Abstract
Systems and methods for implanting scaffolds in a corneal pocket of a cornea are provided. In some embodiments, a reversibly deformable scaffold may have a relaxed state and a deformed state. The scaffold may include a first ring and a second ring, a first connector extending from the first ring to the second ring, and a second connector extending from the first ring to the second ring. In some embodiments, a curvature of the first connector and a curvature of the second connector may extend at least partially radially outwardly relative to a central axis of the first ring and the second ring.
Claims
1. A reversibly deformable scaffold for implanting in a corneal pocket of a cornea and having (i) a relaxed state in which the scaffold has a predetermined peripheral shape before implantation in the corneal pocket, and (ii) a deformed state in which the scaffold is configured to be implanted into the cornea, the scaffold being configured to return to the relaxed state inside the corneal pocket, the scaffold comprising: a first ring and a second ring, the first ring having a first circumference and the second ring having a second circumference, wherein the second circumference is greater than the first circumference; a first connector extending from the first ring to the second ring, the first connector being arcuate in the relaxed state; and a second connector extending from the first ring to the second ring, the second connector being arcuate in the relaxed state; wherein a curvature of the first connector extends at least partially radially outwardly relative to a central axis of the first ring and the second ring, and a curvature of the second connector extends at least partially radially outwardly relative to the central axis of the first ring and the second ring; wherein the scaffold comprises a material having a rigidity that is greater than that of the cornea such that implantation into the corneal pocket results in a flattening of a central region of the cornea.
2. The scaffold of claim 1, wherein the first connector and the second connector are coplanar.
3. The scaffold of claim 1, wherein the first ring extends in a first plane, the second ring extends in a second plane that is parallel to the first plane, and the first connector extends in a third plane that is perpendicular to the first plane and the second plane.
4. The scaffold of claim 3, wherein the third plane intersects the central axis.
5. The scaffold of claim 1, wherein a radius of curvature of the first connector is less than a radius of curvature of the cornea.
6. The scaffold of claim 4, wherein the second connector extends in a fourth plane that is perpendicular to the to the first plane and the second plane, the fourth plane being different than the third plane.
7. The scaffold of claim 6, wherein the third plane is perpendicular to the fourth plane.
8. The scaffold of claim 1, wherein the scaffold, in the relaxed state, is formed in the shape of a truncate dome.
9. The scaffold of claim 1, wherein the scaffold is configured to reduce astigmatism when placed in the corneal pocket.
10. The scaffold of claim 1, wherein, upon implantation, the first ring is closer to the central region of the eye than is the second ring.
11. A method for treating myopia, the method comprising: inserting a reversibly deformable scaffold into a corneal pocket of a cornea, the scaffold being in a deformed state during insertion, wherein after insertion, the scaffold reversibly expands to a relaxed state in which the scaffold has a predetermined peripheral shape, the scaffold comprising: a first ring and a second ring, the first ring having a first circumference and the second ring having a second circumference, wherein the second circumference is greater than the first circumference; a first connector extending from the first ring to the second ring, the first connector being arcuate in the relaxed state; and a second connector extending from the first ring to the second ring, the second connector being arcuate in the relaxed state; wherein a curvature of the first connector extends at least partially radially outwardly relative to a central axis of the first ring and the second ring, and a curvature of the second connector extends at least partially radially outwardly relative to the central axis of the first ring and the second ring; wherein the scaffold comprises a material having a rigidity that is greater than that of the cornea such that implantation into the corneal pocket results in a flattening of a central region of the cornea.
12. The method of claim 11, wherein the first connector and the second connector are coplanar.
13. The method of claim 11, wherein the first ring extends in a first plane, the second ring extends in a second plane that is parallel to the first plane, and the first connector extends in a third plane that is perpendicular to the first plane and the second plane.
14. The method of claim 13, wherein the third plane intersects the central axis.
15. The method of claim 11, wherein a radius of curvature of the first connector is less than a radius of curvature of the cornea.
16. The method of claim 14, wherein the second connector extends in a fourth plane that is perpendicular to the to the first plane and the second plane, the fourth plane being different than the third plane.
