WO2017182360A1

WO2017182360A1 - Method and system for eye observation and eye therapy, in particular apparatus for laser-assisted cataract surgery

Info

Publication number: WO2017182360A1
Application number: PCT/EP2017/058779
Authority: WO
Inventors: Thomas Nobis; Tobias Damm; Michael Stefan RILL; Marco Hanft
Original assignee: Carl Zeiss Meditec Ag
Priority date: 2016-04-19
Filing date: 2017-04-12
Publication date: 2017-10-26
Also published as: CH713869B1

Abstract

The invention relates to various aspects for a system for eye observation or eye therapy, which support individually or together a user in a workflow in ophthalmology, in particular in cataract surgery and the preparation thereof. According to the first aspect, a two-part scanner having a fast short-stroke part and a slow long-stroke part is combined with a 4-f optical system. According to the second aspect, the radiation beam between the scanners and a lens is transmitted by means of an articulated arm, wherein 4-f optical systems in the articulated arm are used. According to the third aspect, a main lens is provided with specific focal length features in order to achieve a large working distance and hence to give the user freedom in his workflow. According to the fourth aspect, a particularly precise and fast referencing is carried out between a pre-operative biometry image and a current image during the instantaneous observation or the subsequent intervention. According to the fifth aspect, a preferred coupling of an observation camera is carried out, which, in terms of space, has a particularly small adverse effect on the ocular region of the patient.

Description

Method and system for eye observation and therapy, in particular apparatus for laser-assisted cataract surgery In the field of eye observation and therapy, systems are increasingly used which perform various functions, in particular the acquisition of structural information about the eye and the making of interventions on the eye by means of therapy radiation, in particular incision generation or material removal with laser radiation. The invention therefore relates to a corresponding apparatus for eye treatment or treatment, the illumination or therapy radiation leads to the eye.

Eye monitoring and / or therapy systems are i. d. R. used in a complex workflow. An example of this is laser-assisted refractive eye surgery or laser-assisted cataract surgery. In refractive eye surgery, cut surfaces are created by means of laser radiation within the cornea, which isolate a volume and make it removable. The volume is sized so that its distance from the

Corneal curvature changes in a manner that compensates for a previously acquired ametropia. In cataract surgery, the natural, opaque lens of the eye is replaced by an artificial intraocular lens (IOL). For this purpose, a hole is cut into the capsular bag of the eye lens on its front side. Through this hole, the lens is removed after previous fragmentation and an artificial intraocular lens (IOL) is used. For the necessary access to the anterior chamber, a cut is made in the cornea and / or sclera.

In addition, to reduce corneal astigmatism, corneal incisions, e.g. B. arcuate cuts, possible. After surgery, it may be necessary in the case of a so-called "Nachstars" to completely or partially remove the rear capsular bag

Incorporating cuts into the capsular bag (on its front and / or back) is referred to herein as "capsulotomy." Cataract surgery is the most commonly performed surgery on the human eye and is therefore more consistently focused

Improvements regarding the quality of the operation result, efficiency in the

Operation execution and risk minimization. Recent developments and advances in ophthalmic femtosecond (fs) laser technology, especially in the field of refractive ophthalmic surgery, and optical coherence tomography (OCT) as

Imaging technology is increasingly automating cataract surgery. Short pulse lasers are used to "cut" eye tissue using photodisruption, a technology hereafter referred to as laser assisted cataract surgery (LCS). According to current application principles, the capsulotomy (eg circular cutting of the anterior capsular bag of the eye lens), the

Lentil fragmentation (division of the kernel of the eye lens), the access incisions in the cornea / sclera (main access and auxiliary incisions), and possibly the incisions on the cornea

Laser radiation performed. This laser radiation is treatment laser radiation or therapeutic laser radiation as it alters ocular tissue.

In US 6325792 B1 it is proposed to pulse a femtosecond laser in the

Focusing the lens to "liquefy" the lens - this corresponds to the above-mentioned lens fragmentation - or to cut the capsular bag

Positioning of the pulse focus of the femtosecond laser is performed using a

Ultrasound imaging.

In US 5246435 it is disclosed to focus pulses of a short-pulse laser in a three-dimensional Schnittm uster in the natural lens of the eye to fragment through the cuts and the subsequent blistering the lens into fragments and thereby liquefy. US 6454761 B1 proposes optical coherence tomography (OCT) instead of ultrasound imaging for the automatic positioning of laser pulses in ophthalmological operations on the cornea or other transparent structures, e.g. B. when eliminating a cataract in the eye lens to use.

The increasing maturity of femtosecond laser technology and OCT technology meanwhile allows a combination and integration of these two technologies and the establishment of largely automated femtosecond laser systems in cataract surgery. To deflect the femtosecond pulses, fixed objectives and fast mirror scanners for lateral x / y deflection of the laser beam in the eye and slowly adjustable lenses for z-deflection of the focus position along an optical axis of the eye are used on the one hand. Such systems are described for example in US 2006/195076 A1 or US 2009/131921 A1. On the other hand, systems are also known in which the objective is moved laterally slowly using a fast-moving lens for z-deflection of the focus along the optical axis of the eye. Such a system performs a so-called. Lens scan and is z. As described in DE 1 0201 1 085046 A1.

During the first years of development of the LCS some application-related problems, in particular through the introduction of a fluid interface as a mechanical-optical

Contact between the laser system and the eye were solved, see US 2012/0078241 A1 or US 6019472, was the integration of the technologies into a device and less the integration of the technologies in an overall work or a working environment in the foreground. In particular, the interaction between the femtosecond laser and the surgical microscope, which is furthermore necessary in cataract surgery, shows considerable deficits in the systems available on the market. Most of the currently known systems are independent of the surgical microscope and, because of their size, are often out of the operating room later used for the actual implantation of the intraocular lens (IOL). As a result, a time-consuming repositioning and transferring the patient is usually necessary. Only recently has this deficit been identified and corresponding improvements

proposed: In DE 102010022298 A1 and US 2012/316544 A1 it is proposed that the

To couple the femtosecond laser directly to a surgical microscope during the surgical procedure. However, the required components according to the current state of the art are still too large for such a system that such a system would be too large during the IOL implantation phase and would therefore be too restrictive and hindering for the surgeon. According to WO 2008/098388 A1, a femtosecond laser for corneal refractive eye surgery is inserted as needed under an operating microscope, as it were between the surgical microscope and the patient, and docked to the eye. Here, the surgical microscope and the femtosecond laser operate quasi sequentially and independently of each other. Above all, they are still separate devices.

Furthermore, the established systems have a number of deficits regarding

specific components, which adversely affect the quality of the surgical result, the efficiency in the operation of the operation or the risk minimization. A micro-objective scan, as also described in WO 2008/098388 A1, is relatively time-efficient in terms of the z-deflection for capsulotomy sections, or for the

Lens fragmentation. However, this approach is very time consuming for access cuts that not only provide small-scale movement along the optical axis of the eye, as disclosed in US 2007/173794 A1. Furthermore, the cut is time critical for systems with fast z-deflection for the capsulotomy. While in fast galvoscan systems a closed path in a lateral x / y plane is not a problem for the capsulotomy, in systems with fast z-deflection where the closing of the web takes time, safety is critical the eye can move during this time. Even with corneal access and auxiliary cuts, the advantage of a fast z-deflection of the laser beam does not come into play, since here, too, especially long lateral tracks have to be covered.

From DE 202004007134 U1 a Spiegelgelenkarm with 4f optics is known. The various functionalities present in a combined device for eye observation or therapy must satisfy the anatomical conditions of the human eye as well as the practical requirements of the environment during the operation.

The invention is therefore based on the object of specifying a device for eye observation and / or therapy, which are optimized with regard to the integrated components and functions, in particular with regard to the workflow in ophthalmology. The invention is in particular the object of specifying a system for eye observation or therapy of the type mentioned that without adverse mediation on a

Depth range of several millimeters has the lowest possible spherical aberration and thus reaches a focus in a very small focus.

This object is achieved by the invention in terms of five different aspects of

A device or a method for eye observation and / or therapy, which are defined in the independent claims.

The aspects of the invention as a whole allow the combination with other functions for a complex device thus assisting a user in the workflow of the

Ophthalmology, especially in cataract surgery. The aspects can be realized individually or in any combination of two, three or four. It is also possible to combine all aspects in one device. The latter complete combination will be explained below in embodiments with reference to the drawings. However, the invention is not limited to realize all aspects simultaneously, as already the realization of any subsets and subgroups is advantageous and achieves the success of the invention to support an operator in workflows of ophthalmology, especially in cataract surgery.

As far as in this description of eye observation or therapy is spoken, the corresponding system or method, of course, should also cover variants that are able to perform optional eye observation and eye therapy or

Coupling eye observation and therapy with each other. The "or" is thus not to be understood as exclusive or. Various aspects of an eye tracking or therapy system are described which individually or collectively assist a user in an ophthalmic workflow, particularly cataract surgery and its preparation. According to a first aspect, a two-part scanner comprising a fast one short-stroke and a slow long-stroke part via a 4-f optics combined. According to a second aspect, the radiation between the scanner and a lens is transmitted via an articulated arm, with 4-f optics being used in the articulated arm. According to a third aspect, a lens is provided with certain focal length features to provide a large working distance and freedom for the user in his workflow. According to a fourth aspect, a particularly precise and fast

Referencing between a preoperative bio-mode image and a current image during the current observation or following procedure. According to a fifth aspect, a preferred coupling of an observation camera, the spatial Lich in the region of the patient's eye is particularly little affected.

A preferred system for cataract surgery has in particular the following features: a short-pulse laser source;

a divergence - varying focusing unit for the slow depth variation of the

Laser focus in the eye with a focus range of approx. 1 0 to 15 mm;

a divergence - varying focusing unit for fast depth variation of the

Laser focus in the eye with a focus area of approx. 1 mm;

a fast x-y scanning system for lateral focus variation with a scan field between 1 mm and 6 mm;

- A compact applicator with laterally movable lens for laser treatment on a field of approx. 13 mm, which can be oriented in different azimuths to the patient's head;

an articulated arm with multiple joints to the free position of this applicator in space;

- An interface to the surgical microscope for the docking process, the

Operating microscope must allow observation through the applicator;

a (preferably infrared and / or green and / or green-yellow) video co-observation of the laser treatment;

- an optical coherence tomography unit (OCT) for the planning of

Laser treatment with the least possible back reflexes;

a fixed console that contains as many of the optical components as possible, but above all all fast-moving parts. An optical device that fulfills all the above-mentioned features must overcome a number of technical hurdles. These are aggravated by physical-technological or biological limits. In particular, a corresponding optical system must be used Pay attention to the anatomical contours of the orbit of the human head, ie within a conical outer contour, until a minimum distance from the eye is reached;

a consistently good quality of the laser focus and in particular a high, in particular unchangeable numerical aperture in the entire SD

Ensure treatment volume;

ensure the spectral and / or geometric and / or other separation of the individual optical functionalities;

Do not move any moving parts with as small a mass as possible in order not to jeopardize the impact of the recoil during acceleration and deceleration, and the

To minimize treatment time to m;

Avoid intermediate foci on optical components, as they could otherwise be damaged by the short pulse radiation;

Zwischenfoki also in air, d. H. away from optical components, only with a numerical aperture <0, 10, preferably <0.05, generate, in order to avoid air breakthroughs by the short pulse radiation.

A first aspect of the invention provides the system with an embodiment that combines a large focus range and fast focus adjustment. These features are usually counter-rotating, as mechanisms that allow focus position adjustment along the optical axis over a long distance are usually not fast. Therefore, according to the first aspect, there is provided a system for eye observation or therapy comprising a radiation source providing illumination or therapy radiation and a focusing means for focusing the radiation into focus

Observation or therapy volume bundles, with the focusing m ind. a focussing lens and a variable, divergence-varying optical element arranged in front of it, which adjusts a z-position of the focus, wherein the

divergence-varying optical element comprises a first divergence-varying optical module having a first z-position adjustment speed and a first z-position adjustment path and a second divergence-varying optical module having a slower second z-position

Layer displacement speed and a larger second z-position displacement path, wherein each divergence-varying optical module generates a plane of constant cross-section variable focal length and a 4-f optics images the plane of the divergence-varying optical module in an input plane of the other divergencevariierenden optical module and thus the Intersection variation between the modules transmits.

The system must cover a large axial therapy / observation area, especially when used for cataract surgery. Would the optical focusing, for example performed by a change in the focal length with a constant beam diameter on the lens of the lens, so necessarily changed the numerical aperture during focusing, which would disturb the optical properties in focus, such as the threshold energy for laser treatment, sensitive. This is therefore not permitted. According to the invention, therefore, in the first aspect, the beam cross section in the rear focal point of the objective remains constant during the z-adjustment. Then the numerical aperture in focus is identical for different eye-side optical intersections.

Accordingly, according to the invention, in the first aspect

(i) the divergence varying element contributes a plane of constant beam cross section

variable optical intersections relative to this plane and

(ii) the optical system images this plane into the back focus of the objective.

Examples of a divergence-varying element are a shape-changing mirror

(Membrane mirror, MEMS mirror, etc.), a specially shaped free-form surface pair (Alvarez element) and a variable lens (liquid lens). However, a preferred implementation is a telescope, z. B. Galilei type whose negative lens is moved axially. Then in the back focus of the other lens of the telescope is the plane with constant

Beam cross section with at the same time variable optical focal length. The light has to collide on the negative lens. Another implementation would be a telescope of Kepler type. However, the real intermediate focus in such a telescope is unfavorable for some short-pulse applications, because if the numerical aperture is too large in the intermediate focus, breakthroughs, ie. H. an ionization of the air can occur. This problem is even greater with telescopes which require a high sensitivity for focusing and thus a large numerical aperture in the intermediate image. The Galilean type is therefore preferred.

