WO2014195059A1

WO2014195059A1 - Laser treatment device for refractive surgery

Info

Publication number: WO2014195059A1
Application number: PCT/EP2014/058202
Authority: WO
Inventors: Faramarz Madjlessi
Original assignee: Faramarz Madjlessi
Priority date: 2013-06-04
Filing date: 2014-04-23
Publication date: 2014-12-11
Also published as: DE102013105738A1

Abstract

The invention relates to a laser treatment device for refractive surgery, comprising a laser emitter (1), in particular a femtosecond laser emitter (1a), for generating optical apertures at cavitation points of a capsule (2) of a lens (3) of an eye (4), and a control device (5) for controlling the laser emitter (1). The invention is characterized in that the control device (5) is set up for controlling the laser emitter (1) for generating marking contours (6) on the capsule (2) on the basis of alignment information, wherein the marking contours (6) make it possible to adjust the angle of a toric intraocular lens (7) inserted in the eye (4).

Description

Laser treatment device for refractive surgery

The invention relates to a laser treatment device for refractive surgery with the features of the preamble of claim 1.

Nowadays, cataracts of the human eye are regularly treated by the insertion of intraocular lenses. Basically, a distinction is made between phakic intraocular lenses - which are used in addition to the natural lens - and pseudophakic intraocular lenses - which completely replace the natural lens. It is known from the prior art to use a femtosecond laser to separate a regularly circular cutout of the front side of the capsule of the lens - which process is called capsulorhexis - and to use this cutout to remove the natural lens and insert the intraocular lens.

Frequently, patients with cataracts also suffer from a corneal curvature, called astigmatism, on the affected eye, which means additional impairment of vision. Pseudophakic toric intraocular lenses offer a way to simultaneously treat this astigmatism with cataract. Their designation as "toric" derives from the fact that in any case one of the surfaces of such an intraocular lens has the shape of a marginal section of a torus and thus has different refractive indices along its surface axes.Then, if this toric intraocular lens is used and with its surface axes referred to the corresponding cutting axes Thus, the cornea, whose curvature also means toroidal shaping, is correctly aligned, the visual defect caused by the corneal curvature can thus be compensated.

Decisive and at the same time critical point in this process is the permanently accurate angular alignment of the toric intraocular lens to the axis of astigmatism of the cornea, which itself must first be determined. In addition to a possible rotation of the intraocular lens after completion of the insertion process but even the exact alignment during insertion is often difficult. Each degree of angular deviation in alignment means about 3% loss of the effect of the corneal curvature correction, so that with a deviation of 30 degrees or more regularly, no improvement whatsoever more occurs. For the purpose of angular alignment, the toric intraocular lens regularly has adjustment cusps already attached during manufacture which characterizes its major axis.

Since, however, the eye of a lying or only locally anesthetized patient can not be fixed reliably, must also aufsei th of the eye to mark the detected axis of astigmatism done. Here are known from the prior art, various approaches. According to one method, a reference mark is initially defined by means of a color marking, which regularly corresponds to either the horizontal or the vertical direction with respect to the eye of a person standing. Namely, the axis of astigmatism is regularly indicated as an angle relative to such a reference axis. This angle corresponding to the axis of the astigmatism is then removed relative to the reference axis and likewise marked with a color marking. At this color marking then the Justierungsritzen the intraocular lens are aligned.

However, this approach is problematic in several respects. At first, manual marking of axes on the cornea is often poorly accurate. Not only can the angular position of the axis as such be marked differently, but the marked axis may not even hit the center of the lens. The removal of an angle from such a manually marked axis-also inherently erroneous-and the renewed color marking of the further axis determined in this way leads to an error correction with which the accuracy is further reduced. Also, the color marking can only be applied to the cornea, but which is clearly offset to the plane of the actually relevant lens, which is why the resulting parallax forms another source of error. Finally, there is also the risk that the markings will increasingly blur due to dripping of the eye or similar treatment steps.