17. The method of claim 16, wherein the third plane is perpendicular to the fourth plane.
18. The method of claim 11, wherein the scaffold, in the relaxed state, is formed in the shape of a truncate dome.
19. The method of claim 11, wherein implanting the scaffold into the corneal pocket reduces astigmatism.
20. The method of claim 11, wherein, upon implantation, the first ring is closer to the central region of the eye than is the second ring.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0046] FIGS. 1A, 1B, 1C, and 1D illustrate prior art corneal implants.
[0047] FIGS. 2A through 2C illustrates a first embodiment of apparatus of the present invention.
[0048] FIGS. 3A through 3C illustrate side views of a corneal implant as it is advanced and constrained by the apparatus of FIGS. 2A-2C.
[0049] FIGS. 4A through 4D illustrate a second embodiment of the apparatus of the present invention.
[0050] FIGS. 5A through 5D illustrate side views of a corneal implant as it is advanced and constrained by the apparatus of FIGS. 4A-4D.
[0051] FIGS. 6A through 6C illustrate a third embodiment of the apparatus of the present invention.
[0052] FIGS. 7A and 7B illustrate use of the apparatus of FIGS. 6A-6C in implanting an implant in a cornea.
[0053] FIGS. 8A through 8F illustrate preferred corneal implants in accordance with the present invention.
[0054] FIGS. 9A through 9F illustrate a further implantation protocol in accordance with the present invention.
[0055] FIGS. 10A through 10F illustrate a further implantation protocol in accordance with the present inventions.
[0056] FIGS. 11A through 11F illustrate a further implantation protocol in accordance with the present inventions.
[0057] FIGS. 12A and 12B illustrate a tool in accordance with the principles of the present invention for collapsing and advancing a corneal implant.
[0058] FIGS. 13A and 13B illustrate an alternative tool in accordance with the principles of the present invention for collapsing and advancing a corneal implant.
[0059] FIGS. 14A and 14C are cross-sectional views of the tool of 13A and 13B showing the implant as it is advanced as shown in FIGS. 15A through 15D.
[0060] FIGS. 15A through 15D illustrate use of the tool of FIGS. 13A and 13B for advancing and reducing the cross-section of an implant in accordance with the principles of the present invention.
[0061] FIGS. 16 A-F illustrate an alternative tool in accordance with the principles of the present invention for collapsing and advancing a corneal implant.
[0062] FIGS. 17 A-C illustrate a corneal scaffold embodiment of the corneal implant for the treatment of myopia.
[0063] FIGS. 18A-B illustrate a corneal scaffold embodiment of the corneal implant for the treatment of hyperopia.
[0064] FIGS. 19 A-B illustrate a corneal scaffold embodiment of the corneal implant for the treatment of hyperopic astigmatism.
[0065] FIGS. 20 A-B illustrate a corneal scaffold embodiment of the corneal implant which also includes a lens.
[0066] FIGS. 21A-C illustrate an implantation protocol useful for implanting the corneal implant illustrated in FIG. 8F.
DETAILED DESCRIPTION
[0067] FIG. 1A shows a top view of a cataract surgery lens implant 2. A round optic 5 of the implant 2 has haptics 10 which extend from the periphery of the optic. The haptics 10 are used to help the optic center and fixate within the capsular bag. FIG. 1B shows a side view of a cataract surgery lens implant optic 5. Note that the thickness t.sub.1 of the optic 5 is typically 1 mm or more and is substantially greater than the 0.5 to 0.6 mm thickness of the human cornea. The thickness of the optic 5 makes it inappropriate for use as a corneal lens implant. FIG. 1C shows a top view of a corneal implant 15. Note there are no haptics on the corneal implant. FIG. 1D shows a side view of corneal implant 15. Note that the thickness t.sub.2 is substantially less than cataract surgery lens implant 5. The thickness t.sub.2 of corneal implant 15 would in general be less than the thickness of the human cornea.
