Corneal implants and methods and systems for placement

Abstract

A system comprising a hollow member is used to deliver a constrained corneal implant into a corneal pocket. The hollow member may be tapered and the system may further include an implant deformation chamber and an axial pusher to advance the implant through the hollow member.

What is claimed is: 
     
         1 . A method for delivering a corneal implant to a cornea, said method comprising:
 constraining the implant at an initial width;   advancing the implant through a tapered chamber to reduce the width of the width wherein opposed edges of the implant are curved radially inwardly as the implant is advanced; and   releasing the constrained implant into the cornea at the reduced width.   
     
     
         2 . A method as in  claim 1 , wherein the implant comprises a polymer having a tensile strength in the range from 0.1 MPa to 4 MPa and a modulus in the range from 0.1 MPa to 5 MPa. 
     
     
         3 . A method as in  claim 1 , further comprising placing the implant on a thin, flexible carrier prior to constraining the implant and the carrier. 
     
     
         4 . A method as in  claim 1 , wherein constraining comprises closing semi-circular halves of a deformation chamber on the implant. 
     
     
         5 . A method as in  claim 1 , wherein advancing comprises pushing a pusher member against the corneal implant. 
     
     
         6 . A method as in  claim 5 , wherein a forward portion of the pusher member conforms to the interior of the tapered chamber as the pusher member is pushed. 
     
     
         7 . A method as in  claim 1 , wherein the corneal implant is a biological implant. 
     
     
         8 . A method as in  claim 7 , wherein the biological implant comprises a lamellar corneal stromal endothelial transplant or DMEK graft. 
     
     
         9 . A method as in  claim 1 , wherein the implant is a synthetic implant. 
     
     
         10 . A system for delivering corneal implants, said system comprising:
 a hollow member having a proximal end and a distal end configured for insertion into a pocket within a cornea and having an axial hollow passage which tapers in the distal direction; and   an axial pusher disposed in the hollow axial passage of the hollow member to engage and axially advance a constrained corneal implant through the hollow passage,   wherein the axial hollow passage includes inwardly oriented arcuate surface which evert the edges of the corneal implant radially inwardly as the insert is axially advanced through the passage.   
     
     
         11 . A system as in  claim 10 , wherein the axial pusher includes a thin, flexible carrier for the implant and wherein the carrier has edges which are everted together with the edges of the corneal implant. 
     
     
         12 . A system as in  claim 11 , further comprising a corneal implant constrained within the hollow passage on a distal side of the axial pusher. 
     
     
         13 . A system as in  claim 11 , wherein the axial pusher is tapered in a distal direction. 
     
     
         14 . A system as in  claim 13 , wherein the axial pusher is deformable so that it will reduce in diameter as it is distally advanced through the tapered hollow passage. 
     
     
         15 . A system as in  claim 14 , wherein the axial pusher has a cross-sectional profile which is similar in shape to the cross-sectional profile of the hollow passage. 
     
     
         16 . A system as in  claim 15 , further comprising an implant deformation chamber coupled to the hollow member. 
     
     
         17 . A corneal implant comprising:
 a scaffold having a three-dimensional structure including discrete elements defining a shape with a mostly empty volume therein, wherein the shape is selected to provide a vision correction when placed in a corneal pocket.   
     
     
         18 . A corneal implant as in  claim 17 , wherein the shape flattens the cornea when placed in the pocket to correct myopia. 
     
     
         19 . A corneal implant as in  claim 17 , wherein the shape steepens the cornea when placed in the pocket to correct hyperopia. 
     
     
         20 . A corneal implant as in  claim 17 , wherein the shape steepens the central cornea and flattens the steep axis of the cornea when placed in the pocket to lessen hyperopia and reduce astigmatism. 
     
     
         21 . A corneal implant as in  claim 17 , where the shape flattens the central cornea and the steep axis of the cornea when placed in the corneal pocket in order to lessen myopia and reduce astigmatism. 
     
     
         22 . A corneal implant as in  claim 17 , further comprising a lens wherein the shape changes the shape of the cornea when placed in the pocket and the lens provides additional refractive error correction. 
     