An alternative method relies on the use of eye trackers. These are devices that can detect an orientation and rotation of the eye based on reference structures such as the blood vessels of the limbus. In this approach, the target axis on which the intraocular lens is to be aligned is recorded on a previously recorded image of the eye. carried. This information then uses the eye tracker to project the said target axis in a microscope view of the eye during the operation. A rotation of the eye is detected on the basis of the co-rotating reference structures and the projected target axis is moved along accordingly. In the microscope view, the surgeon can thus align the alignment creases of the intraocular lens on this projected target axis. But even this approach has disadvantages. Apart from the fact that a very powerful camera is required. For example, the reference structures may still change before and during surgery - such as by pupil dilation - or become less recognizable. A rapid, irregular movement of the eye can mean that the projection of the target axis can only be tracked with a certain time delay of the eye movement. Finally, the correct alignment can not be checked on the eye itself by the attending physician, but only on the inevitably two-dimensional microscope view.

The object of the invention is thus to develop a known from the prior art laser treatment device for refractive surgery so that the more accurate alignment of a toric intraocular lens is made possible.

The above object is achieved in a laser treatment apparatus for refractive surgery according to the preamble of claim I by the features of the characterizing part of claim 1.

According to the invention it has been recognized that the laser emitter, which is used for the cut in the lens capsule for introducing the intraocular lens, can also be used to generate Marki erungskonturen on the lens capsule, on the basis of which the intraocular lens can be aligned. However, the laser emitter is not as it were directly and manually guided so that the marking contours arise. Rather, an alignment information of the laser treatment device is provided, which then independently based on the target process for generating the marking contours.

This approach overcomes the disadvantages of previous approaches. On the one hand, these marking contours are not only in the microscope view, but This is also available to the real eye and can be recognized without any delay even when the eye is moving. On the other hand, there is no danger of blurring or disappearing. In addition, the laser emitter itself already allows a much more accurate placement than a hand-held marker. Thus, the advantages of both previous approaches under Vermei tion of the respective disadvantages are united.

There are many possibilities for the type and shape of the marking contours as well as for the type of orientation information.

In the preferred embodiments according to claim 2 or 3, the alignment information comprises a reference axis through the center of the lens and an axis position angle related thereto. In this case, the marking contours define a target axis through the center of the lens, which target axis is rotated relative to the reference axis by this axis position angle. In principle, it is a similar procedure as in the manual color marking described above, except that here at least the markers so the marking contours for the final valid target axis are determined by the control device, therefore more accurate and can not blur.

But it can also, as proposed by the dependent claim 4, the target axis for the angular adjustment directly on the eye or on a recording of the eye are given, so without recourse to a reference axis. Such a basic approach can in turn be designed in several different ways.

Thus, it is proposed by the dependent claims 5 to 7, that the target axis is entered directly in relation to a quasi-simultaneous recording of the eye. The attending physician can thus register the desired axis directly on the eye shown at the same time, for example in a microscope view, via a touch screen. However, such a desired axis can also be entered with respect to a recording made at a previous time of the eye, as proposed by the dependent claim 8.

In particular, if then, as proposed by the dependent claim 9, an eye tracker is used, which is defined in relation to the earlier recording of the eye target axis can be adjusted according to this of the current angular position of the eye.

The dependent claims 10 to 13 in turn describe preferred embodiments of the marking contours or their selection with regard to their shape and arrangement.

In the following the invention will be explained in more detail with reference to a drawing showing only one exemplary embodiment. In the drawing shows

1 view of a proposed laser treatment device,

FIG. 2 shows an eye of a patient for treatment by the laser treatment device of FIG. 1 with capsulorhexis shown before insertion of an intraocular lens, FIG.

FIG. 3 shows a toric intraocular lens which is inserted into the eye of FIG. 2 for the combined treatment of cataract and astigmatism, FIG.

FIG. 4 shows the eye of FIG. 2 with inserted intraocular lens from FIG. 3, FIG.

the position of the marking contours being determined with reference to a reference axis,

FIG. 5 shows the eye of FIG. 2 with inserted intraocular lens from FIG. 3, wherein the position of the marking contours with respect to a soil axis has been determined, FIG.

Fig. 6a-f different variants of M arki erungskontu ren. 1 of the drawing shows a proposed laser treatment device for refractive surgery with a patient. Similar laser treatment devices are known from the prior art. FIG. 2 shows the patient's eye to be treated by this laser treatment device, which has a cataract and an astigmatism. The treatment involves insertion of the toric intraocular lens shown in FIG. Figures 4 and 5 respectively depict the eye after insertion of the intraocular lens. The result is physically identical except that the orientation information for angle adjustment is different, as explained below.

