WO2005037090A1 - Method and device for determining the residual defective vision of a patient - Google Patents
Method and device for determining the residual defective vision of a patient Download PDFInfo
- Publication number
- WO2005037090A1 WO2005037090A1 PCT/EP2004/052815 EP2004052815W WO2005037090A1 WO 2005037090 A1 WO2005037090 A1 WO 2005037090A1 EP 2004052815 W EP2004052815 W EP 2004052815W WO 2005037090 A1 WO2005037090 A1 WO 2005037090A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- light
- patient
- light source
- eye
- wavefront
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Ceased
Links
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B3/00—Apparatus for testing the eyes; Instruments for examining the eyes
- A61B3/10—Objective types, i.e. instruments for examining the eyes independent of the patients' perceptions or reactions
- A61B3/1015—Objective types, i.e. instruments for examining the eyes independent of the patients' perceptions or reactions for wavefront analysis
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B3/00—Apparatus for testing the eyes; Instruments for examining the eyes
- A61B3/02—Subjective types, i.e. testing apparatus requiring the active assistance of the patient
- A61B3/028—Subjective types, i.e. testing apparatus requiring the active assistance of the patient for testing visual acuity; for determination of refraction, e.g. phoropters
Definitions
- the invention relates to a method for determining the residual ametropia of a patient during the subjective refraction determination by means of a phoropter and an eye chart, and a device for carrying out this method.
- the refraction of the human eye can be measured in different ways. In principle, a distinction must be made between two different methods: (a) With the "objective” method, the refraction is determined by analyzing a light beam reflected from the retina of a patient's eye. It can also be used in patients, such as small children or the disabled, who cannot provide any information about their eyesight. (b) With the "subjective” method, the patient himself provides feedback on the quality of the eyesight. To do this, he looks through a phoropter or test glasses at an eye chart. Different optical corrections for both eyes are made separately in the patient's viewing direction. He now decides subjectively, by looking at the optotypes on the eye chart, which correction provides the best vision.
- ametropia can usually be corrected in 0.25 D steps with regard to defocus and astigmatism.
- the refraction is determined via the subjective method and thus the correction of a patient's ametropia is determined subjectively, a targeted, optimal ametropia correction is not possible.
- the patient's subjective perception is always based on his own way of seeing. This is where his experience in recognizing optotypes flows in. An objective measured value for the correction of a visual defect that is really required is not possible with this.
- the object of the invention is therefore to create a method with which the refraction of the human eye can be determined more precisely and the quality of the correction of an ametropia can be improved.
- the invention is also based on the object of providing a device which is suitable for carrying out the method.
- a light spot is generated on the retina of an eye of the patient.
- the light emitted by the light spot is fed to a wavefront sensor.
- the aberrations of the light emitted by the light spot are determined by wavefront analysis.
- the "subjective" and the “objective” method are carried out in parallel, whereby, in contrast to the known procedures, the objective method for determining the residual ametropia is already used during the diagnosis of ametropia using the usual subjective method.
- the light spot on the retina is generated by means of a light source arranged on the side of the eye chart of the phoropter.
- the determination of the residual ametropia continues to be carried out according to the subjective method, since he continues to look at the eye chart only through the phoropter.
- the light spot is preferably generated by light in the invisible wavelength range.
- the light emitted by the light spot on the retina also passes through
- Phoropters before they are fed to the wavefront sensor, existing phoropters that do not have an output that delivers the optical correction value that has just been set can be used unchanged. Furthermore, this measure ensures that only low residual ametropia values have to be detected and calculated by the shaft sensor, so that it can be matched to a narrow spectrum of values and can be equipped with a high sensitivity.
- the light emitted by the light spot is - seen from the patient - preferably coupled out behind the phoropter from the patient's viewing direction. This measure makes it possible to record and determine the residual ametropia away from the eye chart. Existing eye charts can therefore be used unchanged.
- a device for carrying out the method according to the invention comprises a point light source, a wave sensor and a coupling in of the beam emitted by the point light source and coupling out of the beam reflected by the retina of the patient's eye in or out of the patient's viewing direction. Seen from the patient, such a device only needs to be introduced into the beam path behind the phoropter in order to be able to carry out the method according to the invention. All existing diagnostic devices such as phoropters and eye charts can then continue to be used unchanged. The device according to the invention is therefore also suitable for retrofitting purposes of already existing systems.
- the point light source preferably comprises an infrared light source in order not to influence the subjective refraction determination in the visible by additional light incidence in the patient's eye.
- the infrared light source can comprise a laser source.
- the device for coupling in the light emitted by the point light source and coupling out the light reflected by the retina of the patient's eye comprises, in a particularly constructively simple and therefore preferred embodiment, a beam splitter which is transparent in the range of visible light but acts as a mirror in the infrared.
- the wavefront sensor preferably comprises a camera chip.
- a camera chip For example, one that works according to the CCD principle can be considered. Since already existing systems are not designed to supplement a device according to the invention, it is advantageous if the latter has the smallest possible dimensions.
- the point light source is therefore only followed by an optical device for generating a parallel light beam, but not a device for precorrection.
- the device designated as a whole by R in the drawing, is set in the beam path S of an eye A of a patient such that the light reflected by the retina N first passes through a conventional phoropter P and a beam splitter 1 of the device R. It comprises a mirror which is transparent in the range of visible light, but which is reflective in the infrared, and which is arranged at an angle of 45 ° to the optical axis O of the system Eye A - Phoropter P - Eye Chart T.
- optical axis Q of the device R there is an optical system consisting of two mutually displaceable converging lenses 2, 3 and an aperture 4 located between them, which serves to generate a parallel light beam L in the infrared.
- a light source 5 and a polarizer 6 connected downstream of it are provided in front of the optical system, from which the polarized infrared light is fed to a polarization beam splitter.
- the latter is designed in such a way that it reflects the light originating from the light source 5 in the direction of the optical axis Q to the beam splitter 1.
- the device R further comprises a polarizer 8, the direction of polarization of which is rotated by 90 ° with respect to the polarizer 6.
- the light passing through the polarizer 8 then strikes a lens array, from which it is fed to a camera chip 10.
