JPH012623A - Ophthalmology measuring device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to an ophthalmological measuring device, and more specifically, to an ophthalmological measuring device, which irradiates a laser beam through an optical system to a predetermined point in the eye, particularly in the anterior chamber, and to detect the laser beam from within the eye. The present invention relates to an ophthalmological measurement device that measures ophthalmological diseases by detecting scattered light.

[Prior Art] Measuring the number of floating particles in the anterior chamber is extremely important in determining intraocular inflammation, ie, aqueous humor. Conventionally, visual judgment by grading using a slit lamp microscope has been frequently used, while photographic measurement has been reported as a quantitative method, but a method that can be easily applied clinically has not yet been developed.

[Problems to be solved by the invention] Conventional visual judgment has the problem that the judgment criteria vary depending on individual differences and the data lacks novelty.To solve this problem, a laser beam is irradiated into the eye. The number of floating objects in the anterior chamber is quantified by receiving and analyzing the scattered light from there. However, the conventional method has a problem in that the volume of the measuring section is limited and the measurement accuracy deteriorates.

Therefore, the present invention was made to solve these problems. It is an object of the present invention to provide an ophthalmological measuring device capable of measuring intraocular floating matter using a J-1 method and with high precision.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention focuses a laser beam on a predetermined point in the eye, preferably a predetermined point in the anterior chamber,
We adopted a configuration in which this laser light is scanned horizontally and vertically to receive the laser scattered light from within the eye.

[Function] In such a configuration, since the laser beam is scanned two-dimensionally, the measurement volume can be increased and measurement accuracy can be improved.

[Example] Hereinafter, the present invention will be described in detail based on the example shown in the drawings.

1 to 3 schematically show the configuration of an ophthalmological measuring device according to the present invention. In the figure, what is indicated by the reference numeral 1 is a laser light source composed of helium neon, argon, etc. A laser light source 1 is arranged on a pedestal 2. The light from the laser light source 1 passes through a laser filter 3,
The light is focused on one point in the anterior chamber 11a of the eye 11 via the vertical scanning mirror 4, the horizontal scanning mirror 4', the prism 5, the prism 6, the lens 7, the beam splitter 8, the lens 9, and the prism 10.

This laser projector is provided with a slit light light source 12, and the light from this light source 12 is transmitted to a slit light shutter 13.
, through the slit 14, the beam splitter 8, the lens 9,
A slit image is formed on the anterior chamber 11a through the prism 10. Since the light from the laser light source mentioned above is focused into a dot shape, this slit image is used to illuminate the surrounding area and easily confirm the position of the convergence point.

Further, the slit width and slit length of the slit 14 can be adjusted or switched via an adjustment knob 15 and a switching knob 16, respectively.

A part of the laser scattered light from the measurement point in the anterior chamber 11a passes through the detection unit 290 and the objective lens 20, is split by the beam splitter 21, and part of it passes through the mask 26 having a lens 22, a prism 23, and a slit 26a for photoelectric conversion. The light enters a photomultiplier tube 27 that functions as an element.

Further, the other scattered light split by the beam splitter 21 can be observed by the examiner 33 through the eyepiece lens 32 via the variable magnification lens 30 and prisms 31 and 34.

Further, the output of the photomultiplier tube 27 is inputted to a counter 40 via an amplifier 28', and the intensity of scattered light detected by the photomultiplier tube is counted as the number of pulses per unit time. The output of this counter 40, ie, the number of sampling times and the total number of pulses, is stored in the memory 25 allocated for each unit time. The data stored in the memory 25 is subjected to arithmetic processing as described later by the arithmetic unit 41,
The number of floaters in the anterior chamber is calculated.

The vertical and horizontal scanning mirrors 4.4' are also connected to sawtooth wave generating circuits 42.4, respectively, as shown in detail in FIG.
2', the mirror drive circuits 43 and 43' for vertical and horizontal scanning are respectively oscillated in the vertical and horizontal directions by the arithmetic unit 41, thereby scanning the laser beam in the horizontal and vertical directions and scanning the laser beam in the anterior chamber. Points can be moved horizontally and vertically. The vertical scanning of the laser beam spot is performed in the vertical direction (vertical direction) with the slit 26a as the center so as not to exceed the slit width, as will be described later.

Further, in the present invention, a fixation lamp 50 made of a light emitting diode or the like and supplied with power from a power source 51 is arranged at a position where the subject can fixate the fixation light. The colored light of the fixation lamp 5o is selected to be different from the colored light of the laser light source 1, such as green if the light from the laser light source is red. Furthermore, the fixation lamp 50 can be rotated in the direction of the arrow by a link mechanism 52 and can be adjusted to a suitable position for the subject.

