Patent Application
20210106463
The invention relates generally to laser-surgical treatment of the human eye. In particular, the invention relates to the application of various forms of treatment of the human eye with the aid of one and the same eye-surgical laser apparatus.
The use of focused pulsed laser radiation for the purpose of generating incisions in the corneal tissue or in other tissue parts of the human eye has been the subject of intense research in human ophthalmology for some time. Instruments are also already on the market that provide a function of incision generation with laser radiation of such a type. Ordinarily in this connection, ultra-short-pulse laser radiation with pulse durations within the femtosecond range comes into operation. However, the invention is not restricted thereto; to the extent that generation of an incision in corneal eye tissue is possible also with shorter or longer pulse durations, these are likewise to be encompassed by the invention; for example, pulse durations within the attosecond range or within the one-digit, two-digit or three-digit picosecond range.
The physical effect that is utilised in the course of generating an incision by means of pulsed laser radiation is so-called laser-induced optical breakthrough, which results in a so-called photodisruption, the magnitude of which is limited roughly to the extent of the radiation focus at the waist point of the radiation. As a result of juxtaposing a large number of such photodisruptions, diverse and comparatively complex incision figures can be generated in the eye tissue.
An exemplary application of the generation of an incision by means of pulsed laser radiation is so-called LASIK (laser in-situ keratomileusis). In this surgical procedure—which is generally to be classified as refractive surgery, that is to say, surgery aimed at the elimination or at least improvement of defective imaging properties of the eye—firstly the human cornea is cut open horizontally (from the point of view of the reclining patient), whereby a small cover (ordinarily called a flap in the specialist field) arises which can be folded aside. After the flap has been folded away, in the stroma of the cornea that has been exposed in this way a so-called ablation is effected by means of laser radiation (for example, excimer radiation with a wavelength of 193 nm), i.e. stromal tissue is respected in accordance with a suitable ablation profile computed beforehand for the patient. After this, the small cover (flap) is folded back, at which point the healing process proceeds comparatively painlessly and quickly. After this intervention the cornea has different imaging properties, in which connection a largely complete elimination of the previous visual disorder is achieved in the best case.
As an alternative to the prior ‘classical’ procedure (mechanical microkeratome), the cutting of the flap can also be realised using laser technology. The existing conceptions for this frequently provide for an applanation (levelling) of the anterior surface of the cornea by abutment of a planar abutment face of a contact element that is transparent to the laser radiation, the flap then being generated by a bed incision situated at constant depth and by a lateral incision extending from the bed incision as far as the surface of the cornea. The levelling of the cornea permits the bed incision to be executed as a two-dimensional incision, for which solely a control of the location of the radiation focus in a plane perpendicular to the direction of propagation of the radiation (designated in conventional notation as the x-y plane) is required, without undertaking a control of the location of the radiation focus in the direction of propagation of the laser radiation (this direction is designated, according to conventional notation, as the z-direction). If a control of the location of the radiation focus in the z-direction is to be effected, this can be done, for example, with the aid of a liquid lens, as described, for example, in EP 1 837 696 from the present applicant. In this respect, reference is made to the aforementioned patent application, the content of which is hereby incorporated into this application. In general, the control of the location of the radiation focus is described in patent applications EP 2 111 831 and WO 2010/142311 from the present applicant, the content of which is hereby incorporated into this application.
Another form of operation in which incisions are generated in the cornea by means of pulsed laser radiation is laser-assisted corneal lenticle extraction. In this case, in the stroma of the cornea a tissue volume—which, for example, has the shape of a small disc—is cut free which can be extracted from the eye through an auxiliary incision. Depending upon the indication (e.g. myopia, hyperopia), the lenticle to be removed may have varying shapes. For the purpose of cutting the lenticle free, the procedure hitherto has frequently been such that firstly a lower incision surface bounding the underside of the lenticle (posterior side of the lenticle) and subsequently an upper incision surface bounding the upper side of the lenticle (anterior side of the lenticle) are generated in the cornea, both incision surfaces frequently being three-dimensional and each requiring a z-control of the radiation focus.
For the purpose of x-y-adjustment of the radiation focus in the cornea, sufficiently fast scanners are available which, for example, operate with galvanometrically controlled scanner mirrors. On the other hand, available z-scanners—that is to say, scanners that enable a focus displacement in the z-direction—are frequently comparatively slow in comparison with galvanometric mirror scanners. In addition, only a limited z-range can be covered with the available z-scanners.
