DE102020215583A1 - Device for generating an increased outflow of aqueous humor to reduce the intraocular pressure in glaucoma - Google Patents

Abstract

With the present device, an increased outflow of aqueous humor is generated to reduce the intraocular pressure for the treatment of glaucoma. The device consists of a laser system, an image recording unit, a coupling unit with a laser scanner and a control and evaluation unit. According to the invention, the laser system is for minimally invasive ablation and/or disruption of the sclera, the image acquisition unit is designed to provide images of the anterior eye, in particular its suprachoroidal space, and the control and evaluation unit is designed to evaluate the images of the suprachoroidal space provided by the image acquisition unit or other sources and to generate control signals for to generate the laser system and the laser scanner. The present invention is suitable for carrying out a minimally invasive ablation and/or disruption of the eye treatment, it can also be used in trabeculectomy.

Description

The present invention relates to a device with which an increased outflow of aqueous humor is generated to reduce the intraocular pressure for the treatment of glaucoma. The device is based on a laser system for minimally invasive ablation and/or disruption of the sclera (sclera) of the eye.

Glaucoma or glaucoma is a disease that causes irreversible damage to the optic nerve fibers. In advanced stages, the optic nerve can even be hollowed out (excavated). The steadily progressive damage to the optic nerve causes an equally steady reduction in the patient's field of vision. Without treatment, this usually leads to complete loss of sight.

The series of all possible causes of glaucoma or the described damage to the optic nerve has not yet been finally clarified, but one of the most important triggers has been an increase in intraocular pressure (IOP) due to impaired aqueous humor drainage identified in the eye.

As a result of such impaired aqueous humor outflow, i. H. an increased outflow resistance, there is an increase in pressure in the eye until the aqueous humor outflow is again in equilibrium with the aqueous humor production at the now increased intraocular pressure. The relationship between the pressure drop ΔP that occurs across the outflow paths, with a flow resistance R present and an aqueous humor flow Q, is ΔP=R*Q. The changed pressure conditions are now suspected of directly damaging the optic nerve through mechanical effects and/or of causing a reduction in the perfusion pressure in the retina, which is important for supplying the optic nerve fibers, through a changed pressure gradient.

A worsening of the outflow of aqueous humor can be caused, for example, by a narrowing of the chamber angle (narrow-angle glaucoma) or also in the case of an open chamber angle (open-angle glaucoma) by changes in the filter tissue of the trabecular meshwork or even its blockage (e.g. in pseudoexfoliative or pigmentary glaucoma), or as a result of a reduction in the cross section of Schlemm's duct or on subsequent collecting vessels or in the episcleral venous system. Tissue changes in the uveoscleral outflow path can also lead to a deterioration in aqueous humor outflow. The latest investigations point to the influence of a third, the uveolymphatic outflow path.

In most cases, lowering the intraocular pressure is considered a therapeutic approach in the treatment of glaucoma. In rarer cases, however, blood pressure adjustments are also made.

The lowering of the intraocular pressure is usually carried out initially with medication, i. H. via substances that either reduce the production of aqueous humor (e.g. beta blockers) or improve outflow through the tissues of the outflow pathways (e.g. prostaglandins). In the latest developments, prostaglandin analogues (bimatoprost) are embedded in biodegradable polymers and used as implantable drug depots for glaucoma treatment (bimatoprost SR with polymer system).

In addition, laser trabeculoplasty (selective laser trabeculoplasty - SLT, argon laser trabeculoplasty - ALT, excimer laser trabeculoplasty - ELT) can also improve the trabecular outflow. This is done in the scriptures US 2020/0078218 A1 and U.S. 2020/0016002 A1 among other things, trabecular meshwork treatments using femtosecond lasers were also proposed.

Also known are canaloplasties in which Schlemm's canal is widened. If the glaucoma progresses, a trabeculotomy (partial removal of the trabecular meshwork) or partial coagulation of the aqueous humor-producing ciliary body tissue is sometimes considered, for example in the form of cyclophotocoagulation (CPC), cyclocryocoagulation (CKC) or ultrasound cyclocoagulation (UCC).

• • Trabekelwerksshunts zur Überbrückung des Trabekelwerks (iSTENT), auch kombiniert mit Schlemm-Kanal-Stenting (HYDRUS). Diese sind relativ risikoarm, aber in ihrer Wirkung eher begrenzt, d. h. sie sind nicht für fortgeschrittene Glaukome geeignet und setzen insbesondere einen ausreichend funktionierenden Abflusspfad durch Schlemm-Kanal, Kollektorgefäße und episklerales Venengefäß voraus, der oft nicht mehr gegeben ist.
• • Suprachoroidalstents (CYPASS, SUPRA), die Kammerwasser in den Suprachoroidalraum ableiten (also zwischen Aderhaut und Sklera), wo es von der Aderhaut aufgenommen wird. Im Prinzip handelt es sich hier um eine Sonderform der Zyklodialyse-Operation, bei der in der Vergangenheit mittels einer Inzision eine Spalte (engl.: Cleft) erzeugt wurde, mittels der Kammerwasser in den Suprachoroidalraum geleitet wurde. Diese Spalte öffnete sich aber manchmal zu weit (IOP-Abfall, Hypotonie) oder schloss sich allerdings manchmal auch wieder, wodurch es dann zu IOP-Anstiegen (Hypertonie kam). Diese Probleme sind durch die Suprachoroidalstents etwas gemildert, aber nicht vollständig beseitigt. Nach [1] ist jedoch bekannt, dass bei Suprachoroidalstents gelegentlich auch Verstopfungen (meist durch Blutklümpchen) vorkommen, die dann mittels YAG-Laser freigeschossen werden konnten. Die Zyklodialysespalten können einige Millimeter tief sein und auch die Suprachoroidalstents weisen entsprechende beträchtliche Längen von z.T. über 6mm auf. Da die Zyklodialysespalte sich zwischen der Aderhaut (Choroid) und der Lederhaut (Sklera) befindet, müssen die Suprachoroidalstents der durch die Form des Augapfels verursachten Krümmung dieser Grenzfläche folgen können und müssen entsprechend flexibel krümmbar sein.

• • Subconjunktivalstents (XEN, Microshunt), die in ein Sickerkissen (Bleb) unter der Bindehaut ableiten. Durch Einsatz dieser Stents schont man die Bindehaut, da man zumindest bei ab-interno Varianten auf Einschnitte in die Bindehaut verzichten kann (XEN). Allerdings zeigt die klinische Erfahrung, dass auch eine Wundmodulation wie unten beschrieben nötig ist.
• • Ein in Entwicklung begriffenes Feld sind den Limbus drainierenden Stents zur Überbrückung der Cornea bzw. des Limbus ( DE 10 2018 203 356 A1 ).

Newer drainage devices are so-called MIGS stents/shunts, which can be divided into the following classes:

• • Trabecular meshwork shunts to bridge the trabecular meshwork (iSTENT), also combined with Schlemm's canal stenting (HYDRUS). These are relatively low-risk, but their effect is rather limited, ie they are not suitable for advanced glaucoma and, in particular, require a sufficiently functioning drainage path through Schlemm's canal, collector vessels and episcleral veins, which is often no longer available.
• • Suprachoroidal stents (CYPASS, SUPRA), which drain aqueous humor into the suprachoroidal space (i.e. between the choroid and sclera), where it is absorbed by the choroid. In principle, this is a special form of cyclodialysis operation, in which in the past a cleft was created by means of an incision, by means of which aqueous humor was guided into the suprachoroidal space. However, this gap sometimes opened too wide (IOP drop, hypotension) or sometimes closed again, resulting in IOP increases (hypertension). These problems are somewhat alleviated by the suprachoroidal stents, but not completely eliminated. According to [1], however, it is known that blockages (usually caused by blood clots) occasionally occur with suprachoroidal stents, which could then be shot free with a YAG laser. The cyclodialysis gaps can be a few millimeters deep and the suprachoroidal stents are also correspondingly long, sometimes over 6mm. Since the cyclodialysis gap is located between the choroid and the dermis (sclera), the suprachoroidal stents must be able to follow the curvature of this interface caused by the shape of the eyeball and must be flexible enough to bend accordingly.

