DE102020206420A1 - UV laser based system for ametropia correction - Google Patents

Abstract

The invention relates to a laser therapy device for ophthalmological purposes which has a multi-part support arm for an application part that can be positioned with respect to an eye, the individual parts of the support arm being connected via swivel joints which are oriented essentially parallel to one another.

Description

The present invention relates to ultra violet laser (UVL) based laser vision correction (LVC) systems, i.e. systems for ametropia correction by means of laser radiation, the corresponding treatment laser emitting in the ultraviolet range, such as excimer lasers or solid-state lasers with wavelengths between approx. 193 nm and 213nm. These systems are typically pulsed systems, i.e. systems that do not emit continuous waves. Such UVL-LVC systems are used to process the cornea of a patient's eye starting from its surface by means of photoablation, or to process a volume starting from the exposed area under a folded-away surface of the cornea of the patient's eye. The invention also relates to corresponding methods for UVL-LVC systems.

Currently used UVL-LVC systems, such as the MEL systems from Carl Zeiss Meditec AG, the Amaris systems from Schwind eye-tech solutions GmbH or the Micron systems from Excelsius Medical GmbH have long been successfully used systems for ametropia correction. Nevertheless, they have a number of inadequacies or disadvantages, for which solutions are to be shown here.

Almost without exception, a rigid laser beam guidance system is provided in today's UVL-LVC systems. Although this facilitates safe laser beam guidance, it makes it necessary to move the patient on a patient bed by means of this patient bed below a fixed system aperture in x, y, z coordinates until the patient's eye intended for treatment is correctly positioned relative to the optical axis of the system. The in US 2013/0226157 A1 described system in which the per se rigid laser arm is positioned as a whole over the patient, but in such a way that the positioning of the patient over the patient bed is still required. For safety reasons, however, the latter often requires the patient beds to be electrically and / or mechanically connected to the basic laser unit, which in turn enforces system approval and requires a large amount of space.

In such UVL-LVC systems, the usual manual static alignment of the eye with respect to cyclorotation takes place, i.e. without automatic correction with the help of registration data, by turning the patient's head on the couch under visual control. As a rule, this is not possible with great accuracy and a rotation of the patient's head during the treatment cannot be ruled out, which is critical for the treatment results if there is no automatic cyclorotation correction.

Contact interfaces for fixing the eye are also known in individual UVL-LVC systems today. However, they are used in such UVL-LVC systems, for example in US 2013/0226157 A1 and US 9592156 B2 described only implemented to stabilize the eye, and do not really play an active role. Many systems work entirely without contact interfaces.

With the introduction of spot-scanning UVL-LVC systems, large working distances have been achieved between the laser exit aperture and the eye. This was also done against the background of the use of microkeratoms, which were used with the patient on the patient's bed of the system to cut the LASIK flap, i.e. a fold-away opening in the cornea. Among other things, this also meant that large working distances were required. Eye-trackers were later introduced to register and compensate for eye movements, thus compensating for eye movements during ablation, since the eye is not fixed. The associated overall optical system concept - which is basically very similar in the various systems - can also be viewed as unfavorable.

Various problems arise for eye tracking in use. Overall, the registration speed of the eye movement is limited and the setting of the scanner mirror for correcting the pulse coordinate is finite in time. In connection with the system performance, the reaction to the eye movement ("response time") is always delayed and therefore never exact. With today's, fast eye-tracker systems (approx. 1000 Hz repetition rate) this is not a problem for the lateral correction (x, y shift; "1st and 2nd eye-tracking dimension"). However, today's fastest system already reacts to the limitations, as the eye tracker speed is even below the limit for the sampling frequency. Based on the previous movement trajectories, a prognosis is made, so to speak, about where the eye will move (“7th eye-tracking dimension”). This is of course a gross simplification, since eye saccades / nystagmas correspond in the broadest sense to statistical movements of the eye. This also shows that with today's technology an increase in the repetition rate hardly makes sense, although this would be interesting for certain applications and in certain ablation time windows (thermal controlled / mild ablation).

