Eye surgery system

Abstract

Ophthalmic surgical system for the treatment of one eye (3), wherein the ophthalmic surgical system comprises: an optic (7), at least one laser light source (31, 59), a measuring module (57) with at least one light detector (69) and a control system (21); wherein the optics (7) are configured to focus laser light generated by the laser light source in a focal plane (33) of the optics (7) at several locations (47); wherein the optics (7) are further configured to guide light emanating from the locations (47) to the measuring module and to focus it at the measuring module; and wherein the control (21) is configured to set a position of the focal plane (33) in the eye depending on a detection signal (70) output by the at least one light detector (69); wherein the optics (7) comprises at least one deflection element (41) configured to shift the location (47) where the laser light passes through the focal plane (33) within the focal plane (33), and wherein the eye surgery system is configured to focus the laser light at a high intensity at location (47) in the focal plane (33) to modify a tissue of the eye; characterized by the fact that the control (21) is configured to move the location (47) along a line (48) so that the laser light is focused successively at the locations which lie on the elongated line; the eye surgery system has a first operating mode and a second operating mode, wherein in the first operating mode the laser light is focused at a low intensity at the locations and the position of the The focal plane (33) is set in the eye, and in the second operating mode the laser light is directed with high intensity to the locations in the The focal plane (33) is focused to modify the tissue of the eye, and the control (21) is configured in the second operating mode to set an intensity of the laser light focused at the locations and / or a speed of displacement of the location along the line depending on the detection signal.

Description

[0001] The present invention relates to an ophthalmic surgical system for the treatment of an eye, and in particular to such an ophthalmic surgical system which facilitates the performance of capsulorhexis. Furthermore, the invention relates to methods for preparing and methods for performing capsulorhexis.

[0002] In cataract surgery, the clouded natural lens of the eye is removed, leaving the structures of the elastic capsular bag in the eye to hold the artificial intraocular lens (IOL). A crucial step in this procedure is called capsulorhexis, which involves creating an opening in the capsular bag to allow the removal of the natural lens. The IOL is then inserted into the capsular bag through this opening. According to current practice, this opening in the capsular bag should be circular and have a diameter adapted to the diameter of the IOL. Traditionally, capsulorhexis is performed using a surgical instrument, such as forceps or a needle. This procedure is complex and requires a highly experienced surgeon to achieve consistently good results.

[0003] Consideration was given to using a high-powered femtosecond laser to modify and weaken the capsular tissue along a circular line that defines the opening to be created within the capsular bag. This would then allow even less experienced surgeons to reliably remove the tissue inside the circular line. However, a high-powered femtosecond laser is very expensive.

[0004] For example, DE 10 2011 109 058 A1, US 2014 / 0163534 A1 and DE 10 2008 005 053 A1 disclose high-performance femtosecond lasers which are used to modify eye tissue in ophthalmic surgery, for example to correct refractive errors or to perform capsolurhexis.

[0005] It was recently proposed to apply a light-absorbing agent to the anterior capsular bag and to use a low-power CW laser to scan a focused laser beam to modify the tissue along a line that defines the opening to be created in the capsular bag. The light-absorbing agent absorbs the laser light to produce a thermal effect on the capsular bag tissue, modifying it in such a way that it is weakened. The tissue inside the closed line can then be removed.

[0006] It is feared that during such a procedure, laser light with a high intensity per unit area will strike tissues of the eye other than the capsular bag, thus undesirably modifying and damaging these other tissues. In particular, damage to the retina is feared.

[0007] It is an object of the present invention to propose an ophthalmic surgery system and a method for preparing capsulorhexis with which laser light can be focused in the area of ​​the capsular bag of an eye.

[0008] This problem is solved by an ophthalmic surgical system with the features of claim 1 and a method for preparing capsulorhexis with the features of claim 14. Advantageous embodiments of the ophthalmic surgical system are specified in claims 2 to 13. A method for performing capsulorhexis comprises applying a light-absorbing agent to the capsular bag of an eye. The agent may, for example, be trypan blue. An ophthalmic surgical system is then used to modify the tissue of the capsular bag with laser light along an elongated line. The elongated line may, for example, be circular, and along this line the tissue of the capsular bag can be modified such that it is weakened and the tissue within the line can be easily removed.

[0009] This procedure includes a capsulorhexis preparation step that does not necessarily require a surgeon and can be performed by an assistant, for example. The capsulorhexis preparation step is carried out after the light-absorbing agent has been applied to the eye's capsular bag. This preparation step essentially involves adjusting the ophthalmic surgical system so that, during the subsequent capsulorhexis procedure, the laser beam is reliably focused within the capsular bag. This ensures a high laser power output per unit area within the capsular bag while protecting surrounding tissue.

[0010] According to exemplary embodiments, the ophthalmic surgery system comprises optics, a laser light source, a measuring module with at least one light detector, and a control unit. The optics are configured to focus laser light generated by the laser light source at multiple locations within the eye within a focal plane of the optics. Thus, the optics are configured to direct the laser light generated by the laser light source to the eye in such a way that the laser light is focused at locations situated on a surface within the eye. Ideally, the surface containing the points where the laser light is focused—that is, the focal plane of the optics—can coincide with the surface of the capsular bag to which the light-absorbing agent has been applied.This focuses the laser light where the light-absorbing agent is located, namely on the surface of the capsular bag, so that the laser light can subsequently generate an effective local thermal effect at these locations, which modifies the tissue of the capsular bag.

