Method for centering a contact lens and refractive surgery laser system

Abstract

The present invention relates to a method for centering a contact lens (16) relative to a patient's eye (12), the method comprising: a) providing a fixed light (20) through the contact lens (16) such that the patient's eye (12) is aligned relative to the contact lens (16) by gazing at the fixed light (20); b) detecting a mapping of a light pattern (24) provided by a light source having a fixed positional relationship relative to the contact lens, wherein the mapping of the light pattern (24) is performed via reflection at a surface of the eye (12); c) displaying, superimposed with virtual markers (26), the mapping of the light pattern (24) through the eye (12) via the contact lens (16), wherein the first of the virtual markers (26, 26a, 26b) The markings make the central axis (200) of the contact lens (16) identifiable, and the second marking of the virtual markings (26, 26a, 26b) makes the reference marking identifiable, the reference marking being derived from a mapping of a light pattern located on the central axis of the contact lens (16); d) the contact lens (16) is laterally positioned relative to the eye (12) such that the distance between the first marking and the second marking is minimized; and e) a location of the eye (12) is determined as the position of the vertex (22) of the eye (12) and the position of the vertex (22) is recorded according to the features of the eye (12) identifiable in the mapping of the eye (12), the second marking being located at the location when the first marking and the second marking occupy the minimum distance between them. The invention also relates to a refractive surgery laser system (10).

Description

Technical Field

[0001] This invention relates to a method for centering a contact lens onto a patient's eye, a method for preparing for refractive surgery, a computing unit, and a laser system for refractive surgery. Therefore, this invention particularly relates to the field of laser systems for refractive surgery. Background Technology

[0002] For refractive surgery of the eye, ophthalmic femtosecond lasers are frequently used, in which refractive eye correction is performed by separating or detaching the laser beam from or from the eye, particularly from the cornea. To couple the laser beam into the eye to be treated, a contact lens with a contact surface is typically used. This contact lens is placed on the patient's eye and magnetically attached to it to secure it. The laser beam can then be coupled into the secured eye through the contact lens and applied in a controlled manner to the eye fixed therein.

[0003] Here, the center of the contact lens, typically defined by the apex of its curved surface, is used as the geometric origin for all cuts performed by the laser within the eye. Therefore, the positioning or centering of the contact lens relative to the eye determines the location of the cuts within the eye. Consequently, precise and controlled positioning and centering of the contact lens are crucial for the accuracy of refractive surgery.

[0004] The positioning of a contact lens typically involves the following three stages:

[0005] Coarse positioning, in which the contact lens is positioned a few centimeters to a few millimeters above the patient's eye, and the contact lens is aligned with the glasses.

[0006] Precise positioning, in which the contact lens contacts the eye and is positioned relative to the eye in its desired final location.

[0007] In the adsorption state, the eye is attracted to the contact lens or vice versa, thus fixing the patient's eye to the contact lens.

[0008] Conventional laser systems used in refractive surgery provide various types of support for surgeons when coarsely positioning the contact lens relative to the patient's eye, such as a fixation beam, which allows the eye to be angularly aligned with the contact lens. However, fine positioning is typically performed by the surgeon, who determines the precise location of the contact lens on the eye, or more precisely, the desired target point on the cornea, based on their own estimation and the type of treatment.

[0009] However, precise localization is considered challenging because it introduces a high degree of uncertainty for many doctors, requiring multiple, even numerous, localization attempts until a satisfactory localization is achieved. Typically, precise localization or centering of a contact lens involves the doctor referring to a printed diagnostic image of the eye to be treated, plotting the desired localization point on the image, and then, based on this point, attempting to center the contact lens on the actual eye. The determined precise localization is not routinely recorded, making subsequent analysis impossible. Therefore, the achieved centering (or deviation from the desired target) must be quantitatively assessed and recorded manually.

[0010] During precise positioning, doctors often intend to move the contact lens or treatment center again while the eye is attached, which is not feasible with conventional systems, thus requiring the eye to be detached from the contact lens and re-secured. Summary of the Invention

[0011] Therefore, the object of the present invention is to provide a method and a refractive surgery laser system that simplifies the precise positioning of a contact lens in the eye for the user or physician and allows for reliable precise positioning in a reproducible manner.

[0012] This objective is achieved by the method, computing unit, and refractive surgery laser system according to the present invention.