In contrast to the refractive eye surgery described previously on the basis of LASIK and also on the basis of corneal lenticle extraction, in which incisions are generated in the cornea, in the case of cataract surgery incisions are implemented in the lens of the human eye. However, solely by virtue of the z-displacement of the laser focus of the laser beam of a laser apparatus being used for the refractive eye surgery with the aid of the z-scanner the focus cannot reach so far into the eye with sufficiently good quality that an incising in the lens (i.e. deeper within the eye) is possible with the same quality as in the cornea.
It is accordingly an object of the present invention to provide a laser system with an eye-surgical laser apparatus, the laser apparatus itself, and a set of interface devices for use in the eye-surgical laser apparatus, by means of which various types of treatment can be carried out with the same eye-surgical laser apparatus. In addition, it is an object of the present invention to provide an appropriate process for laser-surgical eye treatment of various forms of treatment with the aid of the same eye-surgical laser apparatus.
This object is achieved by the subject-matter of the independent claims. Advantageous embodiments arise out of the dependent claims.
In the following, the terms ‘interface device’, ‘interface unit’, ‘patient interface’, ‘patient adapter’ and ‘eye interface’ will be used alternately but are to be understood as being synonymous.
According to a first aspect of the invention, the laser system according to the invention for eye surgery comprises an eye-surgical laser apparatus and a set of interface devices (patient/eye interfaces). The eye-surgical laser apparatus includes optical components for providing pulsed focused laser radiation with radiation properties matched to the generation of photodisruptions in human eye tissue and a control unit for positional control of the radiation focus of the laser radiation. The control unit is designed for executing various control programs that represent various types of incision figure. Each of the interface devices of the set includes a contact body that is transparent to the laser radiation, with an abutment face for abutment against an eye to be treated, and also a coupling portion for detachable coupling of the interface device (patient interface) onto a counter-coupling portion of the laser apparatus, the interface devices of the set differing by virtue of a differing optical effect on the laser radiation provided in the laser apparatus, for example on the laser radiation emerging from the laser apparatus.
It is possible that at least a subset of the interface devices differ by virtue of a differing influence on the location of the radiation focus relative to the abutment face.
The differing optical effect may, for example, consist in the fact that, depending upon the coupling of one of the interface devices onto the counter-coupling portion, the focal point of the laser radiation relative to the abutment face in the case of one and the same laser apparatus comes to be situated at a different position in the eye (i.e. at a different focus location). For example, depending upon the coupled interface device the focus location (the position of the focal point) may come to be situated in the cornea of the eye, in the lens of the eye or at a different point on or in the eye, for example in the iridocorneal angle of the eye. It is, for example, conceivable that the focus location (i.e. how deep the focal point is situated in the eye in the z-direction with respect to the abutment face) in the case of coupling of a first interface device is between 250 μm and 350 μm, in particular between 280 μm and 320 μm and preferentially at 300 μm. Such an interface device would be suitable for operational application for the purpose of machining the cornea with the aid of the eye-surgical laser apparatus. Similarly, it is conceivable that the focus location in the case of coupling of a second interface device lies, for example, between 4 mm and 6 mm, in particular between 4.5 mm and 5.5 mm and preferentially 5 mm, below a contact lens of the interface device. Such an interface device would be suitable for operational application for the purpose of machining the lens with the aid of the eye-surgical laser apparatus.
The differing optical effect may further consist in the fact that, depending on the coupled interface device, a different range of adjustment in the z-direction (i.e. a different range of depth of focus) is possible or is set with one and the same laser apparatus. For example, depending upon the coupled interface device the range of depth of focus (i.e. the range of adjustment of the focal point in the z-direction) may have been matched or may be matched to the machining of the cornea of the eye, of the lens of the eye or of another point on or in the eye. It is, for example, conceivable that the range of depth of focus (i.e. how far the focal point can be adjusted with the aid of a z-scanner in the z-direction of one and the same laser apparatus) in the case of coupling of a first interface device is between 1 mm and 1.4 mm, in particular between 1.1 mm and 1.3 mm and preferentially at 1.2 mm. Such an interface device would be suitable for operational application for the purpose of machining the cornea with the aid of the eye-surgical laser apparatus. Similarly, it is conceivable that the range of depth of focus in the case of coupling of a second interface device lies between 8 mm and 16 mm, in particular between 10 mm and 14 mm and preferentially at 12 mm. Such an interface device would be suitable for operational application for the purpose of machining the lens with the aid of the eye-surgical laser apparatus. The value of the depth of focus that is required for the respective application may be set, for example, by a z-scanner and the patient interface.