• • Subconjunctival stents (XEN, Microshunt), which drain into a bleb under the conjunctiva. The use of these stents protects the conjunctiva, since incisions in the conjunctiva can be dispensed with, at least in the case of ab-interno variants (XEN). However, clinical experience shows that wound modulation as described below is also necessary.
• • A field in development is stents draining the limbus to bridge the cornea or the limbus ( DE 10 2018 203 356 A1 ).

Lasers have been used in therapy and surgery on the eye for years with various systems in clinical use and in research.

For example, low-power lasers, which can directly cause only reversible tissue heating, are used in combination with photosensitizers for photodynamic therapy of age-related macular degeneration (AMD for short).

More powerful lasers with outputs in the range of 1W and in particular the wavelength 532nm are used, for example, for photocoagulation of the retina as part of therapy for diabetic retinopathy or for "Argon Laser Trabeculoplasty" (abbreviated: ALT) to reduce intraocular pressure in glaucoma. Approx. 100 laser pulses with 100ms and 400 to 600mW are used in the ALT, which are focused to a spot diameter of approx. 50µm. A relatively large amount of energy from visible laser radiation is therefore introduced into the eye, which e.g. leads to glare.

Also for the treatment of glaucoma, mostly in the advanced stage, the coagulation of the ciliary body, which produces the aqueous humor, is used in the context of cyclophotocoagulation (CPC) in order to lower the intraocular pressure. For this purpose, laser diodes with a wavelength of 810 nm and several watts of average power are used, which are applied transsclerally and coagulate the ciliary body via a thermal effect. Between 10 and 40 spots are applied with energies between 1.25 and 3 watts and a pulse duration of 1.5 to 2 seconds. However, since this treatment is painful, it must be carried out at least under local anesthesia.

In order to reduce the side effects of coagulation, selective thermal laser procedures are being investigated more intensively and are already being used clinically. Selective absorption is known in particular for melanin-containing cells in the eye, with lasers in the green spectral range being used here in particular, since there is a higher absorption coefficient of melanin for this wavelength (532 nm) compared to longer wavelengths.

The one in the US5549596A The glaucoma treatment described to reduce intraocular pressure is based on selective laser trabeculoplasty (SLT for short). The technical data of such a laser system for SLT treatment are described in [2]. The treatment is carried out at a wavelength of 532nm, with a pulse length of 3ns and a pulse energy of approx. 1mJ on a spot diameter of 400µm in the trabecular meshwork of the eye successively over a circumference of 180° or even 360°.

SLT treatment can be further optimized by using scanners in the beam path ( US8568393B2 ).

SLT is already used quite frequently in the early and middle stages of glaucoma, for example to be able to reduce the administration of glaucoma drops and thus reduce their side effects. According to the latest findings, SLT is also recommended as initial therapy. However, the effect of the SLT is only limited to a temporary improvement in the trabecular outflow for the aqueous humor and therefore often cannot completely stop the progression of the glaucoma disease, so that more effective measures are necessary, such as trabeculectomy or the implantation of a tube shunt.

In addition to laser treatment of the trabecular meshwork, ablation laser surgery of the sclera using a CO ₂ laser is also known ( US9480599B2 ). The technical data of such a laser system are described in [3]. However, this technique is mainly a support for very invasive surgical interventions, which it does not fundamentally replace.

Surgical and sometimes combined drug therapy of glaucoma through the preparation of scleral flaps and blebs is similar (http://ioptima.co.il/technology/class-procedure-flow/). The aim of this near-surface laser processing is mainly tissue conditioning to achieve a desired tissue scarring process, similar to "wound modulation" through the intraoperative use of antifibrotics such as mitomycin C (MMC).

In the US8827990B2 Among other things, the use of lasers with pulse lengths > 100ns is proposed in order to introduce holes into the trabecular meshwork from the outside in order to increase the aqueous outflow and thereby reduce the intraocular pressure. For example, incisions are made through the conjunctiva of the eye to in front of the trabecular meshwork, in order then to ablate parts of the trabecular meshwork using a laser, for example. In particular, channels for the drainage of aqueous humor to Schlemm's canal should be prepared. However, the pulse lengths used mean that unnecessary damage to the surrounding tissue and, as a result, undesirable healing processes and scarring can be expected.

In the U.S. 2016/0113816 A1 describes a method using an infrared laser in the wavelength range at 6 µm, with which the sclera is softened due to the relatively high absorption of the stroma in order to carry out presbyopia and glaucoma treatments. Furthermore, unspecified, thermally effective laser systems with pulse lengths in the range of ms and power of approx. 250mW are proposed, which even require cooling of the surface of the eye to avoid burns.

The first minimally invasive therapies with thermal lasers (wavelength 1.56 µm, power 0.9 W with a very long, thermally effective pulse duration of 200 ms) were also examined in [4]. Here, a thermomechanical effect is induced using a laser to stimulate pores in the tissue through coagulation. However, these are not generated in a geometrically defined manner, so that unstable results and undesirable healing processes such as scarring are to be expected.

Another minimally invasive laser application is the creation of micropores in the skin to promote the penetration of drugs of certain molecular sizes ( EP 2 275 051 B1 ). In particular, erbium lasers with a wavelength of around 3 µm and pulse durations of up to 150 ns are used.

A minimally invasive laser generation of microchannels in the corneal epithelium is WO 2020/219931 A1 disclosed.

In the WO 2013/095695 A1 describes a solution for treating the anterior corner of the eye using focused photodisruptive laser pulses. Pulse durations of less than 50 picoseconds are used to cut channels in various anatomical structures within the anterior corner of the eye, in particular using a femtosecond laser (fs-laser) ab-internally to cut a channel into the suprachoroidal space. However, it remains unclear how the sufficient processing depth is realized and how the injuries of blood vessels are prevented or the resulting bleeding is dealt with, which the writing itself mentions as a problem.

A disadvantage of all previously used methods for glaucoma surgery in scleral tissue is the temporary effect of the measures, which are attributed in particular to healing processes in the tissue. In order to suppress these healing processes, minimally invasive methods with less damage to the surrounding tissue are required, which promise a greater long-term effect.

Known surgical methods, with cuts caused by mechanical instruments and laser procedures with thermal side effects, should be ruled out on the basis of the clinical findings to date. So far, unfortunately, no other surgical interventions in the sclera have become known that can treat the tissue more gently but can still improve the permeability of the sclera to lower the intraocular pressure.

Due to the sometimes high optically absorbing and scattering effect of scleral tissue and also due to the presence of blood vessels in the sclera, the use of almost athermic laser procedures, such as those used for laser ablation of the transparent cornea in the context of refractive laser surgery on the eye using excimer lasers, is necessary , not seen by the professional. Locally limited photodisruption can also be performed using femtosecond lasers (short: fs lasers), as used in refractive and cataract surgery of the transparent cornea and the lens of the eye is not used in the sclera.