[0011] The ophthalmic surgery system supports the adjustment of the focal plane, in which the laser light is focused, relative to the eye so that it essentially coincides with, for example, the capsular bag. For this purpose, the optics are configured to direct light emanating from the capsular bag to the measuring module and focus it there. At least a portion of the light focused in the area of ​​the measuring module strikes at least one of its light detectors, which outputs a detection signal corresponding to the incident light. The control system is configured to activate components of the ophthalmic surgery system based on this detection signal in order to adjust the position of the focal plane, in which the laser light is focused, relative to the eye.For example, the control system can change and adjust the position of the focal plane based on the detection signal until the intensity of the light hitting the at least one light detector is maximized.

[0012] According to an exemplary embodiment, the optics are variable optics comprising an actuator for changing the distance of the focal plane from the optics. For example, the actuator can move an optical element of the optics relative to other optical elements of the optics to change the distance of the focal plane from the optics. The controller can then be configured to control this actuator depending on the detection signal output by the at least one light detector.

[0013] According to another exemplary embodiment, the eye surgery system comprises a stand that holds the optics relative to the eye, the stand including an actuator for changing the distance between the optics and the eye. For example, the actuator can be a motor drive that generates a translational or rotational movement in a component or pair of components of the stand. The control system is configured to control this actuator depending on the detection signal output by the at least one light detector.

[0014] According to exemplary embodiments, the measuring module comprises a beam-limiting detection aperture arranged in a beam path between the focal plane within the eye and the at least one light detector, such that the light detector can only detect light that has passed through the detection aperture. The optics can be configured to focus light emanating from locations in the focal plane at the detection aperture. The detection aperture can, for example, be designed as an opaque plate with a circular opening through which the light detected by the light detector can pass. The opening can have a diameter of, for example, 0.001 mm or 0.02 mm.

[0015] According to exemplary embodiments, the optics are configured to map locations within the focal plane onto the detection aperture. This achieves the effect that the majority of the light detected by the light detector originates from the same locations in the eye where the laser light is focused. The measuring module is thus configured to selectively detect light emanating from locations within the focal plane positioned in the eye. This allows the control system to position this focal plane within the eye with high precision, such that the focal plane essentially coincides with the capsular bag, which becomes detectable in this way after the application of the light-absorbing agent.

[0016] According to exemplary embodiments, the detection signal represents an intensity of the light striking the light detector, and the control can then be configured to adjust the position of the focal plane in the eye as a function of the detection signal so that the intensity of the light striking the light detector is maximized.

[0017] According to another embodiment, the measuring module comprises a first light detector and a second light detector, both of which receive light emanating from the focal plane within the eye. For example, a beam splitter may be provided to divide the beam path so that each light detector is located in a portion of the beam path. The measuring module further comprises a first detection aperture located in the beam path between the focal plane and the first light detector, and a second detection aperture located in the beam path between the focal plane and the second light detector, the two detection apertures being arranged along the beam paths at different distances from the focal plane. The first and second detection apertures may each be configured as a single detection aperture, as previously explained.

[0018] According to exemplary embodiments herein, the detection signal of the first light detector represents a light intensity incident on the first light detector, and the detection signal of the second light detector represents a light intensity incident on the second light detector, wherein the control is configured to adjust the position of the focal plane in the eye such that the light intensity incident on the first light detector and the light intensity incident on the second light detector have a predetermined ratio and, in particular, are equal. In the latter case, the optics may map the focal plane within the eye to a location along the beam path situated between the first and the second detection apertures.This means that, for example, the first detection aperture in the beam path is positioned in front of the image of the focal plane, and the second detection aperture in the beam path is positioned behind the image of the focal plane. Such an arrangement with two detection apertures and two light detectors allows for quick and reliable adjustment of the optics and the focal plane defined by these optics within the eye relative to the eye.

[0019] According to further exemplary embodiments, the measuring module comprises a plurality of light detectors arranged along the beam path at varying distances from the focal plane within the eye. Each light detector can provide a detection signal representing the light intensity of the light incident on that particular detector. According to further exemplary embodiments, the measuring module includes an astigmatic optical element, such as a cylindrical lens, which focuses light emanating from a location within the focal plane within the eye along a line. The plurality of light detectors can then be arranged such that their distance from the surface within the eye increases in the direction of the line focus, so that several of the light detectors are illuminated with measuring light simultaneously.Those light detectors that are arranged along the line at the position of the beam path where an optical image of the location in the focal plane inside the eye is created will detect a maximum light intensity, so that, conversely, the location of the focal plane inside the eye can be deduced from this position.

[0020] According to exemplary embodiments, the ophthalmic surgery system comprises a beam-limiting illumination aperture, which is arranged in the beam path between the laser light source and the focal plane within the eye such that only laser light passing through the illumination aperture can reach the area. The illumination aperture can be designed like the detection aperture, for example, as a plate with a circular opening.