[0013] The invention relates in a first aspect to a method for centering a contact lens (16) relative to a patient's eye (12). The method includes a) providing a fixed light (20) through the contact lens (16) such that the patient's eye (12) is aligned relative to the contact lens (16) by focusing on the fixed light (20). Furthermore, the method includes b) detecting a mapping of a light pattern (24) provided by a light source having a fixed positional relationship relative to the contact lens, wherein the mapping of the light pattern (24) is performed via reflection at a surface of the eye (12). Furthermore, the method includes c) displaying, superimposed with virtual markers (26), the mapping of the light pattern (24) through the eye (12) via the contact lens (16), wherein a first mark of the virtual markers (26, 26a, 26b) enables the identification of the central axis (200) of the contact lens (16), and a second mark of the virtual markers (26, 26a, 26b) enables the identification of a reference mark derived from the mapping of the light pattern located on the central axis of the contact lens (16). Furthermore, the method includes d) positioning the contact lens (16) laterally relative to the eye (12) such that the gap between the first mark and the second mark is minimized; and e) when the first mark and the second mark occupy the minimum gap between each other, determining the location of the second mark of the eye (12) as the position of the vertex (22) of the eye (12) and recording the position of the vertex (22) according to the features of the eye (12) that are identifiable in the mapping of the eye (12).

[0014] In another aspect, the present invention relates to a method for preparing for refractive surgery of the eye using a laser system. The method includes, according to the invention, a method for centering a contact lens relative to the eye and achieving coverage of the pupil of the eye by the optical zone of the microlens to be removed during the refractive surgery.

[0015] In another aspect, the present invention relates to a computing unit designed to drive a refractive surgery laser system to perform the method according to the invention.

[0016] In another aspect, the present invention relates to a refractive surgery laser system with a contact lens, preferably a femtosecond laser system. The laser system is designed to: a) provide fixed light through the contact lens, such that the patient's eye is aligned relative to the contact lens by focusing on the fixed light. Furthermore, the laser system is designed to: b) detect a mapping of a light pattern provided by a light source having a fixed positional relationship relative to the contact lens, wherein the mapping of the light pattern is performed via reflection at the surface of the eye. Furthermore, the laser system is designed to: c) display, overlaid with virtual markers, the mapping of the light pattern via reflection at the surface of the eye through the contact lens, wherein a first marker of the virtual markers enables the identification of the central axis of the contact lens, and a second marker of the virtual markers enables the identification of a reference marker, which is derived from the mapping of the light pattern located on the central axis of the contact lens. Furthermore, the laser system is designed to: d) laterally position the contact lens relative to the eye such that the distance between the first and second markers is minimized; and e) when the first and second markers occupy the minimum distance, determine the location of the second marker of the eye as the position of the vertex of the eye and record the position of the vertex according to features of the eye that can be identified in the mapping of the eye.

[0017] Providing a fixed light through the contact lens means that the contact lens itself provides the fixed light, for example, by means of a corresponding light source integrated into the contact lens, or that the fixed light is provided by a separate light source and transmitted through the contact lens to the eye. Here, the fixed light is a visible light signal provided to the patient's eye for orientation, such that when the patient's eye fixates on the fixed light, the eye occupies the desired orientation. According to an alternative embodiment, a light source having a fixed positional relationship relative to the contact lens can also be used as the fixed light. According to other embodiments, one or more additional light sources can be provided as the fixed light.

[0018] Here, "centering the contact lens relative to the eye" means placing the contact lens in the desired position for performing refractive surgery on the eye. Centering is not mandatory, requiring the central axis of the contact lens to coincide with the optical axis of the eye. More precisely, the contact lens can also be centered to another position on the eye besides the desired position for the surgical treatment.

[0019] Here, the mapping of the eye and the display of the virtual marker mean making it visible to the user, for example, by means of a display unit such as a computer monitor or other display device. The virtual marker being virtual here means that the virtual marker may optionally only be shown in the display, for example, on a computer monitor, but not projected onto the eye or otherwise located at the eye. However, according to other alternative implementations, the virtual marker may also be projected onto the eye.

[0020] Here, the fixed positional relationship of the light source relative to the contact mirror means that the position of the contact mirror, and optionally the position of the central axis of the contact mirror, can be clearly determined from the position of the light source. For this purpose, the light source can optionally be directly disposed in and / or at the contact mirror. According to an alternative embodiment, the light source is at least partially annular and at least partially surrounds the contact mirror in the circumferential direction. The light pattern of such a light source can exist in the form of a halo, wherein the midpoint of the halo is optionally located on the central axis of the contact mirror.

[0021] Here, the light pattern is a geometric arrangement of light that is identifiable in the mapping. The light pattern is designed such that points drawn in the light pattern can be detected, such as the midpoint and / or the geometric centroid and / or corner points and / or other definitively identifiable points in the light pattern, and the relative position of the central axis of the contact mirror can then be derived from these points.