Thus, all approaches made so far of the laser-assisted realization of drainage of the aqueous humor to reduce the intraocular pressure in glaucoma have not yet proven sufficiently.

The present invention is therefore based on the object of offering a new laser-assisted solution for a low-risk, effective, non-invasive or minimally invasive aqueous humor drainage that protects the conjunctiva to reduce the intraocular pressure in glaucoma. Furthermore, the solution should be suitable for adjusting an existing aqueous humor drainage with regard to the outflow of aqueous humor afterwards, also non-invasively.

According to the invention, the object is achieved by the features of the independent claims. Preferred developments and refinements are the subject matter of the dependent claims.

This object is achieved with the device for generating an outflow of aqueous humor to reduce the intraocular pressure in glaucoma, consisting of a laser system, an image recording unit, a coupling unit with a laser scanner and a control and evaluation unit, in that the laser system is used for minimally invasive ablation and /or disruption of the sclera, that the image recording unit is designed to provide images of the anterior eye, in particular its suprachoroidal space, and that the control and evaluation unit is designed to provide images of the suprachoroidal space provided by the image recording unit or other sources evaluate and generate control signals for the laser system and the laser scanner. In addition to the choroid (sclera), the suprachoroidal space can also include tissue layers (conjunctiva) and the surface of the eye itself. The image recording unit should in particular be designed to provide recordings of the suprachoroidal space intraoperatively and in particular during and between tissue processing steps using the laser, since structural and positional changes in the tissue involved can occur here, which must be taken into account when controlling the laser. In particular, it is advantageous if inclusions of gases that can form during laser processing are also temporarily recorded and taken into account in the recordings. Such gas formations can even be deliberately used to support the separation of tissue layers, for example the opening of a cyclodialysis gap between the choroid and the sclera.

Furthermore, it is preferred that the imaging unit is designed to detect at least larger blood vessels and aqueous humor collection vessels in the suprachoroidal space and possibly also in the conjunctiva (for example via color and/or optical coherence angiography, OCTA). By evaluating the recordings from the suprachoroidal space, the control unit generates control data for the laser scanner, with which an injury to these vessels is ruled out by suitable positioning of the laser processing area. The advantage here is that the sclera itself has fewer vessels, so that sufficient alternative laser processing areas can usually be selected. In general, the venous network of the plexus venosus sclerae, which serves to drain aqueous humor from Schlemm's canal, as well as the arteries supplying the ciliary body and partly running through the sclera (arteria ciliaris anterior) should be preserved.

Since, according to the invention, minimally invasive laser systems are used without or with only a very small tissue coagulating effect, this is particularly important, since otherwise severe bleeding will occur in the case of vascular injuries without the coagulating laser effect, which can disrupt the laser treatment itself and trigger undesirable healing processes with scarring as a result of the bleeding .

The significantly higher density of blood vessels in the choroid compared to the dermis can be used advantageously for structure recognition in the OCTA evaluation.

A first group of advantageous configurations relates to the laser system used, in particular with regard to its wavelength and pulse duration.

In this case, a first laser system based on a wavelength in the ultraviolet or infrared spectral range is designed to perforate the sclera from its surface by drilling holes of predetermined depths. Here, the high water and tissue absorption in these spectral ranges is used,

In contrast, a second laser system based on a fs laser system in the VIS or NIR is designed to cut tissue in the suprachoroidal space without perforating the sclera. Here, the non-linear plasma absorption that only occurs in the focus due to high intensities is used.

A second group of advantageous configurations relates to the contact glass, which are required for the applications of an fs laser system.

In this case, the contact glass has a contact surface and contact optics, the contact surface of the contact glass being designed to suck on the cornea and/or conjunctiva. The contact optics, through which the laser beam of the fs laser system is focused into the tissue, is designed to press on the conjunctiva and/or dermis and to achieve an applanating effect.

This compression of the scleral tissue temporarily minimizes the layer thickness of the optically scattering sclera and increases transparency. In this way, in particular, the ultrashort pulse laser can be focused with less intensity loss in deeper layers of the sclera in order to produce inner perforation chambers there by photodisruption and the associated perforation of the tissue. Inner volumes can also be cut out and removed using tweezers through an opening (or on a flap) that has also been prepared with the ultrashort pulse laser. This creates what are known as "oozing cushions", which previously had to be produced mechanically by surgery, using a precisely programmable and tissue-friendly technology.

Alternatively, it is also possible to realize a liquid interface between the contact optics and the cornea or conjunctiva that is filled with water, for example. Liquid films on the cornea and conjunctiva are particularly beneficial in order to smooth out otherwise scattering surface irregularities and also to enable more efficient penetration of the laser light into the tissue by adjusting the refractive index between tissue and contact optics and at the same time to keep the tissue hydrated. In the case of liquid interfaces, it is necessary for the laser radiation used to be absorbed within only small or acceptable limits with the liquid layer thicknesses used, which can be easily implemented in particular with fs lasers in the NIR and water as the liquid.

In addition to liquids, gels, such as colorless viscoelastics, are also suitable, as are also used in operations on the inside of the eye.

According to a third group of advantageous configurations, methods based on optical coherence tomography (OCT) or ultrasound (US) are used as optical imaging methods for the image recording unit. Its variants for angiography are particularly preferred, for example by processing signal phase variations as a result of blood flows, such as Doppler signals. Methods of contrast imaging of laser speckle on blood vessels [14] can also be used for image acquisition, although the penetration depth there is limited to a few tenths of a millimeter. However, the imaging unit should preferably enable imaging over the entire thickness of the dermis (sclera), more preferably into the choroid, for example using an OCT scan depth of >1.5mm, preferably >5mm. Such large scan depths can easily be implemented using modern swept-source OCTs, for example.

As is already the case with OCT, the image recording unit should also include the means required for lighting (light sources, possibly polarization modifiers or spectral filters to highlight blood vessels) for other types of image recording (e.g. stereo cameras, confocal imaging). In the case of ultrasound systems, this should also include transducers or phased arrays that emit ultrasound waves.

In this case, the image recording unit can be designed in such a way that it records the suprachoroidal space intraoperatively, or intraoperatively records images of the anterior eye with landmarks (registration features). These recordings of the anterior eye with landmarks can be registered intraoperatively with preoperatively obtained recordings of the suprachoroidal space in order to achieve a targeted control of the laser scanner for laser processing in the suprachoroidal space. The limbus, iris structures, blood vessels, Schlemm's canal or the scleral spur can be used as landmarks.

The preoperative acquisition of two- or three-dimensional images of the suprachoroidal space can be done, for example, with diagnostic devices such as: anterior chamber OCT, Scheimpflug camera, ultrasound devices, confocal scanners, NIR cameras or so-called red-free cameras.

A final group of advantageous configurations relates to the control and evaluation unit, which is designed to evaluate the recordings of the suprachoroidal space made available by the image recording unit and to generate control signals for the laser system and the laser scanner. In particular, the recordings of the suprachoroidal space made available by the image recording unit are also evaluated with regard to landmarks in order to use these as reference points for the control signals to be generated.

Furthermore, the control unit is preferably designed to detect at least larger blood vessels in the recordings of the suprachoroidal space and also including the conjunctiva (conjunctiva) and to ensure by generating suitable control signals that these are not damaged during laser processing. Examples are the marginal loop vessels supplying the cornea or the anterior ciliary arteries supplying the ciliary body. The size of vessels can be evaluated via the number of branches to the main vessels, for example the anterior ciliary artery or anterior ciliary vein, or also via an OCT-based determination of vessel diameters.