- An infrared light beam with a flat wavefront is generated by the light source 5. This is polarized by means of the polarizer 6 and brought into the beam path along the optical axis Q by means of the beam splitter 7. The polarized infrared light is expanded by means of the telescopically arranged lenses 2, 3 and the diaphragm 4 located between them and is fed to the retina N of the eye A via the mirror 1. It passes through the Phoropter P.
- the infrared light emitted by the retina N then again passes through the phoropter and is supplied to the beam splitter 7 by means of the beam splitter 1 via the lens 2, the pinhole 4 and the lens 3. When it passed through the eye, it became
- Infrared light polarized such that it partially passes through the beam splitter 7 and the polarizer 8.
- the polarizer 8 filters out such light that was generated, for example, by reflections on lenses and does not originate from the fundus.
- the light passing through the polarizer 8 penetrates a lens array 9 and is finally captured by the camera chip 10.
- the wavefront analysis is now carried out by displaying the wavefront in a way that, in addition to the actual shape, also provides information about ametropia of the eye, which can be used directly in ophthalmology. It is based on the Zemike polynomial, which was introduced by F. Zernike in a work on the phase contrast method for wavefront analysis. These Zernike polynomials describe the wave fronts of classic aberrations of optical systems with one polynomial each, as well as the higher orders thereof.
- the method of wavefront analysis is based on a modification of the Hartmann 's screen test.
- the wavefront to be analyzed is divided into many sections using a pinhole array. These individual light sources each represent a main maximum on a screen, the position of which depends on the shape of the incident wavefront.
- the local tilt of the wavefront W (xi, yi) at one point (xi, yi) is via the relationship:
- the information about the wavefront thus lies in the positions of the maxima.
- this front can be determined and represented in the form of Zernike polynomials.
- This method is subject to a measuring range, which is shown below.
- the shift of the maxima always represents an averaging over an aperture.
- a wavefront with discontinuities that fall on the edges of the aperture cannot be recognized as such, since only local tilting is perceived.
- the measuring range of such a wavefront sensor is not unlimited. It is determined by the distance between the screen, the diameter of the screens and the distance between the screens.
- the neighboring slopes of the wavefront must not exceed a maximum angle difference (with a change of sign), since otherwise the focus points can no longer be resolved separately.
- the reconstruction and representation of the wavefront from the measured displacements Dxi and Dyi takes place in three steps: First, the slope of the wavefront is reconstructed using orthogonal polynomials, since it is directly correlated with the individual focus point deviations via the following relationship.
- the function W (x, y) represents the wavefront, a the distance between the lens array and the camera chip and the running parameter i stands for the individual measured maxima.
- the actual wave front is then determined by means of a coefficient comparison from the slope of the wave front obtained and is represented in Taylor polynomials.
- the first step the reconstruction of the slope, takes place via an adjustment method that works according to the method of the smallest quadratic deviation.
- An auxiliary wave front WH is applied, which can be represented by orthogonal polynomials Ln up to order M, equation (3).
- n JL.5 ⁇ [. (, j J. & l ⁇ ⁇ (A))
- Equations (6) can be transformed into:
- the data recorded by the camera chip are first read into the main memory of the computer.
- the images captured in this way are prepared in terms of brightness, contrast and any artifacts.
- the subsequent image analysis is about extracting all relevant parameters from the image data.
- the center of gravity coordinates and the shape of the individual focus points are of particular interest.
- the information from the shape and position of the focus points can be used to make detailed statements about the shape of the wavefront, which is directly related to the aberration.
- the shape of the wavefront can be represented, for example, with the Zernik polynomials often used in optics.
- the results of the wavefront analysis are now brought to the user using graphical display methods.
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Health & Medical Sciences (AREA)
- Medical Informatics (AREA)
- Biophysics (AREA)
- Ophthalmology & Optometry (AREA)
- Engineering & Computer Science (AREA)
- Biomedical Technology (AREA)
- Heart & Thoracic Surgery (AREA)
- Physics & Mathematics (AREA)
- Molecular Biology (AREA)
- Surgery (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Eye Examination Apparatus (AREA)
Abstract
Description
Verfahren und Vorrichtung zur Ermittlung der Restfehlsichtigkeit eines Patienten Method and device for determining the residual ametropia of a patient
Die Erfindung betrifft ein Verfahren zur Ermittlung der Restfehlsichtigkeit eines Patienten während der subjektiven Refraktionsbestimmung mittels eines Phoropters und einer Sehtafel sowie eine Vorrichtung zur Durchführung dieses Verfahrens.The invention relates to a method for determining the residual ametropia of a patient during the subjective refraction determination by means of a phoropter and an eye chart, and a device for carrying out this method.
Die Refraktion des menschlichen Auges kann auf unterschiedliche Arten gemessen werden. Prinzipiell ist zwischen zwei unterschiedlichen Methoden zu unterscheiden: (a) bei der „objektiven" Methode wird die Refraktion durch Analyse eines von der Netzhaut eines Auges des Patienten reflektierten Lichtbündels bestimmt. Sie kann auch bei Patienten -wie Kleinkindern oder Behinderten - genutzt werden, die keine Auskunft über ihr Sehvermögen geben können. (b) bei der „subjektiven" Methode liefert der Patient selbst die Rückmeldung über die Güte der Sehkraft. Hierzu schaut er durch einen Phoropter oder eine Testbrille auf eine Sehtafel. Dabei werden unterschiedliche optische Korrekturen für beide Augen separat in die Blickrichtung des Patienten eingebracht. Er entscheidet nun subjektiv durch Betrachtung der Optotypen auf der Sehtafel, welche Korrektur das optimale Sehvermögen liefert.The refraction of the human eye can be measured in different ways. In principle, a distinction must be made between two different methods: (a) With the "objective" method, the refraction is determined by analyzing a light beam reflected from the retina of a patient's eye. It can also be used in patients, such as small children or the disabled, who cannot provide any information about their eyesight. (b) With the "subjective" method, the patient himself provides feedback on the quality of the eyesight. To do this, he looks through a phoropter or test glasses at an eye chart. Different optical corrections for both eyes are made separately in the patient's viewing direction. He now decides subjectively, by looking at the optotypes on the eye chart, which correction provides the best vision.
