JP3013356B2 - Anterior segment imaging device - Google Patents

Anterior segment imaging device

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Publication number
JP3013356B2
JP3013356B2 JP63117483A JP11748388A JP3013356B2 JP 3013356 B2 JP3013356 B2 JP 3013356B2 JP 63117483 A JP63117483 A JP 63117483A JP 11748388 A JP11748388 A JP 11748388A JP 3013356 B2 JP3013356 B2 JP 3013356B2
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Japan
Prior art keywords
image
slit
anterior chamber
optical
eye
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Expired - Fee Related
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JP63117483A
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Japanese (ja)
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JPH01285241A (en
Inventor
一之 佐々木
俊昭 水野
信幸 矢野
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株式会社ニデック
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Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anterior chamber examination, and more particularly, to an anterior eye section photographing apparatus for quantitatively measuring an anterior chamber shape.

[Prior art and problems to be solved]

It may be necessary to measure the shape of the anterior chamber in diagnosing eye diseases. In the diagnosis of glaucoma, measurement of the angle (width) of the anterior chamber angle and the anterior chamber depth are important factors.

However, the conventional corner inspection has been qualitatively performed using a corner mirror and a slit lamp. In general, Shaffer's five-stage classification is used to determine the angle (width) of a corner, but it is only a rough guide because there is no method for clinically accurately measuring the angle of a corner. Also, the determination of the size differs depending on the angle between the corner mirror and the eye to be examined. As described above, this inspection requires a high level of skill and has a problem that the reliability of the judgment cannot be ensured.

In order to solve such a problem, a method of measuring a corner angle using a B-mode cross-sectional image of an ultrasonic diagnostic apparatus has recently been proposed. However, since the resolution of an ultrasonic image is poor, there is a disadvantage that the measurement result obtained by this method has low accuracy.

As for the measurement of the volume of the anterior chamber, a method that can easily measure the volume has not been developed at present.

An object of the present invention is to provide an apparatus for easily measuring the shape of the anterior chamber (angular angle of the anterior chamber, anterior chamber angle, anterior chamber cross-sectional area, anterior chamber volume, etc.) in view of the above-described problems of the related art. It is in.

[Means for solving the problem]

In order to achieve the above object, the first invention is directed to:
In an anterior ocular segment imaging apparatus that arranges an imaging optical system and a slit projection surface according to the principle of Scheimpflug, a slit cutting unit that slits the subject's eye in the meridian direction of the subject's eye, where the slit length is set to be larger than the anterior chamber diameter, Image distortion correction means for processing an image captured by the imaging optical system to correct image distortion, and at least one of an anterior chamber corner angle and an anterior chamber cross-sectional area based on the image corrected by the image distortion correction means. Means for reading the position information of the displayed image in order to calculate the above.

According to a second aspect of the present invention, in the anterior ocular segment imaging apparatus in which the imaging optical system and the slit projection surface are arranged according to the principle of Scheimpflug, the slit length is set to be larger than the anterior chamber diameter and the eye to be examined is slit in the meridian direction of the eye to be examined A slit cutting unit for cutting, a rotating unit for rotating the slit cutting unit and the photographing optical system around an optical axis, respectively, and an image for processing a plurality of images photographed by the photographing optical system and correcting image distortion The image processing apparatus further includes a distortion correcting unit, and a unit that reads position information of the displayed image in order to calculate an anterior chamber volume based on the plurality of images corrected by the image distortion correcting unit.

According to a third aspect of the present invention, there is provided an anterior ocular segment photographing apparatus in which a photographing optical system and a slit projection surface are arranged according to the Scheimpflug principle, wherein a photographing optical system having a correction lens for correcting image distortion caused by the optical system and an optical imaging element. System, slit cutting means for slit cutting the eye to be examined in the meridian direction of the cornea, and image correction means for photoelectrically storing an image captured by the imaging optical system, processing the stored photoelectrically captured image, and correcting the image. Means for reading position information of the displayed image in order to calculate the anterior chamber depth based on the corrected image.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. First
The figure is a schematic view of an optical system arrangement of an anterior ocular segment photographing apparatus using the Scheimpflug principle.