[0068] FIG. 2A shows a corneal implant delivery system 18 in partial section. A hollow member 20 having a distal tip 21 (which is preferably beveled or chamfered) defines hollow axial passage 25 (e.g. an axial lumen). Axial pusher 30 has a tip 35 that engages a corneal implant 15 that has been deformed in shape and constrained to fit inside the hollow axial passage 25 of the hollow member 20, as shown in FIG. 2B. The cross-section of hollow passage 25 may be circular, polygonal, or any other shape that is conducive to constraining the corneal implant 15. The hollow axial passage 25 of the hollow member 20 may contain ridges, protrusions, indentations, or recesses (now shown) which help to maintain orientation of the corneal implant as it advances distally of the hollow member (not shown). Axial pusher 30 engages one end of the constrained corneal implant 15 to advance the constrained implant through hollow passage 25. FIG. 2C shows the constrained corneal implant 15 emerging from a distal end of the hollow passage 25 still in its deformed and constrained configuration. By placing the tip of the hollow member 20 through an incision in the cornea, the corneal implant 15 may be advanced into the corneal pocket (not shown) through even a very small incision. In preferred aspects, the corneal implant is able to pass through an entry incision that is less than one-half the width of the corneal implant. In those cases, the hollow member will have an external width from 0.5 mm to 5 mm, preferably from 1 mm to 3 mm and an internal width from 0.3 mm to 4.8 mm, preferably from 0.8 mm to 2.8 mm.
[0069] FIG. 3A shows a side view of corneal implant 15 in its non-deformed, non-constrained shape. FIGS. 3B and 3C shows an end on view of the corneal implant 15 as it is moved within the hollow member 20. Note that the corneal implant 15 has been deformed and constrained into a rolled configuration. The rolled configuration will preferably have a diameter in the range from 0.3 mm to 4.8 mm, more preferably from 0.6 mm to 2.6 mm, to fit into the hollow passage 25 of the hollow member 20.
[0070] FIG. 4A-4D shows a corneal implant delivery system with a deformation chamber 27 and a deforming member 28. In this embodiment of the invention, the corneal implant 15 is placed into the chamber 27 in an unconstrained and not deformed configuration and is then deformed into a folded or rolled corneal implant 17 within deformation chamber 27 by deforming member 28. Deforming member 28 is moved within deformation chamber 27 to deform and fold corneal implant 15 into a folded or rolled corneal implant 17. FIG. 4C shows axial pusher 30 engaging deformed corneal implant 17 by implant mover tip 35. FIG. 4D shows deformed and folded corneal implant 17. Axial pusher 30 engages corneal implant 17 to push the deformed constrained implant inside hollow passage 25. FIG. 4D shows that corneal implant 17 has been advanced by axial pusher 30 out of the hollow passage 25 while retaining a constrained shape. The constrained configuration of corneal implant 17 allows passage into the corneal pocket (not shown) through a small incision. The presence of the optional deformation chamber 27 and deforming member 28, advantageously allows the corneal implant 15 to be easily deformed into a configuration that will allow it to be placed through a small corneal incision into a corneal pocket.
[0071] FIGS. 5A-5D show side views of the corneal implant 15 being deformed into an exemplary deformed and folded or pleated corneal implant 17.
[0072] FIGS. 6A-6C show a top view of an alternative corneal implant delivery system 100. In this embodiment a corneal implant 115 is placed into a deformation area 122. When the wings 123 of the deformation area are closed, a deformation chamber 124 (FIG. 6B) is formed which deforms the corneal implant 115. In this embodiment, the corneal implant 115 is folded in half. A tip 132 of an axial pusher 130 engages corneal implant 115. The hollow member 120 is tapered so that hollow passage 126 is narrower at a distal end 121 that inserts into the corneal pocket. This allows the corneal implant 115 to be deformed into an even smaller cross-section as the implant is advanced distally and through the distal end 121. Advantageously in this embodiment, the implant mover tip 132 may also be deformable to fit within the narrowing hollow passage 126.
[0073] FIG. 7A shows a side cross-sectional view of corneal implant 115 being inserted into corneal pocket 140. FIG. 7B shows the final shape of corneal implant 115 after it has been inserted into corneal pocket 140 and unfurled or otherwise expanded back to its unconstrained size within cornea 145.