In order to achieve a fast and at the same time long-stroke z-adjustment, a combination of a fast focus module with a low focus range and a slow focus module with a large focus range is provided. The modules can be combined in any order, whereby the beam cross-section at the location of the module must remain the same during the focusing. Separate modules must be used in succession in the optical path with a distance different from zero. Then, without further action, the concept of constant beam cross section would be violated. This problem is solved according to the invention in the first aspect by a so-called 4-f system, which images the two planes on each other and transmits the Schnittweitenvariation. Preferably, the module with the low focus stroke (fast focusing) is first arranged in the light direction, and then the module with the large focus stroke in the beam path.

The distance between the two lenses of the 4-f system is always the sum of the two lens focal lengths. The planes of constant beam cross section are located respectively at the outer foci of the two lenses of the 4-f system. In this configuration, the invention achieves in particular that the numerical aperture in the real

Intermediate image in the interior of the telescope during focusing remains unchanged, so in particular does not rise. Thus, the o.g. Ionization over the whole

Focus area can be prevented.

Of course, this last condition does not have to be exactly met, i. H . the image of the plane constant beam cross section does not take place from focus to focal point. However, the detuning m uss fail so small extent, so that the then occurring changes in the numerical aperture in the intermediate image while focusing for the application are still allowed.

An eye tracking or therapy system must be included in the workflow as performed by the user. In particular, a Umbetten or a change in position is to be avoided for a patient as possible. It is therefore provided in the system, the

Radiation transmitted by an articulated arm, so that the coupling of radiation for eye observation or therapy is locally variable. Accordingly, the invention according to the second aspect provides a system for eye observation or therapy comprising an articulated arm having at least two rigid members articulated together by hinges adjustable in various joint positions, a transmission beam path comprising an optical system which transmits radiation as a free-kick with a maximum

Beam diameter along the articulated arm leads, wherein the optical system in the joints around steering mirror, which deflect according to the current joint position radiation, wherein that the optical system in the transmission beam path generates several successive planes same beam cross section and each level by a 4-f optics in the following Plane maps.

For z-focusing, a divergence variation is usually carried out in front of a lens by a divergence-varying optical element, as may for example be provided according to the first aspect. Corresponding mechanical movements performed to control the radiation for eye observation or therapy must be decoupled from the end of the articulated arm in front of which the patient is located. The

divergence-varying optical elements, in particular fast-moving components, are located therefore preferred in a fixed console. Their change in cut width must then be transferred along the articulated arm, ie over a long distance (> 1 m).

The transmission of radiation is preferably via one or more 4-f systems

carried out. The transfer takes place for applicative reasons via the movable

Articulated arm and through the rigid limbs. At the joints are optical mirrors that redirect the light according to the Gelenkarmstellung. However, these mirrors, as well as all other optical elements necessary for the transfer, must not be in any focus position in contact with the laser focus in intermediate images of the 4 f systems. Because of the big one

However, in the focus range required for the application, the intermediate foci within the 4-f systems also move around long axial distances. On this route then no optical elements, d. H. neither articulated mirrors nor lenses of the 4-f system are located. This is accomplished in embodiments by (i) using for transmission a series of 4-f optics adapted to the articulated arm geometry needed for the application. In the

In succession, the rear focal point of the second lens of the front 4-f system is located at the location of the front focal point of the first lens of the subsequent 4-f system. The 4-f systems are not necessarily 1: 1 systems, but can be compared to the beam diameter in the interstices

Enlarge or reduce the output diameter,

(ii) the articular mirrors are preferentially in the regions between the 4-f systems

(i.e. between the lenses mentioned in point (i)),

(iii) the focal lengths and beam diameters of the 4 f systems are chosen such that the numerical aperture in the intermediate image of the 4 f system is:

0.05> NA '> 2.2 -

D

The upper limit of 0.05 is a preferred variant. Generally values up to 0.10 are possible. Here, STMA means the maximum deviation of the focus position in the eye measured from the zero position, which is measured in depth of field. H. from the focus position with collimated beam in front of the movable lens. Let the diameter of the collimated beam on either side of the 4-f system be D. The focal length of the lens of the page in question is f.

For realistic therapy scenarios, for example, the maximum focus position adjustment with respect to the zero position may be ± 7.5 mm. For a numerical aperture for eye therapy of, for example, 0.2, the depth of field in an aqueous solution is about 0.034 mm. It therefore applies STMAX ^B 220. For light with a wavelength of about 1, 0 μιη follows for Beam diameter up to 16 mm a permissible range for the numerical aperture 0, 1 (preferably 0.05)> NA '> 0.03.

The upper limit for the numerical aperture serves to avoid ionization of the air. For the minimal possible beam diameter for the transmission chain, therefore, D> (2,2 / 0, 1) ^* λ ^* ST _M AX and preferably D> (2,2 / 0,05) ^* λ ^* STMAX

For realistic scenarios follows approximately D> 5 mm, preferably D> 10 mm. Because of NA '= D / 2f, for the smallest permissible partial focal length of a 4-f system, f> D (2 ^* 0, 1)> 50 mm, preferably f> D (2 ^* 0.05)> 100 mm. Since in the interior of the 4-f systems preferably no joint mirror should be, the joints must have a minimum distance of 100 mm, preferably 200 mm and more.

Since deviations from the zero position to the depth (in the eye) or to the height (away from the eye) may cause different maximum focus deviations, the above-mentioned applies. Condition for the respective lens and the respective beam diameter, to which the intermediate focus moves at the considered feed.

It should also be noted that the planes of constant beam cross-section need not necessarily be located exactly at the front or rear focal points of the lenses of the 4-f systems. Then the numerical aperture changes slightly during the focusing movement. This is permissible as long as the o. G. Limits of the numerical aperture are not exceeded and no Zwischenfoki wander over optical surfaces. The system for eye observation or therapy according to a second aspect of the

The invention provides a radiation source that provides illumination or therapy radiation. A focusing device focuses the radiation into a focus into an observation or therapy volume. The focus covers a focus volume that has a lateral extent and an axial extent. Preferably, the focus has lateral and / or axial extension of not more than 50 μιη. An xy scanner directs the focus in the observation or

Therapy volume lateral. The focusing device has an xy scanner

Subsequent focusing optics and a front of the xy scanner z-scanner on. This adjusts the (axial) depth of focus. A controller controls the z-scanner to adjust the depth. The focusing optics is aberration-corrected relative to a specific setting of the z-scanner and thus a certain depth of focus. This depth position represents a zero level. If the z-scanner is adjusted relative to the zero level, the transmission of the focusing optics changes and this then causes spherical aberration. In preferred embodiments of the focusing optics, this change is linear to z adjustment. Furthermore, the system comprises an adjustable, z. B. controlled by the control device correction optics. An adjustment of the correction optics changes the spherical aberration in the observation or therapy volume. The correction of the focusing optics takes place to the effect that in the zero level no or only a small spherical aberration occurs. This is a particular setting of the adjustable correction optics that represents a zero setting. If the z-scanner is in a position corresponding to the zero level, the opening error is minimized. This condition is hereinafter referred to as "free of spherical

Aberrations. "When adjusting the z-scanner and thus adjusting the depth of focus from the zero level, the correction optics is given a setting that differs from the zero setting, and so is that the correction optics reflect the changes in spherical aberration caused by the zero aberration Focusing optics caused is compensated.

In a preferred embodiment to the second aspect, the focusing optics changes the spherical aberration in the case of deviations of the focal depth position from the zero plane. the aperture error, linear, ie proportional to the deviation of the depth of focus from the zero plane. At the same time, the correction optics are designed such that their adjustment also causes a proportional change in the spherical aberration in the observation or therapy volume. The control device then only has to take into account the corresponding proportionality factors, ie linearity gradients, and can easily accomplish the opposite adjustment of the z-scanner and correction optics.

Since the z-scanner comprises a mechanically moved component which performs a relatively large stroke, it is preferred for ophthalmological applications to arrange such components as far as possible from the patient. This avoids vibrations and noises that could irritate the patient. It is therefore preferred that the z-scanner comprises a divergence-varying optical element upstream of the xy-scanner, which includes the

Divergence of the illumination or therapy radiation changed adjustable. Particularly preferred here is an embodiment in which the z-scanner is designed as a telescope with a fixed collective lens system and a movable lens system, wherein the correction optical system is integrated into the collective lens system and / or the movable lens system. This integration is then carried out so that the adjustment of the z-scanner from the zero level and the setting of the correction optics deviating from the zero setting are automatically in opposite directions. This embodiment is particularly preferred when the radiation source provides short-pulse therapy radiation. Then you will run the telescope expediently as a Galilean telescope. Alternatively, it is also possible to execute the correction optics separately from the z-scanner. It is preferably arranged in a pupil plane, so that it performs the correction regardless of the deflection angle of the xy scanner. It can have at least one of the following elements: a shape-changing mirror, an open-space pair, an Alvarez element, a variable lens, a liquid lens. The invention takes away from the previous approach, in the optics of the system for all depths to correct the optics so that the opening error is tolerable. Instead, only a correction is made with regard to spherical aberrations, which applies to a plane such as zero plane. For all other levels, an opening error occurs. This is corrected with the correspondingly controlled correction element, so that as a whole the focusing of the illumination or therapy radiation is made as free as possible from spherical aberrations. Femtosecond laser-based systems are usually scanning systems. They cover the treatment field laterally by an xy-scanning element (tilt mirror, rotation prisms, etc.), the xy scanner. For focusing, a divergence-varying element is usually used in front of the scanners. Examples of such divergence-varying elements include: a variable-shape mirror (membrane mirror, MEMS mirror, etc.)

a specially shaped free-form surface pair (Alvarez element)

a variable lens (liquid lens)

a Galilei-type telescope (moving negative lens)

- a telescope of the Keppler type (moving positive lens)

The o.g. Problem is solved in embodiments that

(i) the focusing optics corrects all other optical aberrations in a conventional manner according to the prior art,

(ii) the spherical aberration for a certain depth of focus, the zero level, is corrected with the degrees of freedom of the scanning optics (the zero level does not necessarily have to be part of the addressed focus area),

(iii) the divergence varying element is corrected for spherical aberration at the input divergence associated with (ii), and (iv) in the case of the other input divergence positions, the linear change of the spherical aberration is maintained wholly or at least partially with the opposite sign, ie compensated in total. Fully corrected optics for both divergence varying element and

Focusing optics is not necessary. The spherical aberration at focus is i.d.R. corrected in the middle of the focus area. At the edges a residual error is accepted and compensated. This is advantageous in the transition to shorter wavelengths and / or higher NA.

In the o.g. Elements can be a linear change in the spherical aberration, for example, achieve by: a variable-shape mirror (via targeted additional variable deformation with Fringe Zernike surface type Z9) a specially shaped freeform surface pair (Alvarez element) with purposeful design of the surface pairs, - a variable lens (liquid lens) by specific modification of the lens surface with a Z9-type fringe Zernike surface, a galilei-type telescope (moving negative lens) or a Keppler type (moving positive lens) by design of the spherical lenses, in particular the non-moving lens Lenses (exploiting the variable beam height at the quiescent lens to produce variable contributions to spherical aberration, possibly using aspheres and / or additional spherical lenses).

Any eye tracking or therapy system requires a lens. This is also referred to below as the main objective. It is located in front of the patient's eye. Behind the main lens i. d. R. space needed, z. B. for movable mirror to

Bildfeldverscheibung as well as for the coupling of further functionalities, z. The main objective converts the collimated laser light from the device into a focused one

Laser beam with sufficient numerical aperture for therapy. However, since the patient's eye is treated or observed at different depths, a certain axial focus adjustment range should be accessible on the eye side, ie the above-mentioned collimated zero position should be left. This Fokusverstellbereich is axially about 10 to 15 mm. For this purpose, it is necessary that laser light coming from the device already pre-focused on the Main objective meets. However, this naturally creates an intermediate focus in the applicator. In the case of a short focal length main lens, ie in case its focal length is comparable to the length of the focus area in the eye, the intermediate focus behind the lens comes very close to this. However, such intermediate foci must not coincide with optical surfaces, as they may otherwise damage them. In the above

short-focal case then the space available after the main objective would be too limited. Rather, the focal length of the main objective must be as large as possible in order to be able to place all the elements after the main objective. The long focal length also has a positive effect on the achievable working distance, which should also be as large as possible in order to allow a sufficient distance from the patient's head. However, if the focal length of the main objective is chosen to be large, even the smallest beam angle deviations in the device cause a large stray circle of the therapy laser on the eye. In addition, the beam diameter in the zero position is very large, d. H. the moving optical elements (mirror, main objective) correspondingly heavy.

It is therefore provided according to the third aspect of the invention, a system for

Eye observation or therapy, comprising: a radiation source that provides illumination or therapy radiation, and a focusing device that focuses the radiation into a focus in an observation or therapy volume, wherein the focusing device at least one focusing lens and this has upstream, variable, divergence-varying optical element, which adjusts a z-position of the focus, wherein the focusing device in the observation or therapy volume a numerical aperture below 0, 1, preferably 0.05 realized, the variable, divergenzvariierende optical element to adjust the z-position of the focus over a range between 10 and 15 mm is formed and the focal length of the lens between 20 and 40 mm, preferably between 25 and 35 mm.

