JP2008246227A - Perimeter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a perimeter automatically and accurately calculating a loss ratio of a subject's visual efficiency. <P>SOLUTION: A CPU 7 calculates the loss ratio of the subject's visual efficiency from a result of measurement of a field of vision of the subject with a field of vision dome 10. The CPU 7 allows a user to select a mode for calculating the visual efficiency and its loss ratio or not. When the mode for calculating the visual efficiency and its loss ratio is selected, the visual efficiency and its loss ratio is calculated to output the calculated result to the outside with the result of measurement of the field of vision. When the mode for calculating the visual efficiency and its loss ratio is not selected, just the result of measurement of the field of vision is outputted to the outside. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a perimeter that measures the visual field of a subject in an ophthalmic examination.

  As a conventional perimeter, for example, a Goldman-type perimeter has a hemispherical field dome, and the subject's eye is positioned at the hemispherical center of the field dome. When the fixation point at the center of the inner surface of the dome is fixed, the target is displayed on the inner surface of the dome with a spotlight or LED, the target is moved, and the subject can visually recognize the target. Alternatively, the visual field is measured by causing the subject to operate the response switch when the target is not visible. Specifically, the angle of the remaining visual field (the range in which the visual target can be seen) is measured in multiple directions around the fixed viewpoint.

  The conventional perimeter has only the function of printing out or displaying the measurement result after measuring the visual field in this way.

  As described above, the conventional perimeter has only the function of measuring the field of view and outputting the measurement result, so when determining the loss rate of the visual acuity of the subject, the examiner himself is based on the measurement data of the perimeter It was calculated.

  In this method, the angle of the remaining visual field is measured with a perimeter in eight directions at 45 ° intervals in the circumferential direction around the fixed viewpoint, and the eight angle values of the measurement results are summed and divided by 560. Here, the reason for dividing by 560 is that in the case of an average Japanese, the total of the eight angle values is 560. The visual acuity is obtained by the division. The loss rate of the visual acuity is obtained by subtracting the percentage of the visual acuity from 100%.

  However, performing such calculations is time consuming and burdensome for the examiner, and calculation errors may occur. Further, this loss rate calculation of the visual acuity is based on the measurement result of the remaining visual field angle in only the above eight directions, and the required loss rate is approximate. It is preferable to calculate based on However, this increases the amount of calculation and further increases the burden on the examiner.

  Therefore, an object of the present invention is to provide a perimeter that can automatically and accurately calculate the loss rate of the visual acuity of the subject.

The present invention
Measuring means for causing the subject to fixate the fixed viewpoint at the center of the inner surface of the visual field dome, and measuring the remaining visual fields in multiple directions in the radial direction around the fixed viewpoint as angle values;
The percentage of the value obtained by dividing the total angle value of the multi-directional residual visual field measured for the subject by the total in the healthy subject is defined as the visual acuity rate, and the value obtained by subtracting the percentage of the visual acuity rate from 100% A calculation means for calculating the loss rate;
Output means for outputting the calculation result of the calculation means and the measurement result of the visual field to the outside;
An operation panel for setting a mode for calculating the visual acuity rate and its loss rate,
When the calculation mode is set, the calculation means calculates the visual acuity and its loss rate and outputs the calculation result together with the visual field measurement result. When the calculation mode is not set Only the measurement result of the visual field is output to the outside.

  As is clear from the above description, according to the present invention, the loss rate of the visual acuity of the subject is automatically and accurately calculated based on the measurement result of the subject's visual field, and the calculation result is externally output. An excellent perimeter capable of outputting can be provided.

  Embodiments of the present invention will be described below with reference to the drawings.

  A first embodiment of the present invention will be described with reference to FIGS. First, FIG. 1 shows the configuration of a perimeter in this embodiment.

  In FIG. 1, a CPU 7 controls the entire perimeter according to a control program stored in the ROM 5, and calculates the loss rate of the visual acuity of the subject based on the visual field measurement results as will be described later. Performs arithmetic processing. A RAM 6 is connected to the CPU 7, which is used as a working area for the CPU 7, and is also used for temporary storage of measurement data at the time of visual field measurement and calculation data at the time of loss rate calculation, which will be described later.

  Further, a visual field dome 10 for measuring the visual field of the subject is connected to the CPU 7 via a buffer 9. The field dome 10 has an inner surface formed in a hemispherical shape, and a target is displayed and moved on the inner surface by a spotlight or an LED when measuring the field of view. The control is performed by the CPU 7 via the buffer 9.

  The CPU 7 is connected to a monitor 8 as display means. The monitor 8 comprises a CRT display, a liquid crystal display, or the like, and displays the measurement result of the visual field and the calculation result of the loss rate of the visual acuity.

  Further, the printer 1, the response switch 2, and the operation panel 4 are connected to the CPU 7 via the input / output interface 3.

  The printer 1 is used for recording output of visual field measurement results and visual loss rate calculation results.

  The response switch 2 is used by the subject to input a response operation during visual field measurement.