Furthermore, a purely lateral tracking is a limitation, since the rotation of the eye around the z-axis ("dynamic cyclorotation"; 6th eye tracking Dimension ") and the rolling movements around the horizontal and vertical eye axis ( 3 . and 4th Eye-Tracking Dimension ") must be taken into account. Finally, the distance (z-distance) to the laser exit aperture can also vary, which can also be compensated for by appropriate tracking (6th eye-tracker dimension). Despite all the technical subtleties and correction options, these systems are not able to react exactly to the eye position: the limited quality of the registration and the speed of the registration and correction do not allow this. The influence on the refractive results is usually very small and hardly detectable.

In connection with eye tracking, however, other problems arise in uncooperative patients who have fixation instability, nervousness, cognitive deficits or the fixation target. The eye surgeons then have to fix the eyes manually using a clamp or a foam spatula during the ablation in order to make an ablation possible at all. This happens relatively often and is due to the fact that the eye movement is led out of the so-called (limited) "Eye-Tracker Hotzone" and the system then has to stop.

With today's systems, constant environmental conditions cannot be set over the operating site, or only to a very limited extent.

It is known that the influence of varying environmental conditions, such as air humidity and the associated changes in the hydration state of the cornea, the composition of the air (in the case of evaporation, e.g. from solvents) or the temperature can have a considerable impact on the refractive results. It is also known that it is advantageous to ensure that the state of hydration of the cornea is maintained during the ablation or to prevent it from drying out. Two effects must be distinguished for hydration: a) the physiological differences in the hydration of the cornea as a variation between different patients, and b) the maintenance of hydration during the ablation itself. Both influences lead to an increased spread of the refractive result (via, for example, an increased spread in the prediction “attempted vs. achieved”). There are various studies here in the specialist literature. In particular, the influence of the hydration of the cornea is therefore significant.

Another very important factor influencing the refractive results is related to the amount and accumulation of ablation products (“debris”) over the ablated cornea, i.e. the surgical site. It is well known that the irradiated UV ablation pulses are absorbed and scattered in the debris. As a result, the effective pulse fluence, which significantly controls the ablation process, is modified in an uncontrolled manner. This can lead to considerable fluence deviations in the sequence of the ablation pulses. In myopia treatments, for example, there is a risk of central divisions of the cornea post-operatively (central islands). Today's systems therefore mostly have an extraction system or a combined air supply and extraction system for the debris. Due to the large distance between the inlets and outlets, however, a really effective removal of the debris is only feasible to a limited extent in practice. In principle, this would require an exchange of the entire volume of air over the treated cornea between successive pulses at a pulse repetition rate of 500 Hz to 1000 Hz. In the worst case - especially if the suction of the ablation products is not optimal or directed - "crooked" ablations and thus e.g. induced coma or SIA (surgically induced astigmatism) can occur.

Systems that additionally supply air also run the risk of dehydration of the cornea. This can also only be prevented to a limited extent. Overall, due to the open arrangement in today's systems, the surgical site cannot be decoupled from the rest of the operative environment (e.g. room air currents).

The sterile and safe storage of the flap is extremely important for a LASIK procedure. A flap is typically only 100 µm thick and after the LASIK incision is only attached to the cornea by a very narrow “hinge”, the hinge. Maintaining the hydration of the flap is very important for pathological reasons, but also to maintain the shape of the flap, since dehydrated flaps shrink within seconds. After the treatment, a shrunk flap no longer “fits” well into the stromal bed (which of course is also due to the change in shape of the stroma surface due to the ablation), which in turn can lead to postoperative complications (e.g. “epithelial ingrowth”). If possible, flaps should not be folded, pulled or otherwise stressed. The "calzone technique" used earlier is therefore rarely used by experts today. In addition, it is imperative to avoid that the flap comes to rest in possibly non-sterile areas of the eye. This can be done despite the sterile preparation of the eye, e.g. through tear film or contact with non-sterile parts of the eyelids.

In the absence of a solution integrated into today's systems, users sometimes cut their own flap shelves from sterile foam spatulas (or similar material), which are then moistened and used as a safe and sterile shelf for the serve delicate flap. So a solution is being sought to end this situation.

