JPH04117941A - Perimeter with fixation view monitoring means - Google Patents

Abstract

PURPOSE:To eliminate the part in which a target for measuring a visual field cannot be shown, and to measure all visual fields by constituting the perimeter so that a front eye part image of a person to be examined, opposed correctly to a dome can be observed from a position tuned obliquely against the front eye part which does not obstruct recognition of the person to be examined to the target. CONSTITUTION:By both minimum mirrors 18a, 18b, a front eye part image of an eye E to be examined is led to a fixation view monitoring camera 17 for monitoring obliquely the front eye part. Both the minimum mirrors 18a, 18b are placed in a position which does not obstruct a visual field of a person P to be examined for recognizing a target S2, that is, in the outside of a range (visual field of about 60 degrees) required for measuring the visual field of the person P to be examined, opposed correctly to a dome 15. The fixed view monitoring camera 17 and both the minimum mirrors 18a, 18b constitute an image signal forming part 19. The front eye part image of the eye E to be examined, led to the fixation view monitoring camera 17, is sent out to a signal converter 20 as a front eye part image signal E1 formed by a signal forming circuit 17a.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a perimetry with fixation monitoring means that measures the visual field while monitoring the fixation state of a subject.

[Prior Art] Conventionally, a perimetry 1 with a visual monitoring means as shown in FIG. 5 is known.

The visual field meter 1 with fixation monitoring means has a dome 2 having a substantially hemispherical shape, and is inserted into the through hole 3 directly facing the inner surface of the dome 2 through a through hole 3 formed at the inner surface pole position of the dome 2. The anterior segment of the subject's eye EP, which is gazing at the presented fixation target, is monitored. EO is an examiner's eye. As a monitoring method, dome 2
There is a method of directly monitoring through the through hole 3 using a telescope 4 installed on the back, or a method of indirectly observing the image taken in through the through hole 3 by photographing it with a CCD camera or the like and converting it into an image (not shown). .

[Problems to be Solved by the Invention] However, in the conventional monitoring method, a through hole 3 having an opening to obtain a sufficient amount of observation light must be provided in the dome 2, which makes it difficult to measure the field of view. There was a problem in that it was not possible to present an optotype in the 3 portion of the through hole, and it was not possible to measure that portion.

This invention was made in view of the above problems, and
The purpose is to provide a perimetry with fixation monitoring means that can measure the entire visual field, eliminating the areas where visual targets for measuring the visual field cannot be presented.

[Means for Solving the Problems] In order to achieve the above object, the perimeter with fixation monitoring means according to the present invention provides a fixation target at the inner pole position of a substantially hemispherical dome, and a fixation target of the fixation target. A perimeter with a fixation monitoring means that measures a subject's visual field by displaying optotypes around the subject and monitors the fixation state by observing the anterior segment of the subject's eye. The means is provided in a position that does not obstruct the visual field of the subject who recognizes the optotype on the inner surface of the tom, and obliquely observes the anterior segment of the subject's eye that directly faces the dome to obtain an anterior segment image signal. an image signal forming section that forms an image signal forming section; a signal converter that converts, based on the anterior eye segment image signal of the image signal forming section, an image forming signal that forms an image of the subject's eye from a substantially directly facing direction; It is characterized by comprising an image forming section that forms an image according to an image forming signal.

[Function] With the perimetry with fixation monitoring means according to the present invention, the fixation monitoring means can be moved directly to the dome from a position oblique to the anterior segment of the eye that does not obstruct the subject's recognition of the visual target. It is possible to observe the anterior segment image of the subject, and to measure the entire visual field of the subject while monitoring the fixation state.

[Example] Hereinafter, an example of a perimeter with a visual monitoring means according to the present invention will be described based on the drawings.

As shown in FIGS. 1 and 2, the perimeter 10 with fixation monitoring means has a housing 11 and a substantially hemispherical dome 15 built into the housing 11.