The differing optical effect may further consist in the fact that, depending on the coupled interface device, a differing spot diameter of the focal point is obtained with one and the same laser apparatus. For example, depending upon the coupled interface device, the spot diameter of the focal point may have been matched to the machining of the cornea of the eye, of the lens of the eye or of another point on or in the eye. It is, for example, conceivable that the spot diameter in the case of coupling of a first interface device lies between 1 μm and 6 μm, in particular between 2 μm and 5 μm and preferentially between 3 μm and 5 μm. Such an interface device would be suitable for operational application for the purpose of machining the cornea with the aid of the eye-surgical laser apparatus. Similarly, it is conceivable that the spot diameter in the case of coupling of a second interface device lies between 3 μm and 14 μm, in particular between 4 μm and 12 μm and preferentially between 5 μm and 10 μm. Such an interface device would be suitable for operational application for the purpose of machining the lens with the aid of the eye-surgical laser apparatus.
The differing optical effect may further consist in the fact that, depending on the coupled interface device, a differing scan-field diameter (i.e. a differing diameter of the region that is capable of being irradiated by the laser beam in the x-y direction/plane) is obtained with one and the same laser apparatus. For example, depending upon the coupled interface device, the scan-field diameter may have been matched to the machining of the cornea of the eye, of the lens of the eye or of another point on or in the eye. It is, for example, conceivable that the scan-field diameter in the case of coupling of a first interface device lies between 9 mm and 15 mm, in particular between 11 mm and 13 mm, and preferentially amounts to 12 mm. Such an interface device would be suitable for operational application for the purpose of machining the cornea with the aid of the eye-surgical laser apparatus. Similarly, it is conceivable that the scan-field diameter in the case of coupling of a second interface device lies between 5 mm and 9 mm, in particular between 6 mm and 8 mm, and preferentially amounts to 7 mm. Such an interface device would be suitable for operational application for the purpose of machining the lens with the aid of the eye-surgical laser apparatus.
The differing optical effect on the laser radiation provided in the laser apparatus preferably has the result that a small and at least almost equally large (uniform) focus is present in all machining regions within the eye. In particular, this results in a good, adapted focusing, in a low pulse energy of the laser radiation, and/or in a slight burdening of the patient.
Furthermore, at least a subset of the interface devices may differ by virtue of a differing shape and/or location of at least one optical boundary surface. The optical boundary surface may be, for example, a face of a contact lens that is present in the corresponding interface device, which usually serves for abutment of the eye. It is also possible that the optical boundary surface is constituted by a face of an optical ancillary element that is present in the interface device in addition to the contact lens. Accordingly, it is also conceivable that at least a subset of the interface devices differ by virtue of a differing number of optical elements. These optical elements may, for example, include the contact lens for abutment against the eye or the optical ancillary element, for example a lens (refractive optical element) or a diffractive optical element.
At least one of the interface devices may include an applanation cone that is designed to be coupled onto the eye and onto focusing optics of the laser apparatus. However, several, a large number of or all of the interface devices may include an applanation cone of such a type.
The laser apparatus may further include an adaptive optical element that is arranged upstream of focusing optics of the laser apparatus in the direction of propagation of the laser radiation. The adaptive optical element may include an adaptive mirror or a light-transmitting adaptive system. The adaptive optical element may in this case provide for the compensation of a possibly increased wavefront aberration. Such an increase may occur, for example, if a laser system is used for differing applications. In particular, an enlarged range of depth of focus that is required for this may necessitate a correction in the course of incising in the lens.
At least one of the interface devices may include a coding/code that enables the laser apparatus to execute, depending on the coding/code, the control program in the control unit. For example, the laser apparatus may recognise the coding/code and call an associated control program (assigned to the coding/code) in the control unit, preferentially automatically.