According to the invention, in the third aspect, the focal length of the main objective is in the range between 20 mm and 40 mm, preferably between 25 mm and 35 mm. In order nevertheless the for the o.g. Co-observation required working distance to produce, the main objective is preferably designed as a combination of a positive lens and a spaced negative lens. In this case, the positive lens and / or the negative lens have one or more aspherical surfaces in order to minimize the aberrations for the therapy focus and to reduce the mass of the moved main objective. If the aspherical surface (s) were omitted, several spherical lenses with a higher mass could be used instead.

In order to minimize the pulse broadening of the short pulse laser, the positive lens is preferably made of a crown glass with a Abbe number> 50. To the aberrations altogether too Further, the positive lens is further preferably made of a material having a refractive index> 1, 6 manufactured.

To further minimize pulse broadening, the negative lens is preferably designed as a cemented or uncemented group, i. H. from a combination of a positive and a negative lens with a total of negative refractive power. The negative lens of the cemented element is in this case preferably made of a high-index flint glass with Abbe number <40 and refractive index> 1, 7. The positive lens of the cemented element is preferably made of a high-index crown glass with Abbe number> 50 and refractive index> 1, 6.

The negative lens of the main objective is preferably designed to be laterally adjustable in order to compensate for the axis profile remaining due to the prism tilting.

The main lens is preferably movably coupled to two mirrors to perform biaxial field shifting. It is then in the sense of this description a movable lens.

A fourth aspect of the invention assists the user in the interaction of diagnosis or biometry and further observation and / or therapy of an eye.

Especially in cataract surgery, it is necessary for astigmatic patient eyes, the orientation of a toric intraocular lens to be implanted or the position of

Correction cuts on the cornea, which are intended to remedy astigmatism, to precisely align the eye. For this reason, astigmatism axes are determined in the preoperative measurement of the eye, in so-called biometry. At the same time, a reference image is generated, and the position of the axes is stored together with the reference image.

Based on the reference image, the position of the axes must then be determined again during a subsequent observation of the eye or during a surgical procedure. It is therefore expedient to map reference structures in the reference image, which allow a later current image to be assigned in order to determine the position of the determined eye structures (for example, in the current image) from a relative position of structural parameters of the eye (for example astigmatic axis) and position of the reference structures in the reference image

Astigmatic axis) easy to find again. In particular, for an operative procedure or its preparation, it is expedient to find principal axes of an astigmatic eye and to superimpose them in the current picture.

It is therefore provided in a fourth aspect of the invention, a system for

Eye observation or therapy, comprising: a biometric device which generates at least one reference image of the eye, which contains at least one reference structure of the eye, min. a structure parameter of the eye, preferably an astigmatism axis, determined and determines its relative position to the reference structure, an observation or therapy device comprising an imaging device for generating a current image of the eye, which also contains the reference structure of the eye, and an image processing device for

Identifying the reference structure of the eye and determining its current position and determining the current position of the structure parameter from the current image and the reference image, wherein the biometrics device generates the reference image of the eye in a spectral channel using a spectral region in which Absorption dye in blood vessels of the sclera has an absorption maximum, or produced in a spectral channel in which fluoresces a fluorescent dye in the blood vessels of the sclera, and the

Imaging device generates the current image of the eye in the same spectral channel.

The fourth aspect envisages exploiting a specific spectral channel for both biometry and later registration in the current image by absorbing an absorbing dye present in the blood (e.g., at least 30% absorbency) and It is dark and particularly rich in contrast to the environment or a fluorescent dye fluoresces. As an absorbing dye, for example, the hemoglobin present in the blood comes into question, which absorbs particularly well in the green spectral range, so then in a corresponding spectral channel then well, d. H. rich in contrast. Due to the approach according to the invention, the retrieval of the reference structures in the current image, which is also referred to as image registration, is carried out in a particularly simple and reliable manner, since the blood veins used appear particularly rich in contrast in the reference image and the current image due to the spectral filtering. According to the invention, according to the fourth aspect, a reference image from the biometric measurement of the eye is used, which is filtered in a specific spectral channel in which the current image is also filtered. This eliminates the need for complicated algorithms to register the images with one another or to locate the position of the eye structures to beimproved in the current image (for example astigmatism axes).

A particularly preferred variant of the fourth aspect is based on the hemoglobin in the blood. Since the hemoglobin in the blood absorbs light particularly well in the green-yellow spectral range, particularly high-contrast reference image images of vein structures with green or yellow or green-yellow, in particular red-free, illumination are obtained. To use these images as input data for laser therapy (eg, laser therapy devices for cataract surgery), the therapy system also uses such illumination. Ideally, this is a spectrally matched lighting

(Illumination max. Should be between 520 nm and 580 nm wavelength) directly at Device-eye interface. In a special version, the green, yellow or green-yellow light is generated by LED and led via a patient interface with built-in light guides to the patient's eye. Since both the reference image of the biometrics system and the live image of the

Using the same illumination on the therapy system, you can create very similar images of the patient's eye, enabling robust image registration.

The spectral properties of the "green light" are to be tuned so that maximum contrast of the reference structures is achieved - the illumination maximum should be between 520 nm and 580 nm, since hemoglobin is the essential dye of the reference structures.

This "reference structure-optimized illumination" can be used both in the biometry device and in the observation / therapy device.

Optionally, the registration between biometric, non-dilated reference image and the dilated, sucked with the patient interface eye in one step. Aspects are essential: 1. The detectable image field through the patient interface is large enough, so that around the

Limbus enough reference structures (blood vessels, etc.) are visible, so that a registration is possible. Image data of the iris are optionally hidden during this process, so that they do not interfere with the registration. This makes the registration procedure more robust and is equally possible with non-dilated irises and dilated irises.

2. The illumination when taking both pictures, d. H. in biometrics and

sucked image is spectrally largely similar, it is z. B. substantially green, yellow or green-yellow, so that vessels are very clearly visible. The advantage is not only the easier handling and the higher precision by eliminating any intermediate steps.

In systems for ophthalmology, observation of the eye are particularly important. This is especially true when the system applies eye-therapeutic radiation to the eye. Therefore, according to a fifth aspect of the invention, there is provided a system for eye observation or therapy, comprising: a first beam path for first treatment or observation radiation leading to the eye, which extends to the eye along one main optical axis, a second beam path for the second Observation radiation, which extends along an optical minor axis, and a prism splitter, which, as seen from the eye coupled the second beam path in the first beam path and seen away from the eye has an entrance surface and a first and a second exit surface, wherein the prism splitter the first beam path along the optical minor axis between the entrance surface and the first exit surface, and the minor optical axis extends away from the second exit surface, wherein the minor optical axis is ± 20 ° parallel to the major optical axis and the prism splitter is a combination of a beam deflecting Leman prism twice and one with the Leman prism cemented

Additional prism is formed, the Leman prism seen from the eye decouples the second beam path at one of the entrance surface first deflection from the first beam path, at least. At least two deflecting redirects and the main optical axis substantially (± 20 °) parallel or whole offset parallel to the second

Exit surface leads, the additional prism is cemented to the first deflection surface and having a surface parallel to the entrance surface, which forms the first exit surface, and between the additional prism and the first deflection a dichroic or intensity splitter layer is formed.

A co-observation through the second beam path is thus coupled by a specially shaped prism.

The required for this purpose, prism arrangement according to the invention

uses in its basic form an arrangement similar to that of a Bauernfeind prism, using an additional total reflection surface to the beam path of

Follow up, d. H. to steer away from the patient's head. (Sprenger-Lemane prism without roof edge),

also contains a right-angled prism, which can be combined with the o.g. Prism is cemented. This creates the opportunity for dichroic separation of the beam paths on the cemented surface. The opposite exit and entry surfaces are parallel to each other for the light passing through,

allowed by its geometry, angle of incidence at the cemented dichroic

Divider layer <30 ° set. This allows for a simpler, production-ready design for the splitter layer. The dichroic splitter preferably deflects a portion of the light (eg, λ = 750-950 nm and / or yellow-green light) to the side while the remainder, e.g. B. parts of visible light (for example, λ = 400 ... 700 nm) and the therapy laser light (for example, λ = 1000 ... 1 100 nm) passes completely unhindered, is defined by an angle in the range between 0.5 ° and tilted 3 ° in order to block back reflections of the OCT beam path on the plane surfaces, is designed so that the observation light is directed on the side facing away from the patient's eye upwards and perpendicular to the associated exit surface, increased by the higher-than-air compared to the effective material

Working distance for the therapy optics, which is conducive to the integration of all functionalities,

contains a glass path, which is also tilted at a same angle in the range between 0.5 ° and 3 ° in an azimuth twisted by 90 ° to the prism mentioned above. This compensates for the astigmatism occurring due to the tilting of the upper prism, and redirects the back reflections of the OCT light to the same extent. The additional glass path also increases the working distance by a further amount.

In addition, it is easy to integrate into the permissible cone contour.

is further paired with the associated, e.g. movable objective of therapy optics. This has a provision that can compensate for a fixed amount of coma on the axis. This provision may be, for example, a laterally displaceable lens or a specially shaped free-form element in the pupil.

The system in embodiments may in all aspects comprise a short pulse laser system including a short pulse laser source, a beam path, and an applicator head for directing short pulse laser radiation from the short pulse laser source to the eye to be operated. A short-pulse laser source is a laser source which does not emit the light continuously but in pulsed form. This means that the light is emitted in time-limited portions. The pulse rates of such a short-pulse laser are usually in the femtosecond or picosecond range. But also pulse rates in the

Attosecond range are possible. Due to the pulsed light emission very high intensities can be realized, which are suitable for laser-tissue interactions via Mehrphotonen- absorption, such. As the photodisruption or plasma-induced photoablation needed. This is the case in all applications where not only on the surface material is removed, but interactions in all three dimensions is achieved.

The beam path ensures that the short-pulse laser radiation emitted by the short-pulse laser source is conducted to an exit location. It can be realized for example by a light guide or by a mirror system. The applicator head, which is attached to the

Short-pulse laser source connects opposite end of the beam path, forms the exit point of the short-pulse laser radiation. There is the lens with a plurality of optical elements according to the aforementioned third aspect. It is advantageous if the short-pulse laser system further describes an x / y deflection system, also referred to as x / y scanning system, as well as a deflection system or scanning system for the z-direction and / or a divergence varying Lens system has. The possibility of deflecting the focus of the short-pulse laser radiation in the x-direction and y-direction as well as in the z-direction in a volume which follows the exit location of the short-pulse laser radiation can also be realized by a plurality of deflection devices for one direction, for example a scanner for a slow movement over a larger area and for a very fast movement over a small area, as provided in said first aspect.

The system optionally includes a surgical microscope with a tripod and a microscope head. The microscope head contains the optics and the object illumination of the surgical microscope. With such a surgical microscope, it is possible at any time to provide a visual overview of the status of the treatment. The surgical microscope, however, also contributes to the fact that an eye to be treated can be aligned with the system under optimal illumination. The system optionally also includes a control unit which is used to control the

Implementation of a short-pulse laser eye surgery is set up. The control unit can be designed in one piece or in several parts. The components of the device are advantageously connected to the control unit via communication paths. In the case of multi-part control unit, all components of the control unit are also advantageous over

Communication paths interconnected. Such communication paths can be realized by means of appropriate cables and / or wireless.

Furthermore, the system optionally comprises a housing which encloses at least one short-pulse laser source as the radiation source, and two (in the second aspect, an additional) articulated arms, which are arranged on the housing or on an extension of the housing. Each articulated arm comprises a plurality of rigid members, which are hinged together, that each two rigid members are connected by at least one joint.

The microscope head (if present) is arranged on an articulated arm. This articulated arm forms z. B. together with the housing, a tripod of the surgical microscope. At the second articulated arm (which in the second aspect has the optical system), again advantageously at the end remote from the housing of the articulated arm, the applicator head is arranged. The length of the second articulated arm is then such that the entire operating range of the microscope head of the surgical microscope, which is arranged on the first articulated arm, can be exploited. The two articulated arms can thus follow each other in all movements. In this

Embodiment is provided an interface between the applicator head and microscope head, with which the applicator head and the microscope head can be mechanically and optically connected to each other and released again. The interface is optionally characterized by a first structure on the first articulated arm and / or on the microscope head and a second structure on the second articulated arm and / or on the applicator head, which are matched either by the key lock principle or can be connected to one another via an intermediate piece. To combine the applicator head and the microscope head mechanically and optically means, in addition to the mechanical connection and thus the establishment of a fixed relationship of the applicator head and the microscope head to each other, both thereby also to connect with each other optically, so that one

An imaging beam path of the surgical microscope passes through the applicator head. Then there is an optical path for the structures of the eye to be observed with the surgical microscope through the applicator head.

The beam path, in particular for the short-pulse laser radiation, then passes through the second articulated arm according to the second aspect. It is designed so that it can follow all movements of the second articulated arm and in any position of the second articulated arm, the radiation, for. B. can lead to their exit point on the applicator head in the same quality.

Further, the applicator head and the microscope head are both three-dimensionally movable independently of each other and connected to each other. This mobility of the applicator head and the microscope head is also given when the applicator head and the microscope head are connected to each other. This requires appropriate additional

Degrees of freedom in the first and second articulated arm. Due to the mobility of the applicator head alone, but above all connected to the microscope head, the exit location or short-pulse laser radiation is also movable in three-dimensional space - in a preferred variant also with respect to its beam direction at the exit location So

For example, it is also possible to treat the patient in a non-lying position, or indeed in a lying position, but with an employee lying position. The achievable volume in the room is limited by attacks of the joints.

The system can be designed in particular for the short-pulse laser eye surgery, with which not only the cutting of tissue by plasma-induced ablation and / or photodisruption is possible, but also the adhesion of tissue by coagulation and ablation of tissue by ablative effects of the short pulse laser radiation.