Es ist bekannt geworden, die vorbeschriebenen Methoden dahingehend zu kombinieren, um zunächst mittels der objektiven Methode die Refraktion grob zu ermitteln, und anschließend mit der subjektiven Methode die „Feinabstimmung" durchzuführen.It has become known to combine the methods described above in order first to roughly determine the refraction by means of the objective method and then to carry out the “fine tuning” using the subjective method.
Mit den oben beschriebenen Methoden kann die Fehlsichtigkeit üblicherweise in 0,25 dpt Schritten hinsichtlich Defokus und Astigmatismus korrigiert werden. Es besteht allerdings keine Möglichkeit, höhere Ordnungen, wie z.B. das Koma oder die sphärische Aberration auszugleichen und damit zu vermessen. Solange die Refraktionsbestimmung über de subjektive Methode erfolgt und damit die Korrektur einer Fehlsichtigkeit des Patienten subjektiv festgelegt wird, ist eine gezielte, optimale Fehlsichtigkeitskorrektur nicht möglich. Denn die subjektive Wahrnehmung des Patienten basiert stets auf der ihm eigenen Art zu sehen. Hier fließen seine Erfahrungen beim Erkennen von Optotypen mit ein. Ein objektiver Messwert für die wirklich benötigte Korrektur eines Sehfehlers ist hiermit nicht möglich. Der Erfindung liegt daher die Aufgabe zugrunde, ein Verfahren zu schaffen, mit dem die Refraktion des menschlichen Auges präziser ermittelt und so die Güte der Korrektur einer Fehlsichtigkeit verbessert werden kann. Ferner liegt der Erfindung die Aufgabe zugrunde eine zur Durchführung des Verfahrens geeignete Vorrichtung zu schaffen.With the methods described above, ametropia can usually be corrected in 0.25 D steps with regard to defocus and astigmatism. However, there is no way to compensate for higher orders such as coma or spherical aberration and thus measure them. As long as the refraction is determined via the subjective method and thus the correction of a patient's ametropia is determined subjectively, a targeted, optimal ametropia correction is not possible. Because the patient's subjective perception is always based on his own way of seeing. This is where his experience in recognizing optotypes flows in. An objective measured value for the correction of a visual defect that is really required is not possible with this. The object of the invention is therefore to create a method with which the refraction of the human eye can be determined more precisely and the quality of the correction of an ametropia can be improved. The invention is also based on the object of providing a device which is suitable for carrying out the method.
Diese Aufgaben werden durch das in Anspruch 1 wiedergegebene Verfahren sowie durch die in Anspruch 6 wiedergegebene Vorrichtung gelöst.These objects are achieved by the method given in claim 1 and by the device given in claim 6.
Bei dem erfindungsgemäßen Verfahren wird während der subjektiven Refraktionsmessung mittels eines Phoropters und einer Sehtafel, d.h. während der Durchführung der Fehlsichtigkeitsbestimmung nach der „subjektiven" Methode, auf der Netzhaut eines Auges des Patienten ein Lichtfleck erzeugt. Das von dem Lichtfleck emitierte Licht wird einem Wellenfrontsensor zugeführt. Die Aberrationen des von dem Lichtfleck emitierten Lichts wird durch Wellenfrontanalyse ermittelt.In the method according to the invention, during the subjective refraction measurement using a phoropter and an eye chart, i.e. while carrying out the determination of ametropia by the "subjective" method, a light spot is generated on the retina of an eye of the patient. The light emitted by the light spot is fed to a wavefront sensor. The aberrations of the light emitted by the light spot are determined by wavefront analysis.
Bei diesem Verfahren werden die „subjektive" und die „objektive" Methode also parallel durchgeführt, wobei im Gegensatz zu den bekannten Vorgehensweisen die objektive Methode zur Ermittlung der Restfehlsichtigkeit bereits während der Fehlsichtigkeitsdiagnose nach der üblichen subjektiven Methode angewandt wird.In this method, the "subjective" and the "objective" method are carried out in parallel, whereby, in contrast to the known procedures, the objective method for determining the residual ametropia is already used during the diagnosis of ametropia using the usual subjective method.
Bei einer bevorzugten Ausführungsform des Verfahrens wird der Lichtfleck auf der Netzhaut mittels einer auf Seiten der Sehtafel des Phoropters angeordneten Lichtquelle erzeugt. Für den Patienten spürbar erfolgt die Ermittlung der Restfehlsichtigkeit somit weiterhin nach der subjektiven Methode, da er weiterhin lediglich durch den Phoropter auf die Sehtafel schaut.In a preferred embodiment of the method, the light spot on the retina is generated by means of a light source arranged on the side of the eye chart of the phoropter. For the patient, the determination of the residual ametropia continues to be carried out according to the subjective method, since he continues to look at the eye chart only through the phoropter.
Um zu verhindern, dass bei der Anwendung des erfindungsgemäßen Verfahrens die subjektive, optische Wahrnehmung des Patienten beeinflusst wird, wird der Lichtfleck vorzugsweise durch Licht im nicht sichtbaren Wellenlängenbereich erzeugt.In order to prevent the subjective, optical perception of the patient from being influenced when using the method according to the invention, the light spot is preferably generated by light in the invisible wavelength range.
Durchläuft das von dem Lichtfleck auf der Netzhaut emitierte Licht ebenfalls denThe light emitted by the light spot on the retina also passes through
Phoropter, bevor es dem Wellenfrontsensor zugeführt wird, so können bereits vorhandene Phoropter, die nicht über einen Ausgang verfügen, der den gerade eingestellten optischen Korrekturwert liefert, unverändert Verwendung finden. Desweiteren ist durch diese Maßnahme gewährleistet, dass lediglich geringe Restfehlsichtigkeitswerte durch den Wellensensor erfasst und berechnet werden müssen, so dass dieser auf ein schmales Spektrum von Werten abgestimmt und mit einer hohen Empfindlichkeit ausgestattet werden kann.Phoropters, before they are fed to the wavefront sensor, existing phoropters that do not have an output that delivers the optical correction value that has just been set can be used unchanged. Furthermore, this measure ensures that only low residual ametropia values have to be detected and calculated by the shaft sensor, so that it can be matched to a narrow spectrum of values and can be equipped with a high sensitivity.
