Method for minimally invasive, cell-selective laser therapy on the eye

Patent metadata

Field	Value
Publication number	US-11660231-B2
Application number	US-202117202530-A
Country	US
Kind code	B2
Filing date	Mar 16, 2021
Priority date	Apr 8, 2016
Publication date	May 30, 2023
Grant date	May 30, 2023

Abstract

A method for a minimally invasive, cell-selective laser therapy on the eye. The method, based on a short-pulse laser system, allows for different selective types of therapy on the eye. The method is based on a frequency-doubled, continuously working solid-state laser including a pump source and a control unit. The control unit regulates the pump source such that the solid-state laser emits individual pulses with pulse lengths ranging from 50 ns to continuous, wherein pulse lengths ranging from 50 ns to 50 μs are provided for selective therapies and pulse lengths ranging from 50 μs to continuous are provided for coagulative or stimulating therapies, in particular in the range from 1 ms to 500 ms. The proposed method enables a selective treatment of melanin-containing cells in the different areas of the eye via the targeted control of the pump source.

First claim

The invention claimed is:

1. A laser system for a minimally invasive, cell-selective laser therapy at an eye, comprising:
a frequency-doubled, continuously operating solid-state laser with a pumping source and a control unit;
wherein the control unit is configured to regulate the pump source such that the solid-state laser selectively emits individual pulses with pulse lengths between 50 ns and continuous,
wherein the control unit is further configured to allow a user to select the pulse lengths in a first range from 50 ns to 50 μs for selective therapies and in a second range from 50 s to continuously for coagulative or stimulating therapies, and wherein an energy density of the pulses emitted by the laser varies in dependence of the pulse length; and
the laser system further comprising a square optical fiber.

2. The laser system according to claim 1 , wherein the solid-state laser emits individual pulses with pulse length in the first range of 50 ns-500 ns, and in the second range of 1 μs-50 μs, wherein the control unit is further configured to allow the user to select application of a single pulse or up to 30 pulses with a pulse repetition rate of 1 Hz up to 10 kHz to be applied per spot on a retina, with spot sizes ranging between 50 μm and 100 μm, wherein single spots are applied or wherein multiple spots are applied which are bundled in the form of pattern whose shape and spot distance are adjustable.

3. The laser system according to claim 2 , wherein the solid-state laser emits individual pulses within the first range with a first pulse length of 200 ns and within the second range with a second pulse length of 5 μs.

4. The laser system according to claim 2 , wherein the control unit is further configured to allow the user to select the pulse lengths in a range ranging from 50 ns to 500 ns at >50 mJ/cm 2 and in a range ranging from of 1 μs-50 μs, with an energy density of an individual pulse of >500 mJ/cm 2 , for selective laser trabeculoplasty, for selective retina therapy and for retina regeneration therapy.

5. The laser system according to claim 4 , wherein the control unit is further configured to allow the user to select the pulse lengths of 5 μs, with an energy density of an individual pulse of >500 mJ/cm 2 .

6. The laser system according to claim 1 , wherein the solid-state laser emits individual pulses with pulse length in the first range of 50 ns-500 ns, with comprising further parameters as follows:
each spot being a square spot having an edge length of 50 μm, and the square spots being arranged in spot patterns with the square spots being directly set adjacent to each other and with the spot pattern having an outer, approximately octagonal shape with a pattern dimension of 400 μm.

7. The laser system according to claim 6 , wherein the solid-state laser emits individual pulses with pulse length of 200 ns.

8. The laser system according to claim 6 , wherein the solid-state laser emits individual pulses with Pulse energies of 2-50 μJ.

9. The laser system according to claim 8 , wherein the solid-state laser emits individual pulses with pulse energies of 25 μJ.

10. The laser system according to claim 1 , wherein the control unit is designed to vary the pumping current of the pump source in such a way that the pulse lengths and thus the energy density of the individual pulses of an entire pattern or also of the individual pulses within a pattern are adjustable.