The proposed laser treatment device has a laser emitter 1 and here in particular a femtosecond laser emitter 1 a, which - in accordance with its principle known Wirkprinzi - for generating optical breakthroughs cavitation points a capsule 2 a lens 3 of an eye 4 is set up. The proposed laser treatment device further comprises a control device 5 for controlling the laser emitter 1.

The proposed laser treatment device is characterized in that the control device 5 is adapted to control the laser emitter 1 for generating marking contours 6 on the capsule 2 based on alignment information, wherein the marking contours 6 allow angular adjustment of a toric intraocular lens 7 inserted into the eye 4 ,

By marking contours 6 in the present sense, any optically visible markings in or on the capsule 2 are to be understood, which can be introduced into the capsule 2 by means of a laser. These include, for example, both near-surface structures in the manner of notches, scratches o. The like. And remote surface structures on the type of recesses and openings. The marking contours 6 may be provided, for example, linear or flat. It is essential that on the basis of the marking contours 6 an angular adjustment in the plane defined by the viewing direction and the capsule 2 of the eye 4 is made possible. This level is hereinafter referred to as the plane of the eye 4 for the sake of simplicity. A continuous, centered circle around the lens 3 as a contour would not allow such an angular adjustment because of its symmetry, but quite a number of non-rotationally invariant patterns, which will be discussed in more detail below, by way of example. For the purpose of Winkeljustiemng, the toric intraocular lens 7 also regularly from Fig. 3 recognizable Justices 8 - as the counterparts to the marking contours 6 - on, which are arranged on the toric middle part 9 of the intraocular lens 7. In addition to this central part 9 resilient support extensions 10 are arranged, which engage behind the remaining part of the capsule 2 in the inserted state, so as to prevent both falling out of the capsule 2 and a rotation of the toric intraocular lens 7 within the capsule 2.

The term of the orientation information is to be understood in the present case. Not to be understood by this is an immediate, manual aiming of the laser emitter 1 for drawing the marking contours 6. However, subsuming under the term of the orientation information is both presetting a certain point on the capsule 2, around which then the control device 5 by control of the laser emitter 1 independently generates the marking contours 6, as well as the specification of an axis which defines a certain orientation in the plane of the eye 4, and from which then the control device 5 determines suitable positions and shapes of marking contours 6 and by means of the laser emitter 1 generated. It is also included that an angle measure about a specific axis is provided as alignment information and the control device 5 uses this information to determine and generate both the resulting axis and the marking contours 6 corresponding to the resulting axis with respect to their position and possibly their shape.

In other words, the formulation that the control device 5 is arranged to control the laser emitter 1 based on alignment information means that a calculation takes place on the part of the control device 5 which bases the output information and therefrom the precise geometrical positions and respective ones Shape of the marking contours 6 generated. It is therefore crucial that this control comprises a calculation step, which from the Ausrichtungsi information, which only an indirect Position indication for the marking contours 6 represents the exact geometric definition of the marking contours 6 generates. Accordingly, it could also be stated that the control device 5 is set up to generate position information for marking contours 6 based on orientation information and to control the laser emitter 1 based on the position information for generating the marking contours 6 on the capsule 2.

As already mentioned, for the introduction of the toric intraocular lens 7 a section of the capsule 2 is cut out regularly. The corresponding cutout contour 1 1, which is often circular, is shown in FIGS. 2, 4 and 5. In principle, this cutting out can also be carried out mechanically and manually, but the use of a laser emitter 1 and in particular a femtosecond laser emitter 1a offers very good accuracy. Through the cutout contour 1 1, the toric intraocular lens 7 is then used. The time relationship of the producers of the marking contours 6 for cutting out the cutout contour 1 1 will be described in more detail below.

