DEVICE FOR CREATING AN APERTURE DISC IN THE EYE

Description

[0001] The present invention relates to the field of devices intended to correct or reduce refractive errors in the eye, and in particular to a device for creating an aperture stop in the natural lens of the eye, with which the depth of field of the eye is increased, which can lead to improvements, in particular in age-related hyperopia.

[0002] US 2010 / 004641 A1 discloses a system and apparatus for irradiating a lens of an eye with a laser beam and provides a system and apparatus for increasing the amplitude of accommodation and / or a change in refractive power and / or for enabling removal of clear or clouded lens material of a natural crystalline lens. Generally, the system comprises a laser, optics for guiding the laser beam, and a control system for guiding the laser beam onto the lens in a predetermined pattern. Furthermore, a range determination system is provided for determining the shape and position of the lens with respect to the laser. Furthermore, a method and system for guiding a laser beam into the lens of the eye in a predetermined firing pattern is provided.

[0003] A refractive error of the eye is generally corrected with glasses or contact lenses. In the case of ametropia, an object located at infinity is not sharply imaged on the retina when the ciliary muscle is relaxed (near accommodation). If the eyeball is too long compared to the combined refractive power of the cornea and lens, this is called myopia (nearsightedness). Glasses or contact lenses that act as diverging lenses can reduce the refractive power so that a sharp image is projected onto the retina. In the converse case of hyperopia (farsightedness), the refractive power of the eye media is too small in relation to the length of the eyeball. In this case, a convex lens, such as glasses or contact lenses, can correct the refractive error. If the refractive error only exists in one plane, it is called astigmatism (astigmatism). Corresponding cylindrical lenses, such as glasses or contact lenses, can also correct the refractive error.

[0004] In addition to glasses or contact lenses as corrective aids, there are surgical procedures to correct refractive errors.

[0005] Firstly, lasers can be used to remove parts of the cornea, thereby altering the anterior curvature of the cornea in such a way that the optical refractive power of the eye changes accordingly, achieving (almost) normal vision (emmetropia). One advantage of such laser procedures (PRK: photorefractive keratectomy, LASIK: laser in situ keratomileusis, LASEK: laser epithelial keratomileusis) is the flexibility of the correction achieved. Irregular corneal changes can be specifically corrected, something that is often not possible with glasses and contact lenses.

[0006] In addition, implants can be inserted into the cornea to specifically correct refractive errors through their optical power or biomechanical effects (e.g., by changing the curvature of the cornea). Intraocular lenses can also be implanted into the eye to correct refractive errors. These can act in addition to the natural lens or replace it.

[0007] The implant solutions also include a group of implants that utilize the principle of the stenopeic gap (pinhole effect). The pinhole reduces disturbing peripheral rays and thus minimizes spherical aberration in imaging. The circles of confusion on the retina are reduced, thus increasing the depth of field in imaging. Consequently, ametropic eyes achieve greater visual acuity when looking through a pinhole.

[0008] In one version of such an approach, a plastic disc approximately 5 µm thick with an open inner diameter of approximately 1.6 mm and an outer diameter of 3.8 mm is inserted centrally into the cornea of ​​the eye. Surgically, this is usually achieved by using a laser to create a pocket in the cornea in which the implant is fixed.

[0009] In another embodiment, an artificial intraocular lens (IOL) is implanted into the eye. The natural lens is removed. Within the artificial lens is also a pinhole with a free inner diameter of approximately 1.36 mm and an outer diameter of 3.23 mm.

[0010] Finally, the pinhole effect can also be utilized with the help of a contact lens. However, contact lenses can usually move slightly on the cornea. The central opening is moved out of the visual axis, thus impairing optimal vision.

[0011] Examples from the prior art relating to the utilization of the pinhole effect can be found, for example, in US 4,955,904, US 5,757,458, US 5,980,040, WO 2011 / 020078 A1 and US 2013 / 131795 A1.