Das von dem Lichtfleck emitierte Licht wird - vom Patienten aus gesehen - vorzugsweise hinter dem Phoropter aus der Blickrichtung des Patienten ausgekoppelt. Aufgrund dieser Maßnahme ist es möglich, die Erfassung und Ermittlung der Restfehlsichtigkeit entfernt von der Sehtafel durchzuführen. Bereits vorhandene Sehtafeln können somit unverändert Verwendung finden.The light emitted by the light spot is - seen from the patient - preferably coupled out behind the phoropter from the patient's viewing direction. This measure makes it possible to record and determine the residual ametropia away from the eye chart. Existing eye charts can therefore be used unchanged.
Eine Vorrichtung zur Durchführung des erfindungsgemäßen Verfahrens umfasst eine Punktlichtquelle, einen Wellensensor sowie eine Einkopplung des von der Punktlichtquelle emitierten und Auskopplung des von der Netzhaut des Auges des Patienten reflektierten Strahls in bzw. aus der Blickrichtung des Patienten. Eine derartige Vorrichtung braucht vom Patienten aus gesehen lediglich hinter dem Phoropter in den Strahlengang eingebracht werden, um das erfindungsgemäße Verfahren durchführen zu können. Sämtliche bereits vorhandenen Diagnosegeräte wie Phoropter und Sehtafeln können dann unverändert weiter verwendet werden. Die erfindungsgemäße Vorrichtung ist daher auch für Nachrüstungszwecke bereits bestehender Systeme geeignet.A device for carrying out the method according to the invention comprises a point light source, a wave sensor and a coupling in of the beam emitted by the point light source and coupling out of the beam reflected by the retina of the patient's eye in or out of the patient's viewing direction. Seen from the patient, such a device only needs to be introduced into the beam path behind the phoropter in order to be able to carry out the method according to the invention. All existing diagnostic devices such as phoropters and eye charts can then continue to be used unchanged. The device according to the invention is therefore also suitable for retrofitting purposes of already existing systems.
Die Punktlichtquelle umfasst vorzugsweise eine Infrarotlichtquelle, um die subjektive Refraktionsbestimmung nicht durch zusätzlichen Lichteinfall in das Auge des Patienten im Sichtbaren zu beeinflussen.The point light source preferably comprises an infrared light source in order not to influence the subjective refraction determination in the visible by additional light incidence in the patient's eye.
Die Infrarotlichtquelle kann eine Laserquelle umfassen.The infrared light source can comprise a laser source.
Die Einrichtung zur Einkopplung des von der Punktlichtquelle emitierten und Auskopplung des von der Netzhaut des Auges des Patienten reflektiertem Lichts umfasst in einer besonders konstruktiv einfachen und damit bevorzugten Ausführungsform einen Strahlteiler, der im Bereich des sichtbaren Lichts transparent ist, im Infraroten jedoch als Spiegel wirkt.The device for coupling in the light emitted by the point light source and coupling out the light reflected by the retina of the patient's eye comprises, in a particularly constructively simple and therefore preferred embodiment, a beam splitter which is transparent in the range of visible light but acts as a mirror in the infrared.
Der Wellenfrontsensor umfasst vorzugsweise einen Kamerachip. In Betracht kommt beispielsweise ein solcher, der nach dem CCD -Prinzip arbeitet. Da bereits bestehende Systeme nicht auf eine Ergänzung einer erfindungsgemäßen Vorrichtung ausgelegt sind, ist es von Vorteil, wenn letztere möglichst geringe Abmessungen aufweist. Bei einer besonders bevorzugten Ausführungsform ist daher der Punktlichtquelle lediglich eine optische Einrichtung zur Erzeugung eines parallelen Lichtbündels, nicht aber einer Einrichtung zur Vorkorrektur nachgeschaltet.The wavefront sensor preferably comprises a camera chip. For example, one that works according to the CCD principle can be considered. Since already existing systems are not designed to supplement a device according to the invention, it is advantageous if the latter has the smallest possible dimensions. In a particularly preferred embodiment, the point light source is therefore only followed by an optical device for generating a parallel light beam, but not a device for precorrection.
Das erfindungsgemäße Verfahren und die erfindungsgemäße Vorrichtung sollen nun anhand der Zeichnung näher dargestellt werden. Die in der Zeichnung als ganzes mit R bezeichnete Vorrichtung st derart in den Strahlengang S eines Auges A eines Patienten eingestellt, dass das von der Netzhaut N reflektierte Licht zunächst einen üblichen Phoropter P und einen Strahlteiler 1 der Vorrichtung R durchläuft. Er umfasst einen im Bereich des sichtbaren Lichts transparenten, im Infraroten jedoch reflektierenden Spiegel, der in einem Winkel von 45 ° zur optischen Achse O des Systems Auge A - Phoropter P - Sehtafel T angeordnet ist.The method according to the invention and the device according to the invention are now to be illustrated in more detail with reference to the drawing. The device, designated as a whole by R in the drawing, is set in the beam path S of an eye A of a patient such that the light reflected by the retina N first passes through a conventional phoropter P and a beam splitter 1 of the device R. It comprises a mirror which is transparent in the range of visible light, but which is reflective in the infrared, and which is arranged at an angle of 45 ° to the optical axis O of the system Eye A - Phoropter P - Eye Chart T.
In der optischen Achse Q der Vorrichtung R befindet sich ein aus zwei zueinander verlagerbaren Sammellinsen 2,3 und einer dazwischen befindlichen Blende 4 bestehendes optisches System, das zur Erzeugung eines parallelen Lichtbündels L im Infraroten dient.In the optical axis Q of the device R there is an optical system consisting of two mutually displaceable converging lenses 2, 3 and an aperture 4 located between them, which serves to generate a parallel light beam L in the infrared.
Zur Erzeugung des Infrarotlichts ist vor dem optischen System eine Lichtquelle 5 und ein dieser nachgeschalteter Polarisator 6 vorgesehen, von dem das polarisierte Infrarotlicht einem Polarisationsstrahlteiler zugeführt wird. Letzterer ist derart konzipiert, dass er das von der Lichtquelle 5 stammende Licht in Richtung der optischen Achse Q zum Strahlteiler 1 reflektiert.To generate the infrared light, a light source 5 and a polarizer 6 connected downstream of it are provided in front of the optical system, from which the polarized infrared light is fed to a polarization beam splitter. The latter is designed in such a way that it reflects the light originating from the light source 5 in the direction of the optical axis Q to the beam splitter 1.