This optical system is a slit projection system, a slit cross section imaging system,
It consists of an alignment observation system.

The slit projection system 1 has a light source for photographing for projecting a slit image, 2 a condenser lens, and 3 a slit. The anterior chamber diameter varies from individual to individual but is around 13 mm, so the slit image in the anterior segment is 14-15
Adjust to be mm. Reference numeral 4 denotes a prism, reference numeral 5 denotes a slit projection lens, and reference numeral 6 denotes a dichroic mirror which reflects visible light and transmits infrared light. Reference numeral 7 denotes a subject's eye.

Slit section photographing system 20 is a photographing lens, 21 is an aramorphic lens for correcting an image, and 22 is a CCD camera light receiving surface. Anamorphic lenses are cylindrical lenses (including toric lenses as they can be used)
It is composed of a combination of

Note that it is also possible to correct all of the image distortion during the image processing.

The taking lens 20 is arranged at an angle to the optical axis so as to satisfy the Scheimpflug principle. The optical axis of the slit section photographing system is arranged at an inclination of 45 ° with respect to the optical axis of the slit projection system. When using an optical system that is arranged perpendicular to the optical axis of the photographing optical system of the photographing lens and tilts the image plane with respect to the optical axis, it is necessary to prepare a special camera for that purpose.

The alignment observation system 8 is an alignment light source, and the light emitted from this light source is partially used as a light source for fixation because it contains visible light. Reference numeral 9 denotes a target for fixation and alignment consisting of a pinhole, 10 denotes an alignment light projecting lens, and 11 denotes a beam splitter. 12, 14 are alignment imaging lenses, 16 is an alignment reticle projection light source, 17 is a ring-shaped alignment reticle, 19 is a reticle projection lens, and 13 is a beam splitter. Reference numeral 15 denotes a light receiving surface of the CCD camera for alignment. The alignment reticle is not limited to a ring, but may be any as long as alignment is easy.

In addition, this apparatus is designed to be able to photograph the anterior eye section at two or more locations, the slits 1 to 3 are integrally rotated about the optical axis, and the imaging system is a slit projection system 20 to 22. It is structured to rotate in conjunction with the rotation of the slit around the optical axis of the optical disk. In this embodiment, since the light source is an elongated flash tube, the light source 1 is also rotated in consideration of the light amount efficiency. However, an image rotator may be used, or the entire slit projection system may be rotated.

Next, a method of shooting will be described. At the time of photographing, first, an image of the target 9 for fixation and alignment is projected onto the eye 7, and the image is fixed on the subject. On the other hand, the reflection image of the target 9 on the corneal surface is formed on the light receiving surface 15 of the alignment CCD camera by the alignment imaging lenses 12 and 14.
The photographer performs alignment by moving the apparatus left and right and up and down in order to put the corneal reflection image of the optotype 9 into a small circle of the alignment reticle image while watching a monitor (not shown) connected to the CCD camera 15. The alignment in the optical axis direction is performed by moving the apparatus back and forth so that the reflected image becomes the clearest image.

When the alignment is completed by the above operation, the imaging light source 1 is turned on and the slit light is projected on the anterior segment of the subject's eye. The slit cross-sectional image scattered by the anterior segment is taken by the taking lens 20,
The image is projected onto the CCD camera 22 by the anamorphic lens 21 and an image thereof is taken. Most distortion of the captured image has been corrected by the anamorphic lens 21,
Not completely corrected. Therefore, after the image once photographed is stored in the frame memory, the distortion is corrected.

FIG. 2 shows an anterior ocular segment cross-sectional image captured by the present apparatus and corrected for distortion. 24 is the cornea, 25 is the anterior chamber, 26 is the iris, 27
Denotes a crystalline lens, and 28 denotes an anterior chamber angle.