[0021] According to exemplary embodiments, the optics are designed to image the illumination aperture onto the focal plane within the eye, so that a high light intensity can be generated at the location in the focal plane on which the illumination aperture is imaged, in order to modify the tissue of the capsular bag there.

[0022] According to exemplary embodiments, the optics comprise at least one deflection element configured to shift the point where the laser light intersects the focal plane within the focal plane, wherein the control can be configured to shift the point along an elongated line, such that the laser light is focused sequentially at the points lying on the elongated line. In other words, the focused laser light is scanned along the elongated line.

[0023] According to exemplary embodiments, the eye surgery system has two operating modes. In a first operating mode, the laser light is focused at low intensity at locations within the focal plane, and the light emanating from these locations is detected by the measuring module to adjust the position of the focal plane within the eye. In a second operating mode, the laser light is focused at high intensity at these locations to modify the tissue of the eye. In one exemplary embodiment herein, the controller is configured to adjust, in the second operating mode, the intensity of the laser light focused at these locations and / or the speed of moving the location along the line, depending on the detection signal.This makes it possible to achieve the same thermal effect of the laser beam at all locations on a capsular bag colored with a light-absorbing agent, even if the locations differ in terms of the concentration of the light-absorbing agent applied there.

[0024] Embodiments of the invention are explained in more detail below with reference to the figures. These show: Fig. 1 a schematic representation of a first embodiment of an ophthalmic surgery system; Fig. 2 a schematic representation of a measuring module of a second embodiment of an ophthalmic surgery system; Fig. 3 a schematic representation of a measuring module of a third embodiment of an ophthalmic surgery system; Fig. 4 A schematic representation of a top view of a light detector of the measuring module of the Fig. 3; Fig. 5 a schematic representation to explain an optic which focuses laser light along an elongated line; Fig. 6 a schematic representation of an ophthalmic surgery system which includes optics according to Fig. 5 includes; Fig. 7 a schematic representation of an ophthalmic surgery system which includes optics according to Fig. 5 includes; Fig. 8 a schematic representation of an ophthalmic surgery system which includes optics according to Fig. 5 includes; Fig. 9 a flowchart to illustrate a first embodiment of a method for performing capsulorhexis; and Fig. 10 a flowchart to explain a second embodiment of a method for performing capsulorhexis.

[0025] Fig. Figure 1 schematically shows an ophthalmic surgical system 1 for performing capsulorhexis. It is assumed that one eye 3 of a patient has developed a cataract, requiring the replacement of the clouded natural lens contained within the capsular bag 5 of the eye 3 with an intraocular lens (IOL) implant. For this purpose, capsulorhexis is performed, which involves creating an opening in the capsular bag. Through this opening, the natural lens is removed, and the intraocular lens is inserted into the capsular bag. The ophthalmic surgical system 1 is used to assist in performing the capsulorhexis. Specifically, the ophthalmic surgical system 1 can emit a laser beam that focuses laser light at multiple locations along a closed line on the capsular bag to modify the capsular bag tissue, thereby weakening it.The closed, elongated line delineates the opening to be formed in the capsular sac, and the tissue within the closed line can be removed after the tissue has weakened to form the opening in the capsular sac. The method described here for generating capsulorhexis involves applying a light-absorbing agent to the capsular sac. Background information on such a method can be obtained from US 8,409,182 B2, the disclosure of which is incorporated in its entirety into the present application by reference.

[0026] The light-absorbing agent used in the embodiments described here is trypan blue, which can be obtained from Sigma-Aldrich, St. Louis, MO, USA.

[0027] The ophthalmic surgery system 1 comprises an optical component 7, which can be housed in a casing 9. The optical component 7 is supported by a stand 11, which can be fixed to a ceiling, wall, or floor 13 of a room. Since the patient rests with their head and eye on a fixed support relative to the room, the stand 11 includes several movable components 15, which can be shifted relative to each other to position the optical component 7 relative to the eye 3. The stand 11 can also include one or more actuators 17 to shift the movable components 15 relative to each other. These actuators are controlled by a control unit 21 via a control line 19, so that the position of the optical component 7 relative to the eye 3 can be adjusted by the control unit 21.The controller 21 can comprise one or more electronic circuits, such as a processor and memory modules, which may be located inside the housing 9 or outside the housing and at a distance from the optical part 7. The controller 15 can, for example, be implemented as a computer that runs control software and is connected to various components of the ophthalmic surgery system 1 in order to control them.

[0028] The optical part 7 can include a microscope 23 with an objective lens 25 and two eyepieces 27, into which a surgeon can look with both eyes to observe the procedure.

