Method and apparatus for modification of corneal refractive properties

• US 4,724,522 A
• Filed: 05/27/1986
• Issued: 02/09/1988
• Est. Priority Date: 05/27/1986
• Status: Expired due to Term

• Current Assignee: BMB Patent Holding Corporation
• Original Assignee: Barry M. Belgorod
• Inventors: Belgorod, Barry M.
• Primary Examiner(s): Smith, Jerry
• Assistant Examiner(s): Hayes, Gail O.
• Application Number:
  US06/867,313
• Time in Patent Office: 623 Days
• Field of Search: 128/303.1, 364/415, 364/464-465, 219/121 LQ, 219/121 LS, 219/121 LT, 219/121 LG, 219/121 LN, 219/121 LH, 219/121 LA
• US Class Current: 606/5
• CPC Class Codes: A61F 2009/00872 Cornea
• CPC Class Codes: A61F 9/008 using laser
• CPC Class Codes: A61F 9/00802 for photoablation
• CPC Class Codes: A61F 9/00817 Beam shaping with masks

Abstract

A method and apparatus for modifiying corneal refractive properties includes a laser source, computer control, and a plurality of deflectors including at least one rotating and translating deflector. A beam emitted from the laser source is deflected by the rotating and translating deflector in a controlled manner such that the beam strikes the cornea tangentially, ablating or lathing the contacted surface. The apparatus is computer controlled to intra-operatively determine the visual axis, monitor fixation, monitor changing refractive error, adjust the rotating and translating deflector and activate and deactivate the laser. The invention allows the radius of curvature of the cornea to be modified in vivo or in vitro. The cornea is lathed tangentially in either a natural or frozen state in an area centered about its optical axis, encompassing its optical zone. In one embodiment, a rotating arm, rotating in a plane perpendicular to the optical axis of the cornea, transmits the laser beam to the variable deflector.

Claims

1. An apparatus for modifying the refractive properties of the cornea of an eye, comprising:

laser means for emitting a laser beam;

means for deflectng said laser beam to strike said cornea tangentially about the optical zone thereof; and

means for rotating said deflecting means through 360°

, the center of rotation of said deflecting means being positioned substantially along the visual axis of said cornea, such that through rotation of said deflecting means, said laser beam strikes said cornea tangentially over an area substantially centered about the visual axis of said cornea.

2. An apparatus according to claim 1, further comprising:

means for determining whether said visual axis is aligned with said center of rotation and control means for disabling said laser means when said visual axis and said center of rotation are not aligned.

3. An apparatus according to claim 1, further comprising;

autorefraction means for determining the refractive properties of an eye; and

control means for disabling said laser means when said refractive properties meet predetermined conditions.

4. An apparatus according to claim 1, further comprising:

tangentiality detecting means for detecting tangential striking of the cornea by said laser beam;

adjusting means for adjusting said deflecting means to alter the angle and point at which said laser beam strikes said cornea; and

control means for effecting adjustment by said adjusting means until tangentiality is indicated by said tangentiality indicating means.

5. The apparatus according to claim 1, wherein said deflecting means includes means for contouring a laser beam to have a curved cross-sectional profile.

6. The apparatus according to claim 5, wherein said deflecting means includes a curved deflector.

7. The apparatus according to claim 5, wherein said deflecting means includes masking means defining a curved profile.

8. An apparatus for modifying the refractive properties of the cornea of an eye, comprising:

laser means for emitting a laser beam along an incidental axis;

rotating deflection means, having its center of rotation disposed substantially along said incidental axis, comprising first deflecting means disposed along said incidental axis for deflecting said laser beam radially outward, second deflecting means displaced substantially perpendicularly from said incidental axis and aligned with said first deflecting means for deflecting said laser beam from said first deflecting means to a third deflecting means aligned with said second deflecting means in a line substantially parallel to sid incidental axis;

means for maintaining alignment between the visual axis of an eye and said incidental axis; and

means for adjusting said third deflecting means such that said laser beam deflected thereby is adapted to strike the surface of a cornea tangentially, rotation of said rotating deflection means about said incidental axis causing said laser to strike the cornea tangentially over an area substantially centered about the visual axis of said cornea.

9. An apparatus as recited in claim 8, wherein the cross-sectional projection of a laser beam deflected by said third deflecting means substantially corresponds to post-operative corneal curvature.

18. The method of claim 9, further comprising the step of contouring said laser beam to have a curved cross-sectional profile.

