Reversibly deformable artificial cornea and methods for implantation

Abstract

An artificial cornea is formed from a hydro gel polymer and includes a monolithic body having a center optic surrounded by an annular rim. Artificial cornea is inserted into a central anterior opening in a cornea so that the annular rim enters an annular pocket surrounding the opening. The height of the center optic matches the depth of the central opening so that the level of the artificial cornea matches that of the native cornea.

What is claimed is: 
     
         1 . A reversibly deformable artificial cornea comprising:
 a monolithic body having a diameter between 4 mm and 10 mm comprising a center optic surrounded by a rim, wherein the center optic has a diameter in the range from 3 mm to 9 mm and a optic height in the range from 200 μm to 800 μm and the rim has a width in the range from 0.5 mm to 4.5 mm and a median thickness in the range from 50 μm to 200 μm;   wherein the monolithic body is comprised of a polymeric hydrogel having a Young's modulus in the range from 0.3 MPa to 100 MPa when fully hydrated.   
     
     
         2 . An artificial cornea as in  claim 1 , having a tensile strength of at least 1.5 MPa. 
     
     
         3 . An artificial cornea as in  claim 1 , having an elongation to break of at least 100%. 
     
     
         4 . An artificial cornea as in  claim 1 , wherein the optic height of the center optic varies less than ±50 μm. 
     
     
         5 . An artificial cornea as in  claim 1 , wherein an angle between the center optic and the rim varies by less than ±10°. 
     
     
         6 . An artificial cornea as in  claim 1 , wherein the rim circumscribes a posterior edge of the center optic. 
     
     
         7 . An artificial cornea as in  claim 1 , wherein at least an anterior surface of the center optic is convexly shaped to provide a refractive power generally equal to a native cornea. 
     
     
         8 . An artificial cornea as in  claim 7 , wherein a center optic provides a refractive power in the range from 30 diopter to 70 diopter when implanted in a cornea. 
     
     
         9 . An artificial cornea as in  claim 8 , wherein both the anterior and posterior surfaces of the center optic are convexly shaped. 
     
     
         10 . An artificial cornea as in  claim 9 , wherein the anterior surface is flatter than the posterior surface. 
     
     
         11 . An artificial cornea as in  claim 1 , wherein the rim has apertures to allow passage of nutrients and oxygen. 
     
     
         12 . An artificial cornea as in  claim 11 , wherein the apertures occupy from 10% to 90% of the annular area of the rim. 
     
     
         13 . An artificial cornea as in  claim 9 , wherein the apertures are round holes disposed uniformly about the annular rim. 
     
     
         14 . An artificial cornea as in  claim 1 , wherein the polymeric hydrogel comprises material selected from the group consisting of a hydrophilic acrylic material, a hydrophobic acrylic material, a silicone polymer hydrogel, a collagen polymer hydrogel, and an interpenetrating network hydrogel. 
     
     
         15 . An artificial cornea as in  claim 1 , wherein the polymer hydrogel has an oxygen permeability of at least 3 Barrer. 
     
     
         16 . An artificial cornea as in  claim 1 , wherein the polymer hydrogel comprises a material selected from the group consisting of Lotrafilcon A, Lotrafilcon B, Balafilcon A, Comfilcon A, Senofilcon A, Enfilcon A and Galyfilcon A. 
     
     
         17 . An artificial cornea as in  claim 1 , wherein an annular peripheral region of an anterior face of the center optic promotes epithelial growth while the anterior face within the annular peripheral region inhibits epithelial growth. 
     
     
         18 . An artificial cornea as in  claim 17 , wherein the annular peripheral region is covered with an epithelial growth-promoting material, is roughed, or is porous. 
     
     
         19 . An artificial cornea as in  claim 17 , wherein the anterior face of the center optic within the annular peripheral region is covered with a material that inhibits epithelial growth. 
     
     
         20 . A method for implanting an artificial cornea in a cornea having an impaired center region, said method comprising:
 forming in the cornea a central anterior opening having a posterior surface surrounded by a peripheral side wall, wherein the opening has a uniform peripheral depth in the range from 200 μm to 800 μm; and   implanting an artificial cornea in the central anterior opening wherein the implant has a center optic with a peripheral wall having a uniform optic height within ±50 μm of the peripheral depth of the central anterior opening.   
     
     
         21 . A method as in  claim 20 , further comprising:
 forming a lamellar pocket around at least a portion of peripheral side wall of the central anterior opening; and   inserting a rim circumscribing the corneal implant into the lamellar pocket to anchor the implant in the opening.   
     
     
         22 . A method as in  claim 21 , wherein the lamellar pocket is formed around the periphery of the posterior surface of the central anterior opening and the rim surrounding a posterior edge of the center optic of the corneal implant. 
     
     
         23 . A method as in  claim 20 , wherein the central anterior opening is formed to have a diameter smaller than that of the center optic, wherein the corneal tissue seals against the peripheral wall of the center optic to inhibit the ingrowth of epithelial cells, the entry of bacteria, and the loss of fluid. 
     
     
         24 . A method as in  claim 20 , wherein the implant is inserted in a posterior direction through the anterior opening 
     
     
         25 . A method as in  claim 20 , further comprising forming a lateral passage through the cornea into the central anterior opening and inserting the corneal implant through the lateral passage. 
     
     
         26 . A method as in  claim 20 , wherein the artificial cornea anchors without sutures or adhesive. 
     
     
         27 . A method as in  claim 20 , wherein a lamellar pocket is first made across the central cornea and then the central anterior opening is created over the region of the lamellar pocket.