According to a second aspect of the present invention, a set of interface devices is made available for use in the eye-surgical laser apparatus, for example in each instance an interface device (patient interface) for the respective intraocular application. Each of the interface devices includes a contact body that is transparent to the laser radiation of the laser apparatus, with an abutment face for abutment against an eye to be treated, and also a coupling portion for detachable coupling of the interface device onto a counter-coupling portion of the laser apparatus. The interface devices differ: (i) by virtue of a differing influence on the location of a radiation focus of the laser radiation relative to the abutment face and/or (ii) by virtue of a differing shape and/or location of at least one optical boundary surface and/or (iii) by virtue of a differing number of optical elements, resulting in a differing optical effect on the laser radiation made available in the laser apparatus (e.g. resulting in a differing focusing of the beam, deflection of the beam and/or splitting of the beam). In particular, by virtue of the interface devices a differing treatment region (e.g. range of depth of focus) in the x-y-direction and/or in the z-direction can be covered, depending upon which interface device is connected to the laser apparatus.
At least one or a subset of the interface devices may include a planar contact lens. In the case of such a planar contact lens a face that is suitable for abutment against the eye takes the form of a planar abutment face and the face situated opposite the abutment face (the face facing away from the eye) is designed to be plane-parallel to the abutment face. At least one of the interface devices may include an optical ancillary element. For example, the optical ancillary element may be present in the interface device or in one of the interface devices with a planar contact lens. The optical ancillary element may, for example, have been arranged in the interface device in such a manner that a face facing away from the contact lens is shaped in convex or planar manner and a face facing towards the contact lens is concavely shaped. However, other designs of the optical ancillary element are also conceivable. Irrespective of the precise shape of the optical ancillary element, the face facing towards the contact lens and/or the face of the optical ancillary element facing away from the contact lens may have been formed as an optical freeform surface.
At least one of the interface devices may also include a concavo-concave contact lens. In the case of a concavo-concave contact lens of such a type a concave abutment face is provided for abutment against the eye, the face situated opposite the abutment face being concavely shaped. Additionally or alternatively, at least one of the interface devices may include a concavo-convex or concavo-planar contact lens. In the case of a concavo-convex contact lens, a concave abutment face is provided for abutment against the eye and the face situated opposite the abutment face is convexly shaped. In the case of a concavo-planar contact lens, a concave abutment face is provided for abutment against the eye and the face situated opposite the abutment face is shaped in planar manner. Irrespective of the precise configuration of the contact lens, the abutment face and/or the face situated opposite the abutment face may take the form of an optical freeform surface with refractive or diffractive effect.
According to a third aspect of the present invention, use is made of a set of interface devices, the use including the variable operational application of, in each instance, one of the interface devices in an eye-surgical laser apparatus. The laser apparatus includes optical components for making available pulsed focused laser radiation with radiation properties matched to the generation of photodisruptions in human eye tissue and a control unit for positional control of the radiation focus of the laser radiation. The control unit is further designed for executing various control programs that represent various types of incision figure, each of the interface devices including a contact body that is transparent to the laser radiation, with an abutment face for abutment against an eye to be treated, and also a coupling portion for detachable coupling of the interface device onto a counter-coupling portion of the laser apparatus. The interface devices of the set differ by virtue of a differing optical effect on the laser radiation provided in the laser apparatus, and the use includes the operational application of various interface devices of the set, depending on the control program to be executed in the given case.
At least a subset of the interface devices may differ by virtue of a differing influence on the location of the radiation focus relative to the abutment face. Furthermore, at least a subset of the interface devices may differ by virtue of a differing shape and/or a differing location of at least one optical boundary surface. It is also conceivable that at least a subset of the interface devices differ by virtue of a differing number of optical elements.
In the case of an exchange of the interface device the focusing setting of focusing optics of the laser apparatus may remain unchanged. Consequently a differing optical effect in the laser apparatus can be achieved with one and the same laser apparatus by virtue of the fact that the interface devices for the respective application are exchanged and the focusing settings remain unchanged.
In the case of an exchange of the interface device the control unit can control the laser apparatus in such a manner that an adaptive optical element or a light-transmitting adaptive system is introduced into the beam path of the laser radiation. For this purpose a corresponding coding/code on the interface devices may be present, on the basis of which an identification of the interface device takes place. The associated adaptive element or system (assigned to the coding/code) can then be introduced, for example automatically, into the beam path in accordance with the identification. The adaptive optical element or the light-transmitting adaptive system can also be introduced upstream of focusing optics of the laser radiation in the direction of propagation of the laser radiation.
