Methods for producing epithelial flaps on the cornea and for placement of ocular devices and lenses beneath an epithelial flap or membrane, epithelial delaminating devices, and structures of epithelium and ocular devices and lenses

• US 20030220653A1
• Filed: 01/17/2003
• Published: 11/27/2003
• Est. Priority Date: 07/18/2000
• Status: Active Grant

• Current Assignee: Tissue Engineering Refraction Incorporated
• Original Assignee: Tissue Engineering Refraction Incorporated
• Inventors: Perez, Edward
• Granted Patent: US 7,497,866 B2
• Time in Patent Office: Days
• US Class Current: 606/107
• CPC Class Codes: A61B 17/32 Surgical cutting instruments A61B18/042 takes precedence; suture cutters A61B17/0467; instruments for ligaturing or cutting A61B17/128; instruments for rupturing the amniotic membrane A61B17/4208; specially adapted knives for eye surgery A61F9/0133
• CPC Class Codes: A61B 2017/320052 Guides for cutting instruments by marking A61B2090/395
• CPC Class Codes: A61F 2/142 Cornea, e.g. artificial corneae, keratoprostheses or corneal implants for repair of defective corneal tissue
• CPC Class Codes: A61F 2/147 Implants to be inserted in the stroma for refractive correction, e.g. ring-like implants
• CPC Class Codes: A61F 9/013 Instruments for compensation of ocular refraction A61F9/008 takes precedence; Instruments for use in cornea removal, for reshaping or performing incisions in the cornea
• CPC Class Codes: A61F 9/0133 Knives or scalpels specially adapted therefor

Abstract

These methods, devices, and structures are useful in the field of ophthalmology; the devices and methods relate variously to separating or lifting corneal epithelium from the eye preferably in a substantially continuous layer, placing a lens or other suitable ocular or medical device beneath the epithelial membrane, and to the resulting structures formed by those procedures. The de-epilthelialization devices generally utilize a non-cutting separator or dissector that is configured to separate the epithelium at a naturally occurring cleavage surface in the eye between the epithelium and the corneal stroma (Bowman'"'"'s membrane), specifically separating in the region of the lamina lucida. The separator or dissector may have a structure that rolls or vibrates (or both) at that cleavage surface or interface during the dissection step. The separated epithelium may be lifted or peeled from the surface of the eye to form an epithelial flap or a pocket. The epithelium may then be replaced on the cornea after a refractive procedure or after placement of an ocular lens (or other subepithelial device) on the eye. The subepithelial device may comprise a wide variety of synthetic, natural, or composite polymeric materials. The step of replacing epithelial tissue upon the subepithelial device or upon the anterior corneal surface promotes epithelial healing.

Claims

1. A device for separating epithelium from an eye having a cornea with epithelium and a stroma, the device comprising an epithelial delaminator member configured to apply a mechanical force beneath that epithelium to separate the epithelium from the stroma without cutting that stroma.

2. The device of claim 1 wherein the epithelial delaminator member is configured to produce a separated epithelium being substantially free of Collagen Type I and Collagen Type III.

3. The device of claim 1 wherein the epithelial delaminator member is configured to indent the stroma while applying the mechanical force beneath the epithelium.

4. The device of claim 1 wherein the epithelial delaminator member is configured to separate the epithelium in at least one continuous portion.

5. The device of claim 1 wherein the epithelial delaminator member is configured to separate the epithelium in one continuous portion.

6. The device of claim 1 wherein the epithelial delaminator member is configured to separate the epithelium and form an epithelial pocket.

7. The device of claim 1 wherein the epithelial delaminator member comprises a wire having a stiffness and size selected to separate the epithelium from the stroma.

8. The device of claim 7 wherein the wire has a cross section selected from the group consisting of round, square, oval, ellipsoid, rectangular, truncated oval, and bull-nosed.

9. The device of claim 7 wherein the wire has a length and a cross section that is not constant along that length.

10. The device of claim 7 wherein the wire has a prow positioned to lead a passage of the wire when passed t beneath the epithelium.

