SYSTEMS AND METHODS FOR TREATING GLAUCOMA WITH PHOTODISRUPTIVE LASER PULSES

Abstract

The invention relates to systems and methods for delivering highly focused photodisruptive laser pulses with pulse durations <50 picoseconds into the anterior chamber angle region of an eye, creating channels into various anatomical structures within the anterior angle of the eye and thereby facilitating aqueous outflow for the treatment of Glaucoma. The invention includes novel gonioscopy lens systems, patient interface systems and laser delivery systems to deliver such focused laser beams to the anterior angle area and other areas of the eye.

Claims

1. A system containing a laser source, emitting a photodisruptive pulsed laser beam with a laser pulse duration shorter than 50 picoseconds, said laser beam being propagated through a laser delivery system, as a minimum consisting of a beam scanning and a beam focusing unit and the laser beam further being propagated as a converging laser beam through a patient interface in contact with a human eye and finally delivered as a laser focus into an anterior angle region of said eye and were said patient interface incorporates a gonio lens that is configured to allow propagation of said converging laser beam with a converging angle of at least 20 degrees in a vertical plane that is defined as the plane that creates a cross-section through the entire said eye with the center of a cornea of said eye being within this cross-section.

2. A system of claim 1 where the gonio lens includes a mirror that allows the laser beam entering the patient interface to be parallel to a central optical axis of the eye.

3. A system of claim 1 where the patient interface includes a scleral flange.

4. A system of claim 3 where the scleral flange includes a suction channel inside.

5. A system of claim 2 where the gonio lens includes a lens on the top surface that is offset to the central optical axis of the eye to match a central offset of the laser pulse beam path entering the gonio lens.

6. A system of claim 2 where the mirror has a tilt angle to the horizontal plane as defined as the plane of the limbus of the eye of 63 deg+10 deg.

7. A system of claim 1 where the patient interface includes a docking part on top that mounts to the laser delivery system.

8. A system of claim 7 where the patient interface docking part center line is offset to the central optical axis of the eye.

9. A system of claim 2 where the patient interface is configured to allow multiple use such that the laser beam can access the anterior angle region through its mirror path as well as a direct laser beam access to the cornea, to a capsule or to a lens of the eye when the laser beam is bypassing the mirror through a lateral offset that shifts the laser beam entering the patient interface parallel to the central optical axis of the eye and away from the gonio lens mirror towards the central optical axis of the eye.

10. A system of claim 1 where the patient interface is made to be disposable.

11. A system of claim 1 where a gonio lens material includes a liquid that is filled into the patient interface above the cornea prior to a laser procedure.

12. A system of claim 1 where the patient interface is handheld.

13. A system of claim 1 where the beam focusing unit consists as a minimum of a mirror and a focusing lens arranged such that the laser beam first gets reflected on said mirror and then propagates through the focusing lens prior to entering the patient interface.

14. A system of claim 13 where the focusing lens is a single aspherical lens.

15. A system of claim 13 where the laser is scanned in the two lateral dimensions that are perpendicular to the laser beam propagation axis using a single scanning mirror.

16. A system of claim 1 where the laser delivery system is integrated into a surgical microscope.

17. A system of claim 1 where the laser delivery system is integrated into a slit lamp.

18. A system of claim 1 where the laser delivery system is the laser delivery system of a femto-cataract surgical system.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0064] FIG. 1 illustrates a laser focus with a 3 m diameter and a 20 deg convergence angle

[0065] FIG. 2 illustrates a laser focus with a 3 m diameter and a 40 deg convergence angle

[0066] FIG. 3 illustrates a 20 deg laser focus into the anterior angle region of an eye

[0067] FIG. 4 illustrates a 40 deg laser focus into the anterior angle region of an eye

[0068] FIG. 5 shows the concept of total internal reflection

[0069] FIG. 6 illustrates a laser beam path using a direct gonio lens

[0070] FIG. 7 shows a simulated laser beam with different focusing characteristics in the horizontal and vertical axis

[0071] FIG. 8 illustrates a laser focus being scanned back and forward across a tissue interface

[0072] FIG. 9 shows the anatomical features of the anterior angle of an eye

[0073] FIG. 10 illustrates a large photocoagulation zone due to a defocused laser beam

[0074] FIG. 11 shows a aiming beam and treatment laser beam focusing into the angle

[0075] FIG. 12 illustrates an alignment motion for an aiming laser beam

[0076] FIG. 13 shows a circular laser firing pattern in the anterior angle tissue layers

[0077] FIG. 14 shows a corkscrew laser firing pattern in the anterior angle tissue layers

[0078] FIG. 15 shows a elliptical photocoagulation zone in the angle of an eye

[0079] FIG. 16 shows a detailed delivery system design

[0080] FIG. 17 illustrates a detailed patient interface design

[0081] FIG. 18 shows a detailed laser shaping optical delivery system component design

[0082] FIG. 19 shows a detailed laser shaping optical delivery system component design

[0083] FIG. 20 shows a detailed laser shaping optical delivery system component design