11. The laser system according to the claim 1 , wherein the control unit controls the pulse lengths and thus the energy density of the individual pulses of an entire pattern or also of the individual pulses within a pattern are alternating.

12. The laser system according to claim 1 , wherein the control unit comprises an operating menu with one or more predetermined parameter sets for different selective therapy forms in the eye.

13. The laser system according to claim 1 , wherein the following parameters are taken into account in parameter sets of an operating menu of the control unit: spot size, spot distance, shape of the pattern, pulse length, energy density and number of pulses as well as repetition rate.

14. The laser system according to claim 1 , wherein the control unit controls spot sizes for an individual pulse in a range of 50 μm to 100 μm for selective laser trabeculoplasty, laser spots being placed next to each other in a dense packing.

15. The laser system according to claim 14 , wherein the control unit controls the laser spots being placed next to each other in the dense packing as a square spot.

16. The laser system according to claim 14 , wherein the control unit controls the laser to apply a pattern of square laser spots.

17. The laser system according to claim 14 , wherein the control unit controls the laser to apply an octagonal pattern made of 52 square laser spots.

18. The laser system according to claim 1 , wherein the control unit controls the laser to apply maximum patterns of 400×400 μm 2 generated in a trabecular meshwork.

19. The laser system according to claim 1 , wherein the solid-state laser is configured to emit a laser wavelength in the green or yellow spectral range that selectively destroys lipofuscin at a retina.

20. The laser system according to claim 1 , wherein the solid-state laser is configured to emit a laser wavelength of 532 nm, 561 nm, 577 nm or 586 nm, that selectively destroys lipofuscin at the retina.

21. The laser system according to claim 1 , wherein the solid-state laser is configured to emit individual pulses with pulse lengths in the ms-range for thermal millisecond laser coagulation.

22. The laser system according to claim 1 , wherein the control unit is configured to calculate a center size of a damage zone with a lateral and axial expansion from a size of an optical spot at a treatment location, a pulse length, an energy density and to thereby take into account a magnification of a contact glass that was used.

23. The laser system according to claim 1 , wherein the control unit is configured to select parameter sets for the solid-state laser from an ascertained center size of a damage area.

24. The laser system according to claim 1 , wherein the control unit is configured to determine the size of an irreversibly damaged center to then select a spot distance of the individual pulses in such a way that no overlapping of irreversible damage occurs.

25. The laser system according to claim 1 , wherein the control unit is configured to regulate additional distances between the irreversibly damaged center sizes.

26. The laser system according to claim 1 , wherein the control unit is configured to measure a course of a temperature by opto-acoustic detection and to use the temperature as a therapy criterion.

27. The laser system according to claim 1 , wherein the control unit is coupled to a sensor configured to detect an emergence of a blister or a qualitative alteration in an optical reflection or backscattering of light, to reduce a maximum number of pulses if a treatment threshold is reached.

28. A laser system for selective laser trabeculoplasty, wherein a solid-state laser emits individual pulses with pulse length in a range of 50 ns-500 ns, with spot sizes of 50 μm to 100 μm for an individual pulse, wherein square laser spots are applied to a tissue area in close contact adjacent one another within a pattern and are densely packed and the patter

Assignees

• Zeiss Carl Meditec Ag

Inventors

• Dick Manfred
• Kunath-Fandrei Gerald
• Denner René
• Wurlitzer Thomas

Classifications

• A61F2009/00897

  Scanning mechanisms or algorithms · CPC title

• A61F2009/00891

  Glaucoma · CPC title

• A61F9/00781 Primary

  Apparatus for modifying intraocular pressure, e.g. for glaucoma treatment (drainage implants in general A61M27/002) · CPC title

• A61F9/009

  Auxiliary devices making contact with the eyeball and coupling in laser light, {e.g. goniolenses (apparatus for eye examination A61B3/0008)} · CPC title

• A61F2009/00863

  Retina · CPC title