Ferner umfasst die Vorrichtung R einen Polarisator 8, dessen Polarisationsrichtung gegenüber dem Polarisator 6 um 90 ° gedreht ist.The device R further comprises a polarizer 8, the direction of polarization of which is rotated by 90 ° with respect to the polarizer 6.
Das den Polarisator 8 durchsetzende Licht trifft dann auf ein Linsenarray, von dem es einem Kamerachip 10 zugeführt wird.The light passing through the polarizer 8 then strikes a lens array, from which it is fed to a camera chip 10.
Die vorstehend prinzipiell beschriebene Vorrichtung dient der Durchführung des folgenden Verfahrens: Von der Lichtquelle 5 wird ein Infrarot-Lichtstrahl mit einer ebenen Wellenfront erzeugt. Dieser wird mittels des Polarisators 6 polarisiert und mittels des Strahlteilers 7 in den Strahlengang entlang der optischen Achse Q gebracht. Das polarisierte Infrarotlicht wird mittels der teleskopartig angeordneten Linsen 2,3 und der dazwischen befindlichen Blende 4 aufgeweitet und über den Spiegel 1 der Netzhaut N des Auges A zugeführt. Es durchläuft hierbei den Phoropter P.The device described in principle above serves to carry out the following method: An infrared light beam with a flat wavefront is generated by the light source 5. This is polarized by means of the polarizer 6 and brought into the beam path along the optical axis Q by means of the beam splitter 7. The polarized infrared light is expanded by means of the telescopically arranged lenses 2, 3 and the diaphragm 4 located between them and is fed to the retina N of the eye A via the mirror 1. It passes through the Phoropter P.
Das von der Netzhaut N emittierte Infrarotlicht durchläuft dann wiederum den Phoropter und wird mittels des Strahlteilers 1 über die Linse 2, die Lochblende 4 und die Linse 3 dem Strahlteiler 7 zugeführt. Bei Durchgang durch das Auge wurde dasThe infrared light emitted by the retina N then again passes through the phoropter and is supplied to the beam splitter 7 by means of the beam splitter 1 via the lens 2, the pinhole 4 and the lens 3. When it passed through the eye, it became
Infrarotlicht derart polarisiert, daß es den Strahlteiler 7 und den Polarisator 8 teilweise durchsetzt.Infrared light polarized such that it partially passes through the beam splitter 7 and the polarizer 8.
Dabei filtert der Polarisator 8 solches Licht heraus, das beispielsweise durch Reflexionen an Linsen erzeugt wurde und nicht vom Augenhintergrund stammt. Das den Polarisator 8 durchsetzende Licht durchdringt ein Linsenarray 9 und wird schließlich von dem Kamerachip 10 erfasst.The polarizer 8 filters out such light that was generated, for example, by reflections on lenses and does not originate from the fundus. The light passing through the polarizer 8 penetrates a lens array 9 and is finally captured by the camera chip 10.
Während der Durchführung der „subjektiven" Methode, bei der der Patient eine Sehtafel mit Optotypen beobachtet, trifft daher Licht im Infraroten, das von dem Lichtfleck auf der Netzhaut N des Auges A reflektiert wird, auf den Kamerachip 10, die durch das Patientenauge geformt und von dem Phoropter vorkorrigiert wurde.During the implementation of the "subjective" method, in which the patient observes an eye chart with optotypes, light in the infrared, which is reflected by the light spot on the retina N of the eye A, strikes the camera chip 10, which is shaped by the patient's eye and was precorrected by the phoropter.
Die Wellenfrontanalyse erfolgt nun durch eine Darstellung der Wellenfront in einer Art und Weise, die neben der eigentlichen Form gleichzeitig Informationen über Fehlsichtigkeit des Auges liefert, die in der Ophthalmologie direkt verwendet werden kann. Sie basiert auf dem Zemike-Polynom, die von F. Zernike in einer Arbeit über die Phasenkontrastmethode zur Wellenfrontanalyse eingeführt wurden. Diese Zernike- Polynome beschreiben die Wellenfronten klassischer Aberrationen optischer Systeme mit je einem Polynom, sowie die höheren Ordnungen davon.The wavefront analysis is now carried out by displaying the wavefront in a way that, in addition to the actual shape, also provides information about ametropia of the eye, which can be used directly in ophthalmology. It is based on the Zemike polynomial, which was introduced by F. Zernike in a work on the phase contrast method for wavefront analysis. These Zernike polynomials describe the wave fronts of classic aberrations of optical systems with one polynomial each, as well as the higher orders thereof.
Das Verfahren der Wellenfrontanalyse basiert auf einer Modifikation des Hartmann's Screen-Test. Die zu analysierende Wellenfront wird mit Hilfe eines Lochblendenarrays in viele Abschnitte eingeteilt. Diese einzelnen Lichtquellen bilden je ein Hauptmaximum auf einen Schirm ab, dessen Lage von der Form der eingestrahlten Wellenfront abhängig ist. Die lokale Verkippung der Wellenfront W(xi,yi) an einer Stelle (xi,yi) ist über die Beziehung:The method of wavefront analysis is based on a modification of the Hartmann 's screen test. The wavefront to be analyzed is divided into many sections using a pinhole array. These individual light sources each represent a main maximum on a screen, the position of which depends on the shape of the incident wavefront. The local tilt of the wavefront W (xi, yi) at one point (xi, yi) is via the relationship:
<WQt j/;) __ Δ.IV öx υ (D<WQt j /;) __ Δ.IV öx υ (D
direkt mit der Verschiebung des Maximas Dxi korreliert, wobei a den Abstand des Kamerachips zum Linsenarray darstellt.correlated directly with the shift of the Maximas Dxi, where a represents the distance between the camera chip and the lens array.