[0012] Glasses can get damaged or lost in everyday life. Depending on the environment, they can become dirty or fogged up. Irregular vision problems beyond myopia, hyperopia, or astigmatism can only be corrected inadequately or not at all. This also applies to contact lenses, which also require a certain degree of dexterity when inserting and removing them.

[0013] Laser surgery and the use of implants carry the risks of possible infection during and after surgery and / or tissue intolerance to the implant. The use of pinhole implants in the cornea is known to impair tissue nutrient supply (Alio, Jorge L.; et al. (2013): Removability of a small aperture intracorneal inlay for presbyopia correction. In: Journal of refractive surgery 29 (8), pp. 550-556).

[0014] One objective underlying the present invention is, in particular, to restore the reading ability of presbyopic eyes. It is also desirable, or even more so, to correct visual defects caused by aberrations, particularly in the periphery of the optical axis of the eye, while blocking out the marginal rays of light entering the eye. The disadvantages of the prior art are to be completely or at least substantially avoided.

[0015] It is therefore desirable to present a solution that achieves the desired improvements in vision without any restrictions in everyday life and that also entails as little risk as possible in the execution of the treatment itself.

[0016] According to a first aspect of the invention, a device for producing an aperture stop in an eye is proposed, as defined in claim 1.

[0017] A further aspect of the invention provides a method for generating control commands for a laser unit for generating an aperture stop in an eye, as defined in claim 9.

[0018] Since the aperture (pinhole) is created within the eye itself, the problems discussed in the case of external attachment via glasses or contact lenses do not arise. Since the aperture is not surgically implanted, there is no significant risk of infection or intolerance. Since the invention allows for the aperture to be attached non-invasively, a sterile environment (e.g., an operating room) is not required. Furthermore, no substance (dyes, pigments) is introduced into the eye, so there are no concerns about intolerances in this regard either.

[0019] The present invention, in contrast to the prior art, offers the advantage that an aperture can be introduced into the lens of the eye non-invasively—that is, without surgically opening the eye. The aperture filters out peripheral rays. This increases the eye's visual acuity. In particular, the depth of field is increased, and presbyopic eyes thus improve near vision, for example, reading ability.

[0020] Part of the background of the present invention can be found in the following considerations.

[0021] With the help of so-called "ultrashort" laser pulses, it is possible to create disruptive processes inside the eye without surgically opening the eye. The interaction mechanism of so-called photodisruption is based on so-called nonlinear absorption. Initially transparent tissue or material becomes absorbent above a certain laser intensity threshold. The absorbed light energy leads to locally limited microscopic explosions at the focus of the laser beam. "Ultrashort" refers to pulses with a duration of less than one picosecond (10-12 < s).

[0022] Such disruption processes are known per se, for example, from applications such as refractive corneal surgery, in which laser pulses create incisions in the cornea to create flaps or remove tissue. It is also known that ultrashort laser pulses near or just below the disruption threshold photochemically influence the tissue, particularly by changing the optical refractive index. Such mechanisms have also been used to correct refractive errors.

[0023] In these described cases, the cornea should remain optically clear after the laser procedure. In a few isolated cases, a scar may form in the cornea during the postoperative period, leading to optical scattering. However, this is undesirable, and efforts are made to avoid such situations.

[0024] In cataract surgery, it is known to use ultrashort pulses to fragment the gray lens and / or to open the capsule of the lens.

[0025] Ultrashort pulses are also known for treating presbyopia. These ultrashort pulses break up the lens material, which has hardened with age, thereby restoring the flexibility and deformability of the lens, allowing it to reshape itself during the accommodation process. Here, too, the goal is to dose the laser pulses so that the lens remains optically clear after the laser procedure, thus avoiding unwanted glare.

[0026] EP 2 231 084 B1 discloses that laser parameters can be configured such that incident light is diffracted or scattered by the remaining lesions in the lens created by the laser pulses. By creating a large number of such lesions, image-forming properties can be created within the lens according to the principle of diffractive optics. These image-forming properties can be used to correct visual defects.