[0022] Here, the mapping of the light pattern via reflection at the surface of the eye means that the light path is folded at the surface of the eye during optical mapping. Here, the curved surface of the eye can optionally be used as a convex mirror as the optical element for mapping.

[0023] The advantages provided by this invention are: it assists physicians in centering contact lenses, enabling reliable centering. In particular, the advantages provided by this invention are: reliable centering can be performed in a standardized manner and can also be performed by users without years of experience and expertise.

[0024] Furthermore, the present invention offers the advantage of enabling semi-automatic or fully automatic centering of contact lenses via a laser system. Correspondingly, this provides the advantage that manual operation by the user during centering is reduced, minimized, or even completely eliminated. This reduces the knowledge and / or motor skills required of the user. Moreover, it simplifies the activities of the laser system, particularly its operation, for the user. Furthermore, the present invention reduces the risk of user-induced errors.

[0025] This invention also offers the advantages of reliably recording the centering of the contact lens, and particularly of automatically recording the information. This increases the reliability and verifiability of refractive surgery treatments.

[0026] Typically, the described fixation light is aligned perpendicular to the optical axis of the therapeutic optics. Optionally, the fixation light can be at other angles to the optical axis, which appears movable to the patient. Optionally, the fixation light can be switched off. Both of these are achieved by the doctor or user through the way they turn the fixation light on and off and / or move it and observe the eye's reaction: checking whether the patient's eyes are actually looking at the fixation light.

[0027] Optionally, the midpoint of the pupil is used as a feature of the eye that can be identified in the eye's mapping. This provides the advantage that the midpoint can be reliably derived in the eye's mapping, and can also be derived automatically by means of image evaluation. Optionally, the virtual marker also includes a virtual marker for the midpoint of the pupil. This provides the advantage that the location of the pupil midpoint is easily identifiable to the user, and the user can use the midpoint according to the virtual marker for orientation purposes. Optionally, infrared illumination of the eye can be used to simplify the reliable identification of the pupil, and especially the midpoint of the pupil, even in the case of dark eyes or eyes with dark irises.

[0028] Optionally, the light pattern is a ring of light, provided by a light source designed for ring illumination and directed onto the eye through the contact lens. Alternatively, the ring illumination can also be located outside the contact lens. The ring is preferably arranged concentrically around the central axis of the contact lens. The reflection of the ring illumination at the eye can be identified in the display of the eye's reflection. The advantage of using a projection ring is that when the projection ring is not perpendicular and concentrically incident on the apex of the eye facing the contact lens, the shape of the reflection from the projection ring changes due to reflection on the curved surface of the eye. Thus, the positioning of the contact lens relative to the eye can be optionally determined based on the shape deviation of the reflection from the projection ring.

[0029] Optionally, the midpoint of the projection ring forms the midpoint of the light pattern. If the light pattern has additional elements, these elements are preferably arranged concentrically around the midpoint. This simplifies the identification of the contact lens's relative positioning to the eye based on the distortion of the reflected marks of the projected markings. Optionally, the light pattern can have multiple projection rings, which are optionally arranged concentrically with the central axis of the contact lens. Alternatively or additionally, the light pattern can have a predetermined dot pattern.

[0030] According to one feasible implementation, the light pattern has polygons and / or grids and / or crosses. The polygons can optionally be configured as triangles, quadrilaterals, hexagons, or octagons, wherein other numbers of angles are also feasible. Here, the light pattern is optionally configured such that reference marks can be derived from the midpoint and / or centroid and / or from other drawn points of the light pattern, the reference marks being derived from a mapping of the light pattern as located on the central axis of the contact lens. According to an optional implementation, the light pattern is configured such that the shape of the eye surface can be at least partially determined based on the distortion of the mapping of the light pattern via the mapping of the eye surface relative to the ideal surface of the eye.

[0031] Optionally, the mapping of the light pattern is detected via reflection at the surface of the eye, making it possible to identify the light pattern and eye features in the mapping. For example, this can be achieved through mapping with a sufficiently large depth of field so that the light source, the eye surface, and optionally the iris and pupil located below them are clearly imaged in the detected mapping. This provides the advantage that the features of the eye used to record the vertex position can be identified in the same mapping of the light source or light cluster. Optionally, the mapping is performed with a depth of field of at least 10 mm, optionally at least 15 mm, optionally at least 20 mm, and optionally at least 30 mm. This provides the advantage that both the plane of the light source and the plane of the eye features can be detected within the depth of field range.