Only the properties of the short-pulse laser radiation must be in accordance with

Application goals are set.

In a preferred embodiment, the system further comprises an optical coherence tomography (OCT) module including an OCT light source, an interferometer and a detector. The OCT module can also be enclosed by the housing. Especially It is preferred to design the OCT module such that it is set up for coupling in a radiation emitted by the OCT light source selectively into the microscope head or into the applicator head. This can be done for example by means of one or more optical switching points, in the beam path of the OCT light source

emitted radiation as well as the returning from the eye measuring light are provided.

The coupling of the radiation of the OCT light source via the applicator head has the advantage that it can be superimposed easily and mechanically stable with therapeutic short-pulse laser radiation. So both beam paths can be calibrated to each other. This variant is therefore used in practice for the planning and control of the short-pulse laser treatment. The coupling of the radiation of the OCT light source via the microscope head, however, allows the surgeon to make tomographic images of the patient's eye during and / or after the manual operation phase. For example, with the help of this technology, intraocular lenses can be precisely aligned or free particles within

Aqueous humor can be identified and removed. For coupling technically advantageous, it is at closely spaced wavelengths of short pulse laser and OCT lighting a

Ring mirror for merging the short-pulse laser radiation and emitted by the OCT light source radiation into the system for the short-pulse laser eye surgery. The short-pulse laser radiation is z. B. reflected at the annular mirror, while the radiation emitted by the OCT light source of the OCT module propagates through a hole in the ring mirror in the direction of the eye and the OCT detector detects the reflected radiation of the OCT light source from the eye through the hole in the ring mirror , The ring mirror can be movable. Preferably, a 90 ° position of the coupling of the radiation emitted by the OCT light source radiation in the beam path of the short-pulse laser radiation, wherein the

Ring mirror is arranged in a 45 ° position. If the wavelengths of the short-pulse laser radiation and the OCT light source can be separated spectrally or with respect to the polarization, then the laser and the OCT beam path can also be combined via dichroic and / or polarization splitters or combiners.

In a preferred system for short-pulse laser eye surgery, both the first articulated arm and / or the second articulated arm have at least three joints. In the case of three joints, at least two joints, ideally all three joints, have the function of one joint

Ball joints meet d. H. not just a rotation possibility to offer a single axis. Rather, such a hinge must allow a rigid member to be connected to the

adjacent member, which are both hinged, can describe any angle in the room, the radius of action may possibly be limited by other structural obstacles to a portion of the room, but not on a movement within one level. In a specific embodiment, one of the three joints may have only a single axis of rotation. However, preferably only three joints all three joints perform the function of a ball joint. In this way, the optimum mobility of the first and second link arms, both attached to the housing or to an extension of the housing, is secured both in the interconnected state and independently in three-dimensional space. If, on the other hand, joints are used which only offer one possibility for rotation about one axis, then a comparable one is possible

Mobility achieved with at least five joints per articulated arm, which have different axes of rotation. Of these, three joints should allow rotation about vertical axes, and two joints should allow rotation about horizontal axes; H. Represent tilting axes that lead to a tilting of the following after the joint rigid member. Is preferred in this variant - ie when using joints with one each

Possibility of rotation around an axis - an articulated arm which has six joints with one axis of rotation per joint. In this case, three joints should allow for rotation about vertical axes and another three joints for rotation about horizontal axes. Here, the tilting of the following after the joint rigid member or an end piece such as the applicator head or the microscope head is possible. Basically, the joints of each articulated arm realize at least six degrees of freedom, which are given by three vertical and three horizontal axes of rotation, with vertical and horizontal axes of rotation along an articulated arm can alternate. In particular, a pair provides a joint with a vertical axis of rotation and a joint with a horizontal axis

Rotation axis, which are arranged in close proximity to each other, the same function as a ball joint. Among the short-pulse laser sources in ophthalmic surgery are the femtosecond (fs)

Laser sources are by far the most frequently used laser sources. They have proven to be particularly suitable and easy to control for these applications. Therefore, it is advantageous if the system is designed for short-pulse laser eye surgery and a

Femtosecond laser source has.

Optionally, the system also includes a confocal detector in addition to an OCT. By recording an A-scan - ie a one-dimensional depth profile along the optical axis - and / or a B-scan - a two-dimensional scan along the optical axis and perpendicular thereto - two structures of an eye using the OCT and an intensity profile using the confocal detector Going through a z-focus position, an offset and a scaling factor between the OCT signals and the intensity profile can be determined. This allows in succession, the focus position of therapy radiation, z. B. the short-pulse Laser radiation, using OCT signals, in particular of OCT images, to control very precisely.

Optionally, the coherence length or measuring length of the OCT light source in air is more than 45 mm, particularly preferably more than 60 mm. Thereby, the entire anterior chamber portion of an eye is detected within an A-scan, without the optical path length of the

Reference beam path must be adjusted, even if the optical path to the eye changes by a lateral lens movement. The displaceable image field of the system, in particular in the case of a short-pulse laser system for ophthalmic surgery, is preferably greater than 1.0 mm but less than 6.0 mm in diameter, more preferably greater than 1.5 mm but less than 3.0 mm. The image field is located in an image field plane in which it can be moved by a movement of the lens in the x and / or y direction. According to the first aspect, the image field plane itself can be displaced along the optical axis by a scanning movement in the z direction. The cross-section of the movable objective depends in particular on the scanning range of the x / y scanning system. Thus, the focus of the radiation at each location of the three-dimensional scan volume can be selectively deposited by superimposing the beam deflections of the movable lens and the mirror scanners.

The optics, which is arranged in the beam path to the articulated arm, as well as the divergence of the radiation varying modules are preferably mounted on an optical bench. The optical bench itself is optional with three points on, attached to or within a housing, on which preferably also the articulated arm is arranged. All deformations of the mounting surface in the housing thus have no effect on the adjustment state of the optics on the optical bench, but on the position of the optical bench for entry into the articulated arm with his

Beam guidance means. Changes in this position can be compensated with a beam stabilization. It is understood that the features mentioned above and those yet to be explained not only in the specified combinations, but also in others

Combinations or alone can be used without departing from the scope of the present invention. The invention will be explained in more detail for example with reference to the accompanying drawings, which also disclose characteristics essential to the invention. Show it:

1 shows a first system for the short-pulse laser eye surgery; FIG. 2 shows a second system for short-pulse laser eye surgery; FIG.

3 shows a device for independent weight compensation of an articulated arm;

4 shows a short-pulse laser system for eye surgery (beam generation and optics);

5 shows a structure for combining short-pulse laser radiation from the short-pulse laser source and OCT radiation from the OCT light source;

6 shows two illustrations for explaining how the movement of the focus of the short-pulse laser radiation has an effect on the laterally scanning objective of a short-pulse laser system;

7 shows a schematic representation through a beam splitter prism used in the beam path of the first or second system;

8 shows two illustrations for the embodiments of a main objective of the first or second system;

9 shows two representations for clarification of the z scanning technique, in the first or second

System comes into use;

10 and 11 schematic diagrams of a divergence-varying optical element for z

Position adjustment of the focus of the first or second system;

FIG. 12 shows a schematic view relating to a two-stage z-focus adjustment in the first or second system; FIG.

13 shows an optical beam path in which radiation is transmitted along an articulated arm in the first or second system;

Figs. 14 and 15 are schematic diagrams of the coupling of the radiation to the eye

concerning spectral selective illumination / detection for position registration of a

eye,

16 shows a schematic view of an optical system of a device for laser-assisted eye surgery, wherein the beam path from a z-scanner to the eye is shown schematically, FIG. 17 shows a z-scanner of the device of FIG.

Fig. 18 details the adjustment of the focus position in a Augencornea with the device of Figure 1 and

19 different dependencies of the spherical aberration on the depth of the

Focus.

The invention will be described below with reference to eye surgery, which is merely exemplary of various ocular vision or therapy tasks for which the various aspects of the invention are applicable.

In the following embodiments, a short-pulse laser beam source with femtosecond laser or fs laser is used as the short-pulse laser, which are the most commonly used in the field of eye surgery laser short pulse laser - and thus the best studied. Nevertheless, all systems described here are also compatible with other short-pulse Lasers feasible. fs lasers are thus, unless explicitly on the pulse length as

distinguishing feature, as a synonym for short-pulse laser.

To the extent OCT, Optical Coherence Tomography, is used below, OCT is synonymous with any method that can measure distances in the eye, or capture images from the eye or its components, using time-domain Optical Coherence Tomography (TD -OCT), Spectrometer-based Spectral Domain OCT (SD-OCT), or Wavelength Tuning-based Swept Source OCT (SS-OCT).

The system described here, in which the various aspects of the invention are realized purely by way of example in combination, serves for the laser-assisted cataract operation.

By means of the short pulse laser beam source cuts are carried out, for example a

Accession to the anterior chamber of the eye through the cornea, a capsulotomy ie-incision, incisions to comminute the lens nucleus of the eye or incisions on the front of the cornea to correct vision defects.

With regard to the integration of the various components used with respect to one for the operator, ie preferably a doctor, in particular an eye surgeon, optimized

1 and 2, a first and a second system 100 for the short-pulse laser eye surgery are shown, each comprising a fs laser system as a short-pulse laser system 200 m with a short-pulse laser source 210, in this case an fs laser source, a beam path and an applicator head 220 for guiding the fs laser radiation to the eye 900 to be operated.

The structure of the first and second systems 100 for the short-pulse laser eye surgery also includes an operation microscope with an operating microscope head 320. In this case, the entire the surgical microscope and its optics in the microscope head 320 is arranged. The first system 100 for the short pulse laser eye surgery of Fig. 1 further comprises

OCT module 400, which includes an OCT light source 405, an interferometer, and a detector. The second system of FIG. 2 may in principle also contain such an OCT module. For the interaction of the system components shown in FIG. 1 and FIG

Presence of an OCT module but not mandatory.

The first as well as the second system 100 are from a controller, so one

Control unit 500, which is either centrally located as here or distributed in several subunits over the system controlled. For this purpose, communication paths between the Control unit and individual components of the system or between subunits of the control unit can be used. The systems 100 of FIG. 1 and FIG. 2 further include a housing 1 10, which may also be referred to as a console. This housing 1 10 encloses the fs laser source 210 and the control unit as a central control unit 500, in the case of the first system of FIG. 1, the housing 1 1 0 also surrounds the OCT module 400.

The microscope head 320 is attached to a first articulated arm 120 and the applicator head 220 to a second, separate articulated arm 130, through which the applicator head 220, the light of the fs laser source 210 is supplied. For this purpose, a beam path passes through the second articulated arm 130. The first articulated arm 120 and the second articulated arm 130 are attached to the housing 110 and an extension of the housing 110, respectively.

Two parts of an interface 150 are provided on the applicator head 220 and microscope head 320, through which the applicator head 220 and the microscope head 320 can be mechanically and optically connected to one another. For loosening or joining of

Microscope head 320 and applicator head 220, the interface 1 50 on a doctor or automatically switching mechanism.

The second articulated arm 130 has the same degrees of freedom of movement as the first one

Articulated arm 120, the z. B. simultaneously forms the tripod of the surgical microscope 300. By a corresponding number, arrangement and configuration of joints 140 of the articulated arms 120 and 130, the required degrees of freedom are generated by which the applicator head 220 and the microscope head 320 both independently and interconnected are three-dimensionally movable in a volume. In the case of the first system for the short-pulse laser eye surgery 100 of FIG. 1, this is achieved by way of example by means of three joints 140 with ball joint function. In the second system 100 of FIG. 2, equivalent degrees of freedom as those with three hinges 140 m with ball joint function are exemplified by three hinges for rotation about vertical axes 140-O1, 140-02, 140-05 and 140-L1, 140-L2, 140-L5 and a Paralleltragarm 145, which is a rigid member of the first and second articulated arm 120, 130, with horizontal hinges 140-03, 140-04 and 140-L3, 140-L4 for the up and down movement , So a tilting movement, provided.

The lengths of the rigid members of the second articulated arm 130 are designed so that the entire working range of the surgical microscope head 320 in a semicircle of 180 ° in front of the device, so before the system for the short-pulse laser eye surgery 100, can be exploited. The applicator head 220 serves to irradiate short pulse laser radiation into the eye. So he gives off short-pulse laser radiation. It is supplied by the articulated arm 130 from the housing 1 10, in which the fs laser source 210 sits. In principle, one could think of guiding the short-pulse laser radiation in an optical fiber passing through the articulated arm 130.

However, optical fibers are disadvantageous in the case of short pulse laser radiation used for material processing, that is to say also in the present example of cataract surgery in view of the high beam intensity in the short pulses. It is therefore preferred to guide the radiation in the articulated arm 130 with a free-beam optic. The free diameter of the optics is dimensioned so that no vignetting of the

Laser beam results. The rigidity requirements of the bearings and the parts of the second articulated arm 130 are reduced by automatic beam tracking. The second articulated arm 130 further provides options for passing electrical cables, OCT optical fiber 41, and the vacuum tubing for aspirating a patient interface 600 to the patient's eye 900, as well as for aspirating the patient interface to the applicator head 220. At the junction of hinges 140-L2 / 140-L3 and 140-L4 / 140-L5, all cables are routed outside hinges 140 to avoid overstressing the cables against torsion. At the joint 140-L1, the cables are guided concentrically to the optics by the joint 140. Depending on the embodiment variant, a parking arm 190 is provided on the housing 110 with a depositing surface for the applicator head 220 and / or a filing structure 190 adapted to the geometry of the applicator head 220 is attached.

