Photodisruptive Laser Treatment of the Crystalline Lens

• US 20090171327A1
• Filed: 12/23/2008
• Published: 07/02/2009
• Est. Priority Date: 09/06/2007
• Status: Active Grant

• Current Assignee: Alcon Incorporated
• Original Assignee: LensX Lasers, Inc. (Alcon Incorporated)
• Inventors: Kurtz, Ronald M., Raksi, Ferenc, Goldstein, Peter
• Granted Patent: US 9,456,925 B2
• Time in Patent Office: Days
• US Class Current: 606/6
• CPC Class Codes: A61F 2009/00851 Optical coherence topography [OCT]
• CPC Class Codes: A61F 2009/0087 Lens
• CPC Class Codes: A61F 2009/00895 Presbyopia
• CPC Class Codes: A61F 2009/00897 Scanning mechanisms or algorithms
• CPC Class Codes: A61F 9/008 using laser
• CPC Class Codes: A61F 9/00838 Correction of presbyopia
• CPC Class Codes: A61F 9/009 Auxiliary devices making contact with the eyeball and coupling in laser light, e.g. goniolenses apparatus for eye examination A61B3/0008

Abstract

Apparatus and methods of treating a hard lens region of an eye with a laser where one method includes identifying a boundary of the hard lens region, selecting a laser-parameter to enable a photodisruptive procedure in the hard lens region and to control a spreading of bubbles in the hard lens region, modifying a mechanical property of a posterior portion of the hard lens region in a proximity of the identified boundary by the photodisruptive procedure, and modifying a mechanical property of a portion anterior to the modified posterior portion of the hard lens region by the photodisruptive procedure. The laser bubbles can be applied to form incisions which are non transverse to an axis of the eye and intersect the lens fibers.

Claims

1. A method of treating a crystalline lens of an eye with a laser, the method comprising:

selecting a surgical region of the lens;

applying laser pulses to form at least one incision within the selected surgical region, wherein;

an orientation of a portion of the incision is one of an orientation intersecting fibers of the lens and an orientation non-transverse to an axis of the eye; and

the incision modifies a property of the lens.

2. The method of claim 1, wherein the non-transverse orientation of the incision is one of:

an orientation substantially parallel to the axis of the eye; and

an orientation making a less than 90 degree angle with the axis of the eye.

3. The method of claim 1, wherein:

a spatial extent of the incision along the axis of the eye is longer than the spatial extent transverse to the axis of the eye.

4. The method of claim 3, wherein:

the spatial extent of the incision along the axis of the eye is in the range of 0.5 mm-12 mm; and

the spatial extent of the incision transverse to the axis of the eye is in the range of 1-500 microns.

5. The method of claim 1, wherein:

the axis of the eye is one of a visual axis, an optic axis, a line of sight and a pupillary axis.

6. The method of claim 1, wherein:

the incision cuts the fibers into parts approximately at the intersection of the incision and the fibers; and

the modified property of the lens is a weakening of a biomechanical property of the lens.

7. The method of claim 1, wherein:

the incision cuts the fibers at or near sutures of the fibers.

8. The method of claim 1, wherein:

the incision avoids cutting sutures in the lens.

9. The method of claim 1, wherein the applying laser pulses comprises:

applying the laser pulses to generate gas bubbles which form the incision,

wherein an orientation of the incision is aligned with a preferential direction of expansion of the generated gas bubbles.

10. The method of claim 1, wherein the applying the laser pulses comprises:

moving the focal point of the applied laser beam along a posterior to anterior direction within the lens.

11. The method of claim 1, wherein the incision has one of:

an extent at least equal to an extent of a nucleus of the lens;

an X-Y diameter in excess of 2 mm and a Z extent in excess of 0.5 mm; and

an X-Y diameter in excess of 4 mm and a Z extent in excess of 1 mm, wherein the X-Y diameter is a measure of the spatial extent of the entire incision in the direction transverse to the axis.

12. The method of claim 1, wherein:

the method comprises forming no more than one incision; and

the laser pulses are applied in a continuous manner to form the incision without repositioning the laser or interrupting the application of the laser.

13. The method of claim 1, wherein the incision has a form aligned with the axis of the eye, the form being of at least one of:

a cylinder, a set of concentric cylinders, a set of cylinders connected by one or more connecting line, a curved surface, a cone, a spiral, a layered spiral with smooth lines connecting layers of the spiral and a tilted cylinder.

14. The method of claim 1, wherein the incision has a form aligned with the axis of the eye, the form being at least one of:

a plane, two or more crossing planes, a combination of planes and connecting arcs, and a combination of planes and cylinders.

15. The method of claim 1, wherein the applying the laser pulses comprises:

forming incisions in a layer-by layer manner.

16. The method of claim 15, wherein the forming the incisions in a layer-by-layer manner comprises:

applying laser pulses to target locations within a posterior layer of the lens, the target locations belonging to two incisions or two segments of the same incision; and

applying laser pulses to target locations within a layer anterior to the posterior layer, the target locations belonging to the same two incisions or to the same two segments of the same incision.