[0027] In all of the aforementioned applications of photodisruption in the eye, the area irradiated by the laser either remains clear and without optical effect, or it contributes to the image through a change in refractive power (refractive) or scattering (diffractive). In cataract surgery, the lens components fragmented by the laser are surgically removed.

[0028] Within the scope of the present invention, it has been realized that, with a clever choice of laser parameters, the lesions created by the laser can be placed close enough to one another, making the laser-treated area opaque, thus using it as an aperture. With appropriate programming of the laser beam, for example, pinhole apertures can be created in the natural lens of the eye.

[0029] This laser-generated aperture (pinhole) can be used to block the marginal rays of incoming light according to the principle of the stenopean gap (pinhole effect). The marginal rays of an optical system are generally subject to significant aberrations. Blocking these marginal rays serves to improve the image quality of the eye and, in particular, to increase the depth of field. With an increased depth of field, one is able to see objects both near and far clearly, even with a non-accommodating (presbyopic) eye.

[0030] In an advantageous embodiment of one aspect of the invention, the aperture diaphragm has laser-induced lesions at different levels in the axial direction. In other words, the control unit is configured to cause the laser unit to place the laser-induced lesions at different depths (along the visual axis of the eye).

[0031] Generally, terms like "axial" and "lateral" refer to the visual axis of the eye in which the aperture is generated. "Axial" therefore describes a direction along the visual axis, while "lateral" describes a direction perpendicular to the visual axis.

[0032] The most complete possible suppression of light transmission through the aperture area can be better achieved if the aperture stop is in axial

[0033] direction extends over more than a single layer of lesions. The aperture stop can be constructed from a large number of layers with lesions, whereby the layers, particularly if they each have a more or less regular distribution of lesions, are offset laterally from one another, for example by respective fractions of a periodicity of the lateral distribution of the lesions. An axial distribution of the lesions, which is given in the form of layers or the like, is not necessary, however, and the lesions can also be arranged irregularly in this respect, for example randomly or at least quasi-randomly. In extreme cases, each individual lesion can be assigned its own plane.

[0034] In another advantageous embodiment of an aspect of the invention, the control unit is designed to control the laser unit with which successively generated laser-induced lesions are generated such that they are at least a predetermined distance from one another in the lateral and / or axial direction.

[0035] With the introduction of the laser-induced lesion, the lens of the eye is locally disturbed, in particular a blister develops in the area of ​​the lesion, which closes again over time. For the accuracy and effectiveness of the laser irradiation, it is advantageous if the light path does not pass through a lesion or the blister that has not yet regressed.

[0036] In another advantageous embodiment of an aspect of the invention, the control unit is designed to control the laser unit, which leads to a random or quasi-random distribution of the laser-induced lesions within the aperture area.

[0037] It can be intended that the laser-induced lesions are each distributed as densely as possible (under the simplifying assumption of a spherical bubble, which is created when each lesion is created, and with the additional proviso that the respective bubble centers are offset by the bubble diameter, this would be the densest sphere packing with a hexagonal arrangement of the lesions). However, this results in a regular arrangement of the lesions, which can potentially lead to undesirable optical effects. If this regularity is broken at the cost of a reduced density of lesions by subjecting the respective positions of the lesions to a random distribution or by suitable control in a sufficiently irregular distribution (i.e., quasi-randomly), the optical effects can be avoided.

[0038] In another advantageous embodiment of an aspect of the invention, the control unit is designed to control the laser unit for generating the aperture stop such that light transmission through the aperture area of ​​the lens is reduced to 20% or less.

[0039] It has been found that complete suppression of transmission is not necessary for a sufficient improvement in visual performance; it is sufficient to reduce light transmission to a residual level of 20% or less. Although greater suppression of transmission is beneficial and may be desirable in itself, the associated effort may be too great in individual cases to be justified by the additional benefit.