A method of obtaining an anterior chamber angle, an anterior chamber depth, an anterior chamber cross-sectional area, an anterior chamber volume, and the like from the anterior segment image will be described.

As described above, a still image is stored in the frame memory and the distortion is corrected. At the same time as displaying this on the monitor television, a cursor (arrow) operable by a coordinate input device such as a mouse tablet is displayed on the same screen.
With this, each part of the anterior ocular segment image is pointed by the cursor,
The position coordinates are read.

Next, the measurement of the corner angle will be specifically described with reference to FIG.

Move the cursor along the posterior corneal curve and read the coordinates of at least three points (the minimum number required to determine the curvature of the arc is three). Similarly, the coordinates of at least three points are read along the front boundary of the iris. Thereby, the intersection 0 between the extension line of the posterior corneal curve and the extension line of the iris is obtained.
And find each tangent at this intersection. An angle at which these two tangents intersect is determined and defined as a corner angle (θ).

As a method of measuring the anterior chamber depth, the curvatures of the posterior corneal curve and the anterior lens curve are obtained as described above. As shown in FIG. 4, the vertex of the posterior corneal curve is obtained, the intersection of the straight line connecting this vertex and the curve center point (O 1 ) and the anterior lens curve is obtained, and the distance between the intersection and the vertex of the posterior corneal curve is obtained. Is the anterior chamber depth (d).

Measurement of the anterior chamber cross-sectional area, as shown in FIG.
This is nothing but determining the area of the region (hatched) surrounded by the iris and the front surface of the lens. Therefore, a plurality of coordinate positions along the boundary line of this area are input, and the coordinate points are connected by a spline curve or the like to obtain a continuous line indicating the boundary, and the area within the area is obtained.

The anterior chamber volume is determined by connecting the two cross sections three-dimensionally and smoothly from the anterior segment cross-sectional images A and B taken from at least two locations as shown in FIG. The chamber volume can be calculated. In order to improve the measurement accuracy of the anterior chamber volume, the number of cross sections to be imaged may be increased.

In the above-described embodiment, the method of pointing each part of the anterior ocular segment image with the cursor and reading the position coordinates thereof is adopted in consideration of the simplest method, but other methods may be adopted.

In the present embodiment, the image distortion is corrected and displayed on the monitor, but may be corrected only at the time of calculation.

〔The invention's effect〕

According to the present invention, it is possible to easily and quantitatively measure an anterior chamber shape such as an anterior chamber corner angle and an anterior chamber depth.

[Brief description of the drawings]

FIG. 1 is a schematic view of the arrangement of an optical system according to an embodiment of the present invention, FIG. 2 is a view showing a cross-sectional image of an anterior segment taken, and FIGS. It is a figure explaining each measurement of a sectional area and anterior chamber volume. 1 light source for photography, 3 slits, 5 projection slit lens, 20 photography lens, 21 anamorphic lens, 22 light receiving surface of CCD camera

Continuation of the front page (56) References JP-A-61-45725 (JP, A) JP-A-60-145121 (JP, A) "Handbook of Ophthalmic Examination" Medical College P420-421

Claims (3)

