JPH04224731A - Eye pressure measuring apparatus - Google Patents

Abstract

PURPOSE:To provide an eye pressure measuring apparatus which can measure and display an eye pressure value accurately. CONSTITUTION:This apparatus is made up of a means of projecting a luminous flux for detection of alignment on an eye E to be inspected, a photodetecting means to detect the reflected alignment luminous flux from the eye E to be inspected, a means which is adapted to deform the cornea Ec of the eye E to be inspected by blowing an air flow from a nozzle 5 according to an output from the photodetecting means, a means which is adapted to compute an eye pressure value detecting how the cornea Ec of the eye E to be inspected deforms and a means of displaying the eye pressure value. A mark is applied to the eye pressure value to be displayed according to an output from an alignment luminous flux detecting means thereby enabling the displaying of reliability of an eye pressure data.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to an intraocular pressure measuring device, more specifically, a device for deforming the cornea of an eye to be examined by blowing airflow in accordance with the output from a light receiving means that receives an alignment light beam reflected from the eye to be examined. The present invention relates to an intraocular pressure measuring device that measures intraocular pressure.

0002

BACKGROUND OF THE INVENTION For example, intraocular pressure measuring devices are known that measure intraocular pressure by injecting fluid onto the corneal surface and measuring the time until corneal applanation or the pressure signal when the corneal deformation detection signal reaches its maximum. (Japanese Patent Application No. 192331, Japanese Patent Publication No. 63-58577).

[0003] In such an ophthalmological apparatus, an airflow generated by a constant pressure is blown onto the center of the cornea of the eye to be examined, and the time required for the cornea to deform into a flat surface or the time when the corneal deformation detection signal reaches its maximum is measured. The intraocular pressure is calculated from the pressure signal. Whether or not the cornea has been applanated is determined by the maximum amount of light received by a light receiving element that receives light from a light source such as an LED through a lens. In this case, the light source, lens,
A measurement optical system consisting of a light receiving element is incorporated into the apparatus in a predetermined positional relationship with an alignment optical system so that the angle of incidence and the angle of reflection on the applanated corneal surface are equal.

0004

[Problem to be Solved by the Invention] In this case, if the intraocular pressure measuring device and the eye to be examined are not in an accurate predetermined positional relationship, the measurement error will increase. It is positioned at a predetermined operating position such that the above-mentioned reflection occurs during corneal applanation with respect to the eye to be examined. In order to detect this alignment, the examiner visually matches the subject's eye on the observation TV monitor with the positioning mark and searches for the best point of alignment.

However, there is a limit to the ability to perform alignment while visually observing the TV monitor, and for this reason, it is necessary to forcibly operate the switch of the airflow blowing means to blow airflow to the eyes. I was getting pressure values. However, accurate intraocular pressure values cannot be obtained unless airflow is applied to the center of the subject's eye, so if the intraocular pressure value is obtained by forcibly blowing airflow even when the alignment is not perfect, it may be difficult to obtain reliable intraocular pressure values. In some cases, the intraocular pressure value was missing, making it difficult to distinguish it from the accurate intraocular pressure value on the monitor.

[0006] Therefore, the present invention was made to solve these problems, and an object of the present invention is to provide an intraocular pressure measurement device that can accurately measure and display intraocular pressure values.

[0007]

[Means for Solving the Problems] In order to solve this problem, the present invention provides means for projecting an alignment detection light beam onto the eye to be examined, a light receiving means for receiving the alignment reflected light beam from the eye to be examined, and a light receiving means for receiving the alignment reflected light beam from the eye to be examined. means for blowing airflow from a nozzle according to the output from the light receiving means to deform the cornea of the eye to be examined; means for detecting the deformed state of the cornea of the eye to be examined to calculate an intraocular pressure value; and means for displaying the intraocular pressure value. A configuration is adopted in which a mark is attached to the displayed intraocular pressure value according to the output from the light receiving means.

[0008]

[Operation] With this configuration, it is possible to attach a mark to the intraocular pressure value calculated according to the output from the light receiving means indicating the alignment state, so that the obtained intraocular pressure value can be marked with a mark indicating whether it is reliable or inappropriate. A mark indicating gender can be attached, and the accuracy of intraocular pressure measurement can be improved.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained in detail below according to embodiments shown in the drawings.

FIG. 1 shows an example of an intraocular pressure measuring device. In the figure, the reference numeral 1 is a light source for alignment detection, and the light from this light source 1 is transmitted through a mirror 2.
After being reflected, the light is irradiated onto the cornea Ec of the eye E to be examined via an optical system consisting of lenses 3 and 4.

The light beam reflected by the cornea Ec passes through the original optical system, is reflected by the mirror 6, and is received by the photoelectric conversion element 7. The photoelectrically converted output signal is converted into a digital signal by an A/D converter 9 and then input to an arithmetic processing circuit 10 . The image of the cornea Ec of the eye to be examined illuminated by the observation illumination light source 14 enters the observation camera 8 through the optical system of the lenses 4 and 3. The light beam incident on the observation camera 8 is converted into a video signal, which is combined in a composite circuit 12 with the intraocular pressure value obtained from the character generation circuit 11 by air blowing from the nozzle 5, and output to the TV monitor 13.