The present invention is intended to carry out a minimally invasive ablation and/or disruption of the sclera by means of a laser system in order to generate an increased outflow of aqueous humor to lower the intraocular pressure in glaucoma. In principle, however, the device is also suitable for other minimally invasive ablation and/or disruption of the eye, such as replacing the mechanical "needling" in tissue scarring in blebs ("bleb"), which are required for trabeculectomy or tube shunts, among other things. or perforations or cuts in the limbus or cornea. Furthermore, the device can also be used to implement a transscleral SLT (e.g. also with ns lasers) with absorption of laser light in melanin. The risk of injury to blood vessels can be reduced by detecting vessels guided by imaging and leaving them out during laser processing. Since the SLT application goes beyond the sclera and also includes the trabecular meshwork and Schlemm's canal, the imaging area must be increased accordingly. Eye tracking is helpful here in order to safely reach the target structures during laser processing, even in the event of eye movements. In particular, a green wavelength of, for example, a frequency-doubled ultra-short pulse laser is used.

• 1: eine schematische Darstellung der erfindungsgemäßen Vorrichtung,
• 2: die zwei Phasen der Herstellung des Kontaktes des erfindungsgemäßen Kontaktglases mit einem Auge,
• 3: die Lage der Perforationszone am inneren Rand der Sklera,
• 4: eine schematische Darstellung zur Erzeugung einer Perforation im suprachoroidialen Raum,
• 5: eine schematische Darstellung zur Erzeugung einer Aufnahmetasche für den Suprachoroidal-Stent,
• 6: eine schematische Darstellung zur Erzeugung einer Drainagezone am Ende des Stents und
• 7: eine schematische Darstellung zur Erzeugung perforierender Schnitte in Gewebe und ein Stent.

The invention is described in more detail below using exemplary embodiments. to show

• 1 : a schematic representation of the device according to the invention,
• 2 : the two phases of making contact of the contact glass according to the invention with an eye,
• 3 : the location of the perforation zone at the inner edge of the sclera,
• 4 : a schematic representation of the creation of a perforation in the suprachoroidal space,
• 5 : a schematic representation of the creation of a receiving pocket for the suprachoroidal stent,
• 6 : a schematic representation of the creation of a drainage zone at the end of the stent and
• 7 : a schematic representation of the production of perforating cuts in tissue and a stent.

The device for generating an increased outflow of aqueous humor to lower the intraocular pressure in glaucoma consists of a laser system, an image recording unit, a coupling unit with a laser scanner and a control and evaluation unit.

According to the invention, the laser system is designed for minimally invasive ablation and/or disruption of the sclera, and the image acquisition unit is designed to provide images of the anterior eye, in particular its suprachorodial space, and the control and evaluation unit is designed to provide images from the image acquisition unit or other sources to evaluate the recordings made of the suprachoroidal space and to generate control signals for the laser system and the laser scanner. If pre-operatively provided recordings from other sources (e.g. 3-dimensional recordings from an OCT table device or 2-dimensional slit lamp recordings) of the suprachoroidal space are used, these recordings are also used intra-operatively during the evaluation by the control and evaluation unit recorded by the image recording unit available images of the anterior eye based on landmarks (such as the limbus). As a result, control signals for the laser system and the laser scanner can be reliably generated intraoperatively in relation to the respective intraoperative eye position and the preoperatively recorded suprachoroidal space.

This shows the 1 A schematic representation of the device according to the invention consists of a laser system 1, an image recording unit 2, a coupling unit 3 with a laser scanner, a contact glass 4 and a control and evaluation unit 5. Next to the eye 6 there is also a schematic representation of an OCT scan 7, a drainage zone 8 at the end of a drainage implant 9 and the focused laser beam 1' of the laser system 1 is shown.

The device according to the invention can in particular also have a curved (not in 1 shown) Realize drainage zone, the curvature of the dermis (sclera) or the perichoroidal space between the choroid (choroid) and Dermis (sclera) can follow. As a result, a fairly large drainage zone can be realized, which can be extended significantly further in the posterior direction. While a non-curved drainage zone would quickly emerge from the relatively thin dermis (sclera) with a thickness of only 0.5 to 1.5mm, a curved drainage zone can be extended to 5 to 10mm or even 15mm (in long eyes).

The curved drainage zone can be achieved using two variants or combinations of these: On the one hand, the eye can be applanated locally and temporarily through the contact glass, so that an initially non-curved drainage zone is created, which curves after the end of the applanation. On the other hand, the depth of focus or depth of field during tissue processing can be determined by the control unit depending on the location so that the desired curved drainage zone, which can follow the geometry of the dermis, results even with little or no applanation.

The first group of advantageous configurations relates to the laser system used, in particular with regard to its wavelength and pulse duration.

• - Spotdurchmesser: </= 0.7 mm,
• - Ablationstiefe/Puls: 1 bis 10µm,
• - Pulsdauer: 1ns bis 5µs,
• - Schärfentiefe des Fokus: > 1 mm (um Nachfokussierungen zu vermeiden) und
• - Applikation von mehreren Pulsen mit Repetitionsraten von 1 Hz bis 4kHz.

According to a first variant, the laser system for minimally invasive ablation of the sclera is based on a wavelength in the infrared (>1080 nm) and in the ultraviolet spectral range (<400 nm), in particular on a wavelength of <400 nm. The laser system is designed to introduce bores of predetermined depths from the surface of the sclera in order to perforate the sclera. In particular, the following parameters are provided for the laser system:

• - Spot diameter: </= 0.7 mm,
• - Ablation depth/pulse: 1 to 10 µm,
• - Pulse duration: 1ns to 5µs,
• - Depth of focus: > 1mm (to avoid refocusing) and
• - Application of multiple pulses with repetition rates from 1 Hz to 4 kHz.

The lower limit for the spot diameter depends on the laser wavelength and laser beam quality (M number) used, as well as on the correction of imaging errors. Depending on the quality of the laser beam and the amount of correction required, a few tens of micrometers to a few micrometers can be achieved. Focusing optimizations can also be achieved through scattering media using adaptive optical systems [11].

The term depth of field corresponds to the definition commonly used in material processing lasers as twice the Rayleigh length of the laser focus [12].

The term spot diameter should correspond to the beam diameter with "productive intensity". For example, the diameter at which the intensity has dropped to 1/e ² and, in the case of Gaussian laser beams, about 86.5% of the laser intensity is contained [13]. Alternatively, a definition using widths at half maximum (FWHM) is possible.

• - ArF-Excimerlaser mit einer Wellenlänge von 193nm,
• - Stickstofflaser mit einer Wellenlänge von 337nm,
• - Nd:YAG-Laser mit Frequenzverdreifachung und einer Wellenlänge von 355nm oder
• - Nd:YAG-Laser mit Frequenzvervierfachung und einer Wellenlänge von 213nm.

According to the invention, the following laser systems are preferably used for the laser system:

• - ArF excimer laser with a wavelength of 193nm,
• - nitrogen laser with a wavelength of 337nm,
• - Nd:YAG laser with frequency trebling and a wavelength of 355nm or
• - Nd:YAG laser with frequency quadrupling and a wavelength of 213nm.

In this advantageous embodiment, according to the invention, the sclera is perforated with the aid of the laser system mentioned, in that tissue is removed only in the focus point by ablation (essentially athermally) and no thermal damage occurs in the tissue that has not been processed.