[0032] Optionally, during steps a) through e), the contact lens is spaced apart from the eye, wherein the distance between the contact lens and the eye is optionally in the range of 1 mm to 10 cm. This provides the following advantages: the contact lens can be centered before it comes into contact with the eye. Furthermore, this also provides the following advantages: the area of ​​the eye that can be mapped through the contact lens can be matched to the desired location. Additionally, this provides the following advantages: the reflection of the projected mark can be at least partially transmitted through the contact lens, detected, and displayed.

[0033] Optionally, the method further includes (f) reducing the distance between the contact lens and the eye and bringing the eye into contact with the contact lens, and (g) finely positioning the contact lens relative to the eye in the lateral direction such that the central axis of the contact lens is positioned at a predetermined location on the eye; wherein steps f) and g) can optionally be performed in any order and / or multiple times. This provides the advantage that further fine positioning can be performed once the contact lens has made contact with the eye. This is particularly advantageous in that it can compensate for changes caused by bringing the contact lens into contact with the eye, such as eye deformation and, in particular, corneal deformation. Fine positioning can also include multiple executions, both in contact with and spaced apart from the eye, thereby enabling progressive approach to the desired position and / or testing of different positions.

[0034] Optionally, the method further includes determining the Kappa angle based on the position of the vertex and the midpoint of the pupil. This provides the advantage of being able to identify particularly large Kappa angles, which typically cause unintended eye aversion when attached to the contact lens. If a large Kappa angle is found, a message or warning can optionally be output to the user indicating the presence of a large Kappa angle and the associated risks. Optionally, the laser system can also be designed to prevent eye attachment if a Kappa angle deviates by a predetermined amount from a preset value.

[0035] Optionally, the virtual markers may also include virtual markers for predetermined points on the eye, which are predetermined by the user. For example, the user can determine one or more points on the eye, which are also marked by virtual markers in the eye-mapped display. For example, the user can set virtual markers for points where the user centers the contact lens. In other words, the user can preset one or more (alternative) user-defined positioning targets, which can be defined, for example, by a doctor when planning treatment, and optionally, one or more user-defined positioning targets can be displayed separately by virtual markers in the eye-mapped display. Optionally, the user can selectively display or hide the virtual markers. For example, the user can provide the coordinates of the points to be marked. The coordinates of the points can be provided, for example, directly (by means of Cartesian coordinates and / or radial coordinates) with respect to the pupil center or pupil midpoint (especially in the case of a particular pupil size, to account for pupil center offset) or on an eye topography or wavefront image or an OCT-generated image (e.g., Patch diagram, epithelial diagram).

[0036] Optionally, step (c) of the method above also includes at least in part displaying an eye topography and / or wavefront image and / or an OCT-generated image, i.e., a patch diagram and / or an epithelial diagram. Optionally, the user can selectively display or hide one or more of the mentioned elements. Optionally, the user can select the display of one or more of this image information as a partially transparent overlay and / or switch between multiple displays of image information.

[0037] Optionally, the invention also includes detecting the reflection produced at the eye by the projected optical marker and characterizing the shape of the eye based on the detected reflection of the light source. This provides the feasibility of determining the position of the contact lens relative to the eye at least partially automatically by means of image evaluation.

[0038] Optionally, steps d) and / or f) and / or g) are performed by the user, i.e., manually or primarily manually as desired and under the user's guidance. Alternatively or additionally, the method can be performed semi-automatically or fully automatically. This provides the advantage of reducing the knowledge required from the user and simplifying the work to be done by the user. In the case of semi-automatic and fully automatic execution, the user can optionally intervene manually at all times to interrupt the automatic movement, continue it if necessary, or also terminate it and manually continue it. This provides the advantage of enabling user intervention, for example, in the event of a malfunction.

[0039] Optionally, the method includes checking the coverage of the pupil by the optical zone through the microlens, optionally including a safety margin. Preferably, the mesopic pupil is used, and possibly the scotopic pupil as well. This provides the advantage of reducing the risk of incorrect refractive surgery by pre-identifying insufficient coverage and informing the user of this.

[0040] Optionally, the method further includes performing a plausibility check on the obtained distance between the vertex position and the pupil midpoint. This plausibility check can be performed, for example, based on a comparison of the relative position obtained according to the above method steps, and further, the distance from the vertex to the pupil midpoint, with information obtained individually by means of different diagnostic devices, i.e., by means of (Sham) topography and / or OCT.

[0041] Optionally, a digital camera can be used to detect the eye's reflection through the contact lens. The digital camera can, for example, be positioned on the side of the contact lens away from the eye and at least partially detect and probe the light transmitted through the contact lens. According to other embodiments, an analog camera can also be used.