[0012] Drive circuit 1 connected to arithmetic processing circuit 10
When the airflow is blown from the nozzle 5 by 7, the cornea of the eye to be examined is deformed, and when it deforms until it becomes flat, the light receiving element 1
6 detects this, and the arithmetic processing circuit 10 calculates the intraocular pressure. A manual switch 15 for manually operating a drive circuit 17 is connected to the arithmetic circuit 10, as will be described later.

Next, the operation of the apparatus having such a configuration will be explained.

[0014] First, the patient rests his forehead on the forehead rest and sits in a predetermined position. The alignment detection light source 1 is turned on, and the light from the light source 1 is reflected by the mirror 2, then the lens 3,
The cornea Ec of the eye E to be examined is irradiated via an optical system consisting of four components. The light beam reflected by the cornea Ec passes through the original optical system, is reflected by the mirror 6, and is received by the photoelectric conversion element 7. The photoelectrically converted output signal is converted into a digital signal by an A/D converter 9 and then input to an arithmetic processing circuit 10 .

The arithmetic processing circuit 10 displays on the monitor 13 the state in which the eye to be examined is aligned with the apparatus. For example, as shown in FIG. 2, alignment points 20 are displayed according to the amount of light received by the photoelectric conversion element 7. The examiner observes this alignment point 20 and makes further adjustments to achieve alignment so that it is at the best point (for example, the center). The drive circuit 17 is driven automatically or manually so that the alignment is performed at the best point in this manner, and the airflow is ejected from the nozzle 5. When the airflow is blown from the nozzle 5, the cornea of the eye to be examined is deformed. When the cornea deforms until it becomes flat, the light receiving element 16 detects this and the arithmetic processing circuit 10
calculates intraocular pressure based on the time until corneal applanation or the pressure signal when the corneal deformation detection signal is at its maximum.

The intraocular pressure value calculated by the calculation processing circuit 10 is
The character generation circuit 11 converts the data into characters (numeric values) and inputs them into the composite circuit 12. The image of the cornea Ec of the eye to be examined illuminated by the observation illumination light source 14 is input to the observation camera 8 through the optical system of lenses 4 and 3, and is converted into a video signal. It is combined with the pressure value and output to the TV monitor 13. This state is illustrated in FIG. 2, where the calculated intraocular pressure value 21 is displayed on the monitor 13.

As mentioned above, airflow is normally blown when the alignment point reaches the best point, but since it takes time to align to the best point, when the alignment is almost achieved, the best alignment point is reached. Intraocular pressure may be measured by blowing airflow even if alignment is not required. Since the alignment state is related to the amount of light received by the photoelectric conversion element 7, by attaching the mark 23 to the intraocular pressure value 21 according to the amount of light received by the photoelectric conversion element 7, the reliability of the calculated intraocular pressure value can be increased. can be displayed. For example, when the output from the photoelectric conversion element is small, the intraocular pressure value is displayed with an unreliable mark (x mark), and when the output from the photoelectric conversion element is appropriate, the intraocular pressure value is displayed. By displaying a proper mark (for example, a circle mark), it becomes possible to distinguish and display the reliability of the intraocular pressure value.

Although the above-mentioned embodiment has been explained using an intraocular pressure measuring device as an example, the present invention is not limited thereto, and can be used in other ophthalmological measuring devices that require a high degree of alignment.

[0019]

As explained above, the present invention includes a means for projecting an alignment detection light beam onto the subject's eye, a light receiving means for receiving the alignment reflected light flux from the subject's eye, and a nozzle according to the output from the light receiving means. A method for displaying intraocular pressure comprising means for blowing airflow to deform the cornea of the eye to be examined, means for detecting the deformed state of the cornea of the eye to be examined to calculate an intraocular pressure value, and means for displaying the intraocular pressure value. Since the value is marked according to the output from the light receiving means, it is possible to mark the intraocular pressure value calculated according to the output from the light receiving means indicating the alignment status, and the reliability of the data can be displayed. become.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of one embodiment of the present invention.

FIG. 2 is an explanatory diagram when the intraocular pressure measurement results are displayed on a monitor.

[Explanation of symbols]

1 Light source for alignment detection 5 Nozzle 8 TV camera 10 Arithmetic processing circuit 12 Composite circuit

Claims (3)

[Claims] 1. A means for projecting an alignment detection light beam onto the eye to be examined; a light receiving means for receiving the alignment reflected light beam from the eye to be examined; means for deforming the cornea of the eye to be examined, means for calculating an intraocular pressure value by detecting the deformed state of the cornea of the eye to be examined, and means for displaying the intraocular pressure value; An intraocular pressure measuring device characterized by attaching marks according to output. 2. The intraocular pressure measuring device according to claim 1, wherein when the output from the light receiving means is small, an unreliable mark is added to the intraocular pressure value and displayed. 3. The intraocular pressure measuring device according to claim 1, wherein when the output from the light receiving means is appropriate, an appropriate mark is attached to the intraocular pressure value and the intraocular pressure value is displayed.