Are advantageous, as shown in FIG. 3, on one or both articulated arms 120, 130th

Provided spring elements which are coordinated so that the respective associated applicator head 220 or microscope head 320 within a predetermined space around the housing 1 10 and the surgical field without external forces each holds itself in the room. The applicator head 220 weighs about 5 kg and can not be worn by the surgical microscope 300 or microscope head 320. The spring balance of the first articulated arm 120, on which the microscope head 320 is arranged, is designed with a view, eyepieces and optionally monitor up to 1 kg. The second articulated arm 130, on which the applicator head 220 is arranged, therefore contains an apparatus for independent weight compensation, as shown in FIG. 5 is shown. The weight compensation for all masses to be compensated takes place with respect to the joint 140-L3 (140-A in FIG. 3). The part of the second articulated arm 130 between the joints 140-L3 and 140-L4 is designed as a parallel support arm 145. The Paralleltragarm 145 consists essentially of four joints 140-A, 140-B, 140-C, 140-D and four rigid members: the The first rotary head 141 -1, the second rotary head 141 -2, the spring arm 145-1 and the strut 145-2. The weight compensation is realized with a compression spring 147 in the lower spring arm 145-1. The compression spring 147 pulls on a toothed belt 148, which is deflected via two toothed belt wheels 149-1 and 149-2 in the strut 145-2. There, the toothed belt 148 is mounted on a fastening 146-2. The compression spring 147 generates a moment about the hinge 140-A, which is opposite to the torque generated by the weight G point A and compensates for this. The lever arm of the compensation torque is generated by the vertical distance of the toothed belt 148 to the joint 140-A. This lever arm is dependent on the angular position of the spring arm 145-1. The spring constant of the compression spring 147 is dimensioned so that the position-dependent change of both moments is compensated.

This ensures that the weight compensation is within a predetermined tolerance range in the entire swing range. The balanced weight force G is independent of the pivotal position of the articulating arm 130 for the applicator head 220. While pivoting the applicator head 220 changes the distance of the center of gravity from the pivot point 140-A, this does not affect the weight compensation. The moment changing thereby is supported by the strut 145-2 suspended in the pivots 140-C and 140-D.

In one embodiment variant, a video recording unit and a lighting unit are provided. These can be coupled via the applicator head 220 into the beam path to or from the eye 900, as will be explained below with reference to FIGS. 4 and 7.

In a special embodiment variant, in the second articulated arm 130, on which the applicator head 220 is arranged, a hollow core photonic crystal fiber passes, which transmits the short-pulse laser radiation (within the hollow core and with periodic photonic structures analogously to a Bragg mirror). is headed. In this way - similar to the free radiation - only a small pulse broadening by dispersion takes place. Then the second articulated arm 130 serves only the mechanical holding of the applicator head 220, thus no longer influences the beam guidance by its structure itself.

The design of a system for short pulse laser ophthalmic surgery 100 described herein assists in positioning the applicator head and the microscope head on the patient's eye. If the applicator head 220 and microscope head 320 are disconnected, they will be merged by the operator, such as the physician. To do this, the operator places the microscope head 320 on the applicator head 220 on the interface 150, and actuates a latch; or a mechanism automatically leads to locking when a desired position is reached. The operator guides and positions the microscope head 320 over the eye 900 to be operated. Also, the applicator head 220 is above the eye 900 positioned. The operator looks through the eyepiece of the microscope head 320 and lowers the microscope head 320 and thus also the applicator head 220 as far as necessary with further lateral alignment of the microscope head 320 on the eye 900, until the applicator head 220 is in a predefined position above the eye 900, or a patient interface 600 removably attached to the applicator head and containing a contact lens 610 makes contact with the eye 900. The operator performs the processing of an eye tissue 910, ie the lens and / or the capsular bag and / or the cornea with the aid of an fs laser. The operator raises the

Microscope head 320 and thus also the applicator head 220 on. The operator brings the applicator head 220 in the parking position, this sets in an embodiment of the

Applicator head 320 on the storage surface or storage structure 190 on the housing 1 10 on. The operator releases the microscope head 320 from the applicator head 220 via the locking mechanism, or the release takes place automatically when the application head 220 is positioned correctly on the deposition structure 190. The microscope head 320 is thereby separated from the applicator head 220 The operator positions the microscope head over the patient's eye 900. The operator performs the further cuts of phacoemulsification and / or aspiration of the liquefied lens and insertion of the intraocular lens. The operator positions the microscope head 320 in a parking position away from the computer

Surgical field. In one embodiment, the operator sets the microscope head on the applicator head, which is located on the storage surface 190 on the device 100, and locks the locking mechanism or else the locking mechanism is automatically locked upon reaching the connection.

In one embodiment, the control unit 500 calculates, with the aid of acquired OCT images and / or video images, control commands for adjustable elements on the articulated arms 120, 130 or the applicator head 220 and / or the microscope head 320, the necessary data, so that In particular, steps (c) and / or (e), if appropriate also all further steps, with the exception of step (i), are controlled automatically by the control unit 500.

Structurally, the housing 1 1 0, in particular the housing interior is preferably designed so that those components of the short-pulse laser system 200, which are enclosed by the housing, ie the short-pulse laser source 210 (here an FS laser source) and optical

Components can be pushed as part of the beam path, in the mounted state as a whole in and on a container laterally over the column 310 of the surgical microscope 300. The column 31 0 is an extension of the housing 1 10 a support structure for the first articulated arm 120, on which the microscope head 320 is disposed. The enclosed by the housing 1 10 components of the short pulse laser system 200 so in the assembled state the base plate of the surgical microscope 300 deposited and fixed in four places. In the second system for the short-pulse laser eye surgery 100 of FIG. 2, this is done as close as possible to the wheels, which are fixed under the foot plate as a transport device 180, as a rigid attachment with about 6 mm above the foot plate.

In order to guarantee the stability of the optical adjustment for the components of the short-pulse laser system 200 in the housing 1 10 as well as in the second articulated arm 130 are various

Measures possible. Elastic deformations of the supporting parts of the housing 1 10 by changes in position of the first and / or second articulated arm 120, 130 must not on the adjustment state of the optics between fs laser source 210 and entry into the second

Articulated arm 130, on which the applicator head 220 is arranged impact. These elastic deformations are not insignificant, especially considering that both the first articulated arm 120 with the microscope head 320 and the second articulated arm 130 with the applicator head 220, including the device for independent weight compensation in the form of a Paralleltragarms 145 and whose superstructures each have a weight in the

Order of magnitude of 50 kg. When swiveling, there are center of gravity displacements, which can lead to deformations in the range of several tenths of a millimeter. elastic

Deformations of the second articulated arm 130, on which the applicator head 220 is arranged, or its rigid members, are compensated by the own beam stabilization.

Deformations of the optics of the short-pulse laser system 200 in the housing 1 10, ie before entering the second articulated arm, however, can not be compensated. The

Accuracy requirements of the console optics, so the optics, which is arranged in the housing 1 10 behind the short-pulse laser source 210 and in front of the second articulated arm 130, however, lie in the micrometer range.

Fig. 4 shows schematically the beam path from the short pulse laser source to the eye, d. H. inter alia by the second articulated arm 130 and the applicator head 220. FIG. 4 contains various options, which will be described below.

With regard to the stability of the optical design, it is preferable to use the entire optics of the short-pulse laser system 200, which is in the housing 1 10 before entering the second

Articulated arm 130 is located in the beam path of the short-pulse laser radiation, including the

Output of the fs laser source 210, to be arranged on an optical bench or screwed to it. The optical bench itself is fixed with three points on or on the housing 1 10. All deformations of this mounting surface of the housing then have no effect on the adjustment state of the parts on the optical bench, but on the position of the optical bench for entry into the second articulated arm 130. Change of this position can be compensated by stabilizing the beam path by means of active mirror. A first active mirror is located directly on the optical bench. Another active mirror is in the second articulated arm 130. A laser diode 281 in the applicator head 220 sends a laser beam over all Mirror of the second articulated arm 130 including the active mirror on two

Quadrant receiver 282 in housing 1 10, which are fixed to the optical bench. Deviations due to deformations when moving the second articulated arm 130 or by movement of the optical bench are thus recognized and can be compensated by counter-steering on the active mirrors.

The second articulated arm 130 and the electronics or the control unit 500 depend on the housing. Changing forces are achieved by pivoting the first articulated arm 120 on which the microscope head 320 is arranged or the second articulated arm 130 on which the applicator head 220 is arranged. are transferred directly to the wheels 180 and the floor. The device 100 must rest during a laser treatment. Changes in the power conditions by

Unevenness of the floor has a direct effect on the adjustment state of the laser optics. In stationary operation, this influence is compensated by the described beam stabilization once before each operation.

Fig. 4 shows the fs laser system 200 for ophthalmology, in particular for the

Cataract surgery containing an fs laser light source 210. The light pulses of the pulsed laser radiation are focused by an objective 225 into the eye 900. Via a varying module 212 and a second divergence-varying module 212, there is a controlled z-shift of the focus of the pulsed laser radiation. An x / y

Mirror scanner 240, which includes an x-mirror scanner and a y-mirror scanner, or alternatively via a gimbal-mounted mirror scanner or alternatively again via an x-mirror scanner with downstream element for rotational rotation about the optical Axis, via the second articulated arm 130 containing the mirror, the x / y-movable objective 225 and a patient interface 600 containing a contact lens 610, the radiation reaches a focus on or in the eye 900.

Due to the divergence varying modules, which along the optical axis - which corresponds to the z-axis - via a controlled by the control unit 500 adjusting mechanism in the position (its lenses to each other and on the optical axis) are adjusted, the divergence of the pulsed laser radiation is affected , so that the focus position of the pulsed laser radiation along the optical axis, ie in the z-direction, in the eye 900 is changed over further fixed optical elements such as a relay optics 213. This will be explained below with reference to FIGS. 10 to 12.

By the x / y-movable objective 225, the lateral focus position of the pulsed

Laser radiation perpendicular to the optical axis of the device, ie in the x and y direction set. Given the position of the x / y mirror scanner 240, the femtosecond Laser pulses focused on an approximately 5 μιη wide spot in the eye 900. The location of the spot may be adjusted by moving the field of view (by moving the objective 225) and / or scanning by the x / y mirror scanner 240 within the field of view of the objective 225 in the eye 900. Simultaneous scanning by means of the x / y mirror scanner 240 and movement of the movable objective 225 results in a superposition movement. In one embodiment of the short-pulse laser system 200 for eye surgery, the image field of the objective 225 which is swept by the x / y mirror scanner 240 is greater than 1 mm in cross-section but smaller than 6 mm. In a preferred variant, it is greater than 1.5 mm but less than 3 mm.

Too small a picture field requires that z. For example, with laterally smaller cuts in the eye 900, the fast movement of the x / y scanners 240 alone is not sufficient to make a complete cut. As a result, the slow process of the objective 225 then takes much longer to produce the complete cut. Therefore, optionally, the field size of the objective 225 is selected so that access slices in the cornea 910 of an eye 900 having a length of about 1.5 mm in the x-direction and in the intersection with the depth of the corneal tissue 910 have a projected y-width of 2 mm require no movement of the lens 225, but only the scanning with the x / y mirror scanner 240. However, the image field should not be too large, because otherwise the lens 225 too heavy and thus too slow and slow for large-scale Movements, such as B. at the Kapsulotom ie, is.

When coupling the microscope head 320 and the applicator head 220 by means of an interface 150, the beam path for the light to be received by the microscope head 320 passes through the applicator head 220. To ensure this, there are alternative solutions:

In a first solution, a laser optics in the applicator head 220 may be designed such that the mirror 224, whose task is to redirect the laser radiation coming from the fs laser source 21 0 onto the objective 225 in the applicator head 220, has a partial transparency in particular in the range of the visible light needed to observe the eye 900 with the microscope head 320, while the short pulse laser radiation is almost completely reflected. A further lens 335 for adaptation to the radiation coming from the laser optics can be movably arranged in front of the objective 330 of the microscope head 320 in the beam path of the surgical microscope 300. In an alternative second solution, the laser optics, which then contains a fully reflecting mirror 224, can be retracted into the applicator head 220 by means of a carriage. In order to use the microscope head 320 for observing the eye 900, the laser optics from the beam path of the surgical microscope 300, which passes through the applicator head 220, away. During use of the short-pulse laser radiation, the surgical microscope 300 can not be used to observe the eye 900. In order to optionally provide a possibility of observation, with a camera 360, via a beam splitter prism 350, the eye 900 with light for which the camera is sensitive, for. B. I R light and / or yellow-green light, observed, as will be explained below.

For the definition of Bearbeitungsm uster in the eye 900 are with optical

Coherence tomography (OCT) structures of the eye 900, in particular structures of the anterior chamber of the eye 900 measured. In OCT imaging, the light from a short-coherence light source is transmitted laterally across the eye 900, i. H. perpendicular to the optical axis of

Eyes 900 scanned. Light reflected or scattered by the eye 900 is made to interfere with the light of a reference beam path. The measured by a detector

Interference signal is analyzed. From this, the axial distances of structures in the eye 900 can be reconstructed. In connection with the lateral scanning, structures in the eye 900 can thus be detected three-dimensionally.

In order to define a cutting pattern in the eye 900 to be generated with the focus of a short-pulse laser radiation relative to the relevant structures of the eye 900, FIG. 4 shows the (optical) integration of an OCT module 400 in the construction of a short-pulse laser system 100 or 200. In a variant of the construction, the same OCT light source 405 is selectively coupled into the surgical microscope head 320 as well as into the applicator head 220.

