JPH09201334A - Ophthalmological device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ophthalmological device in which conditions of a lacrimal liquid surface layer of a subject eye can be objectively evaluated. SOLUTION: An image of interference patterns formed in a lacrimal liquid surface layer is picked up by a CCD camera 7, and diagnosis of a subject eye is made based on the interference patterns. In the image of the interference patterns, plural areas are set by an area setting means 13, and a color phase of each area is operated by a color phase operating device 9. Evaluation of the lacrimal liquid surface layer is performed by a grade determining circuit 10 based on the operated color phase. In this constitution, grading which conventionally has been made by a diagnoser can be performed by image processing, thereby subjectivity is not included in diagnosis, but reliability can be improved.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an ophthalmologic apparatus,
In particular, the present invention relates to an ophthalmologic apparatus capable of diagnosing dry eye by observing the surface layer of tear fluid of an eye to be examined.

[0002]

2. Description of the Related Art In recent years, VDT (visual display termina)
l) The number of dry eye patients is increasing due to the increase of workers and the drying of rooms by air conditioning. When dry eye occurs, corneal epithelial disorder, conjunctival disorder, and various other ophthalmic diseases may occur at the same time. Diagnosis of dry eye is an important theme in ophthalmic diagnosis.

Conventionally, the diagnosis of dry eye has been performed by a vital stain test (Rose Bengal method, fluorescein method), a tear volume test (Schirmer test, cotton thread method, BUT, clearance test), etc. The suffering of the subject was unavoidable because of the contact. Then, JP-A-62-222143 and JP-A-7-1361
No. 20, Japanese Patent Application No. 6-189734, etc., a method of irradiating the eye to be examined with light to observe interference fringes in the tear film has been attempted. In these devices, a color image of an interference pattern (interference pattern of a color that changes to a rainbow color) formed on the surface of the tear fluid of the eye to be examined is photoelectrically converted by the photoelectric conversion element of the light receiving optical system, and a color image of the interference pattern is obtained. Since the information is displayed on the display means, the diagnosing person can know the state of the surface layer of the tear fluid by observing the interference pattern, and can make a simple diagnosis of dry eye.

[0004]

However, in the conventional apparatus, the diagnosis for that purpose is made by the diagnostician directly looking at the color pattern on the screen to evaluate the grade of the dry eye and depends on the subjectivity of the diagnostician. Therefore, there was a problem that grade classification also differs depending on the viewer.

The present invention has been made to solve the above problems, and an object thereof is to provide an ophthalmologic apparatus capable of objectively evaluating the state of the surface layer of the tear fluid of the eye to be examined.

[0006]

In order to solve this problem, the present invention takes an interference pattern formed on the surface layer of the tear fluid of the eye to be examined, and diagnoses the eye to be examined based on the interference pattern. In the configuration, a configuration is provided in which a means for setting a plurality of areas in the captured image of the interference pattern, a means for calculating the hue of each area, and a means for evaluating the tear surface layer based on the calculated hue are provided. Adopted.

With such a configuration, since the grade classification conventionally performed by a diagnostician can be performed by image processing, subjectivity is not included in the diagnosis and reliability is improved.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a schematic configuration of an ophthalmologic apparatus according to the present invention. In FIG. 1, a reference numeral 1 is a white light source for illuminating an eye E to be inspected and is constituted by a halogen lamp or the like. The light emitted from the white light source 1 passes through the mask 2 that limits the illumination visual field, and then illuminates a predetermined point P on the eye E through the lens 3, the half mirror 4, and the lens 5. The position of the point P is selected as the outermost lipid layer of the tear fluid on the cornea of the eye E to be examined. The light amount of the white light source 1 can be adjusted by a light control circuit (not shown).