[0074] FIG. 8A illustrates a cross-sectional view of a corneal implant prosthesis 50 Corneal implant 50 is meant to replace a portion of the anterior layers of the cornea. In this embodiment there is a central optic 52 that protrudes anteriorly from a rim 54. In preferred aspects, the central optic would protrude anteriorly from the rim by 1 to 600 microns. More preferably, the central optic would protrude anteriorly from the rim by 50 to 400 microns. The central optic 52 will replace diseased anterior corneal tissue that has been removed. The rim 54 is designed to partly or fully surround the center of optic and to fit within the peripheral recesses of a corneal pocket in order to anchor the corneal implant prosthesis to the cornea. The rim may be a continuous skirt as illustrated or may be crenellated or otherwise distributed in sections about the periphery of the center optic. FIG. 8B shows a top view of corneal implant prosthesis 50 which shows the central optic 52 and the rim 54. The rim 54 may optionally contain holes or be porous in nature so as to promote growth of corneal tissue into and through the implant, in order to promote retention and biocompatibility.
[0075] FIG. 8C shows a cross-sectional view of corneal implant prosthesis 60 which is meant to replace a full-thickness area of the cornea. FIG. 8D shows a top view of the same implant prosthesis 60. In this embodiment there is an anterior portion of central optic 62 which protrudes anteriorly from a rim 64. The anterior portion of central optic 62 will replace diseased anterior corneal tissue that has been removed. In preferred aspects, the central optic would protrude anteriorly from the rim by 1 to 600 microns. More preferably, the central optic would protrude anteriorly from the rim by 50 to 400 microns. In addition corneal implant prosthesis 60 has a posterior portion of central optic 66 which protrudes posteriorly from rim 64. In preferred aspects, the central optic would protrude posteriorly from the rim by 1 to 900 microns. More preferably, the central optic would protrude posteriorly from the rim by 50 to 800 microns. The posterior portion of central optic 63 will replace diseased posterior corneal tissue that has been removed. The rim 64 will anchor corneal implant prosthesis 60 within the peripheral recesses of the corneal pocket and provide a water-tight seal. The rim 64 may optionally contain holes or be porous in nature so as to promote growth of corneal tissue into and through the implant, in order to promote retention and biocompatibility. The rim may be formed from any of the lens materials described above.
[0076] FIG. 8E is an enlarged view of the reversibly deformable implant prosthesis 60 shown in FIGS. 8C and 8D. The center optic 62 includes a protruding anterior optic 62 a and optionally a protruding posterior optic 62 b. The rim 64 surrounds the center optic 62 and defines said anterior and posterior protruding optics 62 a and 62 b. Preferably, the implant prosthesis 60 is formed as an integrated or monolithic structure and is free from discontinuities, joints, adhesions, connections, and other fabrication artifacts. In a specific aspect, the sidewall of the anterior protruding optic 62 a is disposed at an angle relative to the plane which intersects the junction of the rim in the anterior optic between 1 and 144. The diameter d.sub.1 of the anterior optic is preferably between 3 mm and 9 mm, while the diameter d.sub.2 of the posterior optic is also between 3 mm and 9 mm, although the two diameters are not necessarily equal. The diameter d.sub.3 of the rim will usually be substantially greater than that of either of the optics, typically being in the range from 3.5 mm to 12 mm.
[0077] The anterior surface of the center optic will typically be curved, more typically being generally spherical with a radius in the range between about 3 mm and 4 mm. The anterior surface of the rim 64 will usually be conical or generally spherical, with spherical surfaces having a radius generally in the range between 1.5 mm and 9 mm, and often being the same as that of the anterior surface of the anterior optic 62 a. The posterior surface of the rim 64 will also generally be conical or spherical, typically being spherical with a radius in the range from about 1.5 mm to about 9 mm. The posterior face of the posterior optic 62 b may be planar or have a radius in the range from 1.5 to 9 mm. The total thickness t of the center optic 60 will typically be in the range from 0.1 mm to 3 mm, with t.sub.1 being in the range from 0.01 mm to 0.15 mm, t.sub.2 being in the range from 0.05 mm to 1.1 mm, and t.sub.3 being in the range from 0.05 mm to 0.5 mm, and t.sub.4 being in the range from 0 mm to 2 mm.