11. The device of claim 7 wherein the wire is twisted along its length.

12. The device of claim 11 wherein the wire is helically twisted along its length.

13. The device of claim 11 wherein the wire is twisted non-uniformly along its length.

14. The device of claim 7 wherein the wire stiffness is selected at least partially by material selection of the wire.

15. The device of claim 7 wherein the wire stiffness is selected at least partially by adjusting the strain placed upon the wire.

16. The device of claim 7 further comprising a yoke supporting the wire.

17. The device of claim 16 wherein the yoke is configured to pass the wire beneath the epithelium at a direction of movement perpendicular to the wire.

18. The device of claim 16 wherein the yoke is configured to pass the wire beneath the epithelium at a direction of movement not perpendicular to the wire.

19. The device of claim 7 further comprising an oscillator configured to oscillate the wire.

20. The device of claim 19 where the oscillator is configured to oscillate the wire at a frequency between 100 and 350 Hz.

21. The device of claim 19 where the oscillator is configured to oscillate the wire at a frequency between 245 and 255 Hz.

22. The device of claim 19 where the oscillator is configured to oscillate the wire at an amplitude between 1.5 and 4.5 mm.

23. The device of claim 20 where the oscillator is configured to oscillate the wire at an amplitude between 2.0 and 3.0 mm.

24. The device of claim 20 wherein the oscillator is configured to oscillate the wire at a direction of movement perpendicular to the wire.

25. The device of claim 20 wherein the oscillator is configured to oscillate the wire at a direction of movement not perpendicular to the wire.

26. The device of claim 7 further comprising a suction apparatus comprising:

epithelial contact surfaces defining a suction chamber,

a slot for directing the wire to the epithelium, and

a vacuum source in vacuum communication with the suction chamber.

27. The device of claim 26 wherein the suction chamber comprises a volume between two epithelial contact surfaces.

28. The device of claim 26 wherein the contact surfaces are ring shaped.

29. The device of claim 26 wherein the suction apparatus further includes a port for entry of an ophthalmologic surgical instrument.

30. The device of claim 1 wherein the epithelial delaminator member is configured to roll as it contacts the stroma and separates the epithelium.

31. The device of claim 30 wherein the epithelial delaminator member is configured to roll passively as it contacts the stroma and separates the epithelium.

32. The device of claim 30 wherein the epithelial delaminator member is configured to roll actively as it contacts the stroma and separates the epithelium.

33. The device of claim 30 wherein the rollable epithelial delaminator member comprises a wire structure comprising at least two wires and the structure selected to separate the epithelium from the stroma.

34. The device of claim 33 wherein the wire structure has a stiffness and size selected to separate the epithelium from the stroma.

35. The device of claim 33 wherein the wire structure comprises more than two wires.

36. The device of claim 33 wherein the wire structure comprises wires laid side-by-side and twisted together along its length.

37. The device of claim 33 wherein the wire structure is helically twisted along its length.

38. The device of claim 33 wherein the wire structure is twisted non-uniformly along its length.

39. The device of claim 33 wherein the wire structure comprises braided wires.

40. The device of claim 30 wherein the rollable epithelial delaminator member comprises a wire structure comprising at least one wire having a non-smooth surface and the surface suitable for separating the epithelium from the stroma.

41. The device of claim 30 wherein the rollable epithelial delaminator member comprises a wire structure comprising at least one wire having a roughened surface suitable for separating the epithelium from the stroma.

71. The method of claim 69 where the step of placing an epithelial delaminator member beneath the epithelium comprises placing an epithelial delaminator member selected from any of claims 1-41.

42. A device for lifting epithelium from an eye having a cornea with an anterior surface comprising an epithelial delaminator configured to apply a mechanical force to the anterior surface to lift the epithelium in a continuous layer.

43. The device of claim 42 wherein the epithelial delaminator comprises a suction apparatus comprising:

a suction chamber having an epithelial contact surface and

a vacuum source,

wherein the suction chamber and the vacuum source are in vacuum communication.