The ablation is carried out with high photon energies, with holes being drilled from the surface of the sclera into its volume for its perforation down to predetermined depths, which is predetermined by the high absorption coefficient of the tissue at these wavelengths.

In principle, a laser system (known according to the state of the art) can also be used for this embodiment variant, which is based on a wavelength in the infrared spectral range at which the tissue absorbs strongly. In contrast to ablation using a UV laser system, ablation depths per pulse of 5 to 50 µm can be achieved with an IR laser system with pulse lengths of up to 5 ms, in particular up to 300 µs (Er:YAG laser at 2.94 µm wavelength). Here, too, bores are made from the surface of the sclera into its volume for its perforation down to predetermined depths.

According to a second advantageous embodiment, the laser system for minimally invasive disruption of the sclera is an ultra-short pulse laser system, in particular an fs laser system, with a contact lens also being present has a contact surface and contact optics through which the laser beam of the fs laser system is focused into the tissue.

• - Wellenlänge im VIS (400...790nm) und nahen infraroten Spektralbereich von ca. 790 ...1080nm, insbesondere 1050nm
• - Spotdurchmesser: < 500µm, bevorzugt < 100µm, besonders bevorzugt < 10µm,
• - Spotabstände: bevorzugt einen ½ oder noch bevorzugter 1 bis 2 Spotdurchmesser,
• - Disruptionstiefe: 50µm bis 1 mm,
• - Pulsdauer: 30fs bis 1ps, insbesondere 300 ... 500fs
• - Schärfentiefe des Fokus: zwischen 5µm und 0,5mm, bevorzugt <0,1 mm oder auch >0,5mm, beispielsweise 5mm im Falle der Nutzung von Laserfilamenten und
• - Applikation von mehreren Pulsen mit Repetitionsraten von 1 Hz bis 100MHz bei Pulsenergien im Mikrojoule- bis Millijoule-Bereich (beispielsweise aus einem fs-System mit Nachverstärker) mit Repetitionsraten bis ca. 500kHz oder aber Repetitionsraten im MHz-Bereich und Pulsenergien im Nanojoule-Bereich (beispielsweise aus einem faserbasierten fs-Oszillator).

According to the second variant, the following parameters are provided for an ultrashort pulse, in particular fs laser system:

• - Wavelength in the VIS (400...790nm) and near infrared spectral range of approx. 790...1080nm, especially 1050nm
• - Spot diameter: <500 μm, preferably <100 μm, particularly preferably <10 μm,
• - Spot spacing: preferably ½ or even more preferably 1 to 2 spot diameters,
• - disruption depth: 50 µm to 1 mm,
• - Pulse duration: 30fs to 1ps, especially 300...500fs
• - Depth of focus: between 5µm and 0.5mm, preferably <0.1mm or even >0.5mm, for example 5mm in the case of using laser filaments and
• - Application of several pulses with repetition rates from 1 Hz to 100MHz with pulse energies in the microjoule to millijoule range (e.g. from an fs system with post-amplifier) with repetition rates up to approx. 500kHz or repetition rates in the MHz range and pulse energies in the nanojoule range (e.g. from a fiber-based fs oscillator).

For fs-laser systems with the mentioned parameters according to the invention, for example, at a wavelength of about 1 μm, a depth of field of about 9 μm is quite practicable. For the wavelength range from VIS to NIR, a depth of focus of up to 5 µm is fundamentally achievable.

Alternatively, a picosecond laser (ps laser) with pulse durations of up to 10ps can be used with otherwise similar laser parameters. Below 30 fs, fs lasers down to approx. 3 fs are also possible in principle, but the technical effort increases immensely, mainly due to the large spectral bandwidth required and the strong dispersion effects.

For example, variable dispersion compensators, such as prism or grating compensators, or even in the form of broadband programmable fs laser pulse shapers [7, 8] are required. However, these laser pulse shapers also allow the optimization of laser material processing ( DE10203198B4 ).

In contrast, the use of fs pulses above 300fs is technically more favorable, since, for example, significantly less effort is required for dispersion compensation in order to keep the laser pulses sufficiently short in the focal area, despite varying optical paths in the tissue, in order to achieve the desired photodisruption.

In this advantageous embodiment, the sclera is perforated according to the invention with the aid of the laser system mentioned in such a way that, without piercing the surface, inner channels (pores) are introduced in the volume by disruption. The laser beam has low absorption in the tissue, so that a larger number of micropores can be introduced into the scleral tissue. In this case, it is advantageous if the micropores are first produced in lower-lying tissue layers and only then in higher-lying tissue layers, so that the laser beam is not unnecessarily weakened by scattering at micropores that have already been produced.

However, a mixed form between disruption and ablation can also be realized by using fs lasers in the UV range (395nm to 192nm). In particular, according to [9], such fs laser radiation can be realized by forming the 2nd, 3rd or higher harmonics with frequency multiplication in non-linear optical crystals. It is also possible to use the fundamental wavelength of the fs-laser in the NIR range mainly for photodisruption in the depth of the tissue and at the same time the frequency-multiplied fs-laser radiation for near-surface photoablation.

In addition to the axial scan of the laser focus, a lateral scan can be used to prepare larger pores compared to the focus diameter.

If the gas produced during photodisruption is to be used to support tissue separation (e.g. detachment of the sclera from the choroid), an axial focus scan from depth to the surface is preferably implemented. This can be done within a "laser drilling" or over a large area in a cut deep in the tissue. If, on the other hand, a discharge of the gas is to be realized in order to achieve tissue separation primarily only through the laser cuts, then the opposite is to scan axially from the tissue surface into the depth of the tissue.

• - Wellenlänge: UV oder IR,
• - Spotdurchmesser: < 0,1mm,
• - Spotabstände: > 0,1 mm, insbesondere größer als der doppelte Spotdurchmesser,
• - Disruptionstiefe: < 0,1mm,
• - Pulsdauer: < 10ps,
• - Schärfentiefe des Fokus: bevorzugt >0,5mm, beispielsweise 5mm (zur Ausnutzung der starken linearen Absorption zur oberflächennahen Gewebebearbeitung und keinen oder geringen Anforderungen an die axiale Fokusnachführung auch schon ohne Laserfilamentbildung) und Applikation von mehreren Pulsen mit Repetitionsraten von 1 Hz bis 100MHz.

According to a third variant, the following parameters are provided for an ultrashort pulse, in particular fs laser system:

• - Wavelength: UV or IR,
• - Spot diameter: < 0.1mm,
• - Spot distances: > 0.1 mm, in particular larger than twice the spot diameter,
• - disruption depth: < 0.1mm,
• - Pulse duration: < 10ps,
• - Depth of field of the focus: preferably >0.5mm, for example 5mm (to utilize the strong linear absorption for tissue processing near the surface and no or low demands on the axial focus tracking even without laser filament formation) and application of several pulses with repetition rates from 1 Hz to 100MHz.

When selecting the pulse energies and repetition rates for the ultra-short pulse laser systems, an average power in the range of approx. 1W should be provided. This is an optimum if the treatment is to be carried out quickly and the average heating of the tissue over the course of the treatment is negligible.

With regard to the selection of the depth of field, it is also possible to select it so large or the numerical aperture NA so small that the fs laser radiation self-focusses as a result of non-linear changes in the refractive index, even if a suitably high laser power is provided in the laser focus. This effect is known from fundamental studies on predominantly transparent media, such as air or glass, and is used to stretch the focus in the millimeter to kilometer range [10]. These stretched foci are also referred to as laser filaments.