[0029] The optical section 7 further comprises a laser treatment and measurement section 28 to supply laser light for modifying the capsular bag. The laser treatment and measurement section 28 includes a treatment laser 31 controlled by the control unit 21 via a control line 29, which generates laser light that is focused in a focal plane 33 to modify the tissue of the capsular bag 5. The laser 31 supplies laser light with a wavelength matched to the light-absorbing agent, which, for example, when using trypan blue, can be in the range of 580 nm to 610 nm. The laser light is emitted by the laser 31 via an optical fiber 35, at the end 36 of which the laser light exits. The end 36 of the optical fiber 35 thus acts as a point light source for a laser beam 37, which is collimated by a lens 38.The laser beam then passes through two semi-transparent mirrors 39 and 40, is reflected by a deflecting mirror 41, and shaped by a lens 43 into a laser beam 44. This laser beam is reflected by a mirror 45 located below the objective lens 25, so that the beam 44 is focused at a point 47 in the focal plane 33. The optics consisting of lenses 38 and 43 focus the fiber end 36 at the point 47 in the focal plane 33. Instead of reflecting the laser beam 44 at the mirror 45 located below the objective lens 25 towards the object field of the microscope 23, it is also possible to use a corresponding mirror in . Fig. The lens 1 is positioned above the objective lens 25, at which the laser beam is reflected towards the object field of the microscope 23 and also passes through the objective lens 25. The objective lens 25 then contributes to focusing the laser beam, so that the lens 43 can be equipped with a correspondingly smaller refractive power or omitted.

[0030] The deflecting mirror 41 can be pivoted in two spatial directions, as shown by arrows 49 in Fig. As indicated in Figure 1, the pivot position of the deflecting mirror 41 is set by an actuator 51, which is controlled by the controller 21 via a control line 52. By pivoting the deflecting mirror 41, it is possible to shift the location 47 where the laser light is focused within the focal plane 33. Instead of a single pivoting mirror that can be shifted in two spatial directions, two pivoting mirrors can also be used, arranged one behind the other in the beam path, each shiftable in one spatial direction by its own actuator.

[0031] The controller 21 is configured to switch on the laser 31 and move the point 47 along a closed circular line in the focal plane 33. Since the capsular bag is stained with the light-absorbing agent, laser power is absorbed there, and its thermal effect modifies the tissue of the capsular bag along the circular line. For this to work, it is essential that the focal plane 33, in which the points 47 are located where the laser light is focused, essentially coincides with the surface of the stained capsular bag. This ensures that the thermal effect of the laser beam on the capsular bag is maximized and the exposure of other parts of the eye 3 to the laser light is correspondingly minimized. To adjust the optics so that the focal plane 33 essentially coincides with the surface of the capsular bag 5, the following features are provided in the embodiment of the Fig. Figure 1 illustrates two possibilities. Firstly, the control unit 21 can actuate the actuator 17 to change the distance of the optical part 7 from the eye 3 and thus the position of the focal plane 33 within the eye 3. Secondly, the lens 43 is a movable optical component that can be shifted in the direction of the laser beam path 44, as indicated by an arrow 53 in Figure 1. Fig. As indicated in Figure 1, the movement of lens 43 is caused by an actuator 54, which is controlled by the control unit 21 via a control line 55. By moving lens 43, the position of the focal plane 33 in the eye can be changed without changing the position of the optics 7 relative to the eye.

[0032] The controller 21 actuates the actuator 17 and / or the actuator 54 depending on detection signals generated by a measuring module 57. The measuring module 57 comprises an alignment laser 59, controlled by the controller 21 via a control line 58, which supplies laser light via an optical fiber 61, such that one end 62 of the optical fiber 61 forms a point light source for the laser light used for alignment. The light exiting the fiber end 62 is collimated by a lens 63 and reflected by the semi-transparent mirror 39, so that it is superimposed on the beam path of the laser light 37 generated by the laser 31. The fiber end 62 and the lens 63 are arranged such that an optical image of the fiber end 62, acting as a point light source, is also formed at location 47 in the plane 33. There, the incident light from the adjustment laser 49 is absorbed, scattered or reflected by the tissue of the eye and the light-absorbing agent.A portion of the scattered or reflected light is reflected by the mirror 45, passes through the lens 43, is reflected by the deflecting mirror 41 and subsequently by the semi-transparent mirror 40, and is focused by a lens 65 onto an opening 67 of an aperture plate 68. The opening 67 forms a detection aperture of the measuring module 57. The lens 65 and the aperture plate 68 are arranged such that an optical image of location 47 in the plane 33 is formed at the opening 67. Light passing through the opening 67 is detected by a light detector 69, which delivers a detection signal representing the intensity of the detected light to the control unit 21 via a signal line 70. Due to the optical mapping of location 47 in the plane 33 onto the aperture 67, the light detector 69 essentially only detects light that originated from location 47 in the focal plane 33, where the laser light is also focused.The control unit 21 can then actuate the actuators 17 and / or 54 until the detection signal supplied by the light detector 69, representing the detected light intensity, is at its maximum. It can then be assumed that the plane 33 coincides with the surface of the capsular bag 5 and that the light from the treatment laser 31 can be focused at maximum intensity on the capsular bag to modify the tissue there. The control unit can then be switched from a first operating mode, in which the light from the adjustment laser 59 is directed towards the eye and the actuators 17 and / or 54 are adjusted depending on the detected light, to a second operating mode, in which the light from the treatment laser 31 is guided along the circular line on the capsular bag by pivoting the mirror 41 using the actuator 51 controlled by the control unit 21.

[0033] In the previously described embodiment, a treatment laser 31 is used to modify the tissue and an adjustment laser 59 is used for adjustment. However, it is also possible to use only the treatment laser 31 for this purpose if it is operated at a lower intensity in the first adjustment mode in order to avoid modifying the tissue of the capsular bag during adjustment. This can be achieved by operating the laser in a mode in which it generates light of lower intensity, or by moving an attenuating element into the beam path of the laser light 37.