[0084] FIG. 21 shows a detailed laser shaping optical delivery system component design

[0085] FIG. 22 illustrates a full system block diagram

[0086] FIG. 23 illustrates a laser firing pattern

[0087] FIG. 24 illustrates a laser firing pattern

[0088] FIG. 25 illustrates the laser beam path of a specific mirror gonio lens

[0089] FIG. 26 illustrates a detailed patient interface design

[0090] FIG. 27 illustrates a detailed patient interface design

[0091] FIG. 28 illustrates a detailed patient interface design

[0092] FIG. 29 illustrates a detailed patient interface design

[0093] FIG. 30 illustrates a detailed patient interface design

[0094] FIG. 31 illustrates a detailed patient interface design

[0095] FIG. 32 illustrates a detailed patient interface design

[0096] FIG. 33 illustrates a detailed patient interface design

[0097] FIG. 34 illustrates a detailed patient interface design

[0098] FIG. 35 illustrates a detailed patient interface design

[0099] FIG. 36 illustrates a detailed patient interface design

[0100] FIG. 37 illustrates a detailed patient interface design

[0101] FIG. 38 illustrates a detailed patient interface design

[0102] FIG. 39 illustrates a detailed patient interface design

[0103] FIG. 40 illustrates a detailed patient interface design

[0104] FIG. 41 illustrates a detailed patient interface design

[0105] FIG. 42 illustrates a detailed patient interface design

[0106] FIG. 43 illustrates a detailed patient interface design

[0107] FIG. 44 illustrates a detailed patient interface design

[0108] FIG. 45 illustrates a detailed patient interface design

[0109] FIG. 46 illustrates a detailed patient interface design

[0110] FIG. 47 illustrates a detailed patient interface design

DETAILED DESCRIPTION OF THE INVENTION

[0111] The word fs-laser throughout this disclosure stands for femtosecond laser and is meant to cover any laser source, that can provide pulse durations smaller than <50000 femtoseconds (50 pico seconds) with a preferable range of 10 fs to 500 fs. The word femtosecond can also be interchanged with the word photodisruptive throughout the entire disclosure. This ultra-short pulse requirement together with a small spot size area (preferably <20 m for circular focus and preferably <400 m.sup.2 for elliptical focus) allows the use of very small pulse energies in the range of <200 micro Joules (preferable range <50 micro joules) while still achieving a photodisruptive (plasma induced optical breakdown) tissue reaction that allows for the creation of a hole (tunnel) in tissue layers in the anterior angle of the eye (e.g the Trabecular Meshwork). FIG. 9 shows the anatomical features of the anterior angle area of the eye. It is critical to keep the pulse energies small since the undesired side effects such as shockwaves and large cavitation bubbles scale with the pulse energy, reduce precision and cause increasing collateral tissue damage around the desired target zone.

[0112] FIG. 1. The small focus requirement leads to a large focusing beam convergence angle (high numerical aperture NA) in the range of 10-90 degrees. A 3 m spot size diameter of a =1060 nm fs-laser beam with an aberration free beam quality factor of M.sup.2=1 requires about 20 degrees (1/e{circumflex over ()}2) of full convergence (often referred to as beam divergence) angle as can be seen in the simulated coherent laser beam 3003 horizontal and 3006 vertical propagation calculation of FIG. 1.

[0113] Because of significant wave front distortions of the laser beam, as it propagates through various optical and eye anatomical interfaces the coherence quality of the wave front is reduced resulting in a larger spot size. To maintain the same small spot size in the example above the full convergence angle to reach a 3 m spot size diameter goes up to about 36 degrees (for an M{circumflex over ()}2 of 1.8) as shown in the simulation in FIG. 2.

[0114] Furthermore these theoretical values are defined as a 1/e{circumflex over ()}2 beam cut off value. If the beam had only exactly that room to propagate and anything outside this envelope would be cut off, then that would result in a larger focus and lost pulse energy due to clipping.

[0115] To prevent this additional aberration and energy loss it is important to allow another 5-10 degrees of accessible angle to prevent excessive clipping and to allow for some misalignment margin.

[0116] The present inventions provide systems and methods for overcoming the limitations described above. In particular the invention provides the following methods and systems:

[0117] A first method to optimize the fs-laser beam parameters to reach, target and create holes into the tissue layers of the anterior angle of the eye: This will address the highly variable (eye to eye and setup to setup related) beam aberration variations and geometrical angle size variations of the anterior angle from eye to eye. This method is described in the following steps from a. to f. [0118] a. (Optional) When a laser delivery system with an adjustable beam convergency angle is used, pre-measured patient data of the anterior angle access angle e.g. through OCT (optical coherence tomography) before treatment is used to course adjust the vertical beam axis convergence angle (and horizontal axis in same way for circular focus version) to roughly match the accessible angle. [0119] b. Use a delivery system with a fixed beam full convergence angle of 30 to 60 deg if circular or 30-60 deg in the vertical axis and 40-90 degrees in the horizontal axis if elliptical. The preferred full convergence angles are 40 deg (+/5 deg) in both axis if a circular beam is delivered and 40 deg (+/5 deg) in the vertical axis and 70 deg (+/10 deg) in the horizontal axis if a delivery system is used that allows elliptical focusing. For most eyes with open angles these preferred settings will achieve a spot size at the anterior angle tissue layers that is close to a practical minimum. For eyes with partially closed angles <45 deg in the vertical access angle, the preferred settings will overfill the accessibility angle and this will result in some partial laser beam clipping in the vertical axis. The laser focus is then targeted into the desired tissue layer surface in the anterior angle of the eye and once the laser focus targeting has been completed the laser starts firing at a low pulse energy preferably <10J. These probing laser pulses below the plasma breakdown threshold are then successively increased in pulse energy until first optical breakdown cavitation bubbles are detected (preferably by a vision system). [0120] c. (optional) see FIG. 8. The focusing lens and therefore the laser focus is scanned back 3031 and forward 3030 (preferably +/<750 m in z-axis 3029 while pulse energy is being increased in the sequence under b. to: assure the detected threshold happened on the surface of the targeted anterior angle tissue (e.g. Trabecular Meshwork) or closely below and not in the aqueous humor and to: calibrate the actual z-distance of a laser delivery system reference point (e.g. upper patient interface plane) to the surface of the targeted tissue layer in the anterior angle (e.g. trabecular meshwork surface). [0121] d. (optional) Once the threshold has been determined as described in step b. (and optional the z-calibration in step c.) the same laser beam is preferably automatically defocused by a predetermined amount using a z-scan of the focusing lens or other lens in the delivery system. The preferred defocusing adjustment moves the laser focus 0.7 mm (+0.5 mm) deeper into the target tissue (towards or into the sclera). This results in an enlargement of the laser beam diameter on the target tissue (surface of the anterior angle tissue layer) to about 500 m FIG. 10, 3201 for a laser beam with a circular convergence angle of 40 deg 3203. After this defocusing adjustment 3202, resulting in a focus position in 3200, the pulse energy is automatically adjusted higher. This pulse energy is adjusted to a level such that the resulting average laser power P.sub.average power=E.sub.laser pulse energy R.sub.laser repetition rate times the applied laser on duration time during this defocused sequence provides an amount of total energy E.sub.total=P.sub.average power t.sub.laser on duration that photo coagulates the tissue area within the defocused diameter. For a preferred laser repetition rate >100 kHz and a preferred circular area of a 500 m diameter beam and a preferred laser on duration of <1 s the preferred laser pulse energy is >10J. Lower available pulse energy can be compensated by increasing the laser on duration to achieve the desired amount of photocoagulation. The laser beam area for this defocused large beam (e.g. 500 m circular diameter) is typically >1000 times larger than typical achieved laser focus on the same surface without defocusing (e.g. 10 m circular diameter). Therefore any conceivable rise in pulse energy (even to e.g. as high as >500J) would still be far below the plasma threshold energy on this large area. Furthermore the new laser focus 0.7 mm below the anterior angle tissue layer surface is, because of significant photon scattering and absorption of the tissue layers between the surface layer and the 0.7 mm deep layer no longer reaching the fluency level required to exceed the plasma breakdown threshold. All laser power is therefore now absorbed and scattered creating a thermal effect in and around the defocused beam zone leading to photocoagulation versus a photodisruptive cutting effect. The penetration depth of the coagulated tissue volume depends beside the total delivered laser energy also on the laser wavelength. The achieved coagulation zone (volume) reduces or prevents any bleeding from the high fluency (above threshold) laser pulses that follow this step (see step e.) and create a hole or channel into the tissue layers. For a typical photodisruptive (ultra short pulsed) laser wavelength around 1050 nm (+50 nm) the absorption length is longer than for shorter wavelengths such as used for example in a 532 nm coagulation laser (similar to SLT and ALT). Such a shorter wavelength, quasi cw (continuous wave) laser with a preferred wavelength of 532 nm or 577 nm or 810 nm can be used as a second laser source instead of the defocused photodisruptive main laser. In that configuration the second source shorter wavelength laser does not need to be focused in a highly converging beam since it only needs to reach a preferred spot size diameter of 500 m (+300 m). Furthermore, if another laser is used for the photocoagulation part, than that part of the procedure can be performed before the non-invasive photodisruptive laser procedure. For example the coagulation of one or multiple treatment zones can be performed minutes or days before the channel creating procedure on a laser slit lamp setup. All the above parameter considerations for a preferred circular laser beam are also applicable to a preferred elliptical laser beam. [0122] e. Once the threshold pulse energy is known from step b. and optional z-calibration from step c. and the optional photocoagulation (step d.) is completed, the laser will preferably automatically adjust the treatment pulse energy in a preset way relative to the threshold energy (preferably 3 to 10 the threshold energy) and preferably automatically fire a preset scanning pattern to create one or multiple holes into the desired target zone layers (e.g. through the Trabecular Meshwork or into the suprachoroidal space) within the coagulated zone, if created. [0123] f. (optional) All steps b. to e. are preferably done in a fully automated sequence immediately following each other and parameters are optimized such that the entire laser procedure time is preferably less than 10 s.