[0042] Optionally, the refractive surgery laser system and, in particular, the digital camera, have a telecentric optics that eliminate or at least reduce the proportional dependence of the distance between the contact lens and the eye. This enables reliable detection of the eye's mapping using the camera even when the distance between the contact lens and the eye differs.

[0043] Here, the computing unit can be optionally integrated into the laser system or configured separately from the laser system. The computing unit can, for example, have a microcontroller and / or CPU and / or personal computer, or be configured as a microcontroller and / or CPU and / or personal computer. The computing unit is optionally designed to: at least partially control the laser system and optionally control the digital camera of the laser system to display the detected eye mapping on a display device and optionally fade in virtual markers. The computing unit can also optionally have other functions.

[0044] Hereinafter, the features and implementations mentioned above and explained below can be considered not only as disclosed in the combinations explicitly listed, but also as included in other technically reasonable combinations and implementations. Attached Figure Description

[0045] Now, further details and advantages of the invention will be explained in more detail with reference to the accompanying drawings, based on the following examples and preferred embodiments.

[0046] The attached diagram shows:

[0047] Figure 1 A schematic diagram of a refractive surgery laser system according to an optional embodiment is shown;

[0048] Figure 2 A schematic diagram illustrating the characteristic parameters of the eye and contact lens;

[0049] Figures 3 to 5The illustration shows a method for centering a contact lens according to an alternative embodiment.

[0050] In the following figures, for simplicity, the same or similar elements in different embodiments are indicated by the same reference numerals. Detailed Implementation

[0051] Figure 1 A schematic diagram of a refractive surgery laser system 10 for performing refractive surgery on the eye 12 of a patient 14, according to an alternative embodiment, is shown.

[0052] Here, the laser system 10 has a contact lens 16, which is coupled to the eye 12 of the patient 14. For this purpose, the patient 14 is positioned lying on the bed 15 so that their line of sight is oriented upward and the laser system 10 can contact and fix the eye vertically from above by means of the contact lens 16.

[0053] Furthermore, the laser system 10 has a femtosecond laser 17 integrated into the laser system 10. The laser beam provided by the femtosecond laser 17 is used here for refractive surgery treatment of the patient 14's eye 12 and can be applied to the eye 12 through the contact lens 16.

[0054] Furthermore, the laser system 10 has a display unit 18, which allows the user or doctor of the laser system 10 to display, via reflection at the surface of the eye 12, a mapping of the patient's eye 14 to be treated, and a mapping of the light source 23 positioned at the contact lens 16. The mapping of the eye 12 to be displayed passes through the contact lens 16, for example, by means of a digital camera (not shown) integrated into the laser system 10. The eye mapping detected by the digital camera can then be output through the display unit 18 along with superimposed virtual markers, allowing the doctor or user of the laser system 10 to examine the eye 12 to be treated and, in particular, its positioning relative to the contact lens 16.

[0055] Here, the laser system 10 is designed to induce relative movement of the patient 14 relative to the contact lens and / or the laser system 10. For this purpose, for example, the contact lens can be moved laterally, i.e., laterally perpendicular to the optical axis of the contact lens 16, to occupy a position suitable for refractive surgery on the eye 12, and also in the longitudinal direction, i.e., along the optical axis of the contact lens, to change the distance between the contact lens 16 and the eye 12, and particularly to fix the contact lens 16 to and from the eye 12. Alternatively or additionally, the patient can move vertically using the bed 15.

[0056] In addition, the laser system 10 includes a computing unit 19, which is designed to control the laser system 10 and display the mapping of the eye 12 on the display unit 18.

[0057] Figure 2 The geometric parameters of the contact lens 16 and the eye 12 are explained using a schematic diagram. In the view shown, the contact lens 16 is positioned above and spaced apart from the eye 12. On the side facing the eye 12, the contact lens 16 has a curved contact surface 16a, the radius of curvature of which approximately corresponds to the radius of curvature of the cornea 12a of the eye 12. Here, the contact lens 16 is transparent to the wavelength of the laser beam and optionally also transparent to the visible spectrum, so as to allow observation of the eye through the contact lens 16. A point source for fixing the light 20 is located on the side of the contact lens 16 away from the eye 12, and this fixing light propagates through the contact lens toward the eye 12 along the central axis or visual axis 200 of the contact lens 16. The terms central axis 200 of the contact lens 16 and visual axis 200 of the contact lens 16 are used synonymously.

[0058] In the view shown, the eye 12 is positioned and oriented such that the optical axis 100 of the eye 12 extends obliquely to the upper right. The optical axis 100 extends through the midpoint C of the eye and extends centrally through the pupil 12c, which is bounded by the iris 12b.