According to a fourth aspect of the present invention, a method for laser-surgical eye treatment is made available wherein pulsed focused laser radiation with radiation properties matched to the generation of photodisruptions in human eye tissue is provided by means of a laser apparatus and the position of the radiation focus of the laser radiation is controlled by means of a control unit, wherein in the case of a first treatment-type a sequence of at least one control program that represents a first type of incision figure is executed by means of the control unit, whereby a first interface device matched to the first treatment-type is placed over a contact body that is transparent to the laser radiation with an abutment face against an eye to be treated, and via a coupling portion is detachably coupled onto a counter-coupling portion of the laser apparatus, wherein in the case of a second treatment-type a sequence of the at least one control program that represents a second type of incision figure, different from the first type of incision figure, is executed by means of the control unit, whereby a second interface device matched to the second treatment-type is placed over a contact body that is transparent to the laser radiation, with an abutment face against an eye to be treated, and via a coupling portion is detachably coupled onto a counter-coupling portion of the laser apparatus.
The aforementioned coding/code of the interface devices may serve to ensure that the associated control program is, for example, automatically recognised, set and executed.
The first treatment-type may include a treatment of the cornea of the eye by means of the laser radiation. The second treatment-type may include a treatment of the lens of the eye by means of the laser radiation.
In an alternative embodiment it is conceivable that the second treatment-type includes a treatment of the iris, of the retina, of the vitreous body or of regions of the iridocorneal angle (e.g. for the purpose of treating glaucoma) of the eye by means of the laser radiation.
In the case of a third treatment-type, a sequence of the at least one control program that represents a third type of incision figure, different from the first and/or second type of incision figure, may be executed by means of the control unit, whereby a third interface device matched to the third treatment-type may be placed over a contact body that is transparent to the laser radiation, with an abutment face against an eye to be treated, and via a coupling portion may be detachably coupled onto a counter-coupling portion of the laser apparatus and the third treatment-type may include a treatment of the iris of the eye by means of the laser radiation.
In the case of a fourth treatment-type, a sequence of the at least one control program that represents a fourth type of incision figure, different from the first, second and/or third type of incision figure, may be executed by means of the control unit, whereby a fourth interface device matched to the fourth treatment-type may be placed over a contact body that is transparent to the laser radiation, with an abutment face against an eye to be treated, and via a coupling portion may be detachably coupled onto a counter-coupling portion of the laser apparatus and the fourth treatment-type may include a glaucoma treatment in the iridocorneal angle of the eye by means of the laser radiation.
In the case of a fifth treatment-type, a sequence of the at least one control program that represents a fifth type of incision figure, different from the first, second, third and/or fourth type of incision figure, may be executed by means of the control unit, whereby a fifth interface device matched to the fifth treatment-type may be placed over a contact body that is transparent to the laser radiation, with an abutment face against an eye to be treated, and via a coupling portion may be detachably coupled onto a counter-coupling portion of the laser apparatus and the fifth treatment-type may include a treatment of the vitreous body of the eye by means of the laser radiation.
In the case of a sixth treatment-type, a sequence of the at least one control program that represents a sixth type of incision figure, different from the first, second, third, fourth and/or fifth type of incision figure, may be executed by means of the control unit, whereby a sixth interface device matched to the sixth treatment-type may be placed over a contact body that is transparent to the laser radiation, with an abutment face against an eye to be treated, and via a coupling portion may be detachably coupled onto a counter-coupling portion of the laser apparatus and the sixth treatment-type may include a treatment of the retina of the eye by means of the laser radiation.
The invention will be elucidated further in the following on the basis of the appended drawings, which are schematic throughout. Shown are:
The laser device shown in
In a manner not shown in any detail but known as such, the laser source 12 may include, for example, a laser oscillator (e.g. solid-state laser oscillator), a pre-amplifier, which increases the pulse power of the laser pulses emitted from the oscillator and simultaneously temporally stretches them, a subsequent pulse-picker, which selects individual laser pulses from the pre-amplified laser pulses of the oscillator, in order in this way to lower the repetition rate to a desired degree, a power amplifier, which amplifies the selected, still temporally stretched, pulses to the pulse energy needed for the application, and a pulse compressor, which temporally compresses the pulses output from the power amplifier to the pulse duration desired for the application.
