Volute subretinal implants

Abstract

A method of transplanting a graft in the subretinal area of a host eye comprises preparing the graft by harvesting from the donor tissue a population of cells in a manner that maintains the population of cells in the same organization and cellular polarity as is present in normal tissue of that type. The population of cells are of a sheet-like form and are assembled with a relatively thin flexible pliable carrier composed of a non-toxic flexible composition which substantially dissolves at body temperature to form a graft. The graft is sufficiently flexible and pliable to be coiled to form a volute ( 76 ) without disturbing the organization and polarity of the cells. The method further comprises coiling the graft to form a volute ( 76 ) with the convolutions of the volute ( 76 ) free of one another for subsequent uncoiling of the graft substantially to its original sheet-like form. An incision is made in the host eye for insertion of the volute ( 76 ). The incision in the eye is smaller than the incision that would be required for insertion of the graft in its uncoiled sheet-like form. The volute is inserted one end first into the host eye through the incision and transported to a position between the retina and the underlying tissue. The volute ( 76 ) uncoils after its insertion to lie in sheet-like form between the retina and the underlying tissue of the host eye. The incision is then closed.

What is claimed is:  
     
         1 . An implant for implantation to the subretinal area of an eye, comprising a coiled implant formed from a flexible composition in sheet form which at least partially degrades when placed in the eye of a human or other mammal, and wherein said implant has a coil diameter less than about two millimeters and is capable of therapeutic subretinal implantation, and said composition comprises a therapeutic material.  
     
     
         2 . The implant of  claim 1 , wherein said coiled implant has an inherent memory and uncoils under said memory to lie in substantially uncoiled sheet-like form at the site of implantation.  
     
     
         3 . The implant of  claim 1 , wherein said therapeutic material comprises a population of cells selected from retinal cells, epithelial tissue, choroidal tissue and Bruch's membrane harvested from donor tissue.  
     
     
         4 . The implant as set forth in  claim 3 , wherein said composition further comprises a carrier that degrades at least in part in the eye of a human or other mammal.  
     
     
         5 . The implant of  claim 1 , wherein said therapeutic material comprises at least one of the group consisting of photoreceptor cells, and retinal pigment epithelial cells.  
     
     
         6 . The implant of  claim 1 , wherein said therapeutic material comprises at least one drug.  
     
     
         7 . The implant as set forth in  claim 1 , in combination with an implement for inserting said coiled implant through an incision in the host eye dimensioned in accordance with the cross-sectional area of the coiled implant to a position between the retina and the underlying tissue of the host eye.  
     
     
         8 . The implant of  claim 3 , wherein said composition further comprises a carrier, wherein said carrier dissolves at least in part in the eye of a human or mammal.  
     
     
         9 . The implant of  claim 5 , wherein said composition further comprises a carrier, wherein said carrier dissolves at least in part in the eye of a human or mammal.  
     
     
         10 . The implant of  claim 6 , wherein said composition further comprises a carrier, wherein said carrier dissolves at least in part in the eye of a human or mammal, wherein said carrier releases said at least one drug.  
     
     
         11 . The implant of  claim 9 , wherein said carrier comprises gelatin.  
     
     
         12 . The implant as set forth in  claim 3 , in combination with an implement for inserting said coiled implant through an incision in the host eye dimensioned in accordance with the cross-sectional area of the coiled implant to a position between the retina and the underlying tissue of the host eye.  
     
     
         13 . The implant as set forth in  claim 5 , in combination with an implement for inserting said coiled implant through an incision in the host eye dimensioned in accordance with the cross-sectional area of the coiled implant to a position between the retina and the underlying tissue of the host eye.  
     
     
         14 . An implement for the formation of an ophthalmic implant, comprising a tubular body open at one end and having a funnel at its other end, wherein a flexible sheet comprising a therapeutic material inserted one end first in the tubular body at the open end thereof and fed along the body into and through the funnel engages an interior surface of the funnel causing the sheet to coil to form a coiled implant, and the coiled implant can exit from a small end of the funnel, and wherein the coiled implants exiting said small end of said funnel are sufficiently small to be placed in the subretinal area of an eye.  
     
     
         15 . The implement of  claim 14 , wherein said implement further comprises a tubular tip, wherein said tip is insertable through a standard size incision into the eye, and coiled implants formed by the funnel can pass through the tip into the subretinal area of a mammalian or human host eye.  
     
     
         16 . The implement of  claim 15 , wherein said tubular tip comprises a beveled edge.  
     
     
         17 . The implement of  claim 14 , wherein said implement further comprises a ramp to facilitate the coiling of an implant.  
     
     
         18 . The implement of  claim 15 , wherein said implement further comprises a plunger for ejecting an implant form said tubular tip.  
     
     
         19 . The implement of  claim 18 , wherein said implement further comprises fluid pressure means for ejecting a coiled implant from said tubular tip.  
     
     
         20 . The implement of  claim 15 , wherein said tubular tip is curved along its longitudinal axis.