The housing 11 is provided with a panel 12 on the front, and the panel 12 is formed with a face receiving hole 12a into which the face of the subject P is received. A face support member 13 for fixing the face is provided in the face support hole 12a, and the face support member 13 has a forehead rest part 1.3a and a chin rest part 13b.
It is composed of. On the side part of the housing 11,
An operation display device 14 having a fixation monitoring screen 14a and an operation screen 14b is provided (see FIG. 2). The fixation monitoring screen 14a displays the anterior segment of the subject's eye E, and the examiner can monitor whether the subject P is gazing at a fixation target S, which will be described later.

A camera storage section 16 having a mirror installation section 1.6a protruding into the dome 15 is formed at the peripheral edge of the dome 15, which is the end of the housing 11.The camera storage section 16 has a signal forming circuit 17a. A fixed vision monitoring camera 17 is installed. A mirror installation part 16a located on the side of the subject P directly facing the dome 15 has an opening 16b formed therein and two very small mirrors 18a and 18b arranged therein. With these two extremely small mirrors 18a18b,
The anterior segment image of the eye E to be examined is guided to a fixation monitoring camera 17 for obliquely monitoring the anterior segment. Both tiny mirrors 1.
8a and 18b are test subjects P who recognize optotypes S2, which will be described later.
The dome 15 is placed at a position where it does not block the visual field of the subject P, that is, outside the range (approximately 60 degrees of visual field) required for measuring the visual field of the subject P who directly faces the dome 15 (see FIG. 1). The fixation monitoring camera 17 and the two very small mirrors 18aJ8b constitute an image signal forming section 19.

The anterior segment image of the subject's eye E guided by the fixation monitoring camera 17 is the anterior segment image signal E formed by the signal forming circuit 17a.
, and is sent to the signal converter 20 as .

By the way, although the anterior segment image obtained by the above observation method is not the same as that seen from the front, the signal converter 20
It can be supplemented in The correction method is shown below.

As shown in FIG. 3, in the image projected on the plane a, each coordinate point aI+a2+33 is bl on the plane.

b2. Corresponds to b3 (see (a)). However, plane a
The image projected on the plane (see (b)) and the image projected on the plane (see (C)) are not the same. Therefore, it is necessary to perform coordinate transformation on plane A as well in order to obtain the same image as the image obtained on plane a. A specific example of this is shown below.

If the distance between 31 and 32 is '-1s, the distance between bI and b2 is L2, and the angle between plane a and plane A is α, then
L2 is expressed by the following formula.

1-2 = LI/Cos α By continuously performing coordinate transformation using this formula, an image that is approximately the same as the image seen from the front can be obtained.

The anterior eye segment image signal E1 sent to the signal converter 20 is converted into an image forming signal that forms an image of the eye E in a substantially facing direction based on the anterior eye segment image signal E. E2
is converted into. The image forming signal E2 is then sent to the image forming section 21, and the image forming section 21 displays on the fixation monitoring screen 14a an image of the subject's eye E from the substantially directly facing direction according to the image forming signal E2. Ru.

These image signal forming section 19, signal converter 20, and image forming section 21 function as fixation monitoring means.

Further, on the inner surface 15a of the dome 15, a fixation target s1 and a visual target S2 are presented.

The fixation target S is a fixation target roughly composed of a light source 22, an infrared filter 23 having, for example, a small circular transmission part in the center through which visible light passes, an index plate 24 punched out in the shape of a cross, and a projection lens 25. A fixation target S is projected onto the polar position of the inner surface 15a of the dome 15 by the light emitting device 26 via the mirror 27 (see FIG. 1).

The optotype S2 is projected onto the dome 15 by the optotype spot light emitting device 32, which is roughly composed of a light source 28, an aperture 29, a liquid crystal filter 30, and a projection lens 31 (see FIG. 1). The projection lens 31 is a liquid crystal filter 30
The optotype spot light set to a predetermined brightness is passed through the guide hole 15b provided on the back surface of the dome 15, and is reflected by the reflecting mirror 33 provided in the projection mechanism 33.
Project to a. The optotype spot light reflected by the reflection mirror 33a is projected onto the inner surface 15a of the dome 15, and the optotype S2 is presented around the fixation target S.

Next, the operation of the perimeter with fixation monitoring means according to this embodiment will be explained.