10. A method for in vivo modification of the refractive properties of a patient'"'"'s eye, comprising the steps of:

(a) maintaining visual fixation;

(b) ascertaining the visual axis of the eye;

(c) activating laser means to emit a laser beam;

(d) directing said laser beam through deflecting means to strike the cornea of the eye tangentially about the optical zone thereof; and

(e) rotating said deflecting means through 360°

substantally about said visual axis while maintaining tangential striking of the cornea by the laser beam.

11. A method according to claim 10, further comprising the steps of:

(f) ascertaining the refractive error of the eye; and

(g) if refractive error is found, repeating the step of (a)-(f).

12. The method of claim 10 further comprising the step of translating said laser beam across said cornea, the rotation and translation of said laser beam resulting in a spiraling pattern of corneal ablation.

13. An apparatus for modifying the refractive properties of the cornea of an eye, comprising:

laser means for emitting a laser beam;

means for deflecting said laser beam to strike said cornea tangentially;

means for rotating said deflecting means through 360°

, the center of rotation of said deflecting means being positioned along the visual axis of said cornea, such that through rotation of said deflecting means, said laser beam strikes said cornea tangentially over an area centered about the visual axis of said cornea; and

means for determining whether said visual axis is aligned with said center of rotation and control means for disabling said laser means when said visual axis and said center of rotation are not aligned.

14. The apparatus according to claim 13, further comprising means for contouring said laser beam to have a curved cross-sectional profile.

15. An apparatus for modifying the refractive properties of the cornea of an eye, comprising:

laser means for emitting a laser beam;

means for deflecting said laser beam for strike said cornea tangentially;

means for rotating said deflecting means through 360°

, the center of rotation of said deflecting means being positioned substantially along the visual axis of said cornea, such that through rotation of said deflecting means, said laser beam strikes said cornea tangentially over an area centered about the visual axis of said cornea; and

tangentiality detecting means for detecting tangential striking of the cornea by said laser beam;

adjusting means for adjusting said deflecting means to alter the angle and point at which said laser beam touches the cornea; and

control means for effecting adjustment by said adjusting means until tangentiality is indicated by said tangentiality indicating means.

16. The apparatus according to claim 15, further comprising means for contouring said laser beam to have a curved cross-sectional profile.

17. A method for in vivo modification of the refractive properties of a patient'"'"'s eye, comprising the steps of:

(a) maintaining visual fixation;

(b) ascertaining the visual axis of the eye;

(c) activating laser means to emit a laser beam;

(d) directing said laser beam through deflecting means to strike the cornea of the eye tangentially;

(e) rotating said deflecting means through 360°

substantially about said visual axis while maintaining tangential striking of the cornea by the laser beam;

(f) ascertaining the refractive error of the eye; and

(g) if refractive error is found, repeating the steps of (a)-(f).

19. A method for modification of the refractive properties of a cornea, comprising the steps of:

(a) activating laser means to emit a laser beam;

(b) directing said laser beam to strike the cornea tangentially about the optical zone thereof; and

(c) rotating said laser beam through 360°

while substantially maintaining tangential striking of the cornea by the laser beam.

20. A method according to claim 19, the rotation of said laser beam being centered substantially about the visual axis of said cornea.

21. The method according to claim 20, further comprising the step of contouring said laser beam to have a curved cross-sectional profile.

22. The method according to claim 19, further comprising the step of contouring said laser beam to have a curved cross-sectional profile.

23. The method of claim 19 further comprising the step of translating said laser beam across said cornea, the rotation and translation of said laser beam resulting in a spiraling pattern of corneal ablation.

24. The method of claim 19 wherein the method is performed in vivo.

25. The method of claim 19 wherein the method is performed in vitro.

26. An apparatus for modifying the refractive properties of the cornea of an eye, comprising:

laser means for emitting a laser beam along an incidental axis;

rotating deflection means, having its center of rotation disposed along said incidental axis, comprising first deflecting means disposed along said incidental axis for deflecting said laser beam outward and second deflecting means displaced a distance from said incidental axis and adapted to deflect said laser beam towards the cornea; and

means for adjusting said first and second deflecting means such that said laser beam deflected thereby is adapted to strike the surface of the cornea tangentially about the optical zone thereof, rotation of said rotating deflection means about said incedental axis causing said laser to strike the cornea tangentially over an area substantially centered about the visual axis of said cornea.

27. An apparatus as recited in claim 26, wherein the cross-sectional projection of a laser beam deflected by said second deflecting means substantially corresponds to pre-determined post-operative corneal curvature.

28. An apparatus as recited in claim 26, further comprising means for contouring said laser beam to have a curved cross-sectional profile.