[0034] In the based on Fig. In the embodiment described in Figure 1, a point light source is optically imaged onto location 47 on the capsular bag. Such a point light source can be generated by a beam-limiting illumination aperture, which is designed as an opening in an aperture plate illuminated with laser light from one side, so that on the other side of the aperture plate the light emerges through the opening as if from a point light source. Such an illumination aperture is also called a pinhole. In the embodiment described in Figure 1, the pinhole is optically imaged onto location 47 on the capsular bag. Fig. In the example 1, such a steel-limiting aperture is formed by the end 36 of the optical fiber 35, from which the light also emerges as from a point light source.

[0035] The following are variations of the eye surgery system of Fig. 1. Here, components corresponding to one another in terms of their structure or function are designated with corresponding numbers, which are further distinguished by an additional letter. To understand such components, reference should be made to the entire preceding and subsequent disclosure.

[0036] In the embodiment of the Fig. 1. The point light source 36 for the laser light to modify the tissue and the point light source 62 for the laser light to adjust are imaged onto location 47 in the focal plane. Conversely, location 47 in the focal plane is imaged onto the detection aperture 67. This means that the point light source 36 and the detection aperture 67 are arranged confocally to each other. Likewise, the point light source 62 and the detection aperture 67 are arranged confocally to each other.

[0037] Suitable filters and / or polarizing elements can be used to prevent light from one laser from being reflected back into the same or the other laser or detector.

[0038] Fig. Figure 2 shows a variant of a measuring module 57a. The measuring light returning from the eye is focused by a lens 65a, with a beam splitter 81 arranged in a beam path behind the lens 65a, so that the beam is split and a beam focus is formed in each of the two planes 821 and 822. A detection aperture is arranged in each of the split beams. However, a first detection aperture with an aperture plate 68a1 and an opening 67a1 provided therein is arranged in the beam path in front of the plane 821 of the focus, while in the other beam path a detection aperture with an aperture plate 68a2 and an opening 67a2 provided therein is arranged in the beam path behind the plane 822 of the focus.In the beam path behind the detection aperture 67a1, a light detector 69a1 is arranged, which can only detect light that has passed through the detection aperture 67a1, and in the beam path behind the detection aperture 67a2, a detector 69a2 is arranged, which can only detect light that has passed through the detection aperture 67a2.

[0039] Thus, with the desired setting of the ophthalmic surgery system, neither of the two detection apertures 67a1 and 67a2 is positioned exactly at the focus onto which a location of the capsular bag is imaged. However, the detection signals output by the light detectors 69a1 and 69a2 can still be used by the controller to determine the plane (33 in Fig. 1) within the eye, in which the laser light is focused for tissue modification and adjustment. For example, the control system can adjust the setting of the plane within the eye based on a ratio of the two detection signals supplied by the two light detectors 69a1 and 69a2. Particularly precise adjustment is possible when the components of the optics are positioned relative to each other such that the planes 821 and 822, in which the image of the focal plane 33 is formed, are arranged at equal distances from the detection apertures 67a1 and 67a2.

[0040] The in Fig. The measuring module shown in section 2 can be used in the following way: Fig. The eye surgery system described in section 1 will be used.

[0041] The Fig. 3 and Fig. Figure 4 shows another variant of a measuring module 57b. The measuring light returning from the eye is not, as in the one shown in Fig. In the embodiment shown in Figure 2, the light is not focused at a point in a plane 82b, but rather along a line in a plane 82b by means of a cylindrical lens 65b. A light detector 69b comprises a plurality of detection elements, which can be arranged in a row along a line or as a field within an area. The line or the area is arranged transversely to the plane 82b and transversely to the beam path of the measuring light returning from the eye. Fig. Figure 4 shows a top view of detector 69b and an intensity distribution of the incident light. Light strikes a waist-shaped region 83 of the surface, while in regions 84 on both sides of the waist-shaped region 83, essentially no light reaches the detector. The plane 82b, in which the line focus is located, intersects the detector surface where the width D of the waist-shaped region 83 is smallest. The intensity of the incident light is also greatest at this point. The position of plane 82b along the beam path can thus be determined by evaluating the detection signals of the detector elements. If the detectors are arranged in a row along a line, the position of plane 82b can be determined where the detection element that detects the greatest light intensity is located.If a field of detector elements is arranged in a plane, the illuminated area 83 and the unilluminated areas 84 can also be determined to pinpoint the location where the width D of area 83 is minimal. By evaluating the detection signals, the control unit of the ophthalmic surgery system can thus determine the position of plane 82b, and by adjusting the settings of the actuators of the ophthalmic surgery system, the control unit can position plane 82b so that it is confocal to a laser light source for generating treatment light or for generating adjustment light.

[0042] The characters Fig. 3 and Fig. The measuring module shown in section 4 can be used in the following way: Fig. The eye surgery system described in section 1 will be used.