In the case according to the invention, this self-focusing can also significantly increase the length of the photodisruptive laser focus compared to the classic depth of focus (i.e. that without self-focusing) resulting from the simple diffraction conditions. According to the practical experience of the inventors, tissue incisions over a range from millimeters (with laser pulse energies in the microjoule range) to even several centimeters (with laser pulse energies in the range of up to 1 mJ) are possible without having to track the laser focus on the tissue surface. Depending on the strength of the scattering of the tissue to be processed, the focal length in the tissue can be lengthened at least somewhat. If such a self-focusing of the laser radiation is used, preferably no contact glass is used.

• - Wellenlänge: VIS oder NIR,
• - Spotdurchmesser: < 0,1 mm,
• - Spotabstände: größer als der Spotdurchmesser,
• - Disruptionstiefe: < 0,1mm,
• - Pulsdauer: < 10ps,
• - Schärfentiefe des Fokus: < 0,1 mm und
• - Applikation von mehreren Pulsen mit Repetitionsraten von 1 Hz bis 100MHz.

According to a fourth variant, the following parameters are provided for an fs laser system:

• - Wavelength: VIS or NIR,
• - Spot diameter: < 0.1 mm,
• - Spot distances: larger than the spot diameter,
• - disruption depth: < 0.1mm,
• - Pulse duration: < 10ps,
• - Depth of focus: <0.1mm and
• - Application of multiple pulses with repetition rates from 1 Hz to 100MHz.

In the area of low tissue/water absorption (VIS and NIR), the disruption is intended to be carried out through the scattering tissue of the sclera, for example in or behind the sclera and in front of the choroid. Photo disruption behind transparent stents is also planned.

According to the invention, the laser system, in particular an ultra-short-pulse laser system, is designed to produce both spaced-apart perforations and channel-like structures or cut surfaces in the tissue. For this purpose, the control unit is designed to generate corresponding control signals for the laser scanner in order to realize corresponding spot distances.

Spaced perforations require spot spacing > than spot diameter. However, in order to create channel-like structures or cut surfaces, it is necessary for the tissue sections to be connected. This is realized by using spot distances of less than one spot diameter. In the case of bubble formation, spot distances of up to 5 spot diameters can also be used to create connected structures.

The second group of advantageous configurations relates to the contact glass, which is required for the applications of an fs laser system. The contact surface of the contact glass is arranged in a ring around the contact optics and is designed to suck the cornea and/or conjunctiva.

According to the invention, the contact optics form a plane with the contact surface of the contact glass, but preferably protrudes out of this in the direction of the eye or is designed to be displaceable in order to press on the conjunctiva and/or sclera and achieve an applanating effect.

This applanating effect significantly improves the coupling of the laser beam into the tissue. In particular, the scattering layer thickness of the tissue can be reduced by additional suction of the contact glass to the cornea (cornea) and/or conjunctiva (conjunctiva), in order to be able to be traced with minimal laser pulse energy behind this layer in the tissue to be able to achieve a disruption in the focal point of the laser. In addition, the pressure on the sclera causes it to drain and increase its transparency.

The effects of dewatering, reduced thickness and increased transparency enable a minimally more invasive processing of the inner volume of this zone by fs lasers, since lower pulse energies can be used for optical breakthrough.

This shows the 2 the two phases of making contact of the contact glass according to the invention with an eye.

the 2A shows the first phase in which the contact surface 4 'of the contact glass on the eye 6 placed. According to the invention, the contact surface 4' is designed to suck on the cornea and/or conjunctiva of the eye 6, which is indicated by the two arrows.

At the in 2 B In the second phase shown, the contact optics 4'' of the contact glass are pushed forward until it protrudes from its contact surface 4' and is pressed on the conjunctiva and/or sclera of the eye 6 and an applanating effect is achieved, which is also indicated here by two arrows is.

The thickness of the conjunctiva and/or sclera of the eye 6 can be reduced by sucking on the contact surface 4' and additionally pressing on the contact optics 4", whereby the coupling of the laser beam of the laser system 1 into the tissue 10 is significantly improved.

Alternatively, a contact glass can also be used, which is similar to the one in DE10 2018 215 030 A1 shown, has a fixed connection between the contact surface and contact optics and is pressed in a single suction phase. However, the contact optics must then still allow the laser processing of the scleral area, ie this must be compared to the DE10 2018 215 030 A1 shown variant for corneal treatment must be widened at least to the laser treatment area above the sclera.

It is also possible to press on a contact optic entirely without suction of the patient's eye. However, one loses the advantage of suction in that it causes a certain fixation of the patient's eye, especially in patients who are not fully anesthetized. In general, contact pressure or suction forces must be limited in order to avoid injuries.

According to the third group of advantageous configurations, methods based on optical coherence tomography (OCT) or ultrasound (US) are used as optical imaging methods for the image recording unit. Variants thereof for angiography are particularly preferred, for example by processing signal phase variations as a result of blood flows, such as Doppler signals.

The last group of advantageous configurations relates to the control and evaluation unit, which is designed to evaluate the recordings of the suprachoroidal space made available by the image recording unit and to generate control signals for the laser system and the laser scanner.

In particular, the recordings of the suprachoroidal space made available by the image recording unit are also evaluated with regard to landmarks in order to use these as reference points for the control signals to be generated.

Furthermore, the control and evaluation unit is designed to control and monitor the suction of the contact surface of the contact glass onto the cornea and/or conjunctiva.

In particular, the control and evaluation unit is designed to generate the control signals for the laser system and the laser scanner only when a time for configuration of the tissue of >1 second, preferably >10 seconds and particularly preferably >1 min has elapsed after suction has taken place.

The contact glass can also be designed to be tempered. For example, it can be largely adjusted to the patient's body temperature in order to minimize the feeling of contact. It is also possible to use temperatures well below body temperature to stimulate a temporary vasoconstriction in order to at least temporarily reduce the blood flow during laser processing in and around the target tissue. In this case, the laser processing is preferably to be carried out within 1 min and particularly preferably within 10 s after the onset of the cooling effect, before the blood flow returns to normal.

Furthermore, the control and evaluation unit is designed to detect the images of the suprachoroidal space made available by the image recording unit with regard to landmarks such as an implant, previous laser treatment zones, test shots, vessels, tissue structures or the like, in order to use these as reference points to be used for the control signals to be generated. In particular, the control and evaluation unit is designed to classify the detected vessels with regard to their size in order to avoid cutting vessels >5 μm, preferably >20 μm and particularly preferably >100 μm.

The detection of vessels or blood flow, particularly in the focus area of the laser, can preferably be carried out, e.g. B. done by Doppler-OCT or speckle flowgraphy.

• - kanalartiger Strukturen,
• - durchgängiger Kanäle bis zu einem Ableitungsgebiet,
• - schwammartiger Kanalnetzes,
• - nicht durchgehender Kanalstücke,
• - ringförmiger Kanäle,
• - flächenartiger Schnitte, vorzugsweise für ein Implantat,
• - von Schnitten um oder an einem Implantat,
• - von Schnitten durch Gewebe und Implantat, o. ä..

In a particularly preferred embodiment, the control and evaluation unit is designed to generate control signals for different laser cuts, such as for the production:

• - canal-like structures,
• - continuous channels up to a discharge area,
• - spongy canal network,
• - non-continuous duct sections,
• - annular canals,
• - areal cuts, preferably for an implant,
• - from cuts around or on an implant,
• - from cuts through tissue and implant, or similar.