First, the subject P is made to face the perimetry 10 with fixation monitoring means, directly facing the dome (see FIG. 4). The face of the subject P is brought into contact with the forehead against the forehead rest part 13a and the chin against the chin rest part 13b, respectively.

Subsequently, the fixation target S1 is presented for the subject P to gaze at, and the visual target S2 is presented for the subject P to recognize. At this time, the anterior segment image of the subject P who is gazing at the fixation target s1 is transmitted to the fixation monitoring camera 1 through the two very small mirrors 18a and 18b.
7, passes through the image signal forming section 19, the signal converter 20, and the image forming section 21, and is displayed on the fixation monitoring screen 14a as an image from a direction substantially directly facing the eye E to be examined.

For this reason, the image signal forming unit 1 that monitors the anterior segment of the eye obliquely
9, it is possible to observe the anterior segment of the subject's eye E without obstructing the field of view of the subject P who recognizes the optotype S2 (first
(see figure). At the same time, an optotype S2 for measuring the visual field can be presented over substantially the entire inner surface 15a of the dome 15,
All visual fields of the subject P can be measured.

Note that the fixation state can also be monitored by the method described below without using the very small mirrors 18a and 18b shown in the above embodiment.

As shown in FIG. 4, a position where the anterior eye segment is obliquely monitored and the visual field of the subject P who recognizes the optotype S2 is not obstructed, that is, a location where the measured visual field of the subject is not obstructed; For example, an ultra-small camera 34 is mounted on the hardware part of the forehead rest 1.3a.
is installed, and the anterior segment of the subject P is monitored using this ultra-small camera 34.

[Effects of the Invention] As explained above, the perimeter with fixation monitoring means according to the present invention has a fixation target provided at the innermost pole position of a substantially hemispherical dome, and also includes visual targets around the fixation target. A perimetry with a fixation monitoring means that can be displayed to measure a subject's visual field and monitor the fixation state by observing the anterior segment of the subject's eye,
The fixation monitoring means is provided in a position that does not obstruct the visual field of the subject who recognizes the optotype on the inner surface of the dome, and obliquely observes the anterior segment of the subject's eye, which faces the dome, to detect the anterior eye. an image signal forming section that forms a partial image signal; and a signal converter that converts the anterior ocular segment image signal of the image signal forming section into an image forming signal that forms an image of the subject's eye from a substantially opposite direction. and an image forming section that forms an image according to the image forming signal.

Therefore, it is possible to carry out simultaneous visual monitoring using an image directly facing the anterior segment of the eye, and it is possible to measure the entire visual field by eliminating areas where optotypes cannot be presented for measuring the subject's visual field. .

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the configuration of a perimeter with fixation monitoring means according to the present invention. FIG. 2 is an overall perspective view of the perimeter with fixation monitoring means. Figure 3 shows the method of correcting the deviation of the anterior segment image.
al is an explanatory diagram of image deviation, (bl is a plan view of the image on plane a, and (C) is a plan view of the image on plane A. FIG. 4 is a schematic explanation showing another example of the same viewing monitoring means. Fig. 5 is an explanatory diagram of a conventional perimeter with fixation monitoring means. 10... Perimeter with fixation monitoring means 15... Dome 15a... Inner surface E... Covered Optometry El... Anterior segment image signal E2... Image forming signal P... Subject S,... Fixation target S2... Visual target

Claims (1)

[Scope of Claims] A fixation target is provided at the innermost pole position of a substantially hemispherical dome, and a visual field is displayed around the fixation target to measure the subject's visual field, and in front of the subject's eye. A perimetry with a fixation monitoring means capable of monitoring the state of fixation by observing the eye, wherein the fixation monitoring means does not obstruct the visual field of the subject who recognizes the optotype on the inner surface of the dome. an image signal forming unit provided at a position that obliquely observes the anterior segment of the subject's eye facing the dome to form an anterior segment image signal; Based on the above, the fixing device comprises a signal converter that converts into an image forming signal that forms an image of the eye to be examined from a direction substantially directly facing the eye, and an image forming section that forms an image according to the image forming signal. Perimeter with visual monitoring means.