[0124] A second method to measure and maximize the vertical angular laser beam access and therefore achieving minimal spot size at the anterior angle tissue layers of an eye. The horizontal convergence angle of the treatment laser beam is fixed to preferably 60 deg (+/20 deg) to create a small spot size in the horizontal axis in the range of <10 m diameter depending on the overall aberrations.

[0125] Step a. The angular opening in the vertical axis is determined with the same femtosecond laser delivery system just prior to firing the photodisruptive femtosecond laser pulses by using a shape adjustable visible aiming laser beam under live observation. FIG. 11 shows an aiming laser beam 3204 being focused collinear to the planned photodisruptive treatment beam 3206 into the target tissue layer of the anterior angle of the eye. In one embodiment, this is done by changing the vertical aiming beam divergence from big to small until no light is clipping on the iris and cornea (both sides of the angle) or doing it reverse (small to big) until light starts to scatter on the outside surfaces of the angle. FIG. 11 shows the lower aiming beam envelope clipping on the iris 3205. This scattered light feedback can be observed live by the surgeon/operator or by an automated video/sensor analysis system. While the beam cone is maximized, in the same time the delivery system is preferably constantly adjusted for centration in the angle of the eye to center the focusing beam cone in the angle to achieve the setting of a maximum allowable vertical angle. This adjustment is illustrated in FIG. 12 The beam 3210 is moved in the directions 3211.

[0126] Step b. Once the maximum vertical accessibility angle to the target region has been determined the aiming beam is scanned back and forward in the z-axis (above and below the target tissue plane) using a delivery system moving lens (e.g. the main focusing lens) until the visible beam diameter on the target tissue layer is minimized. This minimum spot visualization can be performed live by observation of the surgeon through a microscope or preferably by an automated vision system. The now known z-position of the delivery system optics is now used to calibrate the z-distance of a delivery system reference point to the aiming beam focus position on the surface of the target tissue layer.

[0127] Step c. (optional) If the delivery system allows the adjustment of the vertical beam convergence angle for the photodisruptive treatment beam, then the vertical angle is now adjusted to match the maximum determined aiming beam angle from step a. This sets the treatment beam up to achieve a minimum possible vertical spot size on the target tissue layer.

[0128] Step d. (optional) Perform a coagulation step identical to the first method step d.

[0129] Step e. The control system of the laser system now calculates and then sets the optimal photodisruptive laser pulse energy based on the input from step a., b. and c. before the treatment laser is fired. The factors for this calculation are as follows: If the vertical treatment beam angle is adjustable then it has been set to the maximum vertical angle in step a. Since the horizontal focusing angle is fixed, the horizontal spot size axis is fixed as well .sub.0 horizontal fixed. The vertical spot size .sub.0 vertical and therefore the spot size area A is according to formula 1 inverse proportional to the maximum vertical angle .

[00002]$A_{\mathrm{spot}.Math..Math.\mathrm{size}.Math..Math.\mathrm{area}}{}_{0.Math..Math.\mathrm{horizontal}.Math..Math.\mathrm{fixed}}.Math.{}_{0.Math..Math.\mathrm{vertical}}={}_{0.Math..Math.\mathrm{horizontal}.Math..Math.\mathrm{fixed}}.Math.M_{\mathrm{vertical}}^2.Math.\frac{360.Math..Math.}{{}^2.Math..Math.{}_{\mathrm{vertical}}}$

with

[00003]${}_{0.Math..Math.\mathrm{horizontal}.Math..Math.\mathrm{fixed}}=M_{\mathrm{horizontal}}^2.Math.\frac{360.Math..Math.}{{}^2.Math..Math.{}_{\mathrm{horizontal}}}$

the spot size area A becomes:

[00004]$\begin{array}{cc}{A}_{\mathrm{spot}.Math..Math.\mathrm{size}.Math..Math.\mathrm{area}}{M}_{\mathrm{horizontal}}^2.Math.\frac{360.Math..Math.}{{}^2.Math..Math.{}_{\mathrm{horizontal}}}.Math.M_{\mathrm{vertical}}^2.Math.\frac{360.Math..Math.}{{}^2.Math..Math.{}_{\mathrm{vertical}}}& \mathrm{Formula}.Math..Math.2\end{array}$

[0130] The required treatment pulse energy is: Formula 3

E.sub.pulse energy setting=c E.sub.threshold pulse energy

with E.sub.threshold pulse energy being the minimum pulse energy required to achieve a photodisruptive optical breakdown on the desired tissue layer and c being a factor by which the set pulse energy needs to exceed the threshold pulse energy to achieve an efficient photodisruptive tissue effect for cutting and drilling a hole into the tissue layers. The preferred setting for c is 3 to 10. The threshold for the photodisruptive optical breakdown depends on the laser fluency F, being:

[00005]$\begin{array}{cc}{F}_{\mathrm{threshold}}=\frac{E_{\mathrm{threshold}.Math..Math.\mathrm{pulse}.Math..Math.\mathrm{energy}}}{t_{\mathrm{pulse}.Math..Math.\mathrm{duration}}.Math.A_{\mathrm{spot}.Math..Math.\mathrm{size}.Math..Math.\mathrm{area}}}& \mathrm{Formula}.Math..Math.4\end{array}$

Therefore: E.sub.threshold pulse energy=F.sub.thresholdt.sub.pulse durationA.sub.spot size area or: Formula 5

E.sub.threshold pulse energyA.sub.spot size area

Combining formula 2, 3 and 5 leads to:

[00006]$\begin{array}{cc}{E}_{\mathrm{pulse}.Math..Math.\mathrm{energy}.Math..Math.\mathrm{setting}}c.Math..Math.M_{\mathrm{horizontal}}^2.Math.\frac{360.Math..Math.}{{}^2.Math..Math.{}_{\mathrm{horizontal}}}.Math.M_{\mathrm{vertical}}^2.Math.\frac{360.Math..Math.}{{}^2.Math..Math.{}_{\mathrm{vertical}}}& \mathrm{Formula}.Math..Math.6\end{array}$

If the vertical angle is not adjustable, then it has been set to a fixed preferred angle of .sub.vertical=40 deg (+/15 deg). Depending on the measured maximum vertical accessibility angle in step a. this fixed vertical angle .sub.vertical is either smaller or larger than the maximum accessible angle. If it is larger than the maximum accessible angle then a clipping factor f.sub.clip needs to be considered that reduces the laser power on target an enlarges the spot size in the vertical axis. Including this clipping factor the laser control system calculates the required pulse energy setting for the following laser treatment according to Formula 7:

[00007]$E_{\mathrm{pulse}.Math..Math.\mathrm{energy}.Math..Math.\mathrm{setting}}{f}_{\mathrm{clip}}.Math.c.Math..Math.M_{\mathrm{horizontal}}^2.Math.\frac{360.Math..Math.}{{}^2.Math..Math.{}_{\mathrm{horizontal}}}.Math.M_{\mathrm{vertical}}^2.Math.\frac{360.Math..Math.}{{}^2.Math..Math.{}_{\mathrm{vertical}}}$

The beam quality factors M.sub.horizontal.sup.2 and M.sub.vertical.sup.2 depend on the sum of all aberrations of the laser system including the delivery system optics, patient interface, patient contact lens (goniolens) the interface to the eye and to some extend the condition of the cornea and anterior chamber of the eye. Most of these beam quality factors are system specific and are preferably calculated and measured. A high level of accuracy in determining those quality factors is achieved by performing photodisruptive laser threshold measurements using model and cadaver eyes on the final laser system setup. The f.sub.clip loss factor is also determined by performing photodisruptive laser threshold measurements using model and cadaver eyes on the final laser system setup. They are performed for a range (15 deg to 50 deg) of accessibility angles (step a.) and saved as a table within the laser control system. Once the laser procedure has started and the actual vertical accessibility angle has been determined in step a, the control system looks up the corresponding f.sub.clip loss factor and calculates the final laser pulse energy setting E.sub.pulse energy setting according to formula 7.

[0131] Step f. After the control system sets the treatment laser pulse energy, the laser will preferably automatically fire a preset scanning pattern with reference to the laser beam alignment in step a. and the z-calibration in step b. to create one or multiple holes into the desired target zone layers (e.g. through the Trabecular Meshwork or into the suprachoroidal space) within the coagulated zone, if created.

[0132] Step g. (optional) All steps a. to f. are preferably done in a fully automated sequence immediately following each other and parameters are optimized that the entire laser procedure time is preferably less than 10 s.

[0133] A third method for delivering a particular pulse sequence of circular or elliptical spot size femtosecond laser pulses to create a hole(s) or channel(s) into the tissue layers of the anterior angle of an eye. The method describes a scanning pattern that can for example be applied during the laser firing in the first method step e. or the second method step f. to create the hole and channel into the desired target tissue layers. The method is as follows:

[0134] Step a. The beam (round or elliptical focus) will be scanned in a circular pattern to create the hole and channel into the desire target tissue layers. The preferred starting cutting circle diameter is 250 m+/100 m. The preferred spot separation is 10 m+/7 m. The first circle is cut at a z-alignment that brings the focus plane of the treatment laser beam within +/10 m of the surface plane of the target tissue layer.

[0135] Step b. Several additional circles (preferably 10+/7 more) are being cut successively moving deeper into the tissue layers. Each new circle is preferably focused 7 m+/5 m deeper than the last see FIG. 13 or the circles are continuously going deeper into the tissue in a corkscrew type of scanning pattern, see FIG. 14 with the same slope (7 m deeper per revolution).

[0136] Step c. (optional) The laser focus plane is moved back up to the original surface of the top tissue layer and the laser is now scanned over the entire circle area in a raster or spiral pattern with a preferred spot separation of 5 m+/3 m. Similar to step b the focus plane is then lowered by 7 m+/5 m and the same areal cutting is repeated. This is also repeated preferably 10 times.