Die Information über die Wellenfront liegt somit in den Positionen der Maxima. Mit Hilfe der Wellenfrontrekonstruktion, die ein in der Zeichnung nicht dargestellter Computer durchführt, lässt sich diese Front ermitteln und in Form von Zernikepolynomen darstellen. Dieses Verfahren unterliegt einem Messbereich, der im folgenden dargestellt wird. Die Verschiebung der Maxima stellt immer eine Mittelung über eine Blende dar. Eine Wellenfront mit Unstetigkeitsstellen, die auf Blendenränder fallen, lässt sich nicht als solche erkennen, da nur lokale Verkippungen wahrgenommen werden. Der Messbereich eines solchen Wellenfrontsensors ist nicht uneingeschränkt. Er wird durch den Abstand des Schirms, den Durchmesser der Blenden sowie den Abstand der Blenden zueinander bestimmt. Die benachbarten Steigungen der Wellenfront dürfen einen maximalen Winkelunterschied (mit Vorzeichenwechsel) nicht überschreiten, da sonst die Fokuspunkte nicht mehr getrennt aufgelöst werden können. Im Falle der automatischen Schwerpunktsbestimmung der Hauptmaximapunkte, die ohne ein Modell für die Intensitätsverteilung dieser auskommt, müssen diese vollständig voneinander getrennt sein. Durch die Vorkorrektur der Fehlsichtigkeit mit Hilfe des Linsensystems des Phoropters kann davon ausgegangen werden, dass der Wertebereich bei dieser Analyse nicht überschritten wird.The information about the wavefront thus lies in the positions of the maxima. With the help of the wave front reconstruction, which a computer does not show in the drawing, this front can be determined and represented in the form of Zernike polynomials. This method is subject to a measuring range, which is shown below. The shift of the maxima always represents an averaging over an aperture. A wavefront with discontinuities that fall on the edges of the aperture cannot be recognized as such, since only local tilting is perceived. The measuring range of such a wavefront sensor is not unlimited. It is determined by the distance between the screen, the diameter of the screens and the distance between the screens. The neighboring slopes of the wavefront must not exceed a maximum angle difference (with a change of sign), since otherwise the focus points can no longer be resolved separately. In the case of the automatic determination of the center of gravity of the main maximum points, which does not require a model for the intensity distribution of these, these must be completely separated from one another. By correcting the ametropia with the aid of the lens system of the phoropter, it can be assumed that the range of values is not exceeded in this analysis.
Die Rekonstruktion und Darstellung der Wellenfront aus den gemessenen Verschiebungen Dxi und Dyi geschieht in drei Schritten: Zuerst wird die Steigung der Wellenfront mit Hilfe von orthogonalen Polynomen rekonstruiert, da sie über die folgende Beziehung mit den einzelnen Fokuspunktabweichungen direkt korreliert ist. Die Funktion W(x,y) stellt hierbei die Wellenfront dar, a der Abstand Linsenarray und Kamerachip und der Laufparameter i steht für die einzelnen gemessenen Maxima.The reconstruction and representation of the wavefront from the measured displacements Dxi and Dyi takes place in three steps: First, the slope of the wavefront is reconstructed using orthogonal polynomials, since it is directly correlated with the individual focus point deviations via the following relationship. The function W (x, y) represents the wavefront, a the distance between the lens array and the camera chip and the running parameter i stands for the individual measured maxima.
Öl ϊ "( ,Ϊ v , yf ) Λrry Ö\ V(iKi , -<jt- ) Δ$/,- <:λr ' By a * (2)Oil ϊ " (, Ϊ v, y f ) Λrry Ö \ V (iKi, - <j t -) Δ $ /, - <: λr ' By a * (2)
Danach wird mittels Koeffizientenvergleich aus der gewonnenen Steigung der Wellenfront die eigentliche Wellenfront ermittelt und in Taylorpolynomen dargestellt. Um eine hohe Anschaulichkeit der Wellenfront zu erreichen, wird diese nun in Zernikepolynomen entwickelt. Der erste Schritt, die Rekonstruktion der Steigung, geschieht über ein Anpassungsverfahren, das nach der Methode der kleinsten quadratischen Abweichung funktioniert. Es wird eine Hilfswellenfront WH angesetzt, die durch orthogonale Polynome Ln bis zur Ordnung M dargestellt werden kann, Gleichung (3). n JL.5^ [ .( , j J . &l¥π ( A)) A DA ««•3 / T ln n xAJ)The actual wave front is then determined by means of a coefficient comparison from the slope of the wave front obtained and is represented in Taylor polynomials. In order to achieve a clear view of the wavefront, it is now developed in Zernik polynomials. The first step, the reconstruction of the slope, takes place via an adjustment method that works according to the method of the smallest quadratic deviation. An auxiliary wave front WH is applied, which can be represented by orthogonal polynomials Ln up to order M, equation (3). n JL.5 ^ [. (, j J. & l ¥ π (A)) A DA «« • 3 / T l nn xAJ)
(3)(3)
Das Quadrat der Abweichung S der Ableitung der Hilfswellenfront von den gemessenen Verschiebungen dividiert durch die Brennweite, die die Ableitung der gemessenen Wellenfront darstellt, lautet:The square of the deviation S of the derivative of the auxiliary wavefront from the measured displacements divided by the focal length, which represents the derivative of the measured wavefront, is:
(4)(4)
Durch Einsetzen der Gleichung (3) in (4) ergibt sich das Quadrat der Abweichung zu:Substituting equation (3) in (4) gives the square of the deviation to:
s - f f(≤ -.. : kthιM. //* )" -»
(5) Zum minimieren von S wird die Ableitung des Ausdrucks nach Dkj und Dlj null gesetzt, das zu den Minimierungsbedingungen führt:(5) To minimize S, the derivative of the expression after Dkj and Dlj is set to zero, which leads to the minimization conditions:
(6)(6)
Die Gleichungen (6) lassen sich umformen zu:Equations (6) can be transformed into:
(7)(7)
Für die orthogonalen Polynome gilt zumindest über einen diskreten Satz von Punkten innerhalb einer vorgegebenen Fläche, die durch die Linsenverteilung gegeben ist:For the orthogonal polynomials, the following applies at least over a discrete set of points within a given area, which is given by the lens distribution:
(8)(8th)
Wenn die Beziehung (8) gilt, dann lässt sich das Gleichungspaar (8) nach den Koeffizienten kn und In auflösen. Damit hat man die Ableitung der Wellenfront ermittelt.