Further, a human power device such as a joystick 45 equipped with a push button 46 is provided on the pedestal 2.
By operating this, the laser filter 3 and the slit light shutter 13 can be inserted into or removed from their respective optical systems.

Next, the operation of the device configured as described above will be explained. In the measurement, first, the light source 12 is turned on, and a slit image of the slit 14 is formed on a portion of the anterior chamber 11a including the measurement point P via the beam splitter 8.10 and the lens 9. Subsequently, the light from the laser light source is focused on the measurement point P via the optical system.

A part of the light scattered at the measurement point P is directed toward the examiner 33 by the beam splitter 21 for observation, and at the same time enters the photomultiplier tube 27 via the lens 22, prism 23, and mask 26. Ru.

On the other hand, under the control of the arithmetic unit 41, the sawtooth wave generating circuit 42
．． 42', a vertical scanning mirror drive circuit 43, and a horizontal scanning mirror drive circuit 43', the vertical and horizontal scanning mirrors 4.4' are scanned.

In this case, the sawtooth wave generating circuits 42 and 42' generate signals as shown in FIGS. 4A and 4B, respectively, and scan the laser beam. Xi and X2 indicate the measurement start and end points, respectively. Horizontal frequency is Hf, vertical frequency is V
2. When the number of vertical scans is N, the equation H,=V,/H holds true.

The mirror 4.4' is scanned by this signal wave, and the laser beam (beam) is accordingly scanned around the measurement point P. The actual scanning state as seen from the laser projector is shown in Fig. 5. ing. This vertical scanning width is set smaller than the vertical width of the slit 26a in order to remove noise components such as intraocular reflection light and efficiently receive signals based on scattered light.

In this way, the photomultiplier tube receives the laser scattered light incident through the slit 26a, detects the intensity of the scattered light scattered by floating objects in the anterior chamber 11a, and converts it into a pulse train accordingly. The counter 40 counts the number of pulses per unit time, and the counted value is stored in the memory 25 allocated for each unit time.

Since the object to be measured, the floating matter in the anterior chamber, has a size of several microns or more, when the laser beam crosses the floating matter, one peak occurs in the intensity of the scattered light. Therefore, if the measurement unit time is set shorter than the time required for the laser beam to cross the floating object and the floating object is measured, the laser beam will be Since the count value increases only where the floating object is crossed, a waveform as shown in FIG. 6 is obtained. In the figure, each peak is based on scattered light from floating objects. By counting the number of peaks using the arithmetic unit 41, it is possible to measure the number of floating objects present in the volume of the anterior chamber horizontally and vertically scanned by the laser beam.

Note that if the speed at which the laser beam crosses the floating object is constant, the size of the floating object can be calculated from the width of the peak since the beam diameter of the laser beam is known. and 1
To prevent one floating object from being counted twice, the horizontal scanning width is set so that the scanning waveform becomes a sawtooth wave as shown in Figure 5, and the peak interval X is larger than the diameter of the laser beam. decide.

[Effects of the Invention] As explained above, according to the present invention, the laser beam focused on a predetermined point within the eye is scanned in the horizontal and vertical directions, and the scattered laser light is received. The measurement volume within the chamber increases, and measurement accuracy can be improved.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing the external appearance of the device according to the present invention, Fig. 2 is a configuration diagram showing the optical arrangement of the device, Fig. 3 is an optical arrangement diagram showing the laser beam scanning optical system, and Fig. 4 ( A), (B)
5 is a diagram of the signal waveform scanned by the laser beam, FIG. 5 is an explanatory diagram of the scanning locus of the laser beam as seen from the laser projector, and FIG.
The figure is an explanatory diagram showing peaks based on laser scattered light from floating objects.

Claims (1)

[Claims] 1) A laser projector that focuses light from a laser light source on a predetermined point within the eye; a means for scanning the focused laser light in a predetermined direction; A photoelectric conversion element that receives laser scattered light through a mask having a slit of a predetermined width, and a means for processing a signal from the photoelectric conversion element to calculate the number of floating objects in the eye, and the laser beam is horizontally and an ophthalmological measuring device characterized by scanning in the vertical direction. 2) The ophthalmological measurement device according to claim 1, wherein the scanning width of the laser beam in the vertical direction is made smaller than the slit width. 3) The ophthalmological measuring device according to claim 1 or 2, wherein the laser beam is scanned so that the vertical scanning width of the laser beam is larger than the beam diameter of the laser beam.