[0059] In addition, the cornea is called C C The center of curvature is located on the optical axis 100 of the eye. Here, the position of the point source of the fixed light 20 is relative to the corneal C. C The connecting line between the centers of curvature is the corneal measurement axis 300, and the corneal vertex 22 is located at the intersection of the corneal measurement axis and the outer surface of the cornea 12a.

[0060] In addition, the line of sight 400 and the Kappa angle 500 of the eye 12, that is, the angle between the optical axis of the eye and the visual axis 200 of the contact lens 16, are drawn for explanation.

[0061] In the following text, according to Figures 3 to 5 This describes a method for centering the contact lens 16 relative to the eye 12 according to an alternative embodiment. Here, Figures 3 to 5 A schematic diagram of the relative arrangement of the contact lens with respect to the eye 12 is shown in the lower left region, and an exemplary view 1000 of the mapping of the eye 12 with superimposed markings is shown in the upper right region.

[0062] In the first step (i), before performing refractive surgery on eye 12, the physician ensures that eye 12 does not have any problematic irregularities on its surface that could hinder treatment. If this is not the case, preparation for treatment and centering of contact lens 12 proceed.

[0063] In the second step (ii), the contact lens 16 is fixed to the laser system 10 and positioned above the patient's eye 12 at a z-interval of a few centimeters. For this purpose, the patient is reminded to look at the fixed light 20 with their eyes 12.

[0064] In another step (iii), the laser system 10 projects a light pattern 24 onto the eye 12 by means of a light source 23, which, according to an optional embodiment, is configured as a ring of light centered around the center of the contact lens or around the central axis 200. According to an optional embodiment, the light source 23 is disposed in and / or at the contact lens 16 such that light emitted by the light source 23 exits along the edge of the contact lens 16 toward the eye 12, providing an annular light pattern 24 concentric with the central axis of the contact lens 16. The light pattern 24 is at least partially reflected by the cornea 12a and is thus visible in the mapping of the light source 23 and the eye 12, and is shown in the view 1000 of the mapping of the eye 12. According to the illustrated embodiment, the origin of the light rays of the light pattern 24 is concentrically arranged around the central axis 200 of the contact lens. Conversely, the light rays reflected at the surface of the eye are concentrically arranged around the corneal measurement axis.

[0065] In the view 1000 of the mapping recorded through the contact lens 16 of the eye 12, the eye 12 and, in particular, the pupil 12c, as well as the reflection of the light pattern, can be identified. Furthermore, a plurality of virtual markers 26 are shown superimposed on the mapping of the eye 12, wherein virtual marker 26a allows the central axis 200 of the contact lens 16 and the edges of the contact lens 16 to be distinguished, virtual marker 26b allows a reference marker to be distinguished, which is derived from the mapping of the light pattern 24 located on the central axis of the contact lens, and virtual marker 26c allows the midpoint of the pupil 12c, derived from the mapping by means of image evaluation, to be identified.

[0066] Therefore, in step (iv), the doctor is able to identify the contact lens edge, pupil, and projection ring via display 1000.

[0067] Here, the system can optionally continuously and automatically determine the midpoint of the pupil, the central axis of the contact lens 16, and the midpoint of the projection ring, and display the corresponding virtual markers 26a, 26b, 26c in the continuously updated position, so that the doctor can track them together (step (v)).

[0068] In another step (vi), such as Figure 4 As shown, the doctor can then reduce the z-distance between the contact lens 16 and the eye 12. Here, the diameter of the projection ring on the eye increases (see Figure 12). Figure 4(See view 1000). Here, the doctor reduces the z-spacing until the projection ring 24 is larger than the diameter of the pupil 12c, but smaller than the diameter of the contact lens 16.

[0069] In another step (vii), the doctor pauses the contact lens 16 near the eye 12 and again instructs the patient 14 to focus on the fixed light 20 with their eyes 12. The doctor then positions the midpoint of the contact lens 16, or the central axis 200 of the contact lens 16, relative to the patient's eye 12 by lateral displacement (or vice versa) of the contact lens 16, aligning it with the midpoint of the light pattern 24. In this case, the center of the light pattern 24 effectively marks the apex 22 of the eye.

[0070] In another step (viii), the doctor directs the system to store the position of vertex 22 obtained by means of the center of positioning ring 24. The system determines the obtained position as the position of vertex 22 and automatically records the position based on features recognizable in the map shown by the eye 12. According to this embodiment, the midpoint of the pupil 12c is used by the laser system 10 as such a feature because it can be reliably identified and determined by means of image evaluation. However, alternatively or additionally, according to other embodiments, other features of the eye 12 can also be used.