  The operation panel 4 is provided with operation input means such as a light pen and various switches for the examiner to operate the perimeter, and by the operation, measurement conditions such as the position, size, and brightness of the target at the time of visual field measurement are provided. Can be set arbitrarily or by an inspection program.

  Next, the operation at the time of visual field measurement with the above configuration will be described.

  At the time of visual field measurement, the subject's eye to be examined is positioned on the hemispherical center of the visual field dome 10, and the subject is made to fixate the fixation point at the center of the inner surface of the dome. Then, the target is displayed and moved on the inner surface of the visual field dome 10 under the control of the CPU 7 according to the operation input of the operation panel 4. Then, when the subject can visually recognize the target or when the target disappears, the response is input by operating the response switch. The angle of the target position is detected as the angle of the remaining visual field in one direction, and the data is stored in a predetermined storage area of the RAM 6. This measurement is performed in multiple radial directions centered on the fixed viewpoint, and each measurement data is stored in a predetermined storage area of the RAM 6. Of course, this processing is performed under the control of the CPU 7.

  When measurement in all directions set in advance by operating the operation panel 4 is completed, the CPU 7 displays the measurement result on the monitor 8 or prints it out by the printer 1 in accordance with the setting by operating the operation panel 4. Let The form of the display or printout is, for example, a concentric graph as shown in FIG. In this graph, the circumferential direction of the subject's eye is taken in the circumferential direction around the fixed viewpoint, and the remaining angle of the visual field is shown in the radial direction as a distance. The broken line in FIG. 2 shows the measurement result of the visual field of the right eye of a healthy person. Moreover, you may show a measurement result by the numerical value like the following Table 1. Here, the measurement data in each of the above-mentioned eight directions (upper, upper-outer, outer, outer-lower, lower, lower-inner, inner, and inner-upper directions (see FIG. 2)) is shown. In order to accurately obtain the loss rate of the examiner's visual acuity rate, it is preferable to perform multi-directional measurement.

  By the way, in this embodiment, the measurement result of the visual field of the subject is displayed or printed out as described above, and the CPU 7 calculates the visual acuity rate and the loss rate of the subject based on the measurement result. The calculation result is displayed on the monitor 8 or printed out by the printer 1.

  The calculation method itself is the same as the conventional method described above, and the visual field is obtained by summing up the angle values of the remaining visual fields in the eight directions and dividing by 560, and subtracting the percentage of the visual efficiency from 100%. Find the loss rate at According to this method, for example, when the angle values of the remaining visual fields in the eight directions are each 10 degrees, the visual acuity rate and its loss rate are as shown in Table 2 below.

  In order to obtain a more accurate visual acuity rate and its loss rate, the visual field is measured in multiple directions from the above 8 directions, and the visual acuity rate and loss rate are calculated by the calculation method as described above based on the measurement results in the multiple directions. It is preferable to calculate. In that case, even if the amount of calculation increases by performing measurements in more directions, there is no problem because the CPU 7 performs the calculation.

  The calculation of the visual acuity may be performed automatically after the visual field measurement. However, by operating the operation panel 4, it is possible to set a mode for performing the calculation and a mode for not performing the calculation according to the setting. You may make it perform.

  The control procedure of the CPU 7 in that case is shown in the flowchart of FIG. In this control procedure, first, visual field measurement is performed in step S1, and then in step S2, it is determined whether or not the mode for calculating the visual acuity rate and its loss rate is set according to the operation input state of the operation panel 4. .

  If the calculation mode is set, in step S3, the visual acuity rate and its loss rate are calculated based on the visual field measurement result as described above, and in step S4, the calculation result is externally displayed together with the visual field measurement result. To output. That is, it is printed out by the printer 1 or displayed on the monitor 8. For example, the form is as shown in Table 2 above.

  If the calculation mode is not set, only the visual field measurement result is printed out or displayed in step S5.

  As described above, according to the perimeter of the present embodiment, the loss rate of the visual acuity rate of the subject can be automatically and accurately calculated.

  Next, a second embodiment of the present invention will be described with reference to FIGS. First, FIG. 4 shows the configuration of the perimeter in this embodiment. 4, parts common to those in FIG. 1 of the first embodiment are denoted by common reference numerals, and description thereof is omitted.

  As shown in FIG. 4, in the perimeter of the present embodiment, in addition to the configuration common to the first embodiment, a transparent touch panel 11 as a coordinate input device is provided so as to overlap the display surface of the monitor 8. Yes. The touch panel 11 is used by the examiner to perform an input for designating an arbitrary area corresponding to the field of view on the display surface of the monitor 8, and a pen-shaped coordinate input instruction tool called an input pen is brought into contact with the handwriting. The boundary line for designating the area can be input with.

  Based on such a configuration, in this embodiment, after the visual field measurement, the measurement result is displayed on the monitor 8 as an image of the region corresponding to the visual field of the measurement result, and the examiner is touched with the touch panel 11 on the display surface. An input for designating an arbitrary area corresponding to the field of view is performed. This area is specified in order to correct the area displayed as the measurement result based on the experience of the examiner. Based on the area of the designated region, the loss rate of the visual acuity of the subject is calculated and output.