44. The device of claim 43 wherein the suction chamber comprises a wall.

45. The device of claim 43 wherein the suction chamber is a hemispherical cup.

46. The device of claim 45 wherein the cup is transparent.

47. The device of claim 45 wherein the cup is comprised of a deformable material.

48. The device of claim 43 wherein the contact surface is ring shaped.

49. The device of claim 48 wherein the ring shaped contact surface is comprised of a material selected from the group consisting of a metal, a polymer, and an elastomer.

50. The device of claim 43 wherein the suction chamber includes a port or a groove for entry of a fluid.

51. The device of claim 50 wherein the epithelial delaminator further comprises a fluid.

52. The device of claim 51 wherein the fluid comprises hypertonic saline.

53. The device of claim 43 wherein the suction chamber includes a port or a groove for entry of an ophthalmological surgical instrument.

54. The device of claim 43 wherein the vacuum source is a manual pump.

55. The device of claim 43 wherein the vacuum source is a motorized pump.

56. The device of claim 43 further comprising a pressure gauge.

57. The device of claim 43 wherein the vacuum source is a syringe.

58. The device of claim 42 wherein the delaminator is a blunt dissector.

59. The device of claim 58 wherein the delaminator comprises a rotating wire.

60. The device of claim 58 wherein the delaminator comprises a vibrating wire.

61. The device of claim 58 wherein the delaminator comprises a curved spatula.

62. The device of claim 58 wherein the blunt dissector is configured to impart a shearing force.

63. The device of claim 42 wherein the epithelial-delaminator is configured to apply the force by injecting a fluid between the epithelium and the anterior surface.

64. The device of claim 63 wherein the epithelial delaminator further comprises a fluid.

65. The device of claim 64 wherein the fluid comprises hypertonic saline.

66. The device of claim 64 wherein the fluid comprises a silicone solution.

67. The device of claim 63 wherein the fluid is air.

68. The device of claim 42 wherein the epithelial delaminator is configured to apply the force by injecting a gel between the epithelium and the anterior surface.

69. A method for lifting epithelium from an eye having a cornea with an epithelium and stroma, comprising the steps of:

placing an epithelial delaminator member between the epithelium and the corneal stroma, and

moving the epithelial delaminator member to apply a mechanical force beneath the epithelium with a force sufficient to lift the epithelium in a continuous layer but not to cut the stroma.

70. The method of claim 69 where the step of placing an epithelial delaminator member beneath the epithelium comprises placing a rollable epithelial delaminator member

72. The method of claim 69 where the step of applying a mechanical force comprises a step of forming an epithelial flap.

73. The method of claim 69 where the step of applying a mechanical force comprises a step of forming an epithelial pocket.

74. The method of claim 69 where the step of applying a mechanical force comprises a step of peeling the epithelial flap to expose the stroma.

75. The method of claim 69 further comprising the step of performing a surgical step on the stroma.

76. The method of claim 75 where the surgical step comprises reshaping the stroma.

77. The method of claim 76 where the surgical step of reshaping the stroma comprises applying a laser beam to the stroma.

78. The method of claim 77 further comprising the step of measuring a surface of the stroma with an ocular topography, wavefront sensing system for measuring aberrations on that stroma surface prior to applying the laser beam to the stroma.

79. The method of claim 77 further comprising the step of replacing the flap on the stroma.

80. The method of claim 74 further comprising the step of placing an implant on the stroma.

81. The method of claim 74 further comprising the step of placing an ocular lens on the stroma.

82. The method of claim 74 further comprising the step of placing an ocular lens comprising a synthetic polymer on the stroma.

83. The method of claim 80 further comprising the step of replacing the flap on the implant.

84. The method of claim 80 further comprising the step of replacing the flap on the ocular lens.

85. The method of claim 82 further comprising the step of replacing the flap on the ocular lens comprising a synthetic polymer

86. A method for changing the vision of an eye having an anterior corneal surface and an epithelial tissue layer, the method comprising the step of:

lifting from the anterior corneal surface, a substantially continuous epithelial layer with a flap portion connected to the corneal surface to produce an epithelial tissue flap,

introducing an implant onto the corneal anterior surface, and

placing the attached epithelial tissue flap onto the implant.