[0043] Fig. Figure 5 shows a schematic representation of an optical system which does not refocus the light from a point light source 36c to a single point, but simultaneously focuses it along a circular line 48 in a plane 33c. For this purpose, the optical system comprises a lens system of lenses 38c and 43c, each of which can in turn contain two lens elements. Without any other components in the beam path, the lenses 38c and 43c would refocus the point light source 36c to a point located near the plane 33c. However, an optical element 75 is arranged in the beam path between the point light source 36c and the lens 38c, which forms an annular beam 77c from the beam 37c emitted by the point light source 36c. A representation element I1 in Fig. Figure 5 represents the cross-section of beam 77c in the region of optical element 75. There, beam 37a is not yet an annular beam, and the intensity of the beam within the area in Fig. The cross-section of the beam shown in Figure 5, for example, exhibits a substantially constant or Gaussian intensity distribution. A representation element I2 in Fig. Figure 5 represents the cross-section of the ring ray 77c at a point along the ray path between the lens 43c and the plane 33c. There, the cross-section of the ray is bounded by an outer edge with radius r2 and an inner edge with radius r1. A representation element I3 in Fig. Figure 5 represents the beam cross-section of the annular beam 77c at a point in the beam path between the lens 43c and the plane 33c, which is closer to the plane 33c than the point represented by the representation element I2. The annular beam 77c is in turn bounded by an outer edge with radius r2 and an inner edge with radius r1, where the difference between the two radii r2 and r1 is reduced compared to the representation element I2. A representation element I4 in Fig. Figure 5 represents the cross-section of the ring beam 77c in the plane 33c. There, the ring beam is bounded by an outer edge with radius r2 and an inner edge with radius r1. However, the difference between the two radii r2 and r1 is very small, so that the light intensity of the ring beam 77 is essentially focused along a closed line 48. Outside of line 48, essentially no laser light reaches the plane 33c.

[0044] The optical element 75 for generating the ring beam 77c can comprise several suitable elements. In the example of the Fig. In Figure 5, the optical element 75 is designed as an axicon, which is a glass element through which the beam path passes. One surface of the axicon is a planar surface, while the other surface has the shape of a cone. Further examples of suitable optical elements 75 include a holographic element designed to form an annular beam from the beam 73c with the solid cross-section shown in illustration element I1. Furthermore, for example, a mirror with a conical mirror surface or an array of controllable micromirrors (digital mirror array, DMD) can be used as an optical element 75. With an optics system having a structure similar to that shown in the illustration, the optical element 75 can be used as an optical element 75. Fig. Based on the optics described in section 5, it is possible to focus laser light along a ring-shaped line on the capsular bag of an eye in order to simultaneously modify the capsular bag tissue along this line. In particular, it is then not necessary to scan a laser beam focused at only one point along the desired line using deflection mirrors, as is done based on the optics described in section 5. Fig. 1 was explained.

[0045] Conversely, light scattered or reflected by the capsule bag, emanating from line 48, is focused at the location of the light source 36a.

[0046] Fig. Figure 6 schematically shows an ophthalmic surgery system 1d for performing capsulorhexis, which has a similar structure to the one based on the Fig. 1. Eye surgery system explained. In contrast to the eye surgery system of the Fig. 1. The ophthalmic surgery system 1d does not use a laser beam focused at a point in the focal plane of the optics, which is scanned along the closed line with the aid of a swiveling deflection mirror, but rather an optical element 75d to generate a ring beam, as shown by the Fig. As explained in section 5, this is to focus the laser beam simultaneously along the closed line. A pivotable deflecting mirror in the embodiment of Fig. One corresponding deflection mirror 41d can be a non-rotating, fixed deflection mirror. Otherwise, the ophthalmic surgery system 1d has one as described in Fig. The structure of the eye surgery system shown in section 1 corresponds to the structure shown, which is not described in detail below to avoid repetition.

[0047] The laser light for treatment, that is, for modifying the tissue of a capsular bag, is emitted by a laser 31d via a fiber optic 35d, the end of which 36d acts as a point light source for a laser beam 37d. The laser beam 37d is shaped by the optical element 75d into an annular beam 77d. The annular beam 77d is reflected by the mirror 41d, passes through a lens 43d, and is reflected by a mirror 45d positioned in front of an objective lens 25d of a microscope 23d, so that the annular beam 77d is focused in a focal plane 33d along a circular path (compare Fig. 5) is the focus.

[0048] A controller 21d actuates the actuator 17d and / or the actuator 54d depending on detection signals generated by a measuring module 57d. The measuring module 57d comprises an adjustment laser 59d, controlled by the controller 21d via a control line 58d. This laser delivers laser light via an optical fiber 61d, the end of which 62d forms a point light source for the laser light used for adjustment. The laser light used for adjustment is superimposed on the beam path of the laser light used for treatment. Therefore, the light from the adjustment laser 59d is also shaped by the optical element 75d into a ring beam, which is focused in plane 33d at the circular line. In plane 33d, the incident light from the adjustment laser 49d is absorbed, scattered, or reflected by the tissue of the eye and the light-absorbing agent.Part of the light scattered or reflected at the capsule bag is reflected at the mirror 45d and, after passing through the optical element 75d, is focused at an opening 67d of an aperture plate 68d.