In order to shorten the treatment time, the use of beam-forming, for example diffractive, elements for generating multiple foci is also advantageous in this context. This makes it possible to make several cuts z. B. for perforations simultaneously.

The location of the preferred perforation zone in the eye is shown in 3 shown. In addition, the figure shows the pupil 6' and the sclera 6'' of the eye 6. The (marked) perforation zone 6''' is produced according to the invention at the anterior boundary of the sclera 6''. However, the perforation zone does not have to enclose 360° (as shown), but can also cover significantly smaller angular ranges (not shown), for example approx. 10°, and can also be enlarged later depending on the pressure reduction requirement.

According to the invention, the laser processing does not take place on the horizontal meridians of the sclera, i.e. not nasally or temporally, but preferably rather inferiorly or superiorly.

According to the invention, the perforations are preferably achieved by an ab-externo laser therapy (from the outside onto the sclera) and are produced in the sclera step by step in the direction from the inside of the eye to the outside of the eye, thereby forming channel-like structures.

This shows the 4 a schematic representation of the creation of a perforation in the suprachorodial space. For the sake of simplicity, the contact glass is not shown, so that only the eye 6 and the laser beam 1′ focused into the tissue 10 are shown. The laser beam 1' perforates the tissue 10 of the suprachorodial space through canal-like but not interconnected structures 11. This allows facilitated fluid transfer through the thinned tissues between the canal-like structures and better fluid distribution without creating a complete connection between the anterior chamber and the perforated tissues through which otherwise undesired particle transmission could occur (tissue particles or germs).

According to the invention, after transparency-increasing suction (thinning through drainage) of the sclera, cuts are made in the eye tissue by means of an fs laser system, which implement drainage into drainable tissue.

Here, particular use is made of the fact that the cuts made using fs lasers scar little or not at all. This was suggested both by H. Lubatschowski et al. in a study on "lentotomy using fs laser pulses" [5] and also by the clinical results with fs lasers in refractive corneal surgery according to [6].

Also, no other undesired side effects have been reported in the immediate vicinity of ocular tissue perforated by fs lasers. Cuts made with fs lasers do not close and the cut is made largely without force, i.e. there is no risk of undesired tearing.

In one embodiment, parts of a cyclodialysis cleft are produced by means of a planar cut, the size of which can be selected and can also be adjusted according to the desired IOP reduction.

The entrance to the laser-cut cyclodialysis gap is preferably kept open by means of a stent, which corresponds to a shortened form of a conventional suprachoroidal stent.

the 5 shows a schematic representation of the production of a receiving pocket for the suprachoroidal stent. Here too, for the sake of simplicity, the contact glass is not shown, so that only the eye 6 and the laser beam 1′ are shown, which penetrate the tissue 10 of the Suprachorodial space creates a receiving pocket 12 for a suprachoroidal stent. Shown here is the variant with ab-interno laser cuts (laser shines through the anterior chamber onto the opposite chamber angle). The use of a corneal contact lens with a goniomirror is beneficial for this. It is also possible to cut a receiving pocket in an ab-externo variant (ie from the outside through the sclera, similar 4 ).

If, after performing the fs laser cut and inserting the stent, it is found later (weeks to months) that the pressure-reducing drainage effect is not sufficient, the cyclodialysis gap can be widened in a further fs laser cut. For this purpose, this is aligned with the older section or continues it using the imaging process.

Ideally, imaging of the stent and the surrounding tissue is used for this purpose, for example by means of OCT imaging.

The laser can also be used to cut a stent-receiving “pocket” with a shape that assists in holding the stent. A drainage zone for draining off the aqueous humor can preferably be implemented at the end of the stent, for example as a flat drainage zone that widens in the posterior direction in the suprachoroidal space in the form of perforations or channels.

This shows the 6 a schematic representation of the generation of a drainage zone at the end of the stent. The illustration shows the laser beam 1' focused in the tissue 10 of the suprachoroidal space and the drainage zone 8 at the end of the drainage implant 9, with the aqueous outflow 13 into the surrounding tissue being indicated by the dashed arrows. The drainage zone 8 can consist of a variety of unconnected perforations or connected channels or combinations of both, which is indicated by the hatching of the drainage zone 8 in FIG 6 is indicated.

If an at least partially transparent stent is used, cuts can also be made through tissue and stent, which are thus perfectly aligned with one another and are therefore connected to channels for draining aqueous humor. It is useful if the position and location of implants can be used to appropriately "connect" the cut by means of imaging (e.g. OCT or UBM). The implants can also contain structures that allow an improved representation during imaging, for example are particularly backscattering for the OCT light ( US8740380B2 ). It is also possible to make clogged stents or stents with a reduced cross section pass through again with the laser cuts. For this it is necessary that the depth of focus or depth of field is selected to be smaller than the thickness of the stent in the direction of radiation.

the 7 shows a schematic representation of the production of perforating cuts in tissue and stent. Here, too, only the eye 6 and the laser beam 1' focused into the tissue 10 are shown. The laser beam 1' perforates both the tissue 10 of the suprachoroidal space and the drainage implant 9 through channel-like structures 11 that are not connected to one another.

In particular, the proposed device for generating an increase in the outflow of aqueous humor to reduce the intraocular pressure in glaucoma is also suitable for expanding the pressure reduction achieved by treatment that has already taken place or for adjusting the pressure-reducing effect by gradually widening the incisions depending on the pressure reduction achieved.

With the solution according to the invention, a device is made available with which an increased outflow of aqueous humor is generated to lower the intraocular pressure in glaucoma. The device is based on a laser system for minimally invasive ablation and/or disruption of the sclera.

In particular, the present invention is suitable for realizing a low-risk, effective, conjunctival-sparing, non- or minimally invasive aqueous humor drainage for reducing the intraocular pressure in glaucoma. In particular, it is possible to subsequently non-invasively adjust an existing aqueous humor drainage with regard to the amount of aqueous humor discharged.

For this purpose, a minimally invasive ablation and/or disruption of the sclera is provided using a laser system in order to generate an increased outflow of aqueous humor to lower the intraocular pressure in glaucoma.

According to the invention, the flow properties of the sclera are improved by a large number of pores as part of a laser perforation.

According to the invention, it is important for the long-term effect that an athermal laser perforation takes place, which leaves no noticeable thermal damage in particular at the edge of the tissue ablation. This can be achieved with repetitive short laser pulses that work in so-called thermal and/or acoustic confinement.

There is no irreversible tissue damage from thermal or mechanical influences outside of the laser focus or laser processing area or tissue removal. Heating with only reversible tissue influence at the edge of the treatment zones can be accepted.