[0071] The doctor then continues in step (ix) by reducing the z-distance between the contact lens 16 and the eye 12. Here, even though the projection ring 24 is no longer visible in the mapping due to the reduction in the z-distance, as in Figure 5 As shown in view 1000, the vertex position stored by the laser system 10 and recorded according to identifiable features is continued as a virtual marker 26b. Thus, the position of vertex 22 remains identifiable to the doctor and can be used for orientation. The doctor then centers the central axis 200 of the contact lens 16 onto the position of vertex 22 or another point on the eye 12 as defined thereon.

[0072] When the contact lens 16 comes into contact with the eye 12, a meniscus 28 (tear film) is formed between the eye 12 and the contact lens 16, such as Figure 5 As shown in the diagram. The refractive effect of air between the contact lens 16 and the eye 12 is avoided by the meniscus. The cornea 12a deforms or flattens upon contact with the contact lens 16, wherein the radius of curvature of the cornea 12a matches the radius of curvature of the contact surface 16a of the contact lens 16. Here, the laser system 10 takes into account the deformation of the cornea 12a caused by contact and the change in the imaging scale of the mapping caused by the meniscus, and displays the corrected vertex position 22 to the physician.

[0073] In another step (x), the physician is then able to perform fine positioning of the contact lens 16 relative to the eye, following the virtual markings shown in this view. After the fine positioning is complete, the physician is able to confirm the end and allow the eye 12 to adhere and be secured to the contact lens 16.

[0074] The laser system 10 then calculates and records the position of the contact lens 16 relative to the eye 12 and relative to identifiable features of the eye, such as the position relative to the midpoint of the pupil, and optionally calculates and records the diameter of the pupil, and stores it for use in the recording process, so that the information can be prepared for subsequent evaluation for refractive surgery treatment if necessary.

[0075] List of reference numerals

[0076] 10. Laser systems for refractive surgery

[0077] 12 eyes

[0078] 12a cornea

[0079] 12b Iris

[0080] 12c pupil

[0081] 14 patients

[0082] 15 beds

[0083] 16 Contact lenses

[0084] 17 Femtosecond Lasers

[0085] 18 Display unit for displaying the mapping of the eye

[0086] 19 Computing Units

[0087] 20 Fixed light

[0088] 22. Vertex or the position of a vertex

[0089] 23 Light Source

[0090] 24 Light Patterns

[0091] 26 Virtual Tags

[0092] 26a Virtual markings on the central axis and the edge of the contact lens

[0093] 26b Virtual mark of the midpoint of the projection ring or the optical mark of the projection.

[0094] 26c Virtual marker of the midpoint of the pupil

[0095] 28. Curves or tear film

[0096] 100 The optical axis of the eye

[0097] 200 The central axis or visual axis of the contact lens

[0098] 300 corneal measurement axis

[0099] 400 Eyes' line of sight

[0100] 500 Capa

[0101] Display of the mapping of 1000 eyes.

Claims

1. A method for centering a contact lens (16) relative to a patient's eye (12), the method comprising the steps of: a) A fixed light (20) is provided through the contact lens (16) such that the patient's eye (12) is aligned relative to the contact lens (16) by looking at the fixed light (20). b) Detect the mapping of a light pattern (24) provided by a light source (23) having a fixed positional relationship relative to the contact lens (16), wherein the mapping of the light pattern (24) is performed via reflection at the surface of the eye (12); c) Displaying the mapping of the light pattern (24) via the eye (12) through the contact lens (16) overlaid with the virtual marker (26), wherein a first marker (26a) of the virtual marker (26) enables the central axis (200) of the contact lens (16) to be identified and a second marker (26b) of the virtual marker (26) enables a reference marker to be identified, the reference marker being derived from the mapping of the light pattern as located on the central axis (200) of the contact lens (16); d) Position the contact lens (16) laterally relative to the eye (12) such that the distance between the first mark (26a) and the second mark (26b) is minimized; e) When the first mark and the second mark occupy the minimum distance between each other, determine the position of the first mark (26a) of the eye (12) as the position of the vertex (22) of the eye (12), and record the position of the vertex (22) according to the features of the eye (12) that can be identified in the mapping of the eye (12).

2. The method according to claim 1 further includes illuminating the eye with infrared light and identifying the pupil and midpoint of the pupil of the eye illuminated with infrared light.

3. The method according to claim 1, wherein, The midpoint of the pupil (12c) of the eye (12) is used as the feature of the eye (12) that can be identified in the mapping of the eye (12).