[0078] Referring now to FIG. 8F, a further corneal prosthesis 500 constructed in accordance with the principles of the present invention, comprises a center optic 502 having an anterior rim 504 and a posterior rim 506. At least the anterior rim 504 and posterior rim 506 are sufficiently flexible so that they may be collapsed upon introduction into a corneal opening or pocket when introduced in accordance with the methods of the present invention. Often, the center optic 502 will also be compressible. The corneal implant 500 will typically be molded, cast, machined from a single material and will be free from discontinuities and artifacts of fabrication as discussed above with respect to the implant 60. Corneal implant 500 will typically have a total thickness t which is sufficient for implantation in the cornea to span the full thickness of the cornea, typically being in the range from 0.1 mm to 3 mm. The thickness t.sub.1 of the anterior rim 504 between the top of the center optic 502 and the top of the rim is in the range from 0.001 mm to 0.3 mm, while the bottom of the anterior rim is recessed by a distance t.sub.2 in the range from 0 mm to 0.3 mm. The center optic between the anterior rim and the top of the posterior rim 506 will typically have a length t.sub.3 in the range from 0.1 mm to 1.2 mm, while the posterior rim 506 will have a thickness t.sub.4 in the range from 0.01 mm to 2 mm.
[0079] The center optic 502 of the implant 500 will typically be cylindrical and have a diameter selected to correspond to the diameter of the opening formed in the cornea, although often the diameter when the implant is fully hydrated will be slightly greater than that of the opening. Usually, the diameter d.sub.2 of the center optic 502 will be in the range from 3 mm to 9 mm. The widths of the anterior rim 504 and the posterior rim 506 will be greater than the diameter of the center optic 502 since the rims will be holding the center optic in place. Typically, the rims 504 and 506 will have circular geometries, although a variety of other shapes could be used, with the anterior rim having a diameter d.sub.1 in the range from 3.5 mm to 12 mm and the posterior rim having a diameter d.sub.3 in the range from 3.5 mm to 12 mm. Methods for introducing the implant 500 into a corneal opening are described in more detail below with reference to FIGS. 21A-21C.
[0080] FIGS. 9A-9F show a method of treating an anterior corneal disease process using the methods and apparatus of the present invention. In each FIG. 9A-F, a cross-sectional view of the cornea is seen above and a top view is seen below. In FIG. 9A it is shown that pocket 40 has been created posterior to anterior diseased cornea 43. FIG. 9B shows that anterior diseased cornea 43 has been excised with a circular trephine (not shown) to create an open top having a peripheral pocket. The edge of the excision is shown as 45. FIG. 9B also shows corneal implant 50 resting in the deformation area 122. In FIG. 9C the hollow member 120 has been inserted into pocket 40 through external opening 42 and corneal implant 50 has been folded in half within deformation chamber 124. FIG. 9D shows that corneal implant 50 has been further deformed into a more compact shape by its movement through narrowing hollow passage 126 and is being extruded into pocket 40. FIG. 9E shows that corneal implant 50 has been restored to its original shape within corneal pocket 40. Central optic 52 fills the space left by excised diseased anterior cornea 43 and restores optical clarity to the cornea. Hollow member 120 and implant mover 30 have been withdrawn from corneal pocket 40. FIG. 9F shows the final appearance of corneal implant 50 fixated within corneal pocket 40.