The optical switch 18, which may also be designated as a pulse modulator, may, for example, take the form of an acousto-optical modulator or an electro-optical modulator. Generally, the optical switch 18 may contain arbitrary optically active elements that enable a rapid blanking of individual laser pulses. The optical switch 18 may, for example, contain a beam trap, indicated schematically at 20, which serves to absorb radiation pulses to be blanked, which are not to reach the eye 16. The optical switch 18 can deflect such radiation pulses to be blanked from the normal beam path of the radiation pulses of the laser beam 14 and direct them onto the beam trap 20.
In the beam path of the laser beam 14 further optical components are arranged which, in the exemplary case shown, include a z-scanner 22, an x-y scanner 24 and also a focusing objective 26. The focusing objective 26 serves for focusing the laser beam 14 onto a desired machining location on or in the eye 16, in particular in the cornea of the same. The z-scanner 22 serves for longitudinal control of the location of the focal point of the laser beam 14; the x-y scanner 24 serves, on the other hand, for transverse control of the location of the focal point. ‘Longitudinal’ relates in this connection to the direction of beam propagation; this is designated in conventional notation as the z-direction. ‘Transverse’, on the other hand, designates a direction transverse to the direction of propagation of the laser beam 14; according to conventional notation the transverse plane is designated as the x-y plane. A coordinate frame that represents the x-y-z directions in the region of the eye 16 has been drawn in
For the purpose of transverse deflection of the laser beam 14, the x-y scanner 24 may, for example, include a pair of galvanometrically actuated scanner mirrors that are capable of tilting about mutually perpendicular axes. On the other hand, the z-scanner 22 may, for example, contain a longitudinally adjustable lens or a lens of variable refractive power or a deformable mirror, with which the divergence of the laser beam 14 and consequently the z-position of the beam focus can be influenced. For example, such an adjustable lens or mirror may be contained in a beam expander which is not represented in any detail and which expands the laser beam 14 emitted from the laser source 12. The beam expander may, for example, be configured as a Galilean telescope.
The focusing objective 26 is preferably an f-theta objective and is preferentially detachably coupled on its beam-exit side with a patient adapter 28a which constitutes an abutment interface for the cornea of the eye 16. For this purpose the patient adapter 28a includes a contact element 30a that is transparent to the laser radiation and that on its underside facing towards the eye includes an abutment face 32a for the cornea of the eye 16. In the exemplary case shown, the abutment face 32a is realised as a plane surface and serves for levelling the cornea, by the contact element 30a being pressed against the eye 16 with appropriate pressure or by the cornea being aspirated onto the abutment face 32a by underpressure. The contact element 30a, which in the case of plane-parallel design is ordinarily designated as the applanation plate, is fitted to the narrower end of a conically widening carrier sleeve 34a. The connection between the contact element 30a and the carrier sleeve 34a may be permanent, for example by virtue of adhesion bonding, or it may be detachable, for instance by virtue of a screw coupling. It is conceivable, furthermore, to use an optical injection-moulded part with the functions of the carrier sleeve 34a and of the contact element 30a. In a manner not represented in any detail, the carrier sleeve 34a has at its wider sleeve end, which in the drawing is the upper end, suitable coupling structures for coupling onto the focusing objective 26.
It will be understood that the order of the optical switch 18, the z-scanner 22, the x-y scanner 24 and the focusing objective 26 does not have to be as represented in
The laser source 12, the optical switch 18 and also the two scanners 22, 24 (which, if desired, may also have been combined within a single structural unit) are controlled by a control computer 36 which operates in accordance with a control program 40 stored in a memory 38. The control program 40 contains instructions (program code) that bring about, upon execution by the control computer 36, such a control of the location of the beam focus of the laser beam 14 that in the cornea, in the lens or at another location of the eye 16 bearing against the contact element 30a an incision figure arises that, for example in the course of a machining of the cornea, completely severs from the surrounding corneal tissue a corneal tissue volume to be removed within the scope of a corneal lenticle extraction or a corneal keratoplasty. If desired, this incision figure may additionally bring about a segmentation of this tissue volume into a plurality of volume segments individually separated from one another.