(9)(9)
Im zweiten Schritt wird nun wiederum eine Wellenfront, die diesmal in Taylorpolynomen entwickelt wird, angenommen, um mit deren Ableitung unter Zuhilfenahme der Methode des Koeffizientenvergleichs auf die Wellenfront des gemessenen Lichtstrahls zu schließen. In Gleichung (10) ist diese Wellenfront aufgeführt und in Gleichung (11) wird dann der Vergleich der Ableitung durchgeführt.In the second step, a wavefront, which this time is developed in Taylor polynomials, is again assumed in order to deduce the wavefront of the measured light beam with the aid of the coefficient comparison method. This wavefront is listed in equation (10) and the derivative is then compared in equation (11).
w ati, ) = Σ *«> • χgy9~p (10)w ati,) = Σ * «> • χg y 9 ~ p (10)
(11) Somit ist die Wellenfront ermittelt und darstellbar. Eine für diese Anwendung bessere(11) The wavefront is thus determined and can be represented. A better one for this application
Darstellungsweise ist die Benutzung von Zernike-Polynomen. Diese Darstellungsweise ist für die Ophthalmologie sehr vorteilhaft. Die Umrechnung der Wellenfront W(x,y) in die Form der Zernikedarstellung durch die Koeffizienten zi und deren Polynome Zi geschieht nach der folgenden Formel:Representation is the use of Zernike polynomials. This type of presentation is very advantageous for ophthalmology. The conversion of the wavefront W (x, y) into the form of the Zernike representation using the coefficients zi and their polynomials Zi is carried out according to the following formula:
NN
W ( x , y ) = T Zi * Zi i = 0 (12) Die Analyse der Wellenfront, die durch das Patientenauge geformt und von dem Phoropter vorkorrigiert wurde, ergibt somit den erwünschten Datensatz über die mit Hilfe der subjektiven Methode nicht erfassten Restfehlsichtigkeit. Ihre zahlenwertige Ermittlung erfolgt mit Hilfe eines mit der erfindungsgemäßen Vorrichtung verbundenen Rechners, der in der Zeichnung nicht dargestellt ist.W (x, y) = T Zi * Zi i = 0 (12) The analysis of the wavefront, which was formed by the patient's eye and pre-corrected by the phoropter, thus yields the desired data set on the residual ametropia not detected using the subjective method. Their numerical value determination is carried out with the aid of a computer connected to the device according to the invention, which is not shown in the drawing.
Hierzu werden zunächst die von dem Kamerachip erfassten Daten in den Arbeitsspeicher des Rechners eingelesen. In einem ersten Auswerteschritt werden die so aufgenommen Bilder in Bezug auf Helligkeit, Kontrast und eventuelle Artefakte vorbereitet. Bei der daran anschließenden Bildanalyse geht es darum, alle relevanten Parameter aus den Bilddaten zu extrahieren. Von Interesse sind insbesondere die Schwerpunktskoordinaten und die Form der einzelnen Fokuspunkte.For this purpose, the data recorded by the camera chip are first read into the main memory of the computer. In a first evaluation step, the images captured in this way are prepared in terms of brightness, contrast and any artifacts. The subsequent image analysis is about extracting all relevant parameters from the image data. The center of gravity coordinates and the shape of the individual focus points are of particular interest.
Aus den Informationen aus der Form und Lage der Fokuspunkte lassen sich detaillierte Aussagen über die Form der Wellenfront, die in direktem Zusammenhang zu der Aberration steht, machen. Die Form der Wellenfront kann beispielsweise - wie erwähnt - mit den in der Optik oft verwendeten Zernikepolynomen dargestellt werden.The information from the shape and position of the focus points can be used to make detailed statements about the shape of the wavefront, which is directly related to the aberration. As mentioned, the shape of the wavefront can be represented, for example, with the Zernik polynomials often used in optics.
Die Ergebnisse der Wellenfrontanalyse werden dem Anwender nun unter Verwendung grafischer Darstellungsmethoden nahegebracht. Hierzu gehören Diagramme über zeitliche Entwicklungen von interessanten Parametern wie Sphäre, Zylinder, Zylinderwinkel, Augenposition, aber auch Ansichten von 3- D-Wellenfront- und Brechkraftverteilung innerhalb des vermessenden Pupillenbereichs. Diese bereits während des Messverfahrens zugänglichen Informationen ermöglichen eine sofortige Beurteilung der Messungen. The results of the wavefront analysis are now brought to the user using graphical display methods. This includes diagrams over time developments of interesting parameters such as sphere, cylinder, cylinder angle, eye position, but also views of 3D wavefront and refractive power distribution within the measuring pupil area. This information, which is already accessible during the measurement process, enables the measurements to be assessed immediately.