Accordingly, the light reflected back from the eye 900 of the OCT light source 405 is superimposed on the same interferometer with the reference light and detected with the same detector. This is illustrated in FIG. 4, which includes one or more switches 420 controlled by the controller 500, not shown in FIG. The switches 420 guide the light emitted from the OCT light source 405 and that from the eye 900

In a first state, light from the OCT light source 405 returns only via the applicator head 220 and in a second state only via the microscope head 320. This allows, for example, the use of the OCT module together with the microscope head 320, if the Applicator head is not needed, z. B. for the insertion of the intraocular lens (IOL). Then, the applicator head 220 rests in a parked position. The illumination and detection beam path of the OCT module 400 corresponds to the beam path of the fs laser radiation for setting the sections by means of the focus of the fs laser radiation, whereby

Alignment errors can be avoided. This is possible through the switching point or switching points 420, without having to integrate another OCT module.

In order to further improve the integration of the OCT module 400 and to offer alternatives, another solution is sketched in FIG. 4: The short-pulse laser system 200 shown here has the fs laser source 210 and the OCT module 400 including the short-coherence light source 405 and the interferometer, the fs laser radiation being transmitted to the second articulated arm 130 via the x / y mirror scanner 240 for laterally deflecting and subsequently mirroring the second articulated arm 130 Applicator head 220 is supplied, however, the radiation of the OCT short-coherence light source passes here via a (dashed lines) optical fiber 410, without being passed through the x / y mirror scanner 240, to the applicator head 220 has this solution the advantage that the OCT beam path is not exposed to disturbing reflections when passing through the second articulated arm 130. For an integration of the OCT module 400 with the OCT short-coherence light source 405 and the interferometer, FIG. 5 shows a further optional detail that makes it possible, in the short-pulse laser system 200, for the radiation from the fs laser source 210 and from the OCT - Combine short-coherence light source 405 of the OCT module 400 on a common optical axis 215 and to realize a common optical beam path 250 to and from the eye 900. For this purpose, the fs laser radiation 4000 coming from the fs laser source 210 strikes an annular mirror 430 after an fs laser beam-shaping optical system 21 1 and is reflected by it in the direction of the eye 900. By contrast, the radiation of the OCT short-coherence light source 405 of the OCT module 400 extends through a hole arranged centrally in the annular mirror 430 toward the eye 900 and thus on the same path as the fs laser radiation. Also, an OCT detector disposed in the OCT module 400, light from the eye through the hole in the

Ring mirror 430 detected throughout. This has the advantage that, in particular, the high aperture areas are used for the formation of the fs laser radiation by the fs laser beam shaping optical system 21 1. As a result, on the one hand, the focus is improved. On the other hand, focusing the fs laser radiation into the lens of an eye 900 during further passage through the eye 900 in the area of the retina illuminates only the peripheral areas, thereby reducing the risk for the patient of being damaged by radiation in the central macular area. Furthermore, the annular-mirror graduation has the advantage that the radiation of the OCT short-coherence light source 405, that is the OCT measurement and detection beam, is directed onto the optical axis 215 of the short-pulse laser system 200 without a surface which is optically disturbing due to its reflections , This would not be the case with a coupling by means of a dichroic filter or (at almost the same wavelength of the radiation of the OCT short-coherence light source 405 and the fs laser radiation) by means of a color-neutral divider. A color-neutral split would also result in additional intensity losses for both the OCT short-coherence light source 405 radiation and the fs laser radiation.

In order to improve the accuracy of the calibration of the OCT imaging for positioning the focus of the pulsed laser radiation, FIG. 4 shows an optional confocal detector 260, the focal aperture of which is conjugated to the focal position of the fs laser radiation. This confocal Detector 260 also makes it possible to measure structures of the eye when scanning the focus of the fs laser radiation in all spatial directions.

In the description, it has been explained that the objective 225 is movable. In one embodiment, this can be done by laterally moving a conventional objective comprising at least one main lens. In this case, upstream deflecting mirrors can be used whose distance from each other is adjusted. This is shown schematically in FIGS. 6a and 6b, which also show the use of the annular mirror 430 purely by way of example. This ring mirror 430 is one way to superimpose the OCT radiation 406 m with the f1 laser radiation 4000. It is essential that the short pulse laser radiation 4000 and the OCT beam path coincide with the OCT radiation 406 on the common optical axis 21 5 on the movable objective 225.

FIG. 6 a shows in a left and a right representation the two end points of FIG

Displacement of the radiation by the movable objective 225. FIG. 6b schematically shows the structure in three dimensions. The movable objective 225 has two deflection mirrors 4010 and 4012, between which the beam path extends transversely to the axis onto the image field 4002. By shifting the mirror 4012, it is possible to set where the radiation impinges on a lens body 4014 of the movable objective 225 along an optical axis 4000. This lens body 4014 is shown in Fig. 6 differently than the upstream elements 4012, 4010, 430 in the y / x plane, that is perpendicular to the z-plane. Equally perpendicular to the z-plane, an image field 4002 is shown, in which the radiation can be adjusted by the movable objective 225 in the x / y-plane. FIG. 6b shows that the lens body 4014 of the objective 225 is fixedly coupled to the mirror 4012, that is to say it moves with it. This has advantages in terms of imaging quality, since the lens body 4014 of the objective 225 is always irradiated correctly to its optical axis. The three-dimensional

Representation of Fig. 6b can be the Verstellwirkung the mirror 4010 and 4012 along with the respective downstream elements (lens body 4014 of the lens 225 together with the mirror 4012 or mirror 4012 and lens body 4014 when moving the mirror 4010) well recognize.

The left-hand illustration of FIG. 6 a shows the longest beam path which, in the context of FIG

Adjusting it movable lens 225, ie at maximum extended mirror 4012 may occur. The right-hand illustration accordingly shows the shortest beam path when the mirror 4012 is completely retracted. FIG. 6a shows, due to the sectional illustration, only the adjustment of the mirror 4012 in the form of a shortening of the beam path between the mirrors 4010 and 4012. Of course, this shortening would merely be a shift in the image field 4002 realize along an axis. The second shift axis becomes either by rotation of the mirror 4010 and pivoting of the mirror 4012 and the

Lensenkörpers 4014 realized or by shortening the distance between the mirror 4013 and the mirror 430 while simultaneously carrying the mirror 4012 and the lens body 4014th

Due to the large coherence length of the OCT light source 405 in air greater than 45 mm, more preferably greater than 60 mm, it is possible that the entire anterior chamber portion is detected within an A-scan given by the tuning of the swept source source itself when, as a result of the lateral movement of the objective, the optical path to the eye 900 is lengthened or changed, without the optical path length of the reference beam path z. B. be adjusted by moving a reference mirror m uss. In order to compensate for the influence of the movement of the objective 225 on the OCT signal, the path length differences-typically up to 6 mm for different objective positions-are preferably taken into account in the calculation of the A-scans from the OCT signals.

As can be seen in Fig. 4, via a prism 350, a second beam path to

Observation, for example, coupled to a camera 260. In the illustration of FIG. 4, a peasant enemy prism is used. However, the preferred system for the system is the prism splitter 1000 of FIG. 7. It couples a first beam path 1 001 and a second beam path 1 002. The first beam path 1001 falls through the (main) objective 225 onto the eye 900. The second beam path 1002 also runs to the eye 900, but is separated from the prism splitter 1000. Prism stacker 1000 consists of a Leman prism 1003. This prism type is also referred to as a Sprenger-Leman prism or Leman-Sprenger prism. It is, for example, from the publication, Lexikon der Physik, Spectrum akadem ischer Verlag Heidelberg, 1998, or the publication, H. Haferkorn, "Optics:

Physico-technical fundamentals and applications ", Vieweg Verlag, there in Fig. 5.131, or S. Flügge," Optical Instruments / Optical Instruments ", Springer Verlag, there page 218, Fig. 21, known. This prism, hereinafter referred to as the Leman prism, is supplemented in the prism splitter 1000 by an additional prism 1004 which is cemented to the deflecting surface 1005 of the Leman prism 1003 closest to the eye. The additional prism 1004 ensures that the optical axis of the first beam path 1001 is not deflected when passing through the prism splitter 1000. Unlike the Bauernfeind prism of FIG. 4, the second

Beam path 1 004 emitted at its exit surface 1006 parallel to the first beam path 1001 after its exit at the exit surface 1007. At the entrance surface 1008 propagate first and second beam path coaxially.

The prism splitter 1000 is slightly tilted with respect to the optical axis between the objective 225 and the eye 900, for example between 0.5 and 3 degrees around the objective 225 Illumination radiation does not reflect back into the beam path. This would be

for example, in an OCT disturbing. In order to compensate for the tilt, there is additionally provided a plane-parallel compensation prism 1009 between the entry point 1 008 and the eye 900, which lies in the same tilt angle as the prism file 1000 in the superimposed first and second beam path, but with azimuth twisted by 90 degrees. As a result, an astigmatism generated by the tilting of the prism filter 1000 is compensated. In addition, this advantageously increases the working distance.

The main objective 225 in the applicator head 320 is movable, e.g. B. by means of Fig. 6 explained construction. After the main objective 225 m uss, as shown in FIG. 4, space for the

Coupling by means of other beam paths, for example, the beam splitter 350/1000 be. To avoid that after the main objective an intermediate focus arises, that must

Main lens have a certain focal length. The focal length of the main objective is therefore to be selected according to this aspect large, in order to place after the main objective 225 even more elements, such as the prism splitter 1000. A long focal length also has a positive effect on the working distance, so that a sufficient distance to the patient's head is possible. From another point of view, however, is the

Focal length of the main lens to choose small. At long focal lengths, even the smallest beam angle deviations in the device cause a large scattering circle of the laser radiation on the eye, which is very disturbing, especially in the case of short-pulse laser radiation, and must be avoided. In addition, the beam diameter in the zero position of the main objective becomes very large. A particularly good balance is achieved by a main objective with a focal length between 20 mm and 40 mm, preferably between 25 mm and 35 mm. Furthermore, the main objective is designed as a combination of a positive lens and a negative lens spaced therefrom, as shown schematically in FIG. 8, which shows side by side two different variants for the main objective. In both figures, the main objective consists of a positive lens 2001 and a negative lens 2002, which together produce a focus 2000 which is at a working distance d from the last lens element, the positive lens 2001. The negative lens 2002 widens the beam path, the positive lens 2001 focuses it with a long working distance into the focus 2000. The positive lens is preferably made of a crown glass with a Abbe number of at least 50. To minimize aberrations as a whole, it is preferably made of a material having a refractive index of at least 1.6. The negative lens is constructed as a combination lens of a negative lens member 2003 and a positive lens member 2004 in an embodiment included in FIG. 8 in the right-hand illustration. The order of these lens elements is not relevant. Preferably, the positive lens member has the same material properties as the positive lens 2001, and the negative lens member is made of flint glass having an Abbe number of not more than 40 and a refractive index not less than 1.7. The two lens elements can be cemented together. In this Embodiment of a total of three-part main objective 225, a large working distance with aberration correction is advantageously combined.

In cataract surgery in particular, a large axial depth range must be covered in which the laser radiation can generate an optical breakthrough. The numerical aperture should not change. In the case of the ratios shown at the left in FIG. 9, a change in the focal length with constant beam diameter is carried out on the main objective 225 (in the case of the multi-part construction of FIG. 8, for example on the positive lens 2001 or a plane lying between the positive lens 2001 and the negative lens 2002 ), the numerical aperture changes depending on the position of the focus 2000. It is therefore intended to design the beam path such that the beam cross section does not remain constant in the main plane 2005 of the main objective 225, but in the rear one

Focal plane 2006 of the main objective 225. Then, even with different z-positions of the focus, i. H. at different eye-side intersections, the numerical aperture in Focus 2000 remains unchanged. In the system 200, this is achieved by designing the divergence-varying element as a Galilean telescope 2010 (see Fig. 10) composed of a negative lens 201 1 and a positive lens 2012. The negative lens 201 1 is shifted, which is illustrated by an arrow in FIG. 10, to carry out the divergence variation and, as a result, to shift the z position of the focus 2000 in conjunction with the objective 225. As an alternative to a galilei-type telescope, the one shown in FIG

Telescope of the Kepler type possible, which is composed of two positive lenses 2012 and 2013. However, it has a real intermediate focus 2014, which may be disadvantageous depending on the application, in particular in material processing short-pulse laser radiation, since there in cases of large numerical aperture to optical breakthroughs, d. H. Ionization of the air, can come. It is therefore preferable for the first and second systems 200 to perform the divergence variation by means of a Galilean type telescope 2010.

In order to be able to carry out a z-variation that is as fast as possible and at the same time long-stroke, a series connection of two divergence-varying elements, for example telescopes of the Kepler type, is provided, wherein a divergence-varying element has a short

Having adjustment and accordingly allows rapid adjustment, whereas the other divergence-varying element performs a z-direction long-stroke relatively slower adjustment. To maintain a constant beam cross-section, the output plane of the one divergence-varying module 2010 is mapped into an input plane 2017 of the next divergence-varying module. This is shown in FIG. 4. The image is formed by means of a 4 f system comprising two positive lenses 2018 and 2019. The distance between the two positive lenses of the 4 f system is always the sum of the two lens focal lengths. The plane of constant beam cross-section 2016 or 2017 are located in each case at the outer foci of the two lenses 2018 and 2019. Thus, the numerical aperture in the real intermediate image 2020 remains unchanged in the interior of the 4 f system during the focusing, ie in particular does not increase. It can then be designed so that no optical breakthrough occurs in the real intermediate image, ie intermediate focus 2020, with short-pulse laser radiation. Thus, the undesirable Luftionisierung over the entire Fokusverstellbereich can be specifically prevented.