Because of the relatively large working distances Δ of existing UVL-LVC systems, there is hardly any difference in the level of focus. These ULV-LVC systems can therefore be viewed as almost telecentric on the image side. With conventional UVL-LVC systems, the rays hit the cornea at a considerable angle, since the typical radius of curvature RC of the human eye is around 7.86 mm. For these systems, the working distance Δ of typically 250 mm is also relatively large (actually the distance between the device exit aperture contour and the eye is meant, i.e. not directly the size Δ itself). This also leads to the fact that the optical acceptance angle for the return of corneal reflexes into the optical system is very small, which leads to additional restrictions of today's systems.

The disadvantages of the systems on the market will now be described, which result largely directly from the optical concepts and the resulting geometry of the ablation.

Due to the oblique incidence of the rays on the cornea, in all known systems there is a loss of fluence, i.e. the energy density of the laser pulse, which is decisive for the ablation. Two effects in particular must be taken into account here: The losses from deviations in the pulse ablation footprint due to the local geometry of the cornea at the location of the ablation pulse (“geometry factor”) and the Fresnel losses when light is irradiated at interfaces with different refractive indices (air, cornea), which can be calculated using the Fresnel equations. These effects are well known and described.

The pulse ablation shape ("Pulse ablation shape"; corresponds to the fluence distribution of the irradiated ablation laser pulse on a plane perpendicular to the direction of incidence) is deformed by the geometry of the radiation on the cornea to the "Pulse ablation footprint on cornea" and thus changes Fluence distribution compared to the irradiated "Pulse ablation shape".

The Fresnel losses can be calculated with the help of the Fresnel equations with knowledge of the refractive indices of air and cornea (or stroma) and the angle of incidence. The polarization of the light must also be taken into account.

Due to the relatively large working distance of known UVL-LVC systems to the patient's eye, it is difficult or even impossible to use back reflections from the cornea of the patient's eye for analysis, and this also makes centering difficult. The influence of inaccurate centering is well known and has been widely discussed in the literature. The "common" argument that centering errors, i.e. deviations of the ablation center from the target positions on the cornea, as typically given by the "Ophthalmia Pole" for centering on the visual axis, which are referred to below as decentrations, have no influence on spherical corrections, is physically correct only in certain cases such as spherical corrections on spherical corneas. However, visual physiology, among other things, is not taken into account. Decentering will usually lead to a shift in the physiological visual axis. When processing the visual impression in the brain, the eye is "rotated" by the eye muscles so that the light continues to fall into the point of sharpest vision, which basically compensates for the prismatic offset ("tip / tilt"). This can lead to problems with binocular vision (stereopsis), for example, which are known from examinations on badly centered spectacle lenses.

At the latest in the case of aspherical corrections on ellipsotoric corneas, which corresponds to the real, actual scenario, decentering also physically leads to the desired correction not being achieved.

It does not need to be discussed further that decentering has a considerable influence on the results of “Customized Ablation”, since this leads to the induction of higher aberrations (“night vision problems”, etc.) and thus also to the refractive result. Centering as exact as possible is an absolute prerequisite for a good result with topography and wavefront corrections.

• - eine Verschiebung von 0.25 µm mit Coma Z(3,1) um 0.3 mm führt zu ca. -1/8 D Defokus
• - eine Verschiebung von 0.25 µm mit Coma Z(3,1) um 0.3 mm (horizontal/vertikal) führt zu 1/8 D Kardinal Astigmatismus (Z(2,2) / Z(2,-2))
• - eine Verschiebung von 0.5 µm mit Coma Z(3,1) um 0.5 mm führt zu ca. -0.3 D Defokus
• - eine Verschiebung von 0.4 µm mit Coma Z(3,1) um 0.5 mm (horizontal/vertikal) führt zu 0.3 D Kardinal Astigmatismus (Z(2,2) / Z(2,-2))
• - eine Verschiebung von 0.6 µm mit Sphärischer Aberration Z(4,0) um 0.4 mm führt zu ca. -1/8 D Defokus
• - eine Verschiebung von 0.6 µm mit Sphärischer Aberration Z(4,0) um 0.4 mm (horizontal/vertikal) führt zu ca. 1/8 D Kardinal Astigmatismus (Z(2,2) / Z(2,-2))