[0049] Light passing through the opening 67d is detected by a light detector 69d, which transmits a detection signal representing the intensity of the detected light to the control unit 21d via a signal line 70d. In a first operating mode, in which the light from the adjustment laser 59d is directed towards the eye, the control unit 21d adjusts the actuators 17d and / or 54d, depending on the detected light, so that the focal plane essentially coincides with the capsular bag. The control unit can then be switched to a second operating mode in which the light from the treatment laser 31d is focused on the circular line on the capsular bag to modify the capsular tissue.

[0050] The following are variations of the eye surgery system of Fig. 5 and Fig. Section 6 explains which ones use a ring beam.

[0051] Fig. Figure 7 shows another ophthalmic surgery system 1e, which has a similar structure to the one shown in the Fig. 6. Eye surgery system explained. In contrast, eye surgery system 1e does not have a separate laser 59d in Fig. 6 to generate measuring light, which in a first operating mode is used to shift a focal plane 33e, in which the laser light is focused, within an eye 13e. The eye surgery system 1e has a single laser 31e which generates the laser light focused in plane 33e along the circular line for modifying the capsular bag 5e of the eye in the second operating mode. In the first operating mode for setting the focal plane 33e in the eye, a controller 21e of the eye surgery system 1e controls the laser 31e so that only laser light of sufficiently low intensity is focused in plane 33e so as not to modify the tissue there. In this first operating mode, a detector 69e generates a detection signal, which the controller 21e uses to make the settings as determined by the Fig. 1 and Fig. 6 were explained. In the beam path leading from the laser 31e to the plane 33ce, as well as in the beam path leading from the plane 33e to the detector 69e, an optical element 75e is arranged to shape the ring beam.

[0052] In the based on the Fig. 6 and Fig. In the embodiments described in section 7, a single optical element is provided for forming a ring beam, which is penetrated by both the laser light for modifying the tissue and the detected light. Fig. Figure 8 is a schematic representation of an ophthalmic surgery system 1f, which has separate optical elements 75f1 and 75f2 for these two purposes.

[0053] Unlike the eye surgery system of the Fig. 6, in which the optical element 75d is arranged in the common part of the two beam paths divided by the semi-transparent mirror 40d, is in the eye surgery system 1f of the Fig. 8. An optical element 75f1 for forming a ring beam between a laser 31f and a semi-transparent mirror 40f, and another optical element 75f2 in a beam path between the semi-transparent mirror 40f and a detector 69f, in order to focus the ring beam at an aperture 67f of an aperture plate 68f. Otherwise, the structure and function of the components of the ophthalmic surgery system 1f are similar to those of the ophthalmic surgery system of the Fig. 6.

[0054] As in the exemplary embodiment of the Fig. 1. Laser light focused at a point in the focal plane is also used in the ring beam-generating eye surgery systems of the Fig. 6, Fig. 7 and Fig. 8, the point light source for modifying the tissue or for adjusting to locations of a ring-shaped line in the focal plane is imaged, while in turn the ring-shaped line in the focal plane is imaged onto the detection apertures, so that here too the point light sources and detection apertures are arranged confocally to each other.

[0055] Furthermore, the following can also be used based on the Fig. 2, Fig. 3 and Fig. The 5 measurement modules explained in the section based on the Fig. 6, Fig. 7 and Fig. The 8 described eye surgery systems are used to generate at least one detection signal.

[0056] Fig. Figure 9 is a flowchart to illustrate one embodiment of a method for performing capsulorhexis.

[0057] In step 101, a light-absorbing agent is applied to the capsular bag of an eye. In step 103, an ophthalmic surgical system is switched to a first operating mode, and low-intensity laser light is directed at the eye for alignment. In step 105, the light reflected from the eye is detected. In a decision step 107, it is determined whether the light-absorbing agent has been correctly applied to the capsular bag. If so, in step 109, the ophthalmic surgical system is switched to a second operating mode, in which high-intensity laser light is directed at the eye to modify the capsular bag tissue. If not, the system proceeds to step 111, in which the switch to the second operating mode is prevented.

[0058] This procedure can be used with any of the methods based on the Fig. The eye surgery systems described in sections 1 to 4 are performed by moving point 47 along the line along which the capsular bag tissue is to be weakened in the second operating mode using low-intensity laser light. Depending on this movement, the intensity of the light returning from the eye is detected by detector 69. If essentially the same intensities are detected along the line, it can be concluded that the light-absorbing agent was applied as desired. Conversely, if the differences between the maximum and minimum measured light intensities are too large, it can be assumed that the light-absorbing agent was not applied correctly.

[0059] Fig. Figure 10 is a flowchart to illustrate another embodiment of a method for performing capsulorhexis.

[0060] In step 201, a light-absorbing agent is applied to a capsular bag. In step 203, an ophthalmic surgical system is switched to a first operating mode, light returning from the eye is detected, and the system is adjusted accordingly. The system is then switched to a second operating mode in which high-intensity laser light is directed along an elongated line onto the capsular bag. In step 205, the laser light is directed to the next location along the line to modify the tissue there. In step 207, light returning from the eye is detected and analyzed. Depending on the intensity of the light detected in step 207, the intensity of the laser light directed at the capsular bag is modified in step 209, and / or the speed at which the system advances to the next location is adjusted.The duration for which the laser beam is held at the current location is changed. In step 211, it is determined whether all locations along the line have been illuminated. If so, the process is terminated in step 213. If not, the process continues with step 205, in which the laser light is directed to the next location along the line.