[0137] Step d. The focus plane is moved back up to the original surface plane of the top tissue layer and the laser is now repeats the scan pattern from step but with a preferably 30 m+/20 m reduced diameter. This means for the preferred case a new concentric circle diameter of 220 m. Furthermore the amount of cutting circles or corkscrew rotations is now increased by preferably another 10 to a total of 20 circles. This results in a preferred cutting cylinder depth of 207 m=140 m.

[0138] Step e. (optional) repeat step c. with a reduced diameter and extended depth according to step d.

[0139] Step f. Repeat step d. and step c. while further reducing the diameter and extending the cutting depth until the desired hole or channel depth has been achieved. FIG. 24 shows an example of the total scanning pattern after 3 cycles with different diameters 3709, 3708, 3707 and depths have been completed. The preferred cutting channel depth for the Trabecular Meshwork are in the range of 100 m to 300 m while the preferred channel length for an access channel into the suprachoroidal space is between 400 m and 3 mm. Other desired target areas will have other preferred channel lengths.

[0140] Step g. (optional) The laser pulse energy is increased (preferably by a factor of 2+/0.8) and the laser is fired preferably 10 times back and forward along the central z-axis of the holes/channel with a scanning depth amount that is equal to the hole/channel length. FIG. 23 shows the overlapping linear micro destruction zones 3700 to 3706 of the individual laser pulses after the first z-scan. 3300 represents the top tissue layer in the anterior chamber angle region. This step clears any remaining tissue debris out of the channel. This step can be repeated a few times with a few seconds of pause in between to allow the cavitation bubbles to disappear.

[0141] Step h. (optional) The cutting sequence described in step a to step g creates a slight cone shaped channel getting smaller diameter as the channel progresses deeper into the tissue layers. This scanning sequence and cone angle can be reversed by starting with the smallest circle diameter and going outwards while going deeper.

[0142] Step i. (optional) The channel can also be cut with a cross sectional shape of an ellipse. Instead of circles the laser is scanned in elliptical shapes. For example an ellipse with the long axis being vertical has the advantage of easier assuring a channel connection to Schlemm's canal since it runs somewhere behind the Trabecular Meshwork along the horizontal plane see FIG. 15.

[0143] Step j (optional) In step a. instead of placing the first circle z-depth at +/10 m within the top surface layer of the tissue, the first cutting plane is adjusted 20 m below the tissue surface. This thin tissue layer can still be sufficiently penetrated by the laser energy and the resulting cavitation bubble below the surface explodes the above tissue layers away more effectively. This method variation requires a preferably 2 times larger laser pulse energy setting and is therefore not available for certain low cost, low power laser systems.

[0144] Step j. To create multiple holes and channels step a. to step i. are repeated at a different locations.

[0145] A forth method describing a laser scanning pattern to create a channel into the desired tissue layers of the anterior angle of the eye using a low cost minimal complexity laser delivery system.

[0146] Step a. For a low cost laser delivery system that only contains a z-axis scan ability, the channel can be cut by only performing step g. from the third method described above see FIG. 23. The amount of back and forward scanning cycles is now increased to preferably 50 times+/30 times.

[0147] A fifth method to automatically select and target multiple treatment zone(s).

[0148] Step a. Use a vision system to visualize certain landmarks in the tissue layers of the anterior angle of the eye, such as for example the iris root, Schwabe's line or scleral spur.

[0149] Step b. (optional) let the surgeon select the desired target areas and channel size parameters in reference to the visualized landmarks.

[0150] Step c. (optional) the control system selects one or multiple target areas automatically based on the predetermined user preference settings.

[0151] Step d. the surgeon activates the automatically guided laser alignment and treatment sequence to create one or multiple channels.

[0152] Step e. (optional) The control system includes a tracking system that continuously verifies the position of the reference landmarks and adjusts the laser beam position as necessary to compensate for any patient/eye movements.

[0153] Step f. The laser firing sequence follows the principles of the first to the third methods described above.

[0154] A sixth method using a gonio lens or patient interface to increase the vertical anterior angle accessibility angle by applying a controlled and directional amount of pressure in combination with the photodiruptive laser procedure. [0155] Furthermore particularly in the second method, the gonio lens (custom patient interface) can be temporarily pressured against the cornea (similar to dynamic gonioscopy) in a way that opens the angular access significantly in the target zone and therefore allowing greater access. This step would be done just seconds prior to or during the second version method (above) but is also possible prior to the first version. If used with the first version (pre measurement of angle anatomy with other device before laser treatmentminutes to days before-) than the opening effect of a specifically controlled pressuring procedure is measured. With this information the gonio/patient interface pressure procedure can be repeated during the laser treatment and the effect is now known and therefore can be considered in the setting of the femtosecond laser and delivery system tuning for that patient.