Aberrations (or optical modes) couple with decentering. Due to the coupling of the sphere and cylinder to higher-order aberrations (coma, spherical aberration, higher-order astigmatisms), including those that occur in natural (aspherical) eyes, decentering in real eyes, but also with purely spherical-cylindrical corrections, is critical . For example, in the case of decentering, coma couples to astigmatism and defocus or spherical aberration couples to coma, astigmatism and defocus. A few examples are to be given here which initially only show the effects for the primary aberrations (up to the 4th order). The calculations are made from the coordinate transformation of optical modes:

• - a shift of 0.25 µm with Coma Z (3.1) by 0.3 mm leads to approx. -1/8 D defocus
• - a shift of 0.25 µm with Coma Z (3.1) by 0.3 mm (horizontal / vertical) leads to 1/8 D cardinal astigmatism (Z (2.2) / Z (2, -2))
• - a shift of 0.5 µm with Coma Z (3.1) by 0.5 mm leads to approx. -0.3 D defocus
• - a shift of 0.4 µm with Coma Z (3.1) by 0.5 mm (horizontal / vertical) leads to 0.3 D cardinal astigmatism (Z (2.2) / Z (2, -2))
• - a shift of 0.6 µm with spherical aberration Z (4.0) by 0.4 mm leads to approx. -1/8 D defocus
• - a shift of 0.6 µm with spherical aberration Z (4.0) by 0.4 mm (horizontal / vertical) leads to approx. 1/8 D cardinal astigmatism (Z (2.2) / Z (2, -2))

So far only considerations have been made for optical modes which manifest themselves in ablation profiles in the optical zone. The transition zones have not yet been mentioned. In this context, decentering also means that transition zones can extend into the optically active zone, especially in the case of hyperopia corrections. This then leads to disturbances ("night vision complaints post surgery", here is not meant night myopia) in mesopic to scotopic light conditions and thus to patient dissatisfaction.

Pupil centering (centering to the CSC, “Corneal Sighting Center”) can be achieved well and safely in refractive surgery using eye tracking systems (“eye trackers”) as integrated pupil recognition. However, this type of centering is not the preferred choice, since it is now undisputed in the professional world that centering to the ophthalmic pole (visual axis, coaxially sighted corneal light reflex, "CSCLR", condition, see below) would be correct. Experience has shown that small and medium-sized myopia corrections are very uncritical here. It becomes more difficult with larger astigmatisms and myopia corrections and especially hyperopia corrections. Hyperopic eyes are typically characterized by a non-negligible angle between the pupillary axis and the visual axis ("angle kappa"). Corneal Sighting Center and Ophthalmic Pole are no longer sufficiently close to one another, which leads to a difference between "angle lambda" and "angle kappa". In addition, the pupil and the pupil center are not a fixed mark. Both fluctuates with the lighting conditions.

With today's laser systems, centering on the visual axis takes place by searching for the first Purkinje reflex of the fixation laser (“target”). Under patient fixation, the recommended CSCLR condition is fulfilled when the Purkinje reflex comes into the center of the system optics and the optical system axis and the visual axis become coaxial. Due to the optical geometry of today's systems, with a very small acceptance angle for the entry of the reflex into the optical beam path as described above, finding this reflex is not trivial. This is made even more difficult in less cooperative patients, e.g. with weak fixation, as the reflex then disappears permanently. In addition, the "parallax error" of the surgical microscope, i.e. different directions for the reflex in the right and left observer eyes due to the binocular arrangement, make correct alignment more difficult.

An automatic centering according to CSCLR by Purkinje reflex does not exist in today's systems and is also not in prospect, due to the above-mentioned "unfavorable" optical geometry of today's systems. This is presumably one of the reasons why pupil centering is preferred by many users today, despite the problems associated with it, since, in contrast to CSCLR centering using the Purkinje reflex, it is carried out safely and automatically by the systems.