29. An apparatus for modifying the refractive properties of a cornea, comprising:

laser means for emitting a laser beam;

means for directing said laser beam to strike said cornea tangentially about the optical zone thereof; and

means for rotating said laser beam through 360°

, the center of rotation of said laser beam being substantially along the visual axis of said cornea, such that through rotation of said laser beam, said laser beam strikes said cornea tangentially over an area centered substantially about the visual axis of said cornea.

30. An apparatus according to claim 29, further comprising:

means for determining whether said visual axis is substantially aligned with said center of rotation and control means for disabling said laser means when said visual axis and said center of rotation are not substantially aligned.

31. An apparatus according to claim 29, further comprising:

autorefraction means for determining the refractive properties of the cornea; and

control means for disabling said laser means when said refractive properties meet predetermined conditions.

32. An apparatus according to claim 29, further comprising:

tangentiality detecting means for detecting tangential striking of the cornea by said laser beam;

adjusting means for adjusting said deflecting means to alter the angle and point at which said laser beam touches the cornea; and

control means for effecting adjustment by said adjusting means until tangentiality is indicated by said tangentiality indicating means.

33. The apparatus according to claim 29, further comprising means for contouring said laser beam to have a curved cross-sectional profile.

34. The apparatus according to claim 33, wherein said means for contouring includes a curved deflector.

35. The apparatus according to claim 33, wherein said means for contouring includes masking means defining a curved profile.

36. An apparatus according to claim 29, further comprising means for detecting fixation of an operative eye directly from said operative eye.

37. An apparatus for modifying the refractive properties of a cornea, comprising:

laser means for emitting a laser beam;

means for directing said laser beam to strike said cornea tangentially about the optical zone thereof; and

means for rotating said laser beam through 360°

, such that through rotation of said laser beam, said laser beam strikes said cornea tangentially over an area substantially centered about the visual axis of said cornea.

38. An apparatus according to claim 37, wherein rotation of said laser beam is centered substantially about the visual axis of said cornea, said apparatus further comprising means for determining whether said visual axis is substantially aligned with said center of rotation and control means for disabling said laser means when said visual axis and said center of rotation are not substantially aligned.

39. An apparatus according to claim 37, further comprising:

autorefraction means for determining the refractive properties of the cornea; and

control means for disabling said laser means when said refractive properties meet predetermined conditions.

40. An apparatus according to claim 37, further comprising:

tangentiality detecting means for detecting tangential striking of the cornea by said laser beam;

adjusting means for adjusting said deflecting means to alter the angle and point at which said laser beam touches the cornea; and

control means for effecting adjustment by said adjusting means until tangentiality is indicated by said tangentiality indicating means.

41. The apparatus according to claim 37, further comprising means for contouring said laser beam to have a curved cross-sectional profile.

42. A method for modification of the refractive properties of a cornea, comprising the steps of:

(a) activating high intensity radiation means to emit a beam;

(b) directing said beam to strike the cornea tangentially about the optical zone thereof; and

(c) rotating said beam through 360 °

while substantially maintaining tangential striking of the cornea by the beam.

43. A method according to claim 42, the rotation of said beam being centered substantially about the visual axis of said cornea.

44. The method according to claim 43, further comprising the step of contouring said beam to have a curved cross-sectional profile.

45. The method according to claim 42, further comprising the step contouring said beam to have a curved cross-sectional profile.

46. An apparatus for modifying the refractive properties of a cornea, comprising:

high intensity radiation means for emitting a beam;

means for directing said beam to strike said cornea tangentially about the optical zone thereof; and

means for rotating said beam through 360 °

, such that through rotation of said beam, said beam strikes said cornea tangentially over an area substantially centered about the visual axis of said cornea.

47. An apparatus according to claim 46, wherein rotation of said beam is centered substantailly about the visual axis of said cornea, said apparatus further comprising means for determining whether said visual axis is substantially aligned with said center of rotation and control means for disabling said high intensity radiation means when said visual axis and said center of rotation are not substantially aligned.

48. An apparatus according to claim 46, further comprising:

autorefraction means for determining the refractive properties of the cornea; and

control means for disabling said high intensity radiation means when said refractive properties meet predetermined conditions.

49. An apparatus according to claim 46, further comprising:

tangentiality detecting means for detecting tangential striking of the cornea by said beam;

adjusting means for adjusting said deflecting means to alter the angle and point at which said beam touches the cornea; and

control means for effecting adjustment by said adjusting means until tangentiality is indicated by said tangentiality indicating means.

50. An apparatus according to claim 46, further comprising means for contouring said beam to have a curved cross-sectional profile.