[0040] In another advantageous embodiment of an aspect of the invention, the device comprises the laser unit for generating the aperture stop in the lens of the eye, wherein the laser unit comprises a pulse laser for emitting laser pulses, a focusing unit for focusing the laser pulses and a directing unit for aligning the laser pulses.

[0041] The laser unit is not necessarily integrated with the control unit in a single device; the control unit and laser unit can therefore also be provided separately from each other in order to cooperate with each other only during the actual creation of the aperture stop.

[0042] In a preferred variant of the above embodiment, the pulse laser is designed to emit laser pulses with a pulse duration in the range of 10,000 to 10 fs, preferably from 800 to 100 fs, particularly preferably from 300 to 150 fs, with a pulse energy in the range of 100 to 0.01 µJ, preferably from 10 to 0.01 µJ, particularly preferably from 2 to 0.1 µJ, in a wavelength range of 400 to 1,400 nm, preferably from 600 to 1,200 nm, particularly preferably from 800 to 1,100 nm and with a repetition rate in a range of 1 to 100,000 kHz, preferably from 10 to 10,000 kHz, particularly preferably from 100 to 500 kHz, very particularly preferably with a pulse duration of 150 fs, a Pulse energy of 1 µJ, a wavelength in the range of 700 to 1,100 nm and a repetition rate of 200 kHz.

[0043] According to the teaching of EP 2 231 084 B1, laser pulses with a pulse duration of 100 fs, a pulse energy of 1 µJ, a wavelength of 700 to 1100 nm, and a repetition rate of 100 kHz are typical for creating a permanent lesion in the natural lens of the eye. In contrast to the approach of the teaching of EP 2 231 084 B1, however, the aim of this invention is not to generate singular scattering events at the defined distances between the laser lesions, which, in total, result in imaging when transmitted through the lens of the eye. Rather, according to the invention, as little light as possible should be transmitted toward the retina in the area of ​​the created laser lesions, and preferably no transmission toward the retina should occur.

[0044] According to a further aspect of the invention, a computer program is provided with program means that cause a device according to the invention to carry out a method for generating an aperture stop in an eye when the computer program is executed on the device. The computer program can be provided, stored, and / or distributed on a suitable storage medium, such as an optical storage medium or a non-volatile electronic storage medium. It can also be provided together with or as part of a hardware component. The computer program can also be provided in other ways, such as via the Internet or via wired or wireless telecommunications means.

[0045] The scope of the invention is defined by the claims.

[0046] Features of advantageous embodiments of the invention are defined in particular in the subclaims, wherein further advantageous features, embodiments and configurations can also be gathered by the person skilled in the art from the above explanation and the following discussion.

[0047] In the following, the present invention is further illustrated and explained with reference to exemplary embodiments shown in the figures. Fig. 1 schematic representations of an aperture diaphragm in a natural lens of the eye, Fig. 2 a schematic representation to explain the lighting conditions in a lens with the aperture diaphragm and the iris of the eye, Fig. 3 schematic representations to compare a transmission with a single-layer arrangement of lesions and a multi-layer arrangement of lesions, Fig. 4 schematic illustrations of the processes during photodisruption, Fig. 5 schematic illustrations in a case of too close positioning of laser pulses, Fig. 6 schematic representations for the orientation of the aperture diaphragm to the optical axis, Fig. 7 schematic representations of an axial arrangement of laser-induced lesions and Fig. 8 schematic representations to explain processes in the production of an aperture diaphragm according to the invention with prior marking.

[0048] In the accompanying drawings and the explanations to these drawings, corresponding or related elements are - where appropriate - identified by corresponding or similar reference numerals, even if they are found in different embodiments.

[0049] Fig. 1a shows an exemplary side view of a positioning of a laser-generated aperture 1 within a natural lens 2 of an eye, wherein Fig. 1b a corresponding top view of the positioning of the laser-generated aperture 1 within the natural lens 2 of the eye. The visual axis and axial direction are shown in this figure as a vertical line, and a lateral direction as a horizontal line.