Manual centering on the vertex, which usually represents the reference center for the topography, by entering shift coordinates is often used for topography-guided corrections, but also for sphero-cylindrical standard corrections. The latter is possible because for normal eyes the positions of the CV ("corneal vertex", i.e. the point of penetration of the keratometric axis on the cornea under patient fixation) with the ophthalmic pole, i.e. the visual axis, are sufficiently close to one another. This in turn is due to the fact that the center of curvature of the cornea coincides approximately with the second optical node of the eye on the image side (compare Gullstrand, Liou-Brennan eye models). There is no automatic centering to the vertex today. Often the user moves the treatment center manually based only on the visual comparison to a topography measurement. Or he enters shift coordinates into the system, which are usually given in relation to the center of the pupil (CSC) and which are taken from a topography measurement, for example. In both cases the problem is that the pupil diameter during the topography measurement does not match the pupil diameter under the laser due to the differences in illumination. The frequently occurring displacement of the pupil center with the pupil size then results in not optimal centering, since the corneal vertex is not correctly determined.

Today's UVL-LVC systems do not offer a method of tomographic alignment of the Anterior chamber and tomographic centering. This can become important, e.g. in the case of corneal irregularities (e.g. caused by trauma or brief swelling of the corneal surface due to bubbles after femtosecond laser flap generation), which lead to the corneal vertex and / or the Purkinje reflex not being found correctly or in other words, a position is identified as a vertex which does not correspond to the normal physiological vertex position. The pure “surface information” of the cornea is then not, or not sufficiently, suitable for determining the optimal centering.

The object of the present invention is therefore to describe devices and a method which address the above-mentioned problems of currently used UVL-LVC systems. In particular, the positioning of the patient's eye with respect to the laser beam guidance should be simplified.

The invention is defined in the independent claims. The dependent claims relate to preferred developments.
The UVL-LVC system according to the invention comprises a base station with a light source for generating light pulses, a carrier arm that is attached to the base station, an application part that is attached to the carrier arm and can be placed on an eye, the application part means for projecting the Having light pulses on the eye tissue, an optical transmission system which is designed to transmit the light pulses from the base station through the carrier arm to the application part, the carrier arm being made in several parts and the individual parts of the carrier arm being oriented by swivel joints whose axes of rotation are essentially parallel to one another are connected to each other. It is particularly advantageous if the support arm consists of three parts which are connected to one another by two swivel joints.

The application part is also advantageously connected to the distal end of the support arm via a further swivel joint, the axis of rotation of which runs essentially parallel to the axes of rotation of the aforementioned swivel joints.

The system according to the invention further advantageously has positioning means for a rotary movement of the parts of the support arm parallel to a positioning plane for positioning the application part above the eye.

It is advantageous if the support arm is attached to the base station in a height-adjustable manner. For this purpose, the base station can comprise a column to which the support arm is attached, and this column can be vertically movable for vertical positioning of the support arm.

Alternatively, it is preferred that the base station can be positioned vertically. It is also advantageous if the base station has means for beam shaping and beam deflection of the light pulses.

• 1: eine Gesamtansicht des erfindungsgemäßen UVL-LVC-Systems
• 2: eine schematische Ansicht des UVL-LVC-Systems
• 3: ein Ausführungsbeispiel eines Drehgelenks
• 4: das UVL-LVC-System in einer Ruheposition
• 5: eine vergrößerte Darstellung des Anwendungsteils
• 6: eine schematische Darstellung einer alternativen Stereobetrachtungseinheit des Anwendungsteils.

The invention is explained in more detail below, for example with reference to the accompanying drawings, which also disclose features essential to the invention.

• 1 : an overall view of the UVL-LVC system according to the invention
• 2 : a schematic view of the UVL-LVC system
• 3 : an embodiment of a swivel joint
• 4th : the UVL-LVC system in a rest position
• 5 : an enlarged view of the applied part
• 6th : a schematic representation of an alternative stereo viewing unit of the applied part.