[0081] FIGS. 10 A-10F show a method of treating a full-thickness corneal disease (e.g. pseudophakic bullous keratopathy) through the use of the present invention. In each FIG. 10 A-F, a cross-sectional view of the cornea is seen above and a top view is seen below. In FIG. 10A it is shown that pocket 40 has been created within the layers of the diseased cornea 41. The pocket divides the cornea into diseased anterior cornea 43 and diseased posterior cornea 44. FIG. 10B shows that anterior diseased cornea 43 has been excised with a circular trephine (not shown). The edge of the excision is shown in dashed lines as 45. The opening in the anterior cornea within the edge of the excision 45 is shown at reference number 46. FIG. 10B also shows corneal implant 60 resting in the deformation charter or area 122. In FIG. 10C the hollow member 120 has been inserted into pocket 40 through external opening 42 and corneal implant 60 has been folded in half within deformation chamber 122. FIG. 10D shows that corneal implant 60 has been further deformed into a more compact shape by its movement through narrowing hollow passage 126 and is being extruded into pocket 40. FIG. 10E shows that corneal implant 60 has been restored to its original shape within corneal pocket 40. Anterior optic 62 fills the space left by the excised diseased anterior cornea 43. In preferred aspects, after corneal implant 60 has been positioned in the pocket, the posterior diseased cornea 44 can be excised with low profile curved corneal scissors or some other cutting tool (e.g. plasma blade) inserted through external opening 42. FIG. 10F shows the final appearance of corneal implant prosthesis 60. Note that the rim 64 anchors corneal implant prosthesis 60 within the peripheral recesses of the corneal pocket and provides a water-tight seal. In this embodiment, posterior optic 63 protrudes through the space left by excised diseased cornea 44. However, posterior optic 63 is optional and is not necessarily required for the corneal implant to properly function. It is to be understood that the relative dimensions, shapes, and angles of the anterior central optic 62, posterior central optic 63, and rim 64, may each be modified to promote improved retention as well as optical qualities all in keeping within the scope of the present invention.
[0082] In alternative preferred aspects, the corneal implant 60 may be introduced into the pocket 40 using the injector system as described previously in FIGS. 9 and 10 through an opening 46. The hollow member 120 may be inserted through the opening 46, and the corneal implant 60 then injected into the pocket 40. In yet other alternative preferred aspects, the corneal implant 60 may be placed into the pocket 40 by constraining the corneal implant 60 into a small diameter configuration (e.g. with forceps) and inserting it through the opening 46 into the pocket 40 without the use of the hollow member 120 (not shown).
[0083] FIG. 11A-11F show an embodiment of a corneal implant that can be assembled within the corneal pocket. By assembling individual smaller pieces of the corneal implant within the corneal pocket, a relatively large corneal implant can be constructed while using a relatively small external incision. The top portion of FIGS. 11A and 11B show a cross-sectional view of a cornea with an intra-stromal pocket. The bottom portion of FIG. 11A shows a top down view of a cornea with an intra-stromal pocket. In both FIGS. 11A and 11B, it can be seen that the first half of the rim 70 has already been inserted inside the pocket. A second half of the rim 74 is being inserted through the small external incision. Note that because the corneal tissue is partially elastic, the rim may be made of a relatively rigid material e.g. polymethylmethacrylate (PMMA) and still be inserted through the external opening 42 that is less than half of the diameter of the assembled corneal implant. The vertical dashed lines in the top of the figure and the circular dashed lines in the bottom figure represent an opening 76 left by a circular disk of anterior stromal tissue that has been excised (e.g. with a trephine). FIGS. 11C and 11D show that the optic 72 may fit into opening 76. FIGS. 11E and 11F show that the optic 72 has been attached to the two halves of the rim 70 and 74 to complete assembly of the corneal implant. The individual pieces of the corneal implant may be attached to each other by interlocking fittings (not shown), by glue, or any other appropriate mechanical or chemical method of fixation. In this embodiment of the invention the corneal implant is shown as a three piece prosthesis that replaces part of the cornea. However, it is to be understood that the invention includes any corneal implant that can be assembled as two or more pieces within a corneal pocket.
[0084] FIGS. 12A-12B are end views of the back of a deformation chamber 86 on a hollow member 80 which show how the presence of a protrusion 82 within the deformation chamber can help to maintain the orientation of a corneal implant 90 as it is pushed in an axial direction. Deformation chamber 86 includes three hinged sections 80 a, 80 b, and 80 c which make up a hollow member which opens in order to receive corneal implant 90. At the lateral aspects of deformation area 80 are two protrusions 82, which help to hold the rim 94 of corneal implant 90 in place. FIG. 12B shows how sections 80 a, 80 b, and 80 c can be closed by putting together the wings 84 (which together form an axial pusher or implant mover) to create hollow member 80 and deformation chamber 86. Corneal implant 90 is now securely fixated within the hollow deformation chamber 86 by the protrusions 82 and can be manipulated. The corneal implant 90 can then be moved axially along hollow member 80 by an axial pusher or other implant mover (not shown) without inadvertent rotation of the corneal implant.
