JP2004016816A - Corneal shape analysis apparatus obtained by unifying pupil testing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a corneal shape analysis apparatus which examines a pupil by using a single apparatus. <P>SOLUTION: This apparatus is provided with: a video camera (1) which is arranged in series with an optical system provided with lenses (2 and 3); and an external Placido disk (9) is provided with a fixation LED (4), an infrared fixation LED (5), a Neon glow lamp (6), two beam splitter plates (7 and 8). An infrared LED (10) is arranged on a lateral side of the Placido disk (9) for providing grazing light for examining the pupil. Since the horizontal-direction LED (10) which is the infrared LED (10) and the fixation LED (5) are of infrared types and never interfere with a light source for corneal examination using a frequency in a visible light region. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
It is known that a corneal examination and a pupil examination are basically performed in the field of ophthalmology. In fact, the data obtained from these tests is of particular importance not only in terms of diagnosis, but also in that it can provide extremely accurate data before performing refractive surgery.
[0002]
According to the prior art, a corneal examination was performed by a device known as a corneal shape analyzer.
[0003]
This known device comprises, as shown in FIG. 1, a video camera 1 for taking images passing through lenses 2 and 3. The device also includes a fixation LED (light emitting diode) 4, and light from this LED 4 is reflected on the surface of the half-silver-plated glass plate 5 on the silver-plated side. The device is provided with a neon glow lamp 6 which, when lit, illuminates a placid disc or keratography 7 which is fixed by a fixture 8 to a frame 9 of the device. A small monitor 10 is installed outside the frame, and is connected to the video camera 1 by a connection wire 11 to enable quick imaging. The wire 11 is connected to another monitor or computer. In use of the device, the patient's eye 12 is placed in the examination position and wires 13 and 14 are electrically connected to the LED 4 and the neon glow lamp 6, respectively. In use, the glass plate 5 illuminated by the LEDs 4 reflects light from the point at which the patient is looking outside, ie from the fixation center. In this state, a first Purkinje image is formed on the cornea. This image is taken by a video camera via an optical system, and the video camera sends the image to a small monitor 10 via a wire 11. This digital image is then sent to a computer equipped with system software, allowing analysis of the image.
[0004]
The device according to the invention differs from the above-mentioned devices using the usual techniques used by most manufacturers, in that the pupil can also be examined by a single device, and also varies from patient to patient, It is possible to specify the center of the pupil, which changes even with a change in light.
[0005]
In addition, pupil morphology that is unique and changing for each patient can be determined without interrupting the image.
[0006]
In particular, the apparatus according to the present invention can capture changes in the pupil when the illumination conditions are changed, analyze the area of the pupil, and, for each of the eyes to be inspected, for each illumination condition. The center of the pupil can be specified.
[0007]
Thereby, the fixation center and the pupil center can be obtained at the same time by the same device.
[0008]
Obtaining these separate and distinct points is fundamental and important in refractive surgery performed with lasers.
[0009]
In this refractive surgery, an excimer laser is generally used. The excimer laser is a very accurate device.By using two data sources, only the fixation point is considered in the operation, and the pupil area change, and therefore the center of the pupil, cannot be known continuously. Good surgical results are obtained compared to the surgical results.
[0010]
In fact, the area of the pupil varies from the maximum value obtained in the absence of illumination to the minimum value obtained when the brightness of the lamp present in the device is maximum, so that the patient always observes the fixation point. As such, the corneal curvature axis is always considered.
[0011]
Obviously, all intermediate positions can be known by taking a picture with a video camera, and these intermediate positions are stored for use in computer analysis.
[0012]
As shown in FIGS. 3 to 6, the corneal shape analyzer according to the present invention includes a video camera 1 arranged in series with an optical system including lenses 2 and 3. A fixation LED 4, an infrared fixation LED 5, a neon glow lamp 6, and two beam splitter plates 7, 8 are provided. The outer part is provided with a placid disc or keratography 9 with infrared LEDs 10 positioned laterally.
[0013]
The LED 10 was positioned in this position to allow for the provision of glazing light for pupil examination.
[0014]
The LED 10 and the fixation LED 5 are of an infrared type and do not interfere with a light source used for a cornea examination. In corneal examination, frequencies in the visible light region are used.
[0015]
The above-mentioned placid disk 9 is attached to an apparatus frame 12 by bolts 11.
[0016]
A small monitor 13 is connected to the outside of the frame, and is connected to the video camera 1 by wires 14.
[0017]
This wire 14 allows the signal to be sent to another monitor externally. The external monitor is connected to a computer having system software capable of performing image analysis.
[0018]
The various LEDs are connected to one another using wires 15 via a network connection.
[0019]
The neon glow lamp is connected to a potentiometer 17 by a wire 16 and can change the luminous intensity.
[0020]
By using the corneal shape analyzer according to the present invention, a corneal examination and a pupil examination can be simultaneously performed on the eye 18 of the patient to be examined.
[0021]
In the corneal shape analyzer according to the present invention, the infrared LEDs 10 are arranged at different positions according to the necessity in use.
[0022]
In one embodiment (FIG. 5), the infrared LED 10 a is arranged inside the placid disk 9.
[0023]
In the second embodiment (FIG. 6), a group of infrared LEDs 10 b is arranged in parallel with the lamp 6.
[0024]
In the third embodiment (FIG. 7), a single infrared LED 10c is provided together with a beam splitter plate 10d having the same function as the above application.
[0025]
Although the apparatus of the present invention has been illustrated in different embodiments, the present invention is not limited to the drawings of sheets 1 to 6.
[Brief description of the drawings]
FIG. 1 is a transverse sectional view of a conventional corneal shape analyzer.
FIG. 2 is an overall perspective view of a corneal shape analyzer according to the present invention.
FIG. 3 is a longitudinal sectional view of the corneal shape analyzer according to the present invention at a position passing through the center of a Placido disk.
FIG. 4 is a transverse cross-sectional view of the corneal shape analyzer according to the present invention (a line AA in FIG. 3).
FIG. 5 is a longitudinal sectional view showing the first embodiment of the present invention.
FIG. 6 is a longitudinal sectional view showing a second embodiment of the present invention.
FIG. 7 is a longitudinal sectional view showing a third embodiment of the present invention.
[Explanation of symbols]
1 Video camera 2, 3 Lens 4, 5, 10 LED
6 Neon glow lamp 7, 8 Beam splitter 9 Placid disk