[0050] Fig. 2 shows a schematic representation to explain the lighting conditions in a lens with the aperture stop and the iris of the eye. Light 3a entering the eye is naturally blocked by the iris 4 of the eye and further by the laser-generated aperture 1 within the lens 2. Only the central part 3b of the light 3a is transmitted to the retina.

[0051] Fig. 3 shows schematic representations comparing transmission with a single-layer arrangement of lesions and a multi-layer arrangement of lesions. A single-layer arrangement of laser lesions 5a within the lens 2 of the eye can, as in this example, lead to incident light 3a being predominantly scattered in all directions. Even with a very dense lateral arrangement of the lesions 5a, it can still happen that a significant portion of the incident light is still scattered forward (3c) and can thus reach the retina. In contrast, as in Fig. 3b illustrated, several layers of laterally densely packed lesions 5b greatly reduce the probability that photons are scattered towards the retina.

[0052] If, as intended in the context of the present invention, as little light as possible is to pass through the aperture area (surrounding the aperture opening), the laser lesions should be arranged as densely as possible laterally. Since the laser lesions do not absorb light but merely scatter it, it is still possible, even with a very dense lateral arrangement of the lesions, that some of the incident light is scattered forward and thus reaches the retina ( Fig. 3a The scattered photons that reach the retina do not contribute to image formation and are perceived as disturbing. Contrast vision, in particular, is negatively affected.

[0053] However, if several layers of laterally densely packed lesions are created in the axial direction, the probability that photons are scattered toward the retina becomes increasingly smaller. Beyond a certain thickness or number of consecutive layers, even without further special measures regarding the design of the lesions themselves, the amount of transmitted light is so small that the contrast during image formation on the retina is only slightly or acceptably reduced ( Fig. 3b ).

[0054] Fig. 4 shows schematic illustrations of the processes involved in photodisruption.

[0055] Fig. 4a illustrates that photodisruption occurs in the focal plane 6 of the incident laser beam 7 at sufficient laser beam intensity. Due to physical reasons, the interaction zone 8 typically has a prolate shape.

[0056] Fig. 4b illustrates that immediately after the disruption by the evaporating lens material, a gas bubble 9 is formed with a considerably larger extent than the interaction zone 8 of the laser light.

[0057] After a certain time (milliseconds to hours), depending on the size of the gas bubble, the gas has diffused into the surroundings of the lens tissue and the gas bubble has collapsed, as in Fig. 4c What remains is a prolate form of altered lens tissue (here referred to as "laser lesion" 10). Laser lesion 10 is characterized by strongly scattering and absorbing visible light.

[0058] Fig. 5 shows schematic illustrations in a case of too close positioning of laser pulses. If two consecutive laser pulses 7b, 7c have a spatial distance 11 smaller than the diameter of the remaining gas bubble 9, as shown in Fig. 5a shown, the follow-up pulse 7c is directed into the gas bubble 9. If the laser pulse hits the gas bubble 9 within the lens 2, the light of the laser pulse 7d is deflected due to the refraction differences between the lens material and the gas bubble, as shown in Fig. 5b is illustrated.