[0085] Please note at least some portion of the corneal implant could be colored in any of the embodiments of the invention to enhance the aesthetic appearance of the eye or to decrease the amount of light exposure to the eye (e.g. for treatment of aniridia).
[0086] Referring now to FIGS. 13A and 13B, a corneal implant insertion device 200 includes a deformation chamber 202 defined by two-circular hinged sections 204. The hinged sections 204 are attached to wings 206 which permit the hinged sections to be closed in order to capture the corneal implant C, after the implant has been introduced into the deformation chamber, as shown in FIG. 13B.
[0087] Protrusions 210 having interior arcuate surfaces 212 are attached to the hinged sections 204 so that the surfaces 212 form radially inwardly directed ramps, as illustrated in FIG. 14A. Thus, after the corneal implant C is introduced into the deformation chamber 202, as illustrated in FIG. 13B, closure of the chamber using the wings 206 will curl the corneal implant C into a C-shaped profile, as shown in FIG. 14A. This can be an advantage over the corneal insertion tool embodiment of FIGS. 12A and 12B where the edges of the implant are held in a generally open configuration by the outwardly facing surfaces of protrusions 82.
[0088] In a specific embodiment of the corneal implant insertion device of the present invention, the corneal implant C comprises a lamellar corneal stromal endothelial transplant graft of approximately 9 mm in diameter and 100 m to 200 m in thickness. The deformation chamber 220 has a diameter or width D of approximately 9 mm in order to receive the corneal implant C such that its edges are disposed beneath the arcuate surfaces 212 of the protrusions 210, as illustrated in FIG. 13B.
[0089] Referring now to FIGS. 15A through 15D, a pusher shaft 230 having a forward member 232 may be advanced into the deformation chamber 202 of the corneal implant insertion device 200. The forward element 232 will have a profile which is similar to the shape of the hollow passage so that it can pass over the protrusions 210 and will typically be compressible so that it can pass into a tapered region 240 of the insertion device, as shown in FIG. 15D. Thus, the forward member 232 will first be introduced into the constant-diameter portion of the deformation chamber 202, as shown in FIG. 15B, and used to advance the corneal implant C forwardly. The shaft 30 and forward member 232 will continue to be advanced so that the corneal implant C is pushed from the distal tip of the tapered region 240, as shown in FIG. 15C.
[0090] As the corneal implant C is advanced, its edges will be curved or everted inwardly, as illustrated in FIGS. 14A through 14C. In FIG. 14A, the corneal implant C is shown as it is in FIG. 15A. As it advances forwardly, as shown in FIG. 15B, the corneal implant C is reduced in diameter with the edges being pushed radially inwardly, as shown in FIG. 14B. Finally, as the corneal implant C is released from the proximal tip of the tapered region 240, it has a significantly reduced diameter, as shown in FIG. 14C. It is particularly desirable that the corneal implant C be reduced in size to as great an extent as possible but that the leading tips of the implant not touch the interior surface, just as shown in FIG. 14C. This reduces the damage or trauma to the delicate corneal endothelial cells during the implantation protocol.
[0091] In an embodiment illustrated in FIGS. 16A-F, a graft C, such as a DSEK or DMEK graft, is placed stromal side down onto the surface of implant mover 300. Implant mover 300 has a flexible platform 310 which provides a loading area and which consists of a thin flexible material, such as a plastic. FIG. 16A shows the DSEK or DMEK graft C on the platform 310 from a top view. FIG. 16 B shows the DSEK or DMEK graft C on the platform 310 in side profile. FIG. 16E shows the DSEK or DMEK graft on the platform 310 from a front view at the start of the loading process. FIG. 16E is shown at the same time point of the loading process as FIGS. 16A and 16B. FIG. 16 C is a top view which shows that when platform 310 is pulled into a hollow member 320 by implant mover member 300 that the flexible platform 310 will become constrained in size and shape. Because the DSEK or DMEK graft C is flexible it will also become constrained in size and shape inside the flexible platform 310. FIG. 16 D shows a side view at the same time point as 16C. FIG. 16F shows how DSEK or DMEK graft C is restrained inside flexible platform 310 into a small diameter configuration. In FIGS. 16A-D and 16 F an internal arcuate protrusion 330 will force the flexible platform 310 and DSEK graft C to curl in a way that engages only the stromal surface, thereby protecting the delicate corneal endothelium located on the inside of the DSEK or DMEK Graft C. When DSEK or DMEK graft C is to be inserted into the anterior chamber, hollow member 320 is advanced into the corneal or scleral incision. Implant mover 300 is then advanced, allowing flexible platform 310 and DSEK Graft C so that DSEK Graft C can unfurl and be released into the anterior chamber. FIGS. 16A-D show an optional bevel to the end of hollow member 320 which advantageously allows for easier insertion into the ocular incision. The optional bevel has an angle between 1 and 89, preferably between 25 and 65.
