Refractive laser ablation through topography

• US 6,551,306 B1
• Filed: 04/13/1999
• Issued: 04/22/2003
• Est. Priority Date: 04/13/1999
• Status: Active Grant

• Current Assignee: Cesar C. Carriazo
• Original Assignee: Cesar C. Carriazo
• Inventors: Carriazo, Cesar C.
• Primary Examiner(s): Dvorak, Linda C. M.
• Assistant Examiner(s): FARAH, AHMED M
• Application Number:
  US09/290,756
• Time in Patent Office: 1,470 Days
• Field of Search: 606/4, 606/5, 606/6, 606/10-12, 606/13, 623/4-6, 351/211, 351/212
• US Class Current: 606/5
• CPC Class Codes: A61B 3/107 for determining the shape or measuring the curvature of the cornea
• CPC Class Codes: A61F 2009/00872 Cornea
• CPC Class Codes: A61F 2009/00882 based on topography
• CPC Class Codes: A61F 9/00802 for photoablation
• CPC Class Codes: A61F 9/0081 Transplantation

Abstract

A method and system control the depth of corneal ablation during optical surgery by mapping the anterior and posterior surfaces of a patient'"'"'s cornea to obtain full pachymetric topographical mapping of the patient'"'"'s cornea. The patient'"'"'s corneal pachymetric topographical mapping is used to identify a desirable corneal bed, and to guide a surgical laser in ablating a portion of the anterior surface of the patient'"'"'s cornea to produce the desired corneal bed for appropriate vision correction.

Claims

1. A method of controlling the depth of corneal ablation during optical surgery, comprising the steps of:

topographically mapping the anterior and posterior surfaces of a patient'"'"'s cornea to obtain full pachymetry of the patient'"'"'s cornea;

identifying a desirable corneal bed using the patient'"'"'s corneal pachymetric topographical mapping, wherein the desirable corneal bed is beneath a defective portion of the cornea; and

using the patient'"'"'s corneal pachymetric topographical mapping to guide a surgical laser in ablating a portion of the anterior surface of the patient'"'"'s cornea, including a defective portion of the cornea, to produce the desired corneal bed.

2. The method of claim 1, wherein the corneal pachymetric topographical mapping is used to identify whether the cornea exhibits refractive defects.

3. The method of claim 1, wherein the corneal pachymetric topographical mapping is used to identify structural corneal defects.

4. The method of claim 1, wherein the ablated portion of the patient'"'"'s cornea exhibits a constant or known thickness.

5. The method of claim 1, wherein the desirable corneal bed exhibits a uniform or predetermined thickness thereacross.

6. The method of claim 1, further comprising the steps of:

ablating a corneal disc from the anterior surface of a donor cornea, the donor corneal disc having similar diameter and thickness to the ablated portion of the patient'"'"'s cornea; and

placing the donor corneal disc onto the produced desired corneal bed of the patient'"'"'s cornea.

7. The method of claim 6, wherein the thickness of the ablated portion of the patient'"'"'s cornea is such that the descemet and endothelium layers are left intact.

8. The method of claim 1, wherein the mapping step is accomplished with an elevation-type corneal topography system.

9. The method of claim 8, wherein the mapping step is accomplished with an ORBSCAN topography system.

10. The method of claim 1, wherein the ablated portion of the patient'"'"'s cornea exhibits a variable thickness as determined by the patient'"'"'s corneal pachymetric topographical mapping.

11. The method of claim 10, wherein the thickness is varied for correction of myopia.

12. The method of claim 10, wherein the thickness is varied for correction of hyperopia.

13. The method of claim 10, wherein the thickness is varied for correction of astigmatism.

14. The method of claim 10, wherein the thickness is varied for correction of corneal ectasia.

15. The method of claim 10, wherein the thickness is varied for correction of leucoma.

16. The method of claim 10, wherein the thickness is varied for correction of corneal surface irregularities.

17. A method of ocular surgery, comprising the steps of:

mapping the anterior and posterior surfaces of a patient'"'"'s cornea to obtain full pachymetric topographical mapping of the patient'"'"'s cornea;

identifying a desirable corneal bed using the patient'"'"'s corneal pachymetric topographical mapping;

making an incomplete lamellar cut across the cornea, leaving a corneal flap and hinge in place;

folding the corneal flap back over the corneal hinge to expose the corneal bed;

using the patient'"'"'s corneal pachymetric topographical mapping to guide a surgical laser in ablating a portion of the exposed corneal bed to produce the desired corneal bed; and

replacing the corneal flap.

18. The method of claim 17, wherein the ablated portion of the patient'"'"'s cornea exhibits a variable thickness as determined by the patient'"'"'s corneal pachymetric topographical mapping.

19. The method of claim 18, wherein the thickness is varied for correction of myopia.

20. The method of claim 18, wherein the thickness is varied for correction of hyperopia.

21. The method of claim 18, wherein the thickness is varied for correction of astigmatism.

22. A system for controlling the depth of corneal ablation during optical surgery, comprising:

means for mapping the anterior and posterior surfaces of a patient'"'"'s cornea to obtain full pachyrnetric topographical mapping of the patient'"'"'s cornea;

means for identifying a desirable corneal bed using the patient'"'"'s corneal pachymetric topographical mapping, wherein the desirable corneal bed is beneath a defective portion of the cornea;

a surgical laser; and

means using the patient'"'"'s corneal pachymetric topographical mapping for guiding said surgical laser in ablating a portion of the anterior surface of the patient'"'"'s cornea, including a defective portion of the cornea, to produce the desired corneal bed.

23. A system for ocular surgery, comprising:

a system for mapping the anterior and posterior surfaces of a patient'"'"'s cornea to obtain full pachymetric topographical mapping of the patient'"'"'s cornea;

means for identifying a desirable corneal bed using the patient'"'"'s corneal pachymetric topographical mapping;

means for making an incomplete lamellar cut across the cornea, leaving a corneal flap and hinge in place;

a surgical laser;

means using the patient'"'"'s corneal pachymetric topographical mapping for guiding said surgical laser in ablating a portion of the exposed corneal bed revealed by folding back the corneal flap to produce the desired corneal bed.

24. A system for controlling the depth of corneal ablation during optical surgery, comprising:

a system for mapping the anterior and posterior surfaces of a patient'"'"'s cornea to obtain full pachymetric topographical mapping of the patient'"'"'s cornea;

means using the patient'"'"'s corneal pachymetric topographical mapping for identifying a desirable corneal bed;

means for ablating a corneal disc from the anterior surface of a donor cornea;

a surgical laser; and

means using the patient'"'"'s corneal pachymetric topographical mapping for guiding said surgical laser in ablating a portion of the anterior surface of the patient'"'"'s cornea to produce the desired corneal bed, whereby the donor corneal disc can be placed onto the produced desired corneal bed of the patient'"'"'s cornea.

25. The system of claim 24, wherein said surgical laser guiding means is capable of controlling the thickness of the ablated portion of the patient'"'"'s cornea such that the descemet and endothelium layers are left intact.

26. The system of claim 24, wherein said mapping system includes an elevation-type corneal topography system.

27. The method of claim 26, wherein said mapping system includes an ORBSCAN topography system.