17. The method of claim 1, wherein the applying the laser pulses comprises:

applying the laser pulses to form a first ring with a first radius in a posterior layer of the lens;

applying the laser pulses to form a connector line between the first and a second ring in the posterior layer;

applying the laser pulses to form the second ring with a second radius in the posterior layer; and

repeating multiple times the formation of the first ring, the second ring and the connector line in layers sequentially anterior to the posterior layer,

wherein the first rings in the sequential layers form a first cylinder, the second rings form a second cylinder, the cylinders being connected by the connector lines.

18. The method of claim 17, wherein:

the connector lines in sequential layers are one of;

aligned to form connector planes; and

not-aligned from layer to layer.

19. The method of claim 1, comprising:

forming a posterior spiral in a posterior layer;

forming a smooth connector line starting near an end of the posterior spiral in the posterior layer, the connector line smoothly bending and rising to a central region of a layer anterior to the posterior layer; and

forming an anterior spiral starting at the end of the smooth connector line in the central region of the anterior layer.

20. The method of claim 19, wherein the posterior spiral and the anterior spiral are essentially aligned to form a spiral with an extent in the Z direction.

21. The method of claim 1, wherein the applying the laser pulses comprises:

selecting laser-parameters sufficient to create bubbles in the lens, but insufficient to cause harm to a retina of the eye.

22. The method of claim 1, wherein the applying the laser pulses comprises:

applying the laser pulses with laser-parameters insufficient to fragment the lens to a degree suitable for removal, if the incision were transverse to the axis of the eye.

23. The method of claim 22, wherein the laser-parameters comprise:

a laser pulse energy in the range of 0.5 microJ to 50 microJ;

a duration of a laser pulse in the range of 0.005 picoseconds to 25 picoseconds;

a repetition rate of applying laser pulses in the range of 1 kHz to 10 MHz; and

a separation distance of target regions of laser pulses in the range of 1 micron to 100 microns.

24. The method of claim 1, wherein the applying the laser pulses comprises:

applying the laser pulses with varying energy as the incision is formed.

25. The method of claim 24, wherein the energy is varied during at least one of:

a Z directional scanning; and

an X-Y directional scanning.

26. The method of claim 24, wherein the energy is varied in relation to a measurement of an optical property of an eye tissue.

27. The method of claim 1, comprising:

forming the incision on a layer-by-layer basis, wherein one or more layers are at least partially formed along a curved focal plane of a laser delivery system.

28. The method of claim 1, comprising:

a Z directional scanner is adjusted at a slower rate than an X-Y directional scanner when forming a layer of one or more incisions.

29. The method of claim 1, further comprising:

forming a protection layer in a posterior portion of the lens, positioned to block a large portion of the laser pulses applied to form the incision.

30. The method of claim 1, wherein the incision fragments at least a portion of the lens, the method further comprising:

removing the fragmented portion of the lens.

31. The method of claim 30, wherein the applying the laser pulses comprises:

applying laser pulses with laser parameters which do not cause lasting damage to a retina of the eye, wherein

the laser pulses fragment the lens to a degree suitable for removal; and

the time of the fragmentation is less than a minute.

32. An eye-surgical method, the method comprising:

applying laser pulses to form an incision in a lens of an eye, wherein the laser pulses are applied by a laser system which is configured to scan the laser pulses across an entire nucleus of the lens without interrupting the application of the laser pulses.

33. The method of claim 32, wherein:

the incision intersects fibers of the lens.

34. The method of claim 32, wherein:

at least segments of the incision are essentially non-transverse to an axis of the eye.

35. The method of claim 32, wherein the incision is one of:

a cylinder, a set of concentric cylinders, a set of concentric cylinders connected by connecting lines, a cone, crossing planes, crossing planes connected by arcs, a spiral, and a layered spiral with a smooth line connecting layers of the spiral.

36. A laser system for fragmenting a crystalline lens of an eye, comprising:

a pulsed laser configured to generate a laser beam of laser pulses; and

an optical delivery system, wherein

the optical delivery system is configured to apply the laser beam to create an incision in the lens of the eye with a spatial extent along an axis of the eye longer than 2 mm; and

a spatial diameter transverse to the axis of the eye larger than 4 mm,

without interrupting the application of the laser.

37. The laser system of claim 36, wherein

the optical delivery system is configured to move a focal point of the laser in a posterior to anterior direction of the lens.

38. The laser system of claim 36, wherein

the optical delivery system is configured to control the laser to generate a laser beam with laser-parameters:

sufficient to create photodisruption in a selected lens region; and

insufficient to cause damage to a retina of the eye.

39. The laser system of claim 38, wherein the optical delivery system is configured to control the pulsed laser to generate laser pulses with laser-parameters:

an energy in the range of approximately 0.5 microJ to 50 microJ;

a separation of adjacent target areas in the range of approximately 1 micron to 100 microns;

a duration in the range of approximately 0.005 picoseconds to 25 picoseconds; and

a repetition rate in the range of 1 kHz to 10 MHz.