[0156] A first system being a specific contact interface designs that includes gonio lens functionality, creates high angular access to the anterior chamber angle and minimizes beam aberrations to effectively deliver the highly converging laser beam into the anterior angle of the eye.

[0157] A direct view gonio lens that covers the entire cornea and in one implementation also includes a flange see FIG. 6 and in another implementation has a suction ring that covers the limbus and part of the sclera to produce better eye stability. This direct lens will allow maximum angular access to the eye (anterior angle), which will enable a small spot size for the fs-laser as is desired to achieve optical breakdown in the tissue (Trabecular Meshwork). However it will require a significant targeting angle between the laser beams approaching the eye and the normal axis (axis of eye view direction) of the eye. This angle will be in the order of 45 degrees as illustrated in FIG. 6. This allows easy access to the nasal and the temporal part of the anterior angle segments. The superior and inferior parts are more challenging with this gonio lens in both a slit lamp and operation room delivery system version.

[0158] Another preferred implementation to access the entire anterior angle rim is using a mirrored gonio lens that allows the visualization and laser beam to come vertically, parallel to the main optical axis of the eye. See FIG. 27. This diagram shows a handheld custom one mirrored lens similar to a SLT Latina lens, but optimized for maximum angular access of the laser beam. In this lens the beam path opening (convergence angle) can reach 30 deg as illustrated in the beam only view in FIG. 25. 3081 represents the mirror, 3800 the 30 deg converging laser beam. FIG. 27 shows that this lens includes a scleral flange 3813 that increases stability and eye fixation. A suction chanel inside the flange 3814 further increases eye stability. The lens is placed on the cornea using a liquid gel as an interface between the lens and the cornea to avoid any air gaps or bubbles. This lens also includes a lens on the top surface 3811 that is offset to match the laser beam path centrally. Other views of the same design are found in FIGS. 37, 39, 41, 42 45, and 46. This lens further increases the focusing convergence and allows the laser delivery system to propagate a less converging laser beam. This feature reduces the delivery system complexity. Furthermore this top lens allows a normal (vertical) laser beam approach towards the eye and is therefore easier implemented in all three configurations (slit lamp, operating microscope and modified femtosecond cataract workstation delivery system configuration). This gonio lens allows simple access to the entire 360 degree circle of the anterior angle simply by rotating the lens. Therefore multiple holes in the Trabecular Meshwork or other desired targeting zones around the angle of the anterior chamber can be easy created with minimal scanning abilities of the femtosecond delivery system.

[0159] A second system being a specific contact interface designs that includes gonio lens functionality, creates high angular access to the anterior chamber angle and minimizes beam aberrations to effectively deliver the highly converging laser beam into the anterior angle of the eye.

[0160] FIG. 17 shows a mirror gonio lens design with novel features to allow laser beam access to the anterior angle at high degrees of convergence. These features include a scleral flange . . . and a suction ring for increased fixation, a single mirror tilt angle to horizontal of 63 deg+/5 deg for an outer housing that can interface to a delivery system in an offset way and that can be made disposable or handheld. The inner lens material can end in a plane horizontal surface or can end in a curved convex lens shape, adding magnification to the gonio lens design. This lens further increases the focusing convergence and allows the laser delivery system to propagate a less converging laser beam. This feature reduces the delivery system complexity.

[0161] A third system being a specific patient interface designs that connect the laser delivery system to the eye and incorporates a specific gonio lens design that allows photodisruptive laser access to the anterior angle of the eye.

[0162] FIG. 16 also shows the design of a custom direct view gonio lens/patient interface that can be mounted to the final optics block or can be handheld in a simpler manual version.

[0163] A fourth system being a specific patient interface designs that connect the laser delivery system to the eye and incorporates a specific gonio lens design that allows photodisruptive laser access to the anterior angle of the eye.

[0164] FIG. 33 shows a cross-section of a specific interface that incorporates single large mirror, a scleral flange and optional suction channel. It allows a laser convergence access angle of 30 deg. The laser beam in its most centered focusing position relative to the anterior angle enters the patient interface vertical with an offset to the central line of the eye. This design includes a mounting ring on top see FIG. 35 that incorporates indexing, reference and locking features 3805 to be connected to a delivery system. This patient interface is used to connect to a surgical delivery system of a photodisruptive laser system. It can also be adapted to an existing medical laser system such as used for femtosecond LASIK or femtosecond laser assisted cataract surgery. FIGS. 26,28,29,30,31,32,34 and 40 show different cross-sections and views of the same patent interface design. This patient interface is preferably made disposable. Furthermore since this patient interface allows besides the mirror 3834 direct access to the entire cornea from straight above without going through the mirror, see FIG. 35, this design allows multiple use such as a combined femtosecond cataract procedure (cutting a capsulotomy, cornea incisions and lens fragmentation) with a femtosecond glaucoma procedure (cutting one or multiple channels into a target region in the anterior angle of the eye) or a femtosecond LASIK combined with a femtosecond glaucoma (cutting one or multiple channels into a target region in the anterior angle of the eye). The preferred method to use this design in a multiple use surgery is by incorporating a lateral offset shift mechanism into the delivery system docking part. This offset shift mechanism allows the delivery system docking feature FIG. 35, 3805 to be mounted to the patient interface in 2 positions with an offset of FIG. 35, 3832 For the glaucoma procedure part the mirror is centered relative to the delivery system 3831. For the other surgery part the cornea is centered to the delivery system 3833. The combination procedure can be performed in any desired order. This offset shift mechanism is preferably activated by a motor, solenoid or spring force energy.