In FIG. 10, the rear focal plane 2006 of the main objective 225 was entered as a plane of constant beam cross-section. This is merely exemplary in order to explain the function of the divergence-varying module. In order to arrange as few moving parts near the patient as possible, in particular not the moving negative lens 201 1, one transmits the plane constant beam cross-section, the output side of the divergence-varying module 2010, via a transfer image in the rear focal plane of the lens 225. In this way, the mechanical focusing movements, so the mechanical vibrations of the applicator head 320, which is in contact with the

Patient eye is located, are decoupled and you can arrange the Divergenzvariierenden modules in the housing 1 10 and in particular on the aforementioned optics. This transmission is performed by a beam path by means of at least a 4-f system by the articulated arm 130. Fig. 13 shows this transmitting beam path in two different

Positions of the divergence-varying element 2010, wherein for simplicity only a Galilean telescope is located. The transmitting beam path transmits planes 2016 of constant beam cross-section into the rear focal plane 2006 of the main objective 225, which forms the focus in the eye 900. The location of this focus in the eye 900 depends on the setting of the divergence-varying element 2010. A zero position results in a zero plane 2030, around which the focus can be adjusted into a maximum front plane 2031 and a maximum rear plane 2032, respectively. The maximum distance from the zero plane 2030 represents a maximum depth of field STMAX. FIG. 13 shows the beam path for the two extreme positions of the divergence-varying optical element 2010, which in the specific embodiment, as explained with reference to the previous figures, is realized by two modules , which are not shown in Fig. 13, however. The level 2013 constant

Beam cross-section, which is present at the output of the divergence-varying element 2010 is transmitted through at least one 4-f system, two shown in Fig. 13, in the rear focal plane 2003 of the main objective 225. A first 4 f system 2022 has two positive lenses 2023 and 2024 of the same focal length, which are in the known 4-f configuration, so that an intermediate focus 2025 is formed between them. The same applies to a second 4 f system 2026, which has two positive lenses 2027 and 2028 and an intermediate focus 2029. The planes of constant beam cross-section 2016 as well as the rear focal plane 2006 lie in each case in the focal plane of the assigned 4-f system or the corresponding positive lens. Due to the With the large focus adjustment produced by the divergence varying element 2010, the intermediate foci 2025 and 2029 move over comparatively wide axial distances. The respective deflecting mirrors along the articulated arm 130 lie between the last lens of the divergence changing element 2010 and the first lens 2023 of the first 4-f system and the last lens 2024 of the first 4-f element 2022 and the first lens of the following FIG -f element. Generally speaking, the deflection mirrors are each outside the respective 4-f systems. The distances between the 4-f systems, ie between the lenses 2023 and 2024 and 2027 and 2028, respectively, are portions of the transmitting beam path that lie within a rigid member of the articulated arm. In this way, the intermediate foci 2025 and 2029 traveling over a distance range are prevented from being exposed to optical

Elements of the transmitting beam path lie. For the focal lengths and

Beam diameters of the 4-f systems apply the equations and focal length data given in the general part of the description. The same applies to the dimensions of the rigid members or the distances between the joints.

In order to make the operation as easy as possible for the operator, for the optically necessary patient interface 600, which contains a contact lens 610, the construction shown in FIGS. 4 and 15 for processing the eye 900 by means of a system for the short-pulse laser Eye Surgery 100 shown. The design shown here includes a patient interface 600, an applicator head 220 of the system for short pulse laser ophthalmic surgery 100, where the patient interface 600 in FIG. 14 is attached to both the patient's 900 eye and the applicator head 220 of the system for the short-pulse laser ophthalmic surgery 100 and thus fixes the relative position of the eye 900 to the system for the short-pulse laser eye surgery 100 and consequently also to the beam path of the short-pulse laser radiation.

The patient interface 600 includes a contact lens 610, shown in FIG

Embodiment designed as a liquid interface. The contact glass 610 is in one piece, made of a preferably uniform, transparent material and includes a suction ring 612, a jacket 61 1 and an optical element 620 on the upper side of the jacket 61 1. It further comprises two openings 613,614, to the two leads via

Fixing aids are connected or allow the connection of two leads, with one lead is connected to one of the openings 613, 614 or is.

A one-piece contact glass 610, in which all functional elements are integrated, allows easier handling than multi-component contact glasses 610, which are only on the

Patient eye 900 are assembled. Such multi-component contact glasses 610 are z. In documents US 7955324 B2, US 8500723 B2, US 2013/053837 A1,

WO 2012/041347 A1 describes. The two supply lines serve on the one hand the application of negative pressure, here via the lower opening 613, and on the other hand the supply or discharge of liquid into the contact glass 610, when the contact glass 61 0 is docked to the eye 900, via the upper opening 614 ,

In a preferred variant, an overflow outlet 615 is furthermore provided in the upper jacket region of the contact glass 610 remote from the eye 900, via which excess liquid or air can escape from the contact glass 610 during filling. Preferably, the patient interface 600 includes a mechanically releasable coupling element 651 for mechanical fixation of the contact lens 610 on the applicator head 220. Alternatively, it is possible that the patient interface 600 instead of a mechanical interface with mechanically detachable coupling element 651, a contact glass 610 m it contains a further suction structure, which is made of the same material as the contact glass 610. This further suction structure holds the contact glass 610 on the applicator head 220 when negative pressure is applied. Since this is an alternative solution, this is not shown in FIG. 14.

In particular for sterility is a patient interface 600, which in addition a

Applicator head protection 650, which preferably has a recess mit mittig, beneficial. This applicator head protection 650 can be placed over the eye 900 side facing the applicator head 220 and fixed with it, as shown in Fig. 14. This applicator head protection prevents the applicator head 220 during operation, e.g. contaminated by liquids. The recess allows the patient interface 600 to be attached directly to the applicator head 220 with the contact lens 610 such that the applicator head protector 650 does not obstruct the beam path of the short pulse laser radiation between the system for the short pulse laser eye surgery 100 and the optical element 620 of the contact glass 610 represents. If the recess is meager in the applicator head protection

650 realized, a spatial Lich uniform protection of the applicator head 220 is achieved. Advantageously, the applicator head protection 650 by a mechanically releasable coupling element

651 connected to the applicator head 220.

In order to support the docking and in particular the lateral alignment of the application head 220, FIGS. 14 and 15 disclose a lighting system which is particularly suitable for short-pulse laser eye surgery. A light-conducting structure 635 is embedded in the jacket 61 1 of the contact lens 610 , In turn, in the applicator head 220 of the system for the short pulse laser eye surgery 100, a light source 630-1 that emits visible light and / or a light source 630-2 is the light of a particular spectral composition emited, integrated. In particular, during the surgical procedure using short-pulse laser radiation in the eye 900, in which the short-pulse laser radiation is guided via optical elements of the applicator head 220 in the eye 900 and thereby blocks the optical path in a microscope head 320 above or is impaired, for example, the eye 900 may be illuminated with light 630-2, and the light reflected from the eye 900 may be transmitted through a beam splitter prism 350, e.g. B. selectively reflected infrared and green or yellow light, in a camera 360, which can detect this light, are passed. The prism 350 preferably reflects wavelengths used by the short pulse laser source 210 or the OCT light source 405. Light from this wavelength, which is not reflected by the prism 350, passes through the prism 350 without interference.

This construction has the advantage that, in contrast to the alternative solution of illumination by means of illumination present in the operating microscope 300, no reflections are added by the additional optical elements of the applicator head 220 located in the illumination beam path and impair the image.

It is also advantageous if a force sensor 655, which is in contact with the contact glass 610 when the patient interface 600 is docked, is integrated in the applicator head 220. The force sensor 655 and both the visible light emitting light source 630-1 and the light source of the particular spectral composition emitting light source 630-2 are advantageously connected to a controller 500 which also controls the system for the short pulse laser ophthalmic surgery 100, or with an additional control unit 500 'connected to the control unit of the system for the short-pulse laser ophthalmic surgery 1 00 over

Communication channels in contact.

To the transmission of preoperatively measured data z. B. the axial position of the preoperatively measured astigmatism us the eye 900 or the cornea 910 or the target position of access incisions or relaxation sections compared to the preoperatively measured

Astigmatism us axes of the eye 900 and the cornea 910 correctly during surgery to the eye to align, in the prior art, the preoperative data or desired target positions relative to preoperative reference marks established or referenced. Of course, existing reference marks such as vascular structures in the sclera or iris structures, or simply an overall image of the eye 900 with its existing structures are used as reference marks.

In order to recognize these vascular structures particularly well in the sclera, it is provided to provide green or yellow illumination sources 3000, which illuminate the eye in a spectral range in which the hemoglobin of the blood absorbs particularly well. This way will receive a particularly high-contrast image that is recorded on the camera 360, for example. Corresponding examples of possible locations of the illumination source 3000 are shown in FIGS. 4, 14 and 15. The green illumination 3000 is designed to illuminate the limbus 3001 and parts of the eye 900 sclera. In this way, a high-contrast image of the vascular structure in the sclera is obtained.

This vascular structure is used to refer to a previously generated reference image obtained in the biometry of the eye prior to the actual eye observation or the therapeutic intervention to be performed, for example cataract surgery. This reference image may have been generated, for example, with the same system 100 or 200. In addition to the reproduction of the reference structures, for example the blood vessels in the sclera, there is also the related position of structural features of the eye, for example an astigmatism axis. Also in the biometric measurement, which is carried out preoperatively, the eye is illuminated green. Thus, high-contrast images of the same reference structures are available both in the reference image and in the current image, so that the referencing of the current position of the eye to the reference image and thus the correct indication of the eye structures, for example an astigmatism axis, is easily possible in the current image. Alternatives to the use of green or yellow illumination are, of course, the illumination with white light and a corresponding spectral filtering of the reference image or the current image or the illumination with white light spectrally filtered on its way, so that a single illumination source can be used for several purposes. The use of green lighting, however, has the advantage that the high-contrast image can be generated with a camera 360, which already exists anyway. For this purpose, it is then preferred that the splitter layer is suitably dichroic in the beam splitter 350 in order to couple the green illumination to the limbus and the sclera and to use a camera 360 which is sensitive in the green or yellow region.

16 schematically shows the beam path of an fs laser system for ophthalmology, in particular for cataract surgery. This may in particular be one of the systems described above. Pulses of pulsed laser radiation 5002 are focused into the eye 900 by focusing optics 5008. Via a divergence-varying module, which realizes a z-scanner 5004, there is a controlled z-shift of the focus of the pulsed laser radiation 5002. An xy-scanner 5006, z. B. comprises an x-mirror scanner and a y-mirror scanner or alternatively via a gimbal-mounted mirror scanner or alternatively via an x-mirror scanner with downstream element to Rotational rotation about the optical axis, the radiation passes to a focus 5018 on or in the eye 900. A controller 500 controls the scanners 5004, 5006.

The divergence of the pulsed laser radiation 5002 is influenced by the z-scanner 5004, so that the focal position of the pulsed laser radiation 5002 along the optical axis, ie in the z-direction, in the eye 900 is changed via the focusing optics 5008.

The xy scanner 5006 sets the lateral focus position of the pulsed laser radiation 5002 perpendicular to the optical axis of the device, ie in the x and y directions. The

Femtosecond laser pulses are focused on a lateral approximately 5 μιη extended spot in the eye 900. The location of the spot can be adjusted laterally by scanning by means of the xy scanner 5006 within the image field of the focusing optics 5008 in the eye 900. The

Depth adjustment is produced by the z-scanner 5004. It is shown in more detail in FIG. The z-scanner 5004 is formed as a Galilean telescope and includes a movable negative lens 5010 which is longitudinally adjustable in a guide 5012 along the optical axis OA. It cooperates with a fixed positive lens 5014 and adjusts the divergence of the laser radiation 5002.

FIG. 18 schematically shows the adjustment of the laser radiation 5002 in the cornea 5016 of the eye 900. The xy scanner 5006 adjusts the position of the optical axis OA laterally. In the case of a displacement Axy from the rest position, due to the curvature of the cornea 5016, a depth adjustment Δζ must be carried out at the same time in order to keep the focus 5018 on a desired path within the cornea 501 6. The Krümm ung the cornea 501 6 is set by a contact glass 600 to a known level. The contact glass 600 fixes the eye 900.

The z-Scanner 5006 can be used eg. B. as Galilei telescope 2010, which, as shown in Fig. 10, from the negative lens 201 1 and the positive lens 2012 is composed. The

Negative lens 201 1 is shifted, which is illustrated by an arrow in FIGS. 10 and 17, to perform the divergence variation and, as a result, to shift the z position of focus 5018. As an alternative to a telescope of the Galilei type, a telescope of the Kepler type is also possible, which is made up of two positive lenses. In order to avoid a real intermediate focus, which can be disadvantageous depending on the application, in particular in material-processing short-pulse laser radiation, since it there in cases of large numerical aperture to optical breakthroughs, d. H. Ionization of the air, the telescope 2010 is preferred by the Galilei type.