Reflected light from point P (reflected light on the front and back surfaces of the outermost lipid layer of the tear fluid) forms various interference patterns depending on the thickness of the lipid layer and other conditions. The reflected light forming the interference pattern is received by the color CCD camera 7 via the lens 5, the half mirror 4, and the lens 6, and the color image of the interference pattern is photoelectrically converted by the CCD camera 7, and its RG
The B video signal is stored in the video storage device 8. The stored interference pattern image is displayed on the monitor 12 and is also input to the hue calculation device 9 that calculates the hue in each area based on the RGB video signal information. The hue calculation device 9 is connected to the grade determination circuit 10 and determines the dry eye grade based on the hue of the interference pattern. The result is displayed on the output display circuit 11,
It is also displayed on the monitor 12. Further, an area (point) setting device 13 is connected to the video storage device 8, and the screen area of the interference pattern can be divided into a plurality of areas.

In such a structure, the white light source 1 is turned on, and the light from the light source through the mask 2, the lens 3, the half mirror 4, and the lens 5 is the outermost layer of the tear film on the cornea of the eye to be examined. It is projected on the layer. The reflected light from the front surface and the back surface passes through the lens 6 and the CCD of the color CCD camera 7
The light is received by the light receiving surface, and a color image having an interference pattern is received.
Such an interference pattern is shown in FIG.
(A) shows an interference pattern of a healthy person, and (B) shows an interference pattern of a dry eye patient.

The hue calculator 8 calculates the hue in each area set by the area setting device 13 based on the RGB video signal information. That is, when each point is set, the image corresponding to the point is stored in the video storage device 8.
The hue calculation device 8 obtains the hue of the image at that point by the following calculation.

R = IR / (IR + IG + IB) G = IG / (IR + IG + IB) B = IB / (IR + IG + IB) where R, G and B mean red hue, green hue and blue hue, respectively, and IR , IG and IB mean R video signal voltage, G video signal voltage and B video signal voltage, respectively.

The arrangement of the points on the screen is as shown in FIG. 3, for example. Here, the size of the predetermined point is one pixel, but the calculation of R, G, B may be performed, for example, with 10 pixels as one block. Although the number of points is 12 here, the larger the number of points, the better the result.

Each hue R calculated by the hue calculation device,
The numerical results of G and B are shown in FIG. From this table,
The red component (R) is strong at two points 6 and 10, and the interference pattern is red at this part. At other points, there is a large difference in the R, G, and B level values. Since there is no interference pattern, it can be understood that the interference pattern is close to white.

The grade determination circuit 10 makes the following determination based on the result of such calculation.

When R, G and B are 0.3 or more at all points ... Grade 1 R is 0.5 or more at two or more points, and at all other points R, G and B When G and B are less than 5 ... Grade 2 R is 0.5 or more with two or more points, and B is 0.5 or more with another two or more points. When ... grade 3 When the above result is discriminated according to this grade classification example, R shows 0.7 at two or more points, which corresponds to grade 2.

This grading is merely an example. The number of grades can be further increased by increasing the number of combinations of R, G, and B. Further, such grade classification makes it possible to evaluate the dry eye of the subject's eye.

The result of grade discrimination is displayed on the output display device 11 and also on the monitor 12.

[0020]

As described above, according to the present invention, a plurality of areas are set in the photographed image of the interference pattern formed on the tear liquid surface layer of the eye to be inspected, and tears are calculated based on the calculated hue of each area. Since the liquid surface layer is evaluated, it is possible to perform grade classification, which was conventionally performed by a diagnostician, by image processing.
An excellent effect is obtained.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an overall configuration of an ophthalmologic apparatus of the present invention.

FIG. 2 is an explanatory diagram showing an image of an interference pattern observed with the ophthalmologic apparatus of FIG.

FIG. 3 is an explanatory diagram showing set points.

FIG. 4 is a table showing hue values at each point.

[Explanation of symbols]

 1 White Light Source 7 CCD Camera 8 Video Storage Device 9 Hue Calculator 10 Grade Discrimination Circuit 11 Output Display Device 12 Monitor 13 Area Setting Device

Claims (1)

[Claims] 1. An ophthalmologic apparatus which images an interference pattern formed on a tear liquid surface layer of an eye to be inspected and diagnoses the eye to be inspected based on the interference pattern, wherein a plurality of areas are set in a captured image of the interference pattern. An ophthalmologic apparatus comprising: a unit, a unit that calculates a hue of each area, and a unit that evaluates a tear surface layer based on the calculated hue.