It is preferred that the alignment information comprises a reference axis 12a, b through the center 13 of the lens 3 and an axial position angle 14 of an astigmatism of the eye 4. The axial position angle 14 of the astigmatism of the eye 4 is calculated from the position of the two main sections of the eye 4, each with maximum and minimum radius of the cornea. It is further provided that the marking contours 6 define a passing through the center 13 of the lens 3 target axis 15, which is offset from the reference axis 11 by the Achslagenwinkel 14. This scenario is shown in FIG. 4. In principle, each of the two reference axes 12a, b could form the reference of the axial position angle 14; by way of example, in FIG. 4, it is the reference axis 12a.

Thus, a reference axis 12a, b is predetermined, which either corresponds to a geometrically or anatomically known axis or is marked on the eye 4 itself - as can be recognized, for example, by the mechanical color mark mechanism known from the prior art and described above and by the control device 5 or which reference axis 12a, b in any form of the control device 5 is transmitted electronically. additional lent a Achslagenwinkel 14 is given by which offset the target axis 15 is desired.

Based on the reference axis 12a, b and the axial position angle 14, the control device 5 can now calculate the target axis 15 and in turn control the generation of the marking contours 6 defining this target axis 15 based on this target axis 15.

It is particularly preferred that the reference axis 12a has a predefined orientation, in particular a horizontal orientation relative to a Grandblick direction of the eye 4. The reference axis 12a of Figs. 2 and 4 has such an orientation. This horizontal orientation may correspond to the intersection of the lens 3 with a plane which is horizontally aligned with respect to the eye 4 of an upright or seated patient. In this way, a reference axis 12a can be defined, which can be determined by default for the eye 4 of each patient from his anatomy and thus does not have to be chosen arbitrarily.

As an alternative or in addition to this procedure, it is preferably provided that the alignment information comprises a desired axis 16 which runs through the center 13 of the lens 3 and that the marking contours 6 define the desired axis 16. The setpoint axis 16 is specified here directly, ie without reference to a reference axis 12a, b. In principle, such presetting of the desired axis 16 can take place in different ways without resorting to a reference axis 12a, b. On the one hand, the desired axis 16 can be defined by two points, since these automatically define a straight line and a straight line 16 can be assigned to this straight line in a natural manner. Another possibility is to arrange an axis directly on the lens 3 or a representation of the lens 3 and then to view them as the desired axis 16. These various types will be explained below by way of preferred examples.

Thus, according to one possibility, it is preferred that the laser treatment device has a camera 17 for receiving the eye 4 and an operator interface 18 for inputting the orientation information. According to a preferred embodiment, the desired axis 16 is then input via the operator interface 18. and defined with respect to the eye 4 taken substantially at the time of entry.

It is further preferred that the laser treatment device has a visualization device 19 for a representation of the recording, which, as in the case illustrated in FIG. 1, may be a screen 19a. In such a case, the eye 4 of the patient recorded by the camera 17 can be displayed virtually in real time on the screen 19a. An axis can then be superimposed and projected onto the illustrated eye 4, the orientation of which can then be varied by rotation with a control lever 18a of the user interface 18, for example. The final alignment then defines the sol axis 16 in the sense described above, without recourse to a reference axis 12a, b.

It is further preferred that the operator interface 18 comprises a touch screen 19b of the visualization device 19. In this way, the desired axis 16 can be set directly in relation to the image of the eye 4 represented by the visualization device 19.

A further preferred possibility of predetermining the desired axis 16 is that the user interface 18 and in particular the touch screen 19b for presetting the desired axis 16 by selecting points 20 of at least two-dimensional representation of the recording by the visualization device 19 is set. Thus, two points 20 can be predetermined, for example by operation of the touch screen 19b, which thus define the desired axis 16. In this case, the control device 5 can be set up to carry out a subsequent correction of the target axis 16 defined by the points 20 in such a way that any offset to the center 13 of the lens 3 is automatically corrected. In this way, a simple and intuitive input option for the desired axis 16 is provided.

As an alternative to the definition of the desired axis 16 on a substantially real-time recorded image of the eye 4, such a definition can also take place in relation to a previously stored - ie previously made - recording of the eye 4. Here, it is thus preferably provided that the orientation information comprises a stored recording of the eye 4 and that the desired axis 16 in

Reference to the stored recording of the eye 4 is defined.