In contrast to the prior art, the UVL-LVC system according to the invention 1 does not have a rigid laser beam guidance system, but instead a multi-part articulated support arm 2 , as in 1 shown, which is mounted on a mobile laser unit. This has significant advantages. The articulated arm 2 itself is supported by three swivel joints ( DG1 , DG2 , DG3 ) realized, the axes of rotation of the joints running essentially parallel to one another and perpendicular to the xy plane. It is through these joints that the articulated arm can 2 only in x, y direction above the patient's eye 3 moved and positioned. To set the correct height z, the entire system 1 can be adjusted in height or it can be a column 4th relative to the base unit 5 be moved vertically.

So the patient can 6th stationary on a lounger 7th remain. A specially movable lounger 7th not necessary.

This makes it possible to use the UVL-LVC system according to the invention 1 to be used as a mobile system. Because of the small footprint and the articulated arm 2 the system can be used in a very variable manner (e.g. in cramped conditions in the operating room) for the couch 7th and other system to be positioned; that is, without a fixed scheme as in other systems of the prior art. The mobility also enables the necessary cleaning and disinfection in a particularly simple manner.

At the distal end of the articulated arm 2 there is an applied part 8th which is via the swivel joint DG3 is rotatably mounted (angle of rotation to the eye 3 with axis of rotation along z-direction). This includes (in part only indicated) in particular the optical components for imaging the treatment laser 9 on the eye 3 , a 2D or 3D camera system for visualization, optionally an integrated display for the 2D camera or a unit for stereographic superimposition of the images of the 3D camera system, further optionally a surgical microscope which can be combined with a slit lamp, lighting units and an adapter to accommodate a ( Eye) contact interface 10 .

When placing the on the application part 8th attached contact interfaces 10 on the eye 3 is a tilt in relation to the horizontal alignment of the applied part 8th not possible because the swivel joint DG3 has no degree of freedom for this. The alignment or centering of the eye 3 takes place under patient fixation (the patient fixes a corresponding target presented to him optically), then the eye is 3 from the contact interface 10 sucked in and so a fixed positional relationship between the eye 3 and treatment laser 9 manufactured.

Placing the on the application part 8th attached contact interfaces 10 on the eye 3 can also be supported, for example, by a horizontal stripe projection (for example by scanning a suitable laser). The applied part 8th with contact interface 10 can be under control of the projected strip by rotating the applied part 8th itself (swivel DG3 ) on the eye 3 - e.g. to the corner of the eyelid - be aligned to a static cyclorotation of the eye 3 to avoid the system. Any turning of the patient's head during the treatment does not affect the quality of the treatment.

Registration data obtained during the diagnosis of the patient can preferably be used in order to enable an automatic cyclic rotation correction. This is done by following the alignment of the contact interface 10 when the eye is sucked in 3 obtained reference image is used, which is compared with the registration data of the diagnosis in order to calculate a transformation of the laser pulse coordinates to compensate for the cyclorotation.

2 shows a more schematic representation of the UVL-LVC system according to the invention.

The laser head 11 for the ablation laser, power supplies, and other components required to operate the laser are in the mobile base unit 5 housed. From the laser head 11 The treatment laser beam is based on known beam shaping optics and beam deflecting optics (scanners), which are in the structural unit 12th are included, various deflection mirrors, among other things in the swivel joints DG1 until DG3 by means of suitable optics inside the column 4th and the multi-part support arm 2 via the applied part 8th and contact interface 10 up to the patient's eye (not shown here) 3 guided. The base unit 5 can furthermore have camera systems for monitoring, detection systems for example for the quality of the laser beam or also an OCT (Optical Coherence Tomography) system for displaying the eye before or during the operation.

The beam path from the beam exit at the laser head 11 to the application part 8th and the articulated arm 2 can preferably be evacuated before triggering the UV laser pulses in order to reduce laser losses or interactions of the UV radiation with gases in the beam path. In particular, the possible formation of ozone could damage the optical components.

Possibilities for measuring the joint positions (ie angles) of the rotary joints are also advantageous DG1 until DG3 provided, which may be necessary for the conversion of the image in the optical system.