     
         23 . A corneal implant as in  claim 17 , composed of a material such that the body has a tensile strength in the range from 2.5 MPa to 53 GPa and a Young's modulus in the range from 3 MPa to 5 TPa. 
     
     
         24 . A corneal implant as in  claim 23 , wherein the material comprises an acrylic copolymer. 
     
     
         25 . A corneal implant as in  claim 23 , wherein the material comprises a silicone or collagen copolymer. 
     
     
         26 . A corneal implant as in  claim 23 , wherein the shape flattens the cornea when placed in the pocket to correct myopia. 
     
     
         27 . A corneal implant as in  claim 23 , wherein the shape steepens the cornea when placed in the pocket to correct hyperopia. 
     
     
         28 . A corneal implant as in  claim 23 , wherein the shape steepens the central cornea and flattens the steep axis of the cornea when placed in the pocket to lessen hyperopia and reduce astigmatism. 
     
     
         29 . A corneal implant as in  claim 23 , further comprising a lens wherein the shape changes the shape of the cornea when placed in the pocket and the lens provides additional refractive error correction. 
     
     
         30 . A corneal implant as in  claim 23 , wherein the material comprises a metal. 
     
     
         31 . A corneal implant as in  claim 30 , wherein the metal is selected from the group consisting of gold, titanium, and nickel-titanium alloy, copper-zinc-aluminum-nickel alloy, and copper-aluminum-nickel alloy. 
     
     
         32 . A corneal implant as in  claim 23 , wherein the material comprises a fullerene. 
     
     
         33 . A corneal implant as in  claim 32 , wherein the fullerene is selected from the group consisting of carbon nanotubes, spheres, ellipsoids, planes, and ribbons. 
     
     
         34 . A method for delivering a corneal implant to a cornea, said method comprising:
 forming a central anterior opening in the cornea;   introducing the implant to the opening, wherein the implant includes a center optic and a peripheral rim and wherein said peripheral rim is constrained while being introduced; and   releasing the peripheral rim from constraint so that the peripheral rim radially expands to engage corneal tissue circumscribing the central anterior opening.   
     
     
         35 . A method as in  claim 34 , wherein forming comprises creating an opening extending from an anterior corneal surface through the full thickness of the cornea. 
     
     
         36 . A method as in  claim 34 , wherein forming comprises creating a partial opening which does not extend through the full thickness of the cornea. 
     
     
         37 . A method as in any one of  claims 34  to  36 , wherein the implant is introduced in a posterior direction into the central anterior opening. 
     
     
         38 . A method as in any one of  claims 34  to  36 , further comprising forming a pocket through a lateral opening in the cornea, wherein the implant is introduced through the lateral opening into the pocket and the central anterior opening. 
     
     
         39 . A method as in  claim 34 , wherein the corneal implant has a single rim about a mid-sectional region, wherein the rim extends into corneal tissue circumscribing the central anterior opening. 
     
     
         40 . A method as in  claim 34 , wherein the corneal implant has an anterior rim and a posterior rim, wherein the anterior rim radially expands over an anterior corneal surface circumscribing the central anterior opening and the posterior rim radially expands over a posterior corneal surface circumscribing the central anterior opening. 
     
     
         41 . A method as in  claim 34 , wherein the center optic is less compressible than the rim so that the center optic is not substantially compressed as the implant is being introduced. 
     
     
         42 . A method as in  claim 34 , wherein both the rim and the center optic are compressed while the implant is being introduced. 
     
     
         43 . A method as in  claim 34 , wherein introducing comprises advancing the implant through a tube having a width which compresses at least the rim and releasing comprises advancing the implant out of the tube. 
     
     
         44 . A method as in  claim 43 , wherein the implant is introduced through a passage in the tube, wherein the passage is tapered in a distal direction to progressively compress the rim before the implant is released. 
     
     
         45 . A reversibly deformable corneal implant comprising:
 a center optic having an anterior surface, a posterior surface, and a peripheral wall; and   at least one rim circumscribing at least a portion of the peripheral wall;   wherein, at least the rim is radially compressible to allow the implant to be radially constrained for insertion into a corneal pocket or opening.   
     