This previously performed, stored recording and the corresponding definition of the target axis can be done at the proposed, shown in Fig. 1 laser treatment device and in particular by the user interface 18 at an earlier time. Likewise, however, it may have been carried out on a completely different device and possibly by another person, since a camera 17, but no laser emitter 1, is required for this step of defining the nominal axis 16. The thus determined in advance, corresponding orientation information can then be sent to the control device 5. Therefore, it is preferable that the control device 5 is configured to receive the alignment information in electronic form.

Particular advantages arise when, according to a preferred embodiment, the laser treatment device comprises an eye tracker 21 for determining an angle of the eye 4 based on the image of the camera 17. With an Eye-Tracker 2! it is a system or a software, which would be based on characteristic structures 22 of the eye 4, which are marked in Fig. 2, such as vascular patterns in the iris, the retina or the dermis the viewing direction and thus the angle of the eye 4 can determine. In this way, therefore, a desired axis 16, which has been defined with respect to a stored recording of the eye 4, are transmitted to the current angular position of the eye 4, since the eye tracker 21 detect a possible angular offset based on the characteristic structures 22 and thus compensate can. In accordance with this preferred embodiment, the control device 5 is set up to control the laser emitter 1 for generating the marking contours 6 based on the determined angular position.

It is preferred that the control of the laser emitter 1 is also based on a comparison of the stored image with the image of the camera 17, wherein in particular this comparison can be made by the eye tracker 21. Having now presented various preferred possibilities by which a desired orientation of the intraocular lens 7 and, based thereon, also the position of the marking contours 6 can be determined, preferred embodiments of the marking contours 6 will be presented below with reference to FIGS.

With regard to the arrangement of the arkierungskonturen 6 is preferred that two marking contours 6 are arranged opposite to the center 14 of the lens 3. In this way, an angular adjustment of the intraocular lens 7 using the Justierungsritzen 8 done in a particularly simple manner.

It is further preferred that the marking contours 6 are covered by the cutout contour 1 1 of the capsule cutout. Conventionally, the capsule cut is made by a - at least ideally - circular Kapsulorhexis, depending on the applied method, the circular shape is more or less reliably achieved. However, it is also possible to make the capsule cutout so that cut-out projections 23a-c deviating from the circular shape remain as marking contours 6. In this way, the marking contours 6 can firstly be produced simultaneously with the capsule cutout. Second, they are thereby spatially located very close to the alignment slots 8 of the intraocular lens 7, since they are placed on the central part of the intraocular lens 7.

Such marking contours 6 are reproduced approximately in FIG. 6a-in a substantially angular shape and convex-and FIG. 6b-in a further rounded shape and convex. It should be noted that the emergence of further cracks in the capsule 2 should be prevented. Such cracks can arise in particular during insertion and alignment of the toric intraocular lens 7. In addition to the fact that unnecessary injuries to the eye should be avoided anyway, such cracks can also limit the usability of the marking contours 6.

Particularly susceptible to cracking are concave shapes with corners. Based on this consideration, Fig. 6c shows a marking contour 6, which forms a drop-shaped, concave cut-out projection 23c and which by their Drop shape both the occurrence of said crack-prone corners and a "flipping", as might occur in convex cut-out projections 23 a, b avoids.

According to another embodiment, as shown for example in Figs. 6d and 6e, the Markiemngskonturen 6 are spaced from the cutout contour 1 1 of the capsule cutout arranged. Such marking contours 6 thus form capsule cuts 23d-g. In order to avoid the occurrence of the cracks already mentioned above, the marking contour forming such a capsule cut 23d is

FIG. 6 prefers either point or circular with a very small radius, as shown specifically in FIG. 6d. In such an embodiment, the marking contour 6 does not provide a corner, which could represent a point of application for such a crack. Alternatively, FIG. 6e shows marking contours 6, which form linear capsule sections 23e, but which are disjoint and therefore likewise have no corners.

It can also be provided that at least two marking contours 6 are different in shape, as illustrated by the capsule sections 23f, g in FIG. 6f. This is useful if the intraocular lens to be used

7 is not mirror-symmetrical along both principal axes, but also has a defined direction, which can then be aligned in the direction of one of the two different marking contours 6.

