test results, where the absolute scotoma is indicated by a 0 mark, and the threshold value of the comparative scotoma is indicated numerically at the position of the comparative scotoma.

In this way, external prints can also be output for each examination, and the comparison scotoma, absolute, and li points are displayed in accordance with the optotype placement, so visual field abnormalities can be displayed at a glance. Note that it is also possible to print out the results of each test at once after all tests are completed.

The value displayed as the screening level in the above print is set with a predetermined slope within a 25° visual field based on the screening level used in the screening test. The degree of defects such as scotoma can be determined based on the screening level with this gradient. A screening scale with a predetermined slope is printed on the recording paper in Figure 6, and this screening scale is 6 dB at the center relative to the peripheral visual field (OdB) based on standard eye sensitivity.
The gradient is set so that B becomes higher. On the recording paper, the screening level at the relevant position can be determined by adding the value on the screening scale to the screening level value at the time of inspection. Then, it can be determined whether the scotoma is a true defect from the screening level at each target position and the threshold value obtained by measurement.

In the output print, the threshold value is displayed numerically as shown in FIG. 11, and at the same time, the screening level is automatically displayed, so it can be determined whether the scotoma is a true defect or not.

As described above, the perimeter of this embodiment limits the visual field adjustment range to a radius of 25 degrees and the number of visual targets to 85, but it can be used for both relatively simple and detailed inspections. By making it possible to perform highly accurate visual field tests,
It has become possible to detect visual field abnormalities with a high probability.

The present invention has been variously explained above using preferred embodiments, but the present invention is not limited to these embodiments.
Of course, many modifications can be made without departing from the spirit of the invention.

(Effects of the Invention) The perimeter of the present invention is configured as described in 1-1 and can be used for any purpose, from screening tests that can be performed with simple operations, to three-zone tests that perform more precise tests, and threshold tests. It can be selectively performed, and can be operated appropriately depending on the subject to be examined and the examination situation. Furthermore, since the operation is simple, there is no difficulty in handling. As a result, it can be suitably used for screening tests such as mass medical examinations, etc., and at the same time, it has great effects such as being able to perform more precise tests by proceeding to more advanced tests.

[Brief explanation of the drawing]

Figures 1, 2, and 3 are front views, side views, and cross-sectional views showing one embodiment of the perimeter, Figure 4 is an explanatory view showing the arrangement of light emitting diodes, and Figure 5 is an LED support. An explanatory diagram showing the arrangement of light emitting diodes on the board, Fig. 6 is a front view showing an example of recording paper, and Figs. 7 (a>, (b), and (C) are flow charts showing the operation of the control section of the perimeter. Figures 9 and 8 are explanatory diagrams showing types of optotype presentation, and Figures 9, 10, and 11 are front views showing examples of output prints. 10...Body part, 14...Visual recognition Window, 26...
・Operation unit, 27...control switch, 28
...display section, 30...monitor section, 46...
- Screen, 48... LED support plate, 52... Light emitting diode, 58... Auxiliary fixation target, 60... Fixation target, 70... Fovea. 1st, 10th, 33rd. . , ~ □ 4th Figure 5 (.) Figure 7 Figure 8 Figure 9 Figure 10 Figure 11

Claims (1)

[Scope of Claims] 1. LED driving means for presenting an optotype by energizing light emitting diodes provided in a predetermined arrangement on a viewing surface, a screening test program for detecting a scotoma, and a comparison scotoma. a program storage means for storing a three-zone examination program for distinguishing between and absolute scotoma, and a threshold examination program for measuring the threshold value of the comparison scotoma; and a data storage means for storing examination result data. , a display means for displaying test results; a control switch including a selection switch for performing a screening test, a three-zone test, and a threshold test in this order consecutively or separately; reading a predetermined program and controlling the LED driving means according to the program;
C controlling the test result data to be stored in the data storage means and displayed on the display means;
A perimeter meter characterized by comprising a control means such as a PU.