Literature:

• [1] C.I. Perez et al. "Use of Nd:YAG laser to recanalize occluded Cypass Micro-Stent in the early postoperative period", https://doi.org/10.1016/j.ajoc.2018.02.011.
• [2] https://www.ellex.com/products/tango/
• [3] http://ioptima.co.il/technology/the-ioptimate-system-2/
• [4] Baum et al; "Microstructural changes in sclera under thermo-mechanical effect of 1.56 µm laser radiation increasing transscleral humor outflow"; Lasers Surg Med. 2014 Jan; 46(1); 46-53. Abstract: doi:10.1002/lsm.22202. Epub 2013 Nov 21.
• [5] Lubatschowski H, et al. Lentotomy using fs laser pulses: Treatment of presbyopia by creating sliding planes in the lens. Klin monthly ophthalmology 2009; 226: 984 - 990. Abstract: https://www.thieme-connect.de/products/ejournals/abstract/10.1055/s-0028-1109941
• [6] https://www.zeiss.com/content/dam/med/ref_international/products/refractivelasers/femtosecondlasersolution/visumax/pdf/ smile-brochure.pdf
• [7] Stobrawa et al. "A new high-resolution femtosecond pulse shaper," DOI: 10.1007/s003400100576
• [8] Hacker et al. "Micromirror SLM for femtosecond pulse shaping in the ultraviolet", DOI: 10.1007/s00340-003-1180-0
• [9] Hacker et al. "Programmable femtosecond laser pulses in the ultraviolet", DOI: 10.1364/JOSAB.18.000866
• [10] Couairon & Mysyrowicz, "Femtosecond filamentation in transparent media", doi:10.1016/j.physrep.2006.12.005
• [11] Tao et al. "Three-dimensional focusing through scattering media using conjugate adaptive optics with remote focusing (CAORF)", doi.org/10.1364/OE.25.010368
• [12] A. Barz, H. Müller, J. Bliedtner, "Laser Material Processing", Hanser Fachbuchverlag; https://www.hanser-fachbuch.de/buch/Lasermaterialverarbeitung/9783446421684
• [13] B.E.A. Saleh, M.C. Teich, "Fundamentals of Photonics", John Wiley & Sons., Inc. ,
• [14] Dunn, AK, Laser Speckle Contrast Imaging of Cerebral Blood Flow, doi:10.1007/s10439-011-0469-0

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited 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 2020/0078218 A1 [0008]
• US 2020/0016002 A1 [0008]
• DE 102018203356 A1 [0010]
• US5549596A [0016]
• US 8568393 B2 [0017]
• US9480599B2 [0019]
• US8827990B2 [0021]
• US 2016/0113816 A1 [0022]
• EP 2275051 B1 [0024]
• WO 2020/219931 A1
• WO 2013/095695 A1 [0026]
• DE 10203198 B4 [0071]
• DE 102018215030 A1 [0093]
• US 8740380 B2 [0119]

Claims (23)

Device for generating an increase in the outflow of aqueous humor to reduce the intraocular pressure in glaucoma, consisting of a laser system, an image recording unit, a coupling unit with a laser scanner and a control and evaluation unit, characterized in that the laser system for minimally invasive ablation and/or disruption of the sclera, that the image acquisition unit is designed to provide images of the anterior eye, in particular its suprachoroidal space, and that the control and evaluation unit is designed to evaluate the images of the suprachoroidal space provided by the image acquisition unit or other sources and control signals for to generate the laser system and the laser scanner. device after claim 1 , characterized in that the laser system is based on a wavelength in the ultraviolet spectral range, in particular on a wavelength <400 nm. Device according to claims 1 and 2 , characterized in that the laser system is designed to introduce bores of predetermined depths from the surface of the sclera for perforating the sclera. Device according to claims 2 and 3 , characterized in that the following parameters are provided for the laser system: - Spot diameter: </= 0.7 mm in focus, - Pulse duration: 1 to 5 µs, - Depth of field of focus: > 1 mm and - Application of several pulses with repetition rates of 1 Hz up to 4kHz. device after claim 2 , characterized in that the laser system preferably uses the following laser systems: - ArF excimer laser with a wavelength of 193nm, - nitrogen laser with a wavelength of 337nm, - Nd:YAG laser with frequency trebling and a wavelength of 355nm or - Nd:YAG - Laser with frequency quadrupling and a wavelength of 213nm. device after claim 1 , characterized in that the laser system is a ps or fs laser system and that a contact glass is additionally present, which has a contact surface and contact optics, through which the laser beam of the fs laser system is focused into the tissue. Device according to claims 1 and 6 , characterized in that the following parameters are provided for the laser system: - wavelength in the VIS and near infrared spectral range, in particular in the range from 790 to 1080 nm, preferably 1050 nm - spot diameter: 1 - 500 µm, preferably <100 µm in the focus, - pulse duration: 30 fs to 10ps, - depth of focus: 5µm to 5mm and - application of several pulses with repetition rates from 1 Hz to 100MHz. Device according to claims 1 , 3 and 6 , characterized in that the following parameters are provided for the laser system: - Wavelength: UV or IR - Spot diameter: 1 - 0.1mm in focus - Pulse duration: <10ps - Depth of focus: > 0.5mm and - Application of multiple pulses with repetition rates from 1 Hz to 100MHz. Device according to claims 1 and 6 , characterized in that the following parameters are provided for the laser system: - Wavelength: VIS or NIR, - Spot diameter: 1 - 0.1 mm in focus, - Spot distances: greater than the spot diameter, - Pulse duration: <10ps, - Depth of field of focus: 5µm to 5mm and - Application of several pulses with repetition rates from 1 Hz to 100MHz. Device according to claims 7 until 9 , characterized in that the laser system is designed to produce spaced perforations in the tissue and that the control unit is designed to generate control signals for the laser scanner in order to realize spot distances >1 spot diameter. Device according to claims 7 until 9 , characterized in that the laser system is designed to produce channel-like structures or cut surfaces in the tissue and that the control unit is designed to generate control signals for the laser scanner in order to realize spot distances of <5 spot diameters. device after claim 6 , characterized in that the contact surface of the contact glass is formed annularly around the contact optics. Device according to claims 6 and 10 , characterized in that the contact surface of the contact glass is designed to suck on the cornea and/or conjunctiva. Device according to claims 6 and 10 , characterized in that the contact optics forms a plane with the contact surface, but preferably protrudes from this in the direction of the eye or is designed to be displaceable after contact has been made in order to press on the conjunctiva and/or sclera and achieve an applanating effect. device after claim 7 , characterized in that the depth of field of the focus is in the range of 5 µm to 0.5 mm and an axial tracking of the laser focus takes place. device after claim 1 , characterized in that the image recording unit is based on an imaging optical method. Device according to claims 1 and 14 , characterized in that OCT or US-based methods are used as imaging optical methods for the image recording unit. Device according to claims 1 and 6 , characterized in that the control and evaluation unit is designed to control and monitor the suction of the contact surface of the contact glass to the cornea and/or conjunctiva. device after claim 15 , characterized in that the control and evaluation unit is designed to generate the control signals for the laser system and the laser scanner only when a time for configuration of the tissue of> 1 second, preferably> 10 seconds and particularly preferably> 1 min has elapsed after the suction has taken place . device after claim 1 , characterized in that the control and evaluation unit is also designed to detect the images of the suprachoroidal space made available by the image recording unit with regard to landmarks such as an implant, previous laser treatment zones, test shots, vessels, tissue structures or the like in order to to use these as reference points for the control signals to be generated. device after Claim 17 , characterized in that the control and evaluation unit is further designed to classify detected vessels with regard to their size in order to avoid cutting vessels > 5 µm, preferably > 20 µm and particularly preferably > 100 µm. device after claim 1 and 6 , characterized in that the control and evaluation unit is designed to generate control signals for different laser cuts, such as for the production of: - channel-like structures, - continuous channels up to a drainage area, - a spongy channel network, - non-continuous channel sections, - planar cuts, preferably for an implant, - cuts around or on an implant and - cuts through tissue and implant. device after claim 1 , characterized in that the control and evaluation unit is designed to generate control signals for the laser system and the laser scanner in such a way that the minimally invasive ablation and/or disruption of the sclera via arches of more than 2 mm in length that are curved in the non-applanated state of the eye, in particular more than 5mm length in which sclera is passable.

Images