     
         46 . A corneal implant as in  claim 45 , wherein the center optic and at least one rim comprise a monolithic structure. 
     
     
         47 . A corneal implant as in  claim 46 , wherein the monolithic structure was formed by molding. 
     
     
         48 . A corneal implant as in  claim 46 , wherein the monolithic structure was formed by machining a block of material. 
     
     
         49 . A corneal implant as in any one of  claims 45  to  48 , consisting of a hydrogel. 
     
     
         50 . A corneal implant as in any one of  claims 45  to  48 , consisting essentially of a material selected from the group consisting of collagen, polyurethanes, poly(2-hydroxyethylmethacrylate), polyvinylpyrolidone, polyglycerolmethacrylate, polyvinyl alcohol, polyethylene glycol, polymethacrylic acid, silicones, polyfluorocarbons, and polymers with phosphocholine. 
     
     
         51 . A corneal implant as in any one of  claims 45  to  48 , consisting essentially of a material selected from the group consisting of a copolymer of hydroxyethyl methacrylate (HEMA) and methyl methacrylate (MMA). 
     
     
         52 . A corneal implant as in any one of  claims 45  to  48 , consisting essentially of a co-polymer of hydroxyethyl methacrylate (HEMA), methyl methacrylate (MMA), and methacrylic acid. 
     
     
         53 . A corneal implant as in any one of  claims 45  to  48 , comprising: (a) a multi-network hydrogel with a first network interpenetrated with at least one other network, wherein said first network and said other networks are based on biocompatible polymers and at least one of said network polymers is based on a hydrophilic polymer; (b) epithelization promoting biomolecules covalently linked to the surface of said multi-network hydrogel; and (c) corneal epithelial cells or cornea-derived cells adhered to said biomolecules. 
     
     
         54 . A corneal implant as in any one of  claims 45  to  48 , composed at least partially from a material selected from the group consisting of collagen and N-isopropylacrylamide, collagen and 1-ethyl-3.3′(dimethyl-aminopropyl)-carbodiimide, and collagen and N-hydroxysuccinimide (EDC/NHS). 
     
     
         55 . A corneal implant as in  claim 42 , comprising a single rim circumscribing the center optic location intermediate the anterior and posterior surfaces. 
     
     
         56 . A corneal implant as in  claim 51 , wherein the peripheral wall anterior to the rim is oriented at an angle in the range from 1° to 144° relative to the plane that passes through the junction of the peripheral wall and the rim. 
     
     
         57 . A corneal implant as in  claim 50 , wherein the center optic has a cylindrical peripheral wall with a diameter in the range from 3 mm to 9 mm and a thickness in the anterior-posterior direction in the range from 0.1 mm to 3 mm. 
     
     
         58 . A corneal implant as in  claim 57 , wherein the rim has a width in the range from 3.5 mm to 12 mm. 
     
     
         59 . A corneal implant as in  claim 52 , wherein the rim has a generally circular periphery with a concave profile in the posterior direction. 
     
     
         60 . A corneal implant as in  claim 45 , comprising at least an anterior rim circumscribing at least a portion of the peripheral wall at or near the anterior surface and a posterior rim circumscribing at least a portion of the peripheral wall at or near the posterior surface. 
     
     
         61 . A corneal implant as in  claim 55 , wherein the center optic has a cylindrical peripheral wall with a diameter in the range from 3 mm to 9 mm and a thickness in the anterior-posterior direction in the range from 0.1 mm to 3 mm. 
     
     
         62 . A corneal implant as in  claim 56 , wherein the anterior and posterior rims have widths in the range from 3.5 mm to 12 mm. 
     
     
         63 . A corneal implant as in  claim 57 , wherein the anterior and posterior rims have circular peripheries and convex or tapered anterior surfaces. 
     
     
         64 . A corneal implant as in  claim 23 , where the shape flattens the central cornea and the steep axis of the cornea when placed in the corneal pocket in order to lessen myopia and reduce astigmatism.