The swivel joints DG1 until DG3 are preferably designed as plain bearings. However, other embodiments are also possible. For example, the bearings could also be designed as pressure roller bearings. The joints can be braked / locked using electro- or magneto-mechanical systems or similar. 3 shows an example of a suitable swivel joint. The swivel joint has a deflection mirror 13th with a finely adjustable bracket 14th as well as the actual warehouse 15th on. The laser beam 16 is through the deflection mirror 13th high-precision inside the carrier arm 2 on the next following swivel joint or the applied part 8th directed.

4th shows the UVL-LVC system according to the invention 1 in a park position of the articulated arm 2 . The articulated arm is in this position 2 in the "folded" position, eg for transport in the operating room or when the system is not in operation. The parking position has a lock (not shown here) for this purpose. The calibration of the system before use could also take place in this position, for example in that the pulse energy of the UV laser can be determined and regulated in this parking position. Because the deflections (90 ° deflection over 45 ° mirror) of the laser beam 16 in the carrier arm 2 In connection with small scanners deflections require only small deviations of the deflections of 90 °, only very small changes occur Pulse energy depending on the arm positioning.

5 shows a variant of the applied part 8th at the distal end of the articulated arm 2 with a display 17th which e.g. via a touch control operating units for the height adjustment along the z-axis (column 4th or base unit 5 ), Lighting, controls for the contact interface 10 (e.g. suction ablation products, suction eye) can realize. The contact interface 10 itself is made by the user via an interface with the application part 8th tied together.

The application part can also contain a 2D or 3D camera system for visualization. The operation situation can then be visualized on additional screens 18th on the mobile base unit 5 take place, these can also be designed as 3D capable screens.

Optionally, the applied part 8th an integrated display 17th for the 2D camera. The user then has a visual impression in the natural direction directly on the patient's eye 3 .

As an alternative to the 2D display, a stereoscopic view can also be provided, as in 6th shown schematically, which is used for stereographic superimposition of the images from two cameras in a 3D arrangement. The pictures 19th these cameras can then, for example, have a suitable double-sided mirror 20th by the user on a screen 21 to be viewed as. Other embodiments are also conceivable. The view advantageously takes place in the direction of the real patient's eye 3 .
The features of the invention mentioned above and explained in various exemplary embodiments can be used not only in the combinations given by way of example, but also in other combinations or alone, without departing from the scope of the present invention.

A description of a device based on method features applies analogously to the corresponding method with regard to these features, while method features correspondingly represent functional features of the device described.

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• US 2013/0226157 A1 [0003, 0005]
• US 9592156 B2 [0005]

Claims (8)

Laser therapy device for ophthalmological purposes comprising a base station with a light source for generating light pulses, a support arm attached to the base station, an applied part that is attached to the carrier arm and can be placed on one eye, wherein the application part has means for projecting the light pulses onto the eye tissue, an optical transmission system that is designed to transmit the light pulses from the base station through the carrier arm to the application part, wherein the support arm is made in several parts and the individual parts of the support arm are connected to one another by swivel joints, the axes of rotation of which are oriented essentially parallel to one another. Laser therapy device for ophthalmological purposes according to Claim 1 , wherein the support arm preferably consists of three parts, which are preferably connected to one another by two swivel joints. Laser therapy device for ophthalmological purposes according to Claim 1 or 2 , wherein the applied part is connected to the distal end of the support arm via a further swivel joint, the axis of rotation of which runs essentially parallel to the axes of rotation of the preferably two swivel joints. Laser therapy device for ophthalmological purposes according to one of the preceding claims, which has positioning means for a rotary movement of the parts of the support arm parallel to a positioning plane for positioning the application part above the eye. Laser therapy device for ophthalmological purposes according to one of the preceding claims, wherein the support arm is attached to the base station in a height-adjustable manner. Laser therapy device for ophthalmological purposes according to Claim 5 wherein the base station comprises a column to which the support arm is attached, and wherein the column is vertically movable for vertical positioning of the support arm. Laser therapy device for ophthalmological purposes according to Claim 5 , wherein the base station can be positioned vertically. Laser therapy device for ophthalmological purposes according to one of the preceding claims, wherein the base station has means for beam shaping and beam deflection of the light pulses.

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