In this case, one and the same laser treatment device does not have to be set to one type of marking contours 6, but instead can select one of several, depending on the circumstances or according to an express operator request. Accordingly, it is preferred that the control device 5 is set up to select a marking contour shape for the marking contours 6 based on the orientation information and / or based on an operator request from a multiplicity of marking contour shapes. In this case, the various marking contours 6 illustrated in FIGS. 6a each represent different marking contour shapes of the plurality of marking contour shapes. A further preferred direction of the further development of the proposed laser treatment device provides that the alignment information comprises design parameters of the intraocular lens 7. It is conceivable that, depending on the size of the eye 4, the intraocular lens 7 also has a variably configurable diameter. Accordingly, the position of the adjusting scratches 8 can be dependent on this diameter. For simplified angular adjustment, this can then also be taken into account when generating the marking contours 6. Other parameters for the variable design of the intraocular lens 7 are conceivable.

Claims

claims

1. Laser treatment apparatus for refractive surgery with a laser emitter (1), in particular a femtosecond laser emitter (1 a), for generating optical breakthroughs at Kavitationspunkten a capsule (2) a lens (3) of an eye (4) and a control device (5) Control of the laser emitter (1),

characterized,

in that the control device (5) is set up to control the laser emitter (1) for generating marking contours (6) on the capsule (2) on the basis of orientation information, the marking contours (6) providing an angular adjustment of an angle into the eye (4). used toric intraocular lens (7).

2. Laser treatment device according to claim 1, characterized in that the alignment information comprises a reference axis (12a, b) through the center (13) of the lens (3) and an axial position angle (14) of an astigmatism of the eye (4) and that the marking contours ( 6) define a target axis (15) extending through the center (13) of the lens (3), which axis is offset from the reference axis (12a, b) by the axial position angle (14).

3. Laser treatment device according to claim 2, characterized in that the reference axis (12a) has a predefined, in particular one with respect to a basic direction of the eye (4) horizontal orientation.

4. Laser treatment device according to one of claims 1 to 3, characterized in that the alignment information comprises a desired axis (16) which passes through the center (12) of the lens (3), and that the marking contours (6) the desired axis (16). define.

5. Laser treatment device according to one of claims 1 to 4, characterized in that the laser treatment device has a camera (17) for receiving the eye (4) and a Bed i ens ch ni ttste 11 e (18) for inputting the alignment information, preferably, that the desired axis (16) over the Operator interface (18) is input and defined in relation to the substantially captured at the time of input eye (4).

6. Laser treatment device according to claim 5, characterized in that the laser treatment device has a visualization device (19) for displaying the recording, preferably, wherein the user interface (18) comprises a touch screen (19b) of the visualization device (19).

7. Laser treatment device according to claim 6, characterized in that the user interface (18), in particular the touch screen (19b), for presetting the desired axis (16) by selecting points (20) of an at least two-dimensional representation of the recording by the visualization device (19). is set up.

Laser treatment apparatus according to any one of claims 4 to 7, characterized in that the alignment information comprises a stored image of the eye (4) and that the desired axis (16) is defined with respect to the stored image of the eye (4), preferably the control device (5) is adapted to receive the alignment information in electronic form.

9. Laser treatment device according to one of claims 5 to 8, characterized in that the laser treatment device comprises an eye tracker (21) for determining an angular position of the eye (4) based on the image of the camera (17) and that the control device (5) is adapted to the laser emitter (1) for generating the marking contours (6) based on the determined angular position, preferably also based on a comparison of the stored recording with the recording of the camera (1 7), in particular by the eye tracker ( 21).

10. Laserbehandlungsvomchtung according to any one of claims 1 to 9, characterized in that two marking contours (6) about the center (14) of the lens (3) are arranged opposite.

11. Laser treatment device according to one of claims 1 to 10, characterized in that the marking contours (6) of a cutout contour (1 1) of a Kapseiausschnitts are included.

12. Laser treatment device according to one of claims 1 to 1 1, characterized in that at least two marking contours (6) are different in shape.

The laser treatment apparatus according to any one of claims 1 to 12, characterized in that the control means (5) is adapted to select a marker contour shape for the marker contours (6) based on the alignment information and / or based on an operator request from a plurality of marker contour shapes.

14. Laser treatment device according to one of claims 1 to 13, characterized in that the alignment information design parameters of the intraocular lens (7).