87. The method of claim 86 where the step of introducing an implant onto the corneal anterior surface comprises introducing an ocular device comprising a synthetic polymer onto the uncut corneal anterior surface.

88. The method of claim 86 wherein the step of lifting from the substantially continuous epithelial layer produces an epithelial tissue flap containing substantially no corneal tissue.

89. The structure produced by the method of claim 86 comprising the implant in contact with the epithelial tissue flap and the corneal anterior surface.

90. The structure produced by the method of claim 87 comprising the ocular device of a synthetic polymer in contact with the epithelial tissue flap and the corneal anterior surface.

91. The structure produced by the method of claim 88 comprising the implant in contact with the epithelial tissue flap and the corneal anterior surface.

92. A device for lifting epithelium from an eye having a cornea with an anterior surface comprising an epithelial delaminator configured to apply a chemical composition to the anterior surface to lift the epithelium in a continuous layer.

93. The device of claim 92 wherein the epithelial delaminator comprises a well.

94. The device of claim 93 wherein the epithelial delaminator further comprises the chemical composition.

95. The device of claim 94 wherein the chemical composition comprises ethanol.

96. The device of claim 94 wherein the chemical composition comprises a hydrogel comprising a vesicant.

97. The device of claim 96 wherein the vesicant comprises ethanol.

98. The device of claim 96 wherein the vesicant comprises cantharidin.

99. The device of claim 96 wherein the vesicant comprises diallyl sulfide.

100. The device of claim 94 the chemical composition further comprises at least one diluent.

101. The device of claim 100 wherein the at least one diluent comprises acetone.

102. The device of claim 92 wherein the epithelial delaminator comprises an absorbent pad configured and positioned to deliver the chemical composition to the anterior surface.

103. The device of claim 102 wherein the chemical composition comprises ethanol.

104. The device of claim 102 wherein the chemical composition comprises cantharidin.

105. The device of claim 102 wherein the chemical composition comprises diallyl sulfide.

106. The device of claim 102 wherein the chemical composition further comprises at least one diluent.

107. The device of claim 106 wherein the at least one diluent comprise acetone.

108. A method for lifting epithelium from an eye having a cornea with an anterior surface comprising the steps of:

contacting the anterior surface with an epithelial delaminator and

applying a mechanical force to the anterior surface, wherein the force is in an amount sufficient to lift the epithelium in a continuous layer to form an epithelial flap.

109. The method of claim 108 where the step of applying a mechanical force comprises a step of peeling the epithelial flap to expose the anterior surface.

110. The method of claim 108 further comprising the step of reshaping the anterior surface or placing an ocular lens device on the anterior surface.

111. The method of claim 110 further comprising the step of replacing the flap on the anterior surface or on the ocular lens device.

112. The method of claim 108 wherein the mechanical force is an oscillating translational force.

113. The method of claim 108 wherein the mechanical force is an oscillating torsional force.

114. The method of claim 108 wherein the delaminator comprises a blunt dissector.

115. The method of claim 108 wherein the delaminator is a wire.

116. The method of claim 108 wherein the delaminator is a curved spatula.

117. The method of claim 108 wherein the mechanical force is a shearing force.

118. The method of claim 108 wherein the step of applying a mechanical force comprises injecting a fluid between the epithelium and the anterior surface.

119. The method of claim 118 wherein the fluid comprises a hypertonic saline.

120. The method of claim 118 wherein the fluid comprises a silicone solution.

121. The method of claim 118 wherein the fluid is air.

122. The method of claim 108 wherein the step of applying a mechanical force comprises injecting a gel between the epithelium and the anterior surface.

123. The method of claim 108 further comprising the step of heating the anterior surface.

124. The method of claim 123 wherein the heating step comprises contacting the anterior surface with warm water.