[0059] Preferably, the laser parameters are adjusted so that the threshold for photodisruption is exceeded in the focal plane of the laser pulse in order to create a permanent lesion ( Fig. 4a ). However, this results in a small gas bubble being created at the focus of the laser pulse immediately after laser exposure ( Fig. 4b ). The gas is the product of the water vaporized by the laser pulse or of the lens components converted into the gaseous phase. Due to the viscosity and chemical solubility of the generated gases and vapors in the tissue water, it takes some time for the bubble to completely collapse, leaving a typically elliptical, prolate lesion that permanently scatters or absorbs the incoming light ( Fig. 4c ). Usually, the time it takes for the gas bubble to collapse is much longer (milliseconds to hours) than the time interval between two laser pulses (nanoseconds to milliseconds). If the laser is controlled so that a follow-up pulse is placed at a distance smaller than the diameter of the remaining gas bubble, the follow-up pulse is directed into the gas bubble ( Fig. 5a ). In this situation, the light of the laser pulse is deflected due to the refractive differences between the lens material and the gas bubble ( Fig. 5b This can destroy the focus quality of the laser pulse, so that the light intensity at the focus can no longer be maintained sufficiently to exceed the threshold for a photodisruption process. Depending on the size of the gas bubble and the temporal and spatial spacing of the laser pulses, several subsequent pulses can be deflected by a gas bubble and fail to produce photodisruption. This results in lesion patterns that are much further apart than the originally intended pattern of the laser foci. Consequently, the isolation effect of the entire laser area is less effective.

[0060] This reduction in efficiency can be avoided by programming the laser control system so that successive laser pulses are spaced apart by a greater distance than the diameter of the gas bubbles at the time the subsequent pulse arrives.

[0061] The remaining gaps between the laser lesions can be closed in a second and / or multiple pass of laser pulses once the gas bubbles have collapsed.

[0062] If the collapse of the gas bubbles takes longer than scanning the entire surface of a plane of laser lesions, the laser can be programmed to create another layer of laser lesions in a further direction, facing the laser source. The laser lesions are then preferably placed in the gaps left by the laser lesions in the previous plane. This process can be repeated several times, thereby creating a solid body that, once a certain number of layers of laser lesions have been created, allows sufficiently little light to penetrate to the retina.

[0063] In a further embodiment, the laser lesions can be randomly spaced on average. The irregular spatial distribution of the laser lesions prevents the laser lesions from creating an optical grating and causing undesirable diffraction effects.

[0064] If the laser-generated aperture is created by multiple layers of laser lesions, the aperture represents a spatial object. Consequently, in addition to centering the aperture, for example, relative to the visual axis of the eye, not only the lateral alignment of the aperture is important, but also its orientation. With an oblique orientation, the circular opening of the aperture appears elliptical when projected relative to the visual axis or the incident light. Furthermore, the light at the edges of the aperture will cause strong scattering phenomena and glare.

[0065] For this reason, it is advantageous to keep the axial extent (in beam direction) of the aperture as small as possible and yet to superimpose as many layers of laser lesions as possible.

[0066] Fig. 6a illustrates that with correct orientation of the aperture 1 in the lens 2 parallel to the optical axis or the incident light 3a, the central rays of the light beam 3a are transmitted and the marginal rays are blocked by scattering or absorption.

[0067] Fig. 6b illustrates that when the aperture is skewed, the incident light 3a causes scattering at the edges of the aperture opening. Light rays 3c that strike the edges of the aperture are only slightly scattered and can reach the retina. They thus cause an undesirable glare effect.

[0068] Fig. 7 shows schematic representations of an axial arrangement of laser-induced lesions.

[0069] The densest possible arrangement of laser lesions is achieved by spacing the laser pulses in one direction just as far apart as the maximum expansion of a laser-generated gas bubble in the lens tissue. This creates a chain of individual gas bubbles that touch each other but preferably do not merge. Fig. 7a ). In an adjacent section 15, parallel to the first section 14, the individual laser pulses are offset by half the maximum gas bubble diameter d. The minimum distance a of the adjacent section is calculated as: a = 3 4 × d

[0070] After completely scanning a plane, a carpet of lesions 10 is created, which are separated by a distance d from each other. The lesions 10 and thus the circular area effective for absorbing or scattering the incident light 3a have a diameter q. Consequently, such a plane of laser lesions can only scatter or absorb a fraction (q / d) 2< of the incident light ( Fig. 7b ).

