Corneal implants and methods and systems for placement

1. A method for delivering a biological corneal implant having an exterior surface, an interior surface, and laterally opposed edges to a cornea, said method comprising:

constraining the implant so that the laterally opposed edges evert inwardly to provide a C-shaped profile;

advancing the implant through a chamber with a protrusion disposed between the laterally opposed edges to further evert the edges and reduce the width of the implant; and

releasing the constrained biological corneal implant into the cornea or anterior chamber at the reduced width, wherein prior to release the laterally opposed edges of the biological corneal implant remain everted but do not touch the interior surface of the biological corneal implant such that damage to the implant is reduced.

2. A method as in claim 1 , wherein constraining comprises closing semi-circular halves of a deformation chamber on the implant, wherein each half carries an inwardly directed ramp to evert the edges of the implant inwardly as the halves are closed.

3. A method as in claim 1 , wherein advancing comprises pushing a pusher member against a rear edge of the corneal implant.

4. A method as in claim 3 , wherein a forward portion of the pusher member conforms to the interior of the tapered chamber as the pusher member is pushed.

5. A method as in claim 1 , wherein the biological implant comprises a lamellar corneal stromal endothelial transplant.

6. A method as in claim 1 , wherein the protrusion extends over the entire length of the chamber and remains between the opposed edges until the constrained implant is released.

7. A method as in claim 6 , wherein the chamber is tapered to a reduced width in the direction of advancement of the implant.

8. A system for delivering corneal implants, said system comprising:

a deformation chamber having a proximal end, a distal end, and a pair of semi-circular halves hinged to each other along a common side, each semi-circular half having an inwardly oriented arcuate surface along an opposite side, said surfaces being adapted to evert opposite edges of an implant having an exterior surface and an interior surface when said implant is placed between the surfaces of the deformation chamber as the halves are closed;

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, wherein the axial hollow passage is attached to a distal end of the deformation chamber, receives the implant in an arcuate configuration, and includes inwardly oriented arcuate surfaces which further evert the opposite edges of the corneal implant radially inwardly as the insert is axially advanced through the passage, wherein the inwardly oriented arcuate surfaces of the hollow member are disposed on opposite sides of a protrusion which extends axially through the hollow passage to form inwardly directed ramps to curl the opposite edges of the implant into a C-shape wherein the opposite edges are everted but do not touch the interior surface of the implant as the implant is advanced; and

an axial pusher disposed to be advanced through the deformation chamber and the hollow axial passage of the hollow member to engage and axially advance the corneal implant through the hollow passage.

9. A system as in claim 8 , further comprising a corneal implant constrained within the deformation chamber on a distal side of the axial pusher.

10. A system as in claim 8 , wherein the axial pusher is tapered in a distal direction.

11. A system as in claim 10 , wherein the axial pusher is deformable so that it will reduce in diameter as it is distally advanced through the tapered hollow passage.

12. A system as in claim 11 , wherein the axial pusher has a cross-sectional profile which is similar in shape to the cross-sectional profile of the deformation chamber and the hollow passage.