In order to generate the focus as possible without spherical aberrations over a wide z-adjustment in high quality, the focusing optics 5008 is designed so that they are suitable for a certain position of the z-scanner 5004 is corrected for spherical aberration. This position of the z-scanner 5004 corresponds to a zero level. Preferably, it is centered in the z-area to be covered. Upon adjustment of the z-scanner from this null plane, the focusing optic 5008 causes an aperture error (also spherical aberration) which increases linearly with the distance from the zero plane. This relationship is shown in FIG. 5, which shows a curve 5016 for the aperture error F of the focusing optic 5008 as a function of the depth position adjustment of the focus 5018. With curve 5016 alone, the ophthalmic device 5000 would be unusable. However, the fixed lens group 5014 of the z-scanner is designed to produce a spherical aberration upon adjustment of the lens group 5010, which satisfies the curve 5020. It thus acts as a correction optic that automatically compensates for the aperture error of the focusing optic 5008. Thus, when driven by the controller 500 to adjust the z-position of the focus 5018 over a wide z-range, the aperture error is compensated. The correction in the focusing optics 5008, however, is to be made only for the zero level, so that the correction effort in the optical elements is drastically reduced.

The curve of FIG. 19 provides a particularly low control mechanism. However, the focusing optics 5008 and the compensating element, in this embodiment the optical element 5014, must be adapted to one another as precisely as possible. This adjustment can be reduced at the expense of greater control overhead when using z-scanner independent correction optics that cause adjustable, known spherical aberration. The control unit 500 then controls this correction optics such that the aperture error, which is generated z-position-dependent by the focusing optics 5008, is compensated. The focusing optics 5008 also has no spherical aberration in a null plane in this embodiment. This zero level corresponds to a zero adjustment of the correction optics in which this likewise does not produce a spherical aberration. In the embodiment of FIG. 1, this zero setting would expediently be the center position of the z-scanner. With a separate correction optics, it is also possible to compensate for a non-linear course, such as, for example, dotted as curve 5022. Also, the curve for correction optics and focusing optics 5008 then need not necessarily be equal to each other. It is only necessary that the corresponding curves of the spherical aberration are known and stored as a function of the z-position in the control unit 500.

Claims

claims

A system for eye observation or therapy comprising:

a radiation source that provides illumination or therapy radiation, and

a focusing device that focuses the radiation into a focus in an observation or observation field

Therapy volume bundles, wherein the focusing device has at least. A focusing lens and this upstream, variable, divergence-varying optical element, which adjusts a z-position of the focus, wherein

the divergence-varying optical element is a first divergence-varying optical

Module having a first z-position adjustment speed and a first z-position adjustment path and a second divergence-varying optical module having a slower second z-position

Lagenverstellgeschwindigkeit and a larger second z-Lagenverstellweg has, characterized in that

- Each divergencevariierende optical module generates a plane of constant beam cross-section with variable optical focal length and

a 4-f optic is the plane of the one divergence-varying optical module in one

Imaged input plane of the other divergencevariierenden optical module and thus the

Intersection variation between the modules transmits.

2. System according to claim 1, characterized in that both divergencevariierende optical modules designed as a telescope with a fixed converging lens and a further upstream movable lens, in particular, the radiation source provides short-pulse therapy radiation and the telescope is of the Galilean type.

3. Eye monitoring or therapy system, in particular according to claim 1, comprising:

An articulated arm with at least two rigid links that go through in different

Joint positions adjustable joints are hinged together,

a transmission beam path comprising an optical system which guides radiation as a free-stream with a maximum beam diameter along the articulated arm, the optical system having deflecting mirrors in the joints corresponding to the current one

Joint position divert radiation,

wherein the optical system generates in the transmission beam path a plurality of successive planes of the same beam cross section and each plane by a 4-f optics in the following Plane maps, characterized in that in front of an input of the articulated arm, a variable, divergencevariierendes optical element and after the output of the articulated arm is a lens which focuses the radiation into a focus, said the

divergence-varying optical element adjusts a z-position of the focus.

4. System according to claim 3, characterized in that for a numerical aperture NA in the intermediate image of each 4-f optics applies: 0.1> = NA> = 2.2 ^* (A * STMAX) / D, where λ is the wavelength or the average wavelength of the radiation, D is the beam diameter, and STMAX is a maximum displacement of the z-position of the focus by the divergence-varying optical element.

5. System according to claim 3 or 4, characterized in that a numerical aperture NA in the intermediate image of each 4-f optics is between 0.1 and 0.03, wherein the wavelength or average wavelength of the radiation 1 μιη ± 0.1 μιη and the beam diameter is less than 20 mm and greater than 5 mm, preferably greater than 10 mm, wherein the rigid members are preferably at least 100 mm, preferably at least 200 mm, long and a smallest partial focal length of the 4 f optics is greater than 50 mm, preferably over 100 mm.

6. System for eye observation or therapy, in particular according to claim 1 and / or 3 and in particular as a device (5000) for laser-assisted eye surgery, the system comprising:

a radiation source (L) providing illumination or therapy radiation (5002); a focusing device which converts the radiation (5002) into a max. 50 μιη concentrated focus (5018) in an observation or therapy volume,

an xy scanner (5006) for laterally deflecting the focus (5018) in the observation or therapy volume;

wherein the focusing device has a focusing optics (5008) arranged downstream of the xy scanner (5006) and a z scanner which precedes the xy scanner (5006) and adjusts a depth position of the focus (5018),

a control device which controls the z-scanner for setting the depth position of the focus,

characterized in that

the system has an adjustable correction optics controlled by the control device, wherein the adjustment causes a change of the spherical aberration in the observation or therapy volume,

- The focusing optics (5008) is aberration corrected such that the spherical aberration for a particular adjustment of the adjustable correction optics and a certain setting of the z-scanner and thus the depth of focus (5018) is corrected, wherein the particular setting of the adjustable correction optics is a zero setting and the specific one Setting the z-scanner represents a zero level and wherein the focusing optics is designed so that when setting the z-scanner outside the zero level a

Changing the spherical aberration causes in the observation or therapy volume, the control device for adjusting the depth of focus (5018), the z-scanner from the zero level out and the correction optics, the change of the spherical

Aberration, which is caused by the focusing optics (5008) compensated.

7. System according to claim 6, characterized in that the focusing optics (5008) is designed so that it causes a proportional change in the spherical aberration in the observation or therapy volume on adjustment of the z-scanner from the zero level.

8. System according to any one of claims 6 or 7, characterized in that the z-scanner comprises a xy-scanner upstream, divergence-varying optical element (5010), which changes the divergence of the illumination or therapy radiation adjustable.

9. System according to claim 8, characterized in that the z-scanner as a telescope with a fixed lens optic (5014) and a movable lens optics (5010) is formed, wherein the correction optics in the fixed lens system (5014) is included or realized, so in that the adjustment of the z-scanner from the zero level and the adjustment of the correction optics (5014) deviating from the zero setting are automatically coupled, wherein in particular the radiation source (L) provides short-pulse therapy radiation and the telescope is of the Galilean type.

10. System according to one of claims 6 to 9, characterized in that the

Correction optics in a pupil, in particular in front of the xy scanner, is arranged and that the correction optics is controlled by the control device (500).

11. Eye monitoring or therapy system, in particular according to claim 1 and / or 3 and / or 6, comprising:

a radiation source that provides illumination or therapy radiation, and a focusing device that focuses the radiation into a focus in an observation or observation field

Therapy volume bundles, wherein the focusing device has at least one focusing objective and a variable, divergence-varying optical element arranged upstream of it, which adjusts a z-position of the focus,

characterized in that

the focusing device in the observation or therapy volume a numerical

Aperture below 0.1 realized, the variable, divergence-varying optical element is adapted to adjust the z-position of the focus over a range between 10 and 15 mm, and

the focal length of the objective is between 20 and 40 mm, preferably between 25 and 35 mm.

12. System according to claim 1 1, characterized in that the radiation source provides short-pulse laser radiation and the lens is designed as a combination of a positive lens and a negative lens.

13. System according to claim 12, characterized in that the positive lens and / or the negative lens min. Has an aspherical surface which is designed to reduce aberrations.

14. System according to any one of claims 12 or 13, characterized in that the positive lens made of crown glass with a Abbe number of not less than 50 and a refractive index of not less than 1, 6 is made.

15. System according to any one of claims 12, 13 or 14, characterized in that the negative lens is constructed as a combination lens of a negative lens member and a positive lens member, wherein the positive lens member of crown glass having a Abbe number of not less than 50 and a refractive index of not less than 1, 6 and the negative lens member is made of flint glass with a Abbe number of not more than 40 and a refractive index of not less than 1, 7, wherein in particular the negative lens member is cemented to the positive lens member.

16. Eye monitoring or therapy system, in particular according to one or more of claims 1, 3, 6 and 11, comprising:

a biometric device, which generates at least one reference image of the eye, which contains at least one reference structure of the eye, at least one structural parameter of the eye, preferably an astigmatism axis, and determines its relative position to the reference structure,

an observation or therapy device comprising an imaging device for generating a current image of the eye, which also contains the reference structure of the eye, and an image processing device for identifying the reference structure of the eye and determining its current position and determining the current position of the eye

Has structure parameters based on the current image and the reference image,

characterized in that

the biometric device generates the reference image of the eye in a spectral channel in which an absorption dye in blood vessels of the sclera has an absorption maximum, or in a spectral channel in which fluoresces a fluorescent dye in blood vessels of the sclera, and

the imaging device generates the current image of the eye in the same spectral channel.

17. System according to claim 16, characterized in that the spectral channel comprises the green to yellow spectral range between 600 and 500 nm.

18. System according to claim 16 or 17, characterized in that the

Biometric device and / or the imaging device the eye with light in the

Illuminate the spectral channel, preferably with green to yellow light.

19. System according to claim 16 or 17, characterized in that the

Biometric device and / or the imaging device to illuminate the eye with white light and filter the image of the eye on the spectral channel when taking the image.

20. The system according to 19, characterized in that the biometric device and / or the imaging device has a color filter layer or splitter layer, which directs only radiation in the spectral channel to an image pickup element for recording the image.

21. System according to one of claims 16 to 20, characterized in that the

Biometric device and imaging device image the sclera of the eye in the image.

22. A method of eye observation or therapy preparation or therapy, comprising the steps of:

Generating a reference image of the eye containing a reference structure of the eye, determining at least one structural parameter of the eye, preferably one

Astigmatism axis, and determining a relative position of the at least one structural parameter of the eye to the reference structure,

Generating a current image of the eye, which also contains the reference structure of the eye,

Identifying the reference structure of the eye and determining its current position and determining the current position of the structure parameter based on the current image and the reference image,

characterized in that

- The reference image of the eye is generated in a spectral channel in which a

Absorption dye in blood vessels of the sclera has an absorption maximum, or is produced in a spectral channel in which fluoresces a fluorescent dye in the blood vessels of the sclera, and the current image of the eye is generated in the same spectral channel.

23. The method according to claim 22, characterized in that the spectral channel comprises the green to yellow spectral range between 600 and 500 nm.

24. The method according to claim 22 or 23, characterized in that for generating the image, the eye is illuminated with light in the spectral channel, preferably with green to yellow light.

25. The method according to claim 22 or 23, characterized in that for generating the image, the eye is illuminated with white light with light and the image of the eye is filtered onto the spectral channel when taking the image.

26. The method according to any one of claims 22 to 25, characterized in that the sclera of the eye is imaged in the image and wires are used as a reference structure.

27. Eye monitoring or therapy system, in particular according to one or more of claims 1, 3, 6, 11 and 16, comprising:

a leading to the eye first beam path for first therapy or

Observation radiation that runs along a major optical axis to the eye,

a second beam path for second observation radiation, which runs along an optical minor axis, and

a prism splitter, which, viewed in the direction of the eye, couples the second beam path into the first beam path and has an entrance surface and a first and a second exit surface viewed from the eye, wherein the prism splitter guides the first beam path along the main optical axis between the entry surface and the first exit surface , and the minor optical axis is away from the second exit surface,

characterized in that

the minor optical axis is ± 20 ° parallel to the main optical axis and

- The prism separator is formed as a combination of a Leman prism and a cemented with the Leman prism additional prism, wherein

the Leman prism seen from the eye decouples the second beam path from the first beam path at a first deflection surface following the entry surface, redirects at least two deflection surfaces and leads parallel to the second exit surface parallel to the main optical axis,

- The additional prism is cemented to the first deflection and one for

Has entrance surface parallel surface, which forms the first exit surface, and - Is formed between the additional prism and the first deflection a dichroic or intensity divider layer.

28. System according to claim 27, characterized in that the second beam path at an angle of max. 30 degrees to the normal incident on the splitter layer.

29. System according to claim 27 or 28, characterized in that the splitter layer is dichroic and reflects radiation in the wavelength range of 750 to 950 nm or 600 to 500 nm in the second beam path and radiation in the visible wavelength range and in the wavelength range of 1000 to 1 00 nm transmits for the first beam path.

30. System according to any one of claims 27 to 29, characterized in that the Lemane prism roof surface and consequently the first deflection surface is flat.

31. System according to one of claims 27 to 30, characterized in that the

Prismateiler in the first beam path is tilted by an angle of 0.5 to 3 degrees, so that the entrance surface and the first exit surface by the angle of perpendicularity deviate from the main optical axis.

32. System according to claim 31, characterized in that the prism splitter in the first beam path is a plane-parallel glass block upstream or downstream, which also tilted in the first beam path by an angle of 0.5 to 3 degrees, with an azimuth ut by 90 degrees the tilting of the prism filter is twisted, wherein the glass block is preferably arranged downstream of the prism splitter to the eye.

33. System according to one of claims 31 or 32, characterized in that in the first beam path between prism splitter and eye, a lens for focusing the first

Treatment or observation radiation is arranged in or on the eye, which has an optical Komacompensationselement to compensate for caused by the tilting of the prism filter Achskoma has, in particular a laterally displaceable lens or a free-form element in a pupil.

34. System according to claim 22, characterized in that the lens is designed as a combination of a positive lens and a negative lens, wherein the negative lens is laterally adjustable and dam it realizes the optical Komacompensationselement.