  Details of the operation of this embodiment will be described below with reference to the flowchart of FIG. FIG. 5 shows a control procedure at the time of visual field measurement of the CPU 7 in this embodiment.

  In the control procedure of FIG. 5, first, the visual field measurement is performed as described above in step S21, and when the measurement is completed, the measurement result of the visual field in step S22 corresponds to the visual field of the measurement result, for example, in the form shown in FIG. The image of the selected area is displayed on the monitor 8. This display form is the same as in FIG. 2 described above, and is a concentric circle graph centered on the fixed viewpoint, taking the circumferential direction of the eye to be examined in the circumferential direction, and showing the remaining angle of the visual field in the radial direction as a distance. The broken line in FIG. 6 shows the boundary of the region corresponding to the visual field of the measurement result. In addition, here, the region of the visual field of the measurement results in the eight directions described above is shown in the same manner as in FIG. 2, but it is needless to say that measurement in more directions is more preferable.

  Next, in step S23, the examiner is caused to make an input for designating an arbitrary area corresponding to the visual field on the touch panel 11. That is, the boundary line of the designated area is input by handwriting with the input pen. In this case, the examiner views the image of the region corresponding to the field of view of the measurement result displayed on the monitor 8 and inputs the boundary line of the designated region so as to correct the region on the display surface. Enter with the pen handwriting. The coordinates of each point of the line are sequentially detected by the touch panel 11, and the coordinate data is input to the CPU 7 and stored in a predetermined storage area of the RAM 6 by the CPU 7.

  The CPU 7 displays the input line on the monitor 8 based on the coordinate data in parallel with the input of the line. An example of the display is shown in FIG. In FIG. 7, the broken line is the boundary line of the region corresponding to the field of view of the measurement result, and the thick solid line is the boundary line of the designated region that is input.

  In addition, on the image displayed on the monitor 8, as shown in FIG. 8, you may make it display the area designated by handwriting input as mentioned above in a different color from areas other than this area.

  When the input for designating the region is completed, the area of the designated region is calculated based on the coordinate data in step S24.

  Next, in step S25, the visual acuity rate of the subject's visual field and its loss rate are calculated based on the area of the region calculated in step S24. Here, the area of the area corresponding to the measurement result of the visual field of the healthy person is stored in the ROM 5 in advance, and the area of the designated area calculated in step S24 is divided by the area of the area corresponding to the measurement result of the visual field of the healthy person. The visual acuity rate is obtained, and the loss rate is obtained by subtracting the visual acuity percentage from 100%.

  Next, numerical data of the visual acuity rate and loss rate calculated as described above in step S26 is printed out by the printer 1 or displayed on the monitor 8, and then the process ends.

  As described above, according to the present embodiment, the measurement result of the visual field is displayed on the monitor 8 as an image of the area corresponding to the visual field of the measurement result, and the examiner corresponds to the visual field with the touch panel 11 on the display surface. By making an input designating an arbitrary region to be performed, the examiner can easily correct the region corresponding to the measurement result. Based on the area of the corrected region, the visual acuity rate and loss rate can be accurately calculated and output.

  In the above configuration, instead of the touch panel 11, for example, an input for designating the region may be performed by other input means such as a mouse.

It is a block diagram which shows the structure of the perimeter in the 1st Example of this invention. It is a graph which shows the form of the display of the visual field measurement result in the perimeter, or the form of printout. It is a flowchart figure which shows the control procedure of CPU of the perimeter. It is a block diagram which shows the structure of the perimeter in a 2nd Example. It is a flowchart figure which shows the control procedure of CPU of the perimeter. It is a graph which shows the example of a display of the visual field measurement result in the perimeter. In the same perimeter, it is a graph which shows the example of a display of the monitor of the state which performed the input which designates an area | region in order for an examiner to correct | amend the area | region corresponding to the visual field of a measurement result. It is a graph which shows the other example of a display of the monitor of the state which performed the input which designates the said area | region.

Explanation of symbols

1 Printer 2 Response switch 3 I / O interface 4 Operation panel 5 ROM
6 RAM
7 CPU
8 Monitor 9 Buffer 10 Field of view dome 11 Touch panel

Claims (1)

Measuring means for causing the subject to fixate the fixed viewpoint at the center of the inner surface of the visual field dome, and measuring the remaining visual fields in multiple directions in the radial direction around the fixed viewpoint as angle values;
The percentage of the value obtained by dividing the total angle value of the multi-directional residual visual field measured for the subject by the total in the healthy subject is defined as the visual acuity rate, and the value obtained by subtracting the percentage of the visual acuity rate from 100% A calculation means for calculating the loss rate;
Output means for outputting the calculation result of the calculation means and the measurement result of the visual field to the outside;
An operation panel for setting a mode for calculating the visual acuity rate and its loss rate,
When the calculation mode is set, the calculation means calculates the visual acuity and its loss rate and outputs the calculation result together with the visual field measurement result. When the calculation mode is not set A perimeter that outputs only the measurement results of the visual field to the outside.

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