[0092] FIG. 17A shows a top view of a corneal scaffold implant 400 which is designed for correcting myopia. The scaffold implant 400 is formed from discrete elements 402 which provide a peripheral shape which is a truncate dome. An interior volume of the dome is empty and free from structure. FIG. 17B is an oblique view which shows the shape of the cornea C prior to insertion of the corneal scaffold implant 400 for myopia into a corneal pocket through incision I. FIG. 17C shows how the insertion of corneal scaffold implant for myopia 400 flattens the cornea in the direction of the arrow 404 and thereby reduces myopia.
[0093] FIG. 18A shows a top view of a corneal scaffold implant 410 which is designed for the purpose of correcting hyperopia. The implant 410 comprises elements 412 which form a higher truncated dome than implant 400. FIG. 18B shows how the insertion of this corneal scaffold implant for hyperopia 410 steepens the cornea in the direction of the arrow and thereby reduces hyperopia.
[0094] FIG. 19A shows a top view of a corneal scaffold implant 420 which is designed for the purpose of correcting hyperopic astigmatism. The implant 420 comprises two lateral wings 422 joined by a central ring 424. FIG. 19B shows how the insertion of this corneal scaffold implant for hyperopic astigmatism 420 steepens the central cornea in the direction of the arrow and thereby reduces hyperopia and also flattens the steep axis of the cornea thereby reducing astigmatism.
[0095] FIG. 20A shows a top view of a corneal scaffold implant 430 which also contains a lens L shown in hatched lines. FIG. 20B shows how the insertion of this corneal scaffold implant with a lens 430 corrects refractive error by both changing the shape of the cornea (flattening in this case) and by introducing an additional lens to the optical system.
[0096] The scaffold may be formed from the same polymers as described previously by common techniques, such as molding. Many other shapes and structures for the corneal scaffold implant can be devised for the treatment of myopia, hyperopia, astigmatism, higher order aberrations and ectactic corneal diseases. Our invention includes all of the possible three dimensional shapes and structures where it is not possible for a single plane to pass through all of the elements of the structure.
[0097] The corneal implant 500 described previously with reference to FIG. 8F can be reversibly deformed and inserted into a full-thickness opening O in a cornea C, as illustrated in FIGS. 21A-21C. The opening O will typically be smaller than the corneal implant 500 and, in order to insert the implant into the opening, at least the posterior rim will be constrained against the sidewall of the center optic 502, as shown in FIG. 21B. Such constraint may be achieved with the various insert apparatus, including the tapered tubes as described hereinbefore. Alternatively, the deformation could be achieved using conventional forceps or other surgical tools. The implant 502 is inserted fully so that the anterior rim 504 engages the upper surface of the cornea C in the region surrounding the opening O with the posterior rim 506 returning to its unconstrained state and engaging the anterior surface of the cornea, as illustrated in FIG. 21C. Thus, the rims 504 and 506 capture the anterior and posterior surfaces of the cornea to create a watertight seal. Optionally, sutures could be placed through the edges or peripheries of the rims 504 and 506, further optionally through holes (not shown), to secure the implant. Alternatively, the implant 500 could be introduced through a separate incision into the cornea with the anterior plate being constrained as the implant is pushed upwardly or in the anterior direction, with the anterior rim 504 emerging from the top surface and resuming an unconstrained geometry to capture the cornea.
[0098] While the above is a complete description of the preferred embodiments of the invention, various alternatives, modifications, and equivalents may be used. Therefore, the above description should not be taken as limiting the scope of the invention which is defined by the appended claims.