[0071] A second layer of laser lesions can now be created. This layer lies in the direction facing the laser beam and is at a distance a from the previous layer. If the gas bubbles in the layer have decreased in size during the creation of a layer of lesions, the distance can also be selected to be smaller. In a lateral orientation, the grid of laser pulses can be offset so that the lesions of the laser pulses of the newer layer lie between the lesions of the previous layer. In a subsequent, third layer, at a distance a or less from the second layer, another grid of lesions can be created. In this case, the laser foci and the resulting lesions are placed in the projection of the still open gaps of all previous lesions. The sequence of creating the individual layers of lesions in axially different planes is described in Fig.7c shown as examples for the first six layers. Black solid circles were used for the currently generated lesions and open white circles for the previous layers.

[0072] This sequence can be repeated until a sufficient number of lesions has been created to cover the entire aperture area. For example, if 100% of the aperture area is to be covered with lesions, at least (d / q) 2< layers of laser lesions must be created.

[0073] Fig. 8 shows schematic representations to explain processes in the production of an aperture diaphragm according to the invention with prior marking.

[0074] In the case of a constricted pupil (miosis), one or more orientation points 12a, 12b can be lasered into the lens 2 using the laser beam 7, as shown in Fig. 8a For example, these could be two rings indicating the rear (12a) and front (12b) positions of the aperture opening. The lateral position of the markings is limited by the inner edge of the iris 4. Fig. 8b shows the same situation as in Fig. 8a from the surgeon's perspective (top view)

[0075] Fig. 8c shows that with a wide pupil position (mydriasis), without the iris 4 obscuring the beam path of the laser 7, the entire aperture 1 can be lasered into the lens 2. The previously placed markings 12a, 12b help to center the aperture accordingly and orient it along the visual axis 13. Fig. 8d shows the same situation as in Fig. 8c from the surgeon's perspective (top view).

[0076] The laser-generated aperture can be centered and oriented relative to the visual axis of the eye. For example, it is advantageous to position the aperture center midway between the pupil center and the so-called first Purkinje reflex. If the pupil requires medication to dilate during laser application (mydriasis), it is advantageous to first apply a marker, for example, with paint, to the corneal surface when the pupil is constricted.

[0077] Advantageous positioning is achieved by centering and orienting the iris 4 with a constricted pupil (miosis). After the patient's eye has been aligned with the laser device and, if necessary, fixed, for example, using a standard patient interface, the eye is stimulated by comparatively bright light. Consequently, the eye adapts through pupil constriction (miosis). In this situation, the laser 7 can laser one or more orientation points 12a, 12b into the lens 2, for example, two rings that indicate the posterior and anterior positions of the aperture opening ( Fig. 8a, 8b Positioning can be supported by conventional imaging techniques, such as optical coherence tomography (OCT).

[0078] After marking, the light stimulus is removed. Preferably, the eye, or both patient eyes, are left in maximum darkness. Consequently, the eye will once again adapt to the light situation and dilate the pupil (mydriasis). In this situation, the entire aperture 1 can be lasered into the lens 2 without the iris 4 blocking the laser beam path. The previously placed markings 12a, 12b help to center the aperture accordingly and orient it along the visual axis 13. If the natural mydriasis is not sufficient to move the iris 4 completely out of the laser beam path, the mydriasis can be dilated with medication. This procedure has the advantage that after the laser procedure, in bright daylight, the naturally narrowly adapted pupil coincides with the opening of the laser-generated aperture.

[0079] Although various aspects or features of the invention are shown in combination in the figures, it will be apparent to those skilled in the art—unless otherwise stated—that the illustrated and discussed combinations are not the only possible ones. In particular, corresponding units or feature complexes from different embodiments can be interchanged.

[0080] In implementations of the invention, individual components, e.g., a processor, can fully or partially assume the functions of various elements mentioned in the claims. Sequences or processes such as controls, calculations, detections, or the like can be implemented as program means of a computer program and / or as special hardware components.