(57) [Claims]
1. An anterior ocular segment imaging apparatus in which an imaging optical system and a slit projection surface are arranged according to the principle of Scheimpflug, wherein the slit length is set to be larger than the anterior chamber diameter, and the eye to be inspected is slit-cut in the meridian direction of the eye to be inspected. A slit cutting unit, an image distortion correction unit that processes an image captured by the imaging optical system and corrects image distortion, an anterior chamber corner angle, an anterior chamber based on the image corrected by the image distortion correction unit Means for reading position information of the displayed image in order to calculate at least one of the cross-sectional areas.
2. An anterior ocular segment imaging apparatus in which an imaging optical system and a slit projection plane are arranged according to the principle of Scheimpflug, wherein the slit length is set to be larger than the anterior chamber diameter, and the eye to be inspected is slit-cut in the meridian direction of the eye to be inspected. A slit cutting unit; a rotating unit that rotates the slit cutting unit and the photographing optical system around an optical axis; and an image distortion correction unit that processes a plurality of images photographed by the photographing optical system and corrects image distortion. Means for calculating the anterior chamber volume based on the plurality of images corrected by the image distortion correcting means, and means for reading the position information of the displayed image. Shooting equipment.
3. An anterior ocular segment photographing apparatus in which a photographing optical system and a slit projection surface are arranged according to the Scheimpflug principle, wherein a photographing optical system having a correction lens for correcting image distortion due to the optical system and a photoelectric image pickup device. A slit cutting unit that slits the eye to be examined in the meridian direction of the cornea; an image correction unit that optically stores an image captured by the imaging optical system and processes a stored photoelectrically captured image to correct the image; Means for reading the position information of the displayed image in order to calculate the anterior chamber depth based on the displayed image.
JP63117483A 1988-05-13 1988-05-13 Anterior segment imaging device Expired - Fee Related JP3013356B2 (en)

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JP63117483A JP3013356B2 (en) 1988-05-13 1988-05-13 Anterior segment imaging device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP63117483A JP3013356B2 (en) 1988-05-13 1988-05-13 Anterior segment imaging device

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JPH01285241A JPH01285241A (en) 1989-11-16
JP3013356B2 true JP3013356B2 (en) 2000-02-28

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2668893A1 (en) 2012-05-30 2013-12-04 Nidek Co., Ltd Ophthalmologic photographing apparatus
WO2014004818A1 (en) 2012-06-27 2014-01-03 Broadspot Imaging Corporation Multiple-view composite ophthalmic iridocorneal angle imaging system
WO2019240148A1 (en) * 2018-06-13 2019-12-19 株式会社トプコン Slit lamp microscope and ophthalmic system

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4878604B2 (en) * 2007-03-22 2012-02-15 国立大学法人山梨大学 Ophthalmic examination equipment
JP5285994B2 (en) * 2008-08-08 2013-09-11 興和株式会社 Ophthalmic equipment
JP5175781B2 (en) * 2009-03-23 2013-04-03 株式会社トーメーコーポレーション Anterior segment 3D image processing device
JP5421136B2 (en) * 2010-01-21 2014-02-19 株式会社ニデック Anterior segment sectional image analysis method and anterior segment sectional image analysis apparatus
DE102011082363B4 (en) * 2010-10-28 2018-03-29 Oculus Optikgeräte GmbH Illumination system, ophthalmic analyzer and method
JP6304928B2 (en) * 2012-03-30 2018-04-04 キヤノン株式会社 Anterior segment tomogram analysis method and anterior segment tomogram analyzer

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60145121A (en) * 1984-01-04 1985-07-31 Tokyo Optical Eye obstacle examination apparatus
JPH041622B2 (en) * 1984-08-10 1992-01-13 Topcon Corp

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
「眼科検査法ハンドブック」医学書院 P420−421

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2668893A1 (en) 2012-05-30 2013-12-04 Nidek Co., Ltd Ophthalmologic photographing apparatus
US8967807B2 (en) 2012-05-30 2015-03-03 Nidek Co., Ltd. Ophthalmologic photographing apparatus
WO2014004818A1 (en) 2012-06-27 2014-01-03 Broadspot Imaging Corporation Multiple-view composite ophthalmic iridocorneal angle imaging system
EP2866640A1 (en) * 2012-06-27 2015-05-06 Broadspot Imaging Corporation Multiple-view composite ophthalmic iridocorneal angle imaging system
EP2866640A4 (en) * 2012-06-27 2015-10-28 Broadspot Imaging Corp Multiple-view composite ophthalmic iridocorneal angle imaging system
WO2019240148A1 (en) * 2018-06-13 2019-12-19 株式会社トプコン Slit lamp microscope and ophthalmic system

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Publication number Publication date
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