Furthermore, an adaptive optical element or adaptive optical system, taking the form, in exemplary manner, of a mirror 42, may be capable of being introduced into the radiation path of the laser beam 14 upstream of the focusing objective 26. This mirror 42 may have been designed as a deformable mirror. Furthermore, instead of the mirror 42 another adaptive optical element or a light-transmitting adaptive system may have been provided. The mirror 42 is preferentially introduced into the radiation path of the laser beam 14 if a machining of the lens of the eye 16 is to be undertaken in order to lessen (compensate) wavefront aberrations. In the course of a machining of the cornea of the eye 16 the mirror 42 may be located in a null position (inactive position) in which the radiation path that is dashed in
In the case of the laser device 10 shown in
In
The optical effect of the laser device 10 in the case where use is made of patient adapter 28u is distinguished by the fact that the laser beam 14 is focussed in the cornea 16a. This means, inter alia, that the focal point of the laser beam 14 is situated in the cornea. For the machining of the cornea 16a, for a typical eye it is advantageous that the focus location z0 (i.e. the spacing of the focal point from the abutment face 32u of the patient adapter 28u for abutment of the eye 16 for a defined state of the z-scanner 22) may attain a value of about 110 μm. In addition, for the machining of the cornea usually a variable setting of the depth of focus of Δz=0 . . . 1200 μm is required—that is to say, a range of adjustment of the focal point of about 1.2 mm. Furthermore, normally a spot diameter of the focal point of around 3-5 μm and a scan-field diameter ΦF of around 12 mm are required. These properties are satisfied, for example, by patient adapter 28u.
If the settings of the laser device 10 are retained and only patient adapter 28u is replaced by patient adapter 28v, the focal point of the laser beam 14 does not lie in the cornea 16a, but in the lens 16b of the eye 16 (the mean focus location z0 assumes, for example, a value of 5 mm). This is obtained by virtue of a shorter length L2 of patient adapter 28v in comparison with the length L1 of patient adapter 28u. Furthermore, by virtue of patient adapter 28v it is ensured that, for example, a setting of the depth of focus of Δz=3 . . . 12 mm is possible, the spot diameter of the focal point amounts to 5 μm to 10 μm, and the scan-field diameter amounts to about 7 mm. As a result, a machining of the lens 16b of the eye is made possible despite the use of the same laser device 10.
The above remarks are applicable to the use of the further patient adapters 28w, 28x, 28y, 28z. Also when one of these patient adapters 28w, 28x, 28y, 28z is connected to the same laser device 10, a different treatment region is obtained, for example, through the possibility of a differing setting of the depth of focus and the existence of a differing spot diameter as well as a differing scan-field diameter. A summary of typical values of these is to be found at the end of this description.
The significance of the aforementioned parameters will be described further on the basis of
In
Patient adapter 28a is, as shown in
The laser beam 14, which is indicated schematically in
The reference symbols in
Patient adapter 28d in
Patient adapter 28e shown in
Patient adapter 28f shown in
Irrespective of the element (optical ancillary element 35, contact lens 30c, contact lens 30d) on which one or more freeform surfaces have been formed, the at least one freeform surface may have been matched to an average human eye or may have been formed in patient-individual manner. So a patient adapter may include one or more freeform surfaces which in an average human eye bring(s) about the desired adaptation of the focus diameter. However, it is also conceivable to survey the eye prior to the machining of the human eye and to derive patient-individual data therefrom. From the patient-individual (eye-specific) data, freeform surfaces can be calculated which are then formed in the associated patient-individual patient adapters. As a result, the precision of the machining can be increased. It is similarly conceivable to add wavefront corrections by virtue of the adaptive system taking the form, in exemplary manner, of a mirror 42, in order to increase the precision of the machining.
Furthermore, each of the freeform surfaces may have been provided with an optical coating, in order to reduce reflection losses of the laser radiation 14.
As described in connection with the Figures, with the aid of the differing patient adapters 28a to 28e differing treatments can be carried out with the same laser device 10 even if the settings of the laser device remain unchanged. Consequently a system is made available with which differing types of treatment can be realised with one and the same laser device.
In conclusion a Table, to be regarded as exemplary, will be given which specifies values that are typical (but not to be understood as restrictive) for the purpose of treating a certain region of the eye.
This application is a continuation of U.S. application Ser. No. 14/345,908 filed 1 Apr. 2014 which is a section 371 national stage phase of International Application No. PCT/EP2011/005062, filed 10 Oct. 2011, titled “SYSTEM, INTERFACE DEVICES, USE OF THE INTERFACE DEVICES AND METHOD FOR EYE SURGERY,” which is hereby incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 14345908 | Apr 2014 | US |
| Child | 16298954 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 16298954 | Mar 2019 | US |
| Child | 17113307 | US |