[0061] This procedure can be used in particular with any of the methods based on the Fig. The eye surgery systems described in points 1 to 4 are performed.

Claims

[1] Eye surgery system for the treatment of an eye (3), the eye surgery system comprising: an optic (7), at least one laser light source (31, 59), a measuring module (57) with at least one light detector (69) and a controller (21); wherein the optics (7) are configured to focus laser light generated by the laser light source in a focal plane (33) of the optics (7) at a plurality of locations (47); wherein the optics (7) are further configured to guide light emanating from the locations (47) to the measuring module and to focus it on the measuring module; and wherein the controller (21) is configured to adjust a position of the focal plane (33) in the eye in dependence on a detection signal (70) output by the at least one light detector (69); wherein the optics (7) comprises at least one deflection element (41) which is configured to shift the location (47) at which the laser light passes through the focal plane (33) within the focal plane (33), and wherein the eye surgery system is configured to focus the laser light at a high intensity at the location (47) in the focal plane (33) to modify a tissue of the eye; characterized by , that the controller (21) is configured to displace the location (47) along a line (48) so that the laser light is focused sequentially at the locations lying on the elongated line; the eye surgery system has a first operating mode and a second operating mode, wherein in the first operating mode the laser light is focused at a low intensity at the locations and the position of the focal plane (33) in the eye, and wherein in the second operating mode the laser light with the high intensity is applied to the locations in the focal plane (33) is focused in order to modify the tissue of the eye, and the controller (21) is configured to adjust, in the second operating mode, an intensity of the laser light focused at the locations and / or a speed of displacement of the location along the line as a function of the detection signal. [2] Eye surgery system according to claim 1, wherein the optics (7) is a variable optics comprising a first actuator (54) for changing the distance of the focal plane (33) in which the laser light is focused from the optics (7), and wherein the controller (21) is configured to control the first actuator (54) in dependence on the detection signal output by the at least one light detector (69). [3] Eye surgery system according to claim 1 or 2, further comprising a stand (11) which holds the optics (7) relative to the eye (5), wherein the stand comprises a second actuator (17) which is configured to change a distance between the optics (7) and the eye, and wherein the controller (21) is configured to control the second actuator (17) in dependence on the detection signal output by the at least one light detector (69). [4] Eye surgery system according to one of claims 1 to 3, wherein a beam-limiting detection aperture (67) is arranged in a beam path between the focal plane (33) and the at least one light detector (69), so that the light detector (69) can only detect light which has passed through the detection aperture (67), and wherein the optics (7) are configured to focus light emanating from locations (47) in the focal plane (33) at the detection aperture (67). [5] Eye surgery system according to claim 4, wherein the optics (7) are configured to image the locations (47) in the focal plane (33) onto the detection aperture (67). [6] Eye surgery system according to claim 4 or 5, wherein the detection signal represents an intensity of the light incident on the light detector (69), and wherein the controller is configured to adjust the position of the focal plane (33) in the eye in dependence on the detection signal such that the intensity of the light incident on the light detector (69) is maximum. [7] The eye surgery system according to any one of claims 1 to 6, wherein the measuring module comprises a first light detector (69a1) and a second light detector (69a2); wherein a beam-limiting first detection aperture (67a1) is arranged in a beam path between the focal plane (33) and the first light detector (69a1), so that the first light detector (69a1) can only detect light which has passed through the first detection aperture (67a1); wherein a beam-limiting second detection aperture (67a2) is arranged in a beam path between the focal plane (33) and the second light detector (69a2), so that the second light detector (69a2) can only detect light which has passed through the second detection aperture (67a2); and wherein the first detection aperture (67a1) and the second detection aperture (67a2) are arranged along the beam paths at different distances from the focal plane (33). [8] Eye surgery system according to claim 7, wherein a detection signal of the first light detector (69a1) represents an intensity of the light impinging on it and a detection signal of the second light detector (69a2) represents an intensity of the light impinging on it, and wherein the controller is configured to adjust the position of the surface in the eye such that the light intensity impinging on the first light detector (69a1) and the light intensity impinging on the second light detector (69a2) have a predetermined ratio and are in particular equal. [9] Eye surgery system according to one of claims 1 to 8, wherein the measuring module (57b) comprises a plurality of light detectors arranged along the beam path at different distances from the focal plane (33). [10] Eye surgery system according to claim 9, wherein an astigmatic optical element (65b) is arranged in the beam path. [11] The eye surgery system according to claim 9 or 10, wherein the plurality of light detectors are arranged in a row. [12] Eye surgery system according to one of claims 1 to 11, further comprising a beam-limiting illumination aperture (36) which is arranged in a beam path between the laser light source (31) and the focal plane (33) such that only laser light which has passed through the illumination aperture (36) can reach the focal plane. [13] Eye surgery system according to claim 12, wherein the optics (7) are configured to generate an image of the illumination aperture (36) in the focal plane (33). [14] A method for preparing a capsulorhexis, the method comprising: Using the eye surgery system according to one of claims 1 to 13, by adjusting the position of the focal plane (33) so that it is arranged close to or intersects the capsular bag.

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