[0165] A fifth system being a specific patient interface designs that connect the laser delivery system to the eye and incorporates a specific gonio lens design that allows photodisruptive laser access to the anterior angle of the eye.

[0166] FIG. 38 shows a cross-section of a specific interface that incorporates single large mirror 3950, a scleral flange 3843 and optional suction channel 3814. It allows a laser convergence access angle of 30 deg 3852. The laser beam in its most centered focusing position relative to the anterior angle enters the lower half of the patient interface vertical with an offset to the central line of the eye just like the patient interface in the fourth system above. However this design incorporates a secondary mounting feature on the upper half that is offset such that the laser beam now enters the top of the patient interface centrally. This makes the integration and adaptation to a delivery system above easier since most delivery systems have a preferred central axis laser beam exit. This design includes a mounting ring on top see FIG. 36 that incorporates indexing, reference and locking features 3841 to be connected to a delivery system. This patient interface is used to connect to a surgical delivery system of a photodisruptive laser system. It can also be adapted to an existing medical laser system such as used for femtosecond LASIK or femtosecond laser assisted cataract surgery. FIGS. 36 and 44 show different cross-sections and views of the same patent interface design.

[0167] Additional features that apply to some or all of the systems above (first to fifth).

[0168] In another implementation see e.g. FIG. 31 all above custom gonio lens and patient interface designs have an upwards extended scleral flange ring 3820 so that its upper rim is at least 1 mm above the highest (central) cornea point. Prior to the procedure a liquid 3821 such as saline or water is filled into the watertight flange volume and therefore the liquid will replace the gonio lens material. The patient is in this version laying on its back, so that gravity keeps the liquid in place. To stabilize any liquid waves a top flat glass piece 3819 is in another implementation placed on the top in contact with the water. This implementation allows more patient comfort and less pressure rise (IOP) during the procedure. FIG. 31 shows this implementation on the patient interface of the forth system above but it is also considered implemented on the design of the first, second, third and fifth system.

[0169] In another implementation the first, second, third, fourth and fifth system all are made for handheld operation to be used manually at the slit lamp or under the OR microscope as well.

[0170] In another implementation the first, second, third, fourth and fifth system are all made disposable.

[0171] A sixth system being a specific low complexity delivery system that allows delivery of photodisruptive laser pulses into the angle region of the anterior chamber of an eye.

[0172] The delivery system pieces closest to the eye are mounted in a configuration as shown in FIG. 16. The laser scanning pattern described in the third method above require only small scanning angles of the laser beam originating from a final focusing lens (e.g. FIG. 16). The focusing lens will be >2 cm away from the focus point of the laser. Therefore the delivery system scanning angles through the final focusing lens are limited <5 deg from the main optical axis. This feature allows the use of a simple low complexity focusing lens assembly (e.g. a single aspherical lens). Furthermore a single preferably gimbal mounted scanning mirror above the mirror 3399 in FIG. 16 in combination with a z-scannable lens along the laser beam (e.g. the focusing lens 3402 FIG. 16) is used to perform all scanning patterns as described in the third method.

[0173] The preffered beam shaping of the described delivery system along the optical beam path is shown in FIGS. 18, 19, 20 and 21. In FIG. 18, 3001 is the y-axis of the graph representing the beam radius in micro meters. 3002 is the x-axis along the beam propagation in mm. 3502 and 3505 show the focus beam radius in the horizontal and respectively vertical axis as well as the focus position in the x-axis. This calculated laser beam propagation graphs show a detailed lens design to achieve laser beam shaping for an elliptical fs-laser spot size onto the Trabecular Meshwork with approximately 3 m spot size in the horizontal plane and approximately 7 m spot size in the vertical plane.

[0174] FIG. 22. Shows a basic system block diagram, of the entire system including the various laser engines 3608, the delivery system (made out of several units) the control unit 3600 the diagnostic and tracking unit 3601, the beam shaping and scanning unit 3602, the final optics block unit 3604 and the patient interface unit 3606. This system applies to several configurations and shows the components and elements of the herein described femtosecond-laser, delivery system and patient interfaces.

[0175] In another implementation this delivery system is integrated into a standard surgical microscope.

[0176] In another implementation, this delivery system is integrated into a standard slit lamp.

[0177] It should be appreciated that although several different embodiments are shown, any of the features of one embodiment may be used on any of the other embodiments described.

[0178] Although the present invention has been described in considerable detail with reference to the preferred versions thereof, other versions are possible.

[0179] The scope of the appended claims is limited to only some of the invented details here and is therefore not to be considered complete.