KERATOPROSTHESIS

Abstract

A keratoprosthesis includes an anterior collagen layer made of transparent synthetic collagen, and a hydrophobic posterior layer, an anterior surface of the posterior layer being posterior of an anterior surface of the collagen layer.

Claims

1. A method comprising: installing a keratoprosthesis in an eye, the keratoprosthesis comprising an anterior collagen layer made of transparent synthetic collagen and a hydrophobic posterior layer, wherein a most anterior surface of said posterior layer is posterior of a most anterior surface of said anterior layer, anterior and posterior being defined with respect to an anterior-posterior axis of the eye, and wherein said anterior collagen layer serves as a corneal stroma for the eye.

2. The method according to claim 1, wherein said anterior collagen layer is in complete 360° peripheral contact with natural ocular tissue of the eye.

3. The method according to claim 1, further comprising providing an additional anterior layer located on the most anterior surface of said anterior collagen layer.

4. The method according to claim 3, wherein said additional anterior layer is made of epithelial cells of a recipient of said device.

5. The method according to claim 3, wherein said additional anterior layer comprises a contact lens.

6. The method according to claim 1, wherein said anterior collagen layer is bonded to said hydrophobic posterior layer.

7. The method according to claim 1, wherein said anterior collagen layer has a diameter larger than that of said posterior layer.

8. The method according to claim 1, wherein said anterior collagen layer has a diameter equal to that of said posterior layer.

9. The method according to claim 1, wherein said anterior collagen layer has a diameter smaller than that of said posterior layer.

10. The method according to claim 1, wherein said anterior collagen layer is bonded to said hydrophobic posterior layer with a binding agent.

11. The method according to claim 10, wherein said binding agent comprises poly-L-lysine.

12. The method according to claim 10, wherein said binding agent comprises poly-D-lysine.

13. The method according to claim 10, wherein said binding agent comprises polymerized N-isopropyl acrylamide (pNIPAM).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The present invention will be understood and appreciated more fully from the following detailed description taken in conjunction with the drawings in which:

[0010] FIG. 1 is a simplified front view illustration of a keratoprosthesis, constructed and operative in accordance with an embodiment of the present invention.

[0011] FIG. 2 is a cross sectional view of the keratoprosthesis of FIG. 1, in accordance with one embodiment of the present invention.

[0012] FIG. 3 is a cross sectional view of the keratoprosthesis of FIG. 1, in accordance with another embodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

[0013] Reference is now made to FIG. 1, which illustrates a keratoprosthesis 10, constructed and operative in accordance with an embodiment of the present invention.

[0014] The keratoprosthesis 10 includes a central collagen layer 12 made of transparent synthetic collagen, and shaped as a corneal button. The optical properties of the collagen layer 12, such as but not limited to, convexity, optical power, and refractive properties, are selected for the particular patient. A posterior layer 14 is made of a material with good water-sealing or hydrophobic properties, such as but not limited to, PMMA or silicone and others.

[0015] The collagen layer 12, without limitation, has a thickness in the range of 100-550 μm, and a diameter larger than posterior layer 14. With its larger diameter, the collagen layer 12 is in complete 360° peripheral contact with the natural ocular tissue of the recipient. This natural contact should eliminate the problem of corneal melt. However, the invention is not limited to this and the collagen layer 12 may be of the same size or smaller size relative to the posterior layer 14. The posterior layer 14 can be completely posterior to (that is, underneath) the collagen layer 12 (FIGS. 2 and 3) or can be positioned in a pocket of the collagen layer 12 (shown in broken lines in FIG. 2). In any case, the anterior surface (that is, the most anterior surface) of the posterior layer 14 is posterior of the anterior surface (that is, the most anterior surface) of the collagen layer 12.

[0016] The anterior face of the posterior layer 14 may be bonded to the posterior face of collagen layer 12. Suitable binding agents include for example, but are not limited to, poly-L-lysine and poly-D-lysine or Polymerized N-isopropyl acrylamide (pNIPAM)

[0017] The anterior collagen layer serves as a corneal stroma (body) and in a patient with good epithelial reserve, will be covered by the host epithelium. In the embodiment of FIG. 2, an additional anterior layer 16 is disposed over the collagen layer 12. The additional anterior layer 16 may be made of epithelial cells of the recipient, which grows over the collagen layer 12. Alternatively, in the embodiment of FIG. 3, an additional anterior layer 16A is a contact lens, constructed of a suitable lens material, such as but not limited to, PMMA, rigid gas permeable (RGP) polymer, acrylics, silicone and others. The contact lens would be used for those patients with problems of growing epithelial cells, such as with corneal surface problems.

[0018] It will be appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described hereinabove. Rather the scope of the present invention includes both combinations and subcombinations of the features described hereinabove as well as modifications and variations thereof which would occur to a person of skill in the art upon reading the foregoing description and which are not in the prior art.