Claims
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE10348854.5 | 2003-10-20 | ||
| DE2003148854 DE10348854A1 (en) | 2003-10-20 | 2003-10-20 | Method and device for determining the residual defective vision of a patient |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO2005037090A1 true WO2005037090A1 (en) | 2005-04-28 |
Family
ID=34442147
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/EP2004/052815 Ceased WO2005037090A1 (en) | 2003-10-20 | 2004-10-19 | Method and device for determining the residual defective vision of a patient |
Country Status (2)
| Country | Link |
|---|---|
| DE (1) | DE10348854A1 (en) |
| WO (1) | WO2005037090A1 (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3056135A1 (en) * | 2007-06-27 | 2016-08-17 | AMO WaveFront Sciences, LLC | System and method for measuring corneal topography |
| US9462939B2 (en) | 2012-04-05 | 2016-10-11 | Visionix Ltd. | Objective phoropter system |
| CN106659376A (en) * | 2014-09-22 | 2017-05-10 | 卡尔蔡司股份公司 | Method and apparatus for determining eye refraction |
| US10383513B2 (en) | 2015-05-05 | 2019-08-20 | Visionix Ltd. | Objective phoropter |
| JP2021029288A (en) * | 2019-08-16 | 2021-03-01 | 株式会社トプコン | Ophthalmic equipment and ophthalmic system |
| US11096576B2 (en) | 2016-06-14 | 2021-08-24 | Plenoptika, Inc. | Tunable-lens-based refractive examination |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102005046141A1 (en) * | 2005-09-27 | 2007-04-05 | Iroc Ag | Device for binocular sight checking by radiation process for each eye of patient has means for selective establishing of higher order aberrations including coma and spherical aberrations |
| DE102007032564A1 (en) * | 2007-07-12 | 2009-01-15 | Rodenstock Gmbh | Method for checking and / or determining user data, computer program product and device |
| CN102307514B (en) * | 2008-12-01 | 2015-07-22 | 完美视觉科技（香港）有限公司 | Method and device for correcting refraction of human eye |
| EP2371270A1 (en) * | 2010-03-16 | 2011-10-05 | Ignaz Alois Stuetz | Method for compensating for and simulating (anamorphotic) distortion |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4222395A1 (en) * | 1992-07-08 | 1994-01-13 | Amtech Ges Fuer Angewandte Mic | Optical system for measuring refraction of eye with light source - has variable imaging optics adjustable in its power of refraction focussing light emanating from light source on retina of eye |
| US20030025874A1 (en) * | 1996-12-23 | 2003-02-06 | University Of Rochester | Method and apparatus for improving vision and the resolution of retinal images |
| US20030151721A1 (en) * | 2002-02-13 | 2003-08-14 | Lai Shui T. | Apparatus and method for determining objective refraction using wavefront sensing |
-
2003
- 2003-10-20 DE DE2003148854 patent/DE10348854A1/en not_active Withdrawn
-
2004
- 2004-10-19 WO PCT/EP2004/052815 patent/WO2005037090A1/en not_active Ceased
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4222395A1 (en) * | 1992-07-08 | 1994-01-13 | Amtech Ges Fuer Angewandte Mic | Optical system for measuring refraction of eye with light source - has variable imaging optics adjustable in its power of refraction focussing light emanating from light source on retina of eye |
| US20030025874A1 (en) * | 1996-12-23 | 2003-02-06 | University Of Rochester | Method and apparatus for improving vision and the resolution of retinal images |
| US20030151721A1 (en) * | 2002-02-13 | 2003-08-14 | Lai Shui T. | Apparatus and method for determining objective refraction using wavefront sensing |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3056135A1 (en) * | 2007-06-27 | 2016-08-17 | AMO WaveFront Sciences, LLC | System and method for measuring corneal topography |
| US9462939B2 (en) | 2012-04-05 | 2016-10-11 | Visionix Ltd. | Objective phoropter system |
| CN106659376A (en) * | 2014-09-22 | 2017-05-10 | 卡尔蔡司股份公司 | Method and apparatus for determining eye refraction |
| CN106659376B (en) * | 2014-09-22 | 2018-12-14 | 卡尔蔡司股份公司 | Method and apparatus for determining eye refraction |
| US10383513B2 (en) | 2015-05-05 | 2019-08-20 | Visionix Ltd. | Objective phoropter |
| US11096576B2 (en) | 2016-06-14 | 2021-08-24 | Plenoptika, Inc. | Tunable-lens-based refractive examination |
| JP2021029288A (en) * | 2019-08-16 | 2021-03-01 | 株式会社トプコン | Ophthalmic equipment and ophthalmic system |
| JP7349291B2 (en) | 2019-08-16 | 2023-09-22 | 株式会社トプコン | Ophthalmology equipment and systems |
Also Published As
| Publication number | Publication date |
|---|---|
| DE10348854A1 (en) | 2005-05-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| DE60035643T2 (en) | Method and device for measuring refraction properties of the human eye | |
| DE102007032001B4 (en) | Device and method for determining the required correction of the refractive error of an eye | |
| EP1731086B1 (en) | Method of operating an ophthalmological analysis system | |
| DE102011001083B4 (en) | Projector device with self-correction function as well as medical device with the projector device | |
| EP2943114B1 (en) | Aberrometer (or the like) having an astigmatic target | |
| EP2790567B1 (en) | Brightness-dependent adjustment of an eyeglass lens | |
| DE10014400A1 (en) | Ophthalmic wavefront aberration diagnostic tool, has camera that aids in focusing aerial image from lenslet array, on wavefront sensor | |
| EP1662981B1 (en) | Device and method for measuring the surface tomography and wave aberration of a lens system, particularly an eye | |
| DE102005031496B4 (en) | Device for determining the wavefront of light and surgical microscope with device for determining the wavefront of light | |
| EP3730036A1 (en) | Determination of a refraction error of an eye | |
| WO2002060319A1 (en) | Method and device for the subjective determination of image defects of a higher order | |
| DE102013021974B3 (en) | Device for determining an ametropia of an eye | |
| WO2005037090A1 (en) | Method and device for determining the residual defective vision of a patient | |
| EP0492044A1 (en) | Vision test device | |
| EP2148610A1 (en) | Eye measurement method and system | |
| DE3437234C2 (en) | Device for determining the potential visual acuity using a slit lamp microscope | |
| DE102022209490B4 (en) | Method, use of adapted optotypes and device for determining the visual acuity characteristics of a subject | |
| DE102021133152B4 (en) | Method, device and computer program product for determining a sensitivity of at least one eye of a subject | |
| DE10009532A1 (en) | Quality assurance method for eye operations involves using binocular observation instrument to observe surface of eye and test card projected onto retina through eye lens | |
| DE102011009260B4 (en) | Determination of the rotation parameters of the eyes | |
| EP1437085A1 (en) | Apparatus and method for ocular refractometry | |
| DE2940519C2 (en) | Device for subjective refraction determination | |
| WO2025190913A1 (en) | Method and optical device for determining visual acuity characteristics and/or refraction characteristics of a test subject | |
| DE102017115958A1 (en) | System and method for acquiring characteristics of an eye | |
| WO2007000276A1 (en) | Imaging unit for ophthalmological devices, in particular, for fundus cameras and method for the use thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| AK | Designated states |
Kind code of ref document: A1 Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BW BY BZ CA CH CN CO CR CU CZ DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NA NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW |
|
| AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): GM KE LS MW MZ NA SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LU MC NL PL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG |
|
| 121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
| 122 | Ep: pct application non-entry in european phase |