4. The method according to claim 3, wherein, The virtual marker (26) also includes a third marker (26c) that enables the midpoint of the pupil (12c) to be identified.

5. The method according to claim 1, wherein, Step c) also includes at least in part displaying an morphological map and / or wavefront image and / or an OCT-generated image of the eye (12).

6. The method according to claim 5 further includes selectively displaying and / or hiding the topographic image and / or wavefront image and / or OCT-generated image of the eye (12).

7. The method according to claim 5, further comprising displaying the topographic image and / or wavefront image and / or OCT-generated image of the eye (12) as a partially transparent overlay.

8. The method of claim 1, further comprising checking whether the pupil is covered by the optical area of ​​the microlens to be removed from the eye.

9. The method according to claim 8, wherein, The coverage is examined with safety margins in mind.

10. The method of claim 1, further comprising determining the Capa angle (500) based on the position of the vertex (22) and the midpoint of the pupil (12c).

11. The method of claim 10, further comprising outputting a warning and / or notification to the user whenever the determined Capa angle (500) deviates from a preset amount by at least a predetermined amount.

12. The method according to any one of the preceding claims, wherein, The mapping of the light pattern (24) superimposed on the virtual mark (26) is displayed using a display unit.

13. The method according to claim 12, wherein, The virtual marker is displayed only by means of the display unit and is not projected onto the eye (12).

14. The method according to claim 12, wherein, Displaying the mapping of the light pattern (24) superimposed on the virtual marker (26) by means of the display unit also includes displaying the mapping of the eye (12) to be treated.

15. The method according to claim 12, wherein, The display unit includes a computer monitor.

16. The method according to claim 1, wherein, The light pattern (24) includes rings and / or polygons and / or grids, wherein the reference mark can be derived from the midpoint and / or centroid of the light pattern (24), the reference mark being derived from the mapping of the light pattern (24) as located on the central axis (200) of the contact mirror (16).

17. The method according to claim 1, wherein, The mapping of the light pattern (24) is detected by reflection at the surface of the eye (12), making it possible to identify the features of the light pattern (24) and the eye (12) in the mapping.

18. The method according to claim 17, wherein, Map with a depth of field of at least 10mm.

19. The method according to claim 1, wherein, During steps a) to e), the contact lens (16) is spaced apart from the eye (12) and the distance between the contact lens (16) and the eye (12) is in the range of 1 mm to 10 cm.

20. The method of claim 1, further comprising the step of: f) Reduce the distance between the contact lens (16) and the eye (12) and bring the eye (12) into contact with the contact lens (16); g) Finely position the contact lens (16) relative to the eye (12) in the lateral direction, such that the central axis (200) of the contact lens (16) is positioned at a predetermined position on the eye (12); Steps f) and g) can be executed in any order and / or multiple times.

21. The method of claim 1, further comprising detecting the light pattern (24) reflected at the surface of the eye (12) and characterizing the shape of the eye (12) based on the detected reflection of the light pattern (24).

22. The method according to claim 1, wherein, Steps d) and / or f) and / or g) are performed by the user.

23. The method according to claim 1, wherein, The method can be executed semi-automatically or fully automatically.

24. A computing unit (19) designed to drive a refractive surgery laser system (10) to perform the method according to any one of the preceding claims.

25. A laser system for refractive surgery (10), wherein, The laser system (10) is designed for, a) A fixed light (20) is provided through the contact lens (16) so that the patient's eye (12) is aligned with the contact lens (16) by looking at the fixed light (20); b) Detect the mapping of a light pattern (24) provided by a light source (23) having a fixed positional relationship relative to the contact lens (16), wherein the mapping of the light pattern (24) is performed via reflection at the surface of the eye (12); c) Displaying the light pattern (24) overlaid with the virtual marker (26) via the mapping through the contact lens (16) by reflection at the surface of the eye (12), wherein a first mark (26a) of the virtual marker (26) enables the identification of the central axis (200) of the contact lens (16), and a second mark (26b) of the virtual marker (26) enables the identification of a reference mark derived from the mapping of the light pattern (24) located on the central axis (200) of the contact lens (16); d) Position the contact lens (16) laterally relative to the eye (12) such that the distance between the first mark (26a) and the second mark (26b) is minimized; e) When the first mark (26a) and the second mark (26b) occupy the minimum spacing, determine the position of the first mark (26a) of the eye (12) as the position of the vertex (22) of the eye (12), and record the position of the vertex (22) according to the features of the eye (12) that can be identified in the mapping of the eye (12).

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