Claims

1. A device for creating an aperture (1) in an eye, comprising: a control unit for a laser unit, wherein the control unit is configured to control the laser unit to create the aperture (1) in a lens (2) of the eye, wherein the aperture (1) is used to increase the depth of field of the eye and is formed by laser-induced lesions (5a, 5b, 10) which reduce light transmission through an aperture region of the lens (2) surrounding an aperture opening, characterized in that the device further comprises an alignment unit for aligning and / or fixating the eye and a light stimulation unit for light stimulation of the eye in order to narrow the pupil, wherein the control unit is configured to control the laser unit on the basis of the narrowed pupil in orderto produce marks (12a, 12b) defining the aperture opening in the lateral and / or axial direction (13).

2. The device according to claim 1, wherein the aperture (1) has laser-induced lesions (5a, 5b, 10) in different planes in the axial direction.

3. The device according to any one of the preceding claims, wherein the control unit is configured to control the laser unit with which laser-induced lesions (5a, 5b, 10) are sequentially created in such a way that they are spaced apart from each other in the lateral and / or axial direction (13) by at least a predetermined distance (d).

4. The device according to claim 3, wherein the control unit is configured to control the laser unit with which time-wise sequential laser pulses (7, 7b, 7c, 7d) for forming the laser-induced lesions (5a, 5b, 10) are spaced apart by a distance which is bigger than the diameter of the gas bubbles (9) at the moment in time when the subsequent pulse arrives, wherein the control unit is further configured to control the laser unit such that remaining gaps between the laser-induced lesions (5a, 5b, 10) are closed in a following sequence, once the gas bubbles have collapsed.

5. The device according to any one of the preceding claims, wherein the control unit is configured to control the laser unit in a way which results in a random or semi-random distribution of the laser-induced lesions (5a, 5b, 10) within the aperture region.

6. The device according to any one of the preceding claims, wherein the control unit is configured to control the laser unit for creating the aperture (1) in such a way that light transmission through the lens aperture region is reduced to 20% or less.

7. The device according to any one of the preceding claims, comprising the laser unit for creating the aperture (1) in the lens (2) of the eye, wherein the laser unit has a pulsed laser for emitting laser pulses (7, 7b, 7c, 7d), a focusing unit for focusing the laser pulses (7, 7b, 7c, 7d), and an alignment unit for aligning the laser pulses (7, 7b, 7c, 7d).

8. The device according to claim 7, wherein the pulsed laser is configured to emit laser pulses (7, 7b, 7c, 7d) having a pulse duration in the range between 10,000 to 10 fs, preferably in the range between 800 and 100 fs, particularly preferably in the range between 350 and 150 fs, with a pulse energy in the range between 100 and 0.01 µJ, preferably in the range between 10 and 0.1 µJ, particularly preferably in the range between 2 and 0.1 µJ, in the wavelength range between 400 and 1,400 nm, preferably in the range between 600 and 1,200 nm, particularly preferably in the range between 800 and 1,100 nm and with a repetition rate in the range between 1 and 100,000 kHz, preferably in the range between 10 and 10,000 kHz, particularly preferably in the range between 100 and 500 kHz, especially preferably with a pulse duration of 150 fs, a pulse energy of 1 µJ, a wavelength in the range between 700 and 1100 nm and a repetition rate of 200 kHz.

9. A method of generating control commands for a laser unit for creating an aperture (1) in an eye, wherein the control commands cause the laser unit to create the aperture (1) in a lens (2) of the eye, wherein the aperture (1) is used to increase the depth of field of the eye and is formed by laser-induced lesions (5a, 5b, 10) which reduce light transmission through an aperture region of the lens (2) surrounding an aperture opening, characterized in that the control commands cause the laser unit, in cooperation with an alignment unit for aligning and / or fixating the eye, based on a narrowed pupil, which is effected by a a light stimulation unit for light stimulation of the eye in order to narrow the pupil, to produce marks (12a, 12b) defining the aperture opening in the lateral and / or axial direction (13).

10. A computer program, comprising programming means which cause a device according to claim 1 to perform a method of creating an aperture (1) in an eye when the computer program is executed on the device.