Claims (7)

A corneal shape analyzer integrated with a pupil examination device, comprising a video camera (1) arranged in series with an optical system having lenses (2, 3) and an outer platinum disk (9),
A fixation LED (4), an infrared fixation LED (5), a neon glow lamp (6), and two beam splitter plates (7, 8);
An infrared LED (10) is placed beside the placido disc (9) to provide glazing light for pupil examination;
A corneal shape analyzer characterized in that the lateral LED (10) and the fixation LED (5) are of an infrared type and do not interfere with a corneal examination light source using a frequency in the visible light region. 2. The corneal shape analyzer integrated with the pupil inspection device according to claim 1, wherein a corneal inspection and a pupil inspection are simultaneously performed on the eye (18) of the patient to be inspected during use. The corneal shape analyzer according to claim 1, wherein the infrared LED (10) is provided at a different position according to a necessity in use. The corneal shape analyzer integrated with the pupil examination device according to claim 1, wherein an infrared LED (10a) is provided inside the platinum disk (9). The corneal shape analyzer integrated with the pupil inspection device according to claim 1, wherein a group of infrared LEDs (10b) are provided in parallel with the lamp (6). The corneal shape analyzer integrated with the pupil inspection device according to claim 1, wherein a single infrared LED (10c) is provided together with the beam splitter plate (19). The corneal shape analyzer integrated with the pupil inspection device according to claim 1, wherein the center of the pupil is photographed while changing light, and the fixation center and the pupil center are simultaneously provided.

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