Expansion Ring For Eyeball Tissue

Abstract

A length or strand of resilient material is formed into a continuous ring having multiple tissue-engaging portions for engaging and spreading eyeball tissue segments apart. The strand is formed with elongated straight sides joined by corner portions which are enlarged in directions transverse to the length dimension of each adjacent side. The corner portions constitute the tissue-engaging portions and have top and bottom sections and a connecting section that forms a gap for receiving the tissue. Each side of the ring extends from a bottom section of one corner to a top section of an adjacent corner. When the ring is deployed, the tissue is captured in the gaps at the corners of the ring and also is engaged along each side as that side transitions from a position situated below the tissue to a position situated above the issue.

What is claimed is: 
     
         1 . An expansion device for eyeball tissue comprising a strand of resilient material having multiple tissue-engaging portions for engaging and spreading eyeball tissue segments apart, said strand being formed as a continuous ring with straight sides joined by corner portions, said corner portions constituting the tissue-engaging portions, each corner portion having a top section, a bottom section, and a connecting section of the strand extending between and joining the top section and the bottom section and forming a gap therebetween for receiving an edge portion of an eyeball tissue segment, each side extending from a bottom section of a first one of the corner portions to a top section of a second adjacent one of the corner portions, whereby, when the ring is deployed with an edge portion of an eyeball tissue segment captured in the gaps of adjacent corner portions, the side that extends between said first and second corner portions transitions across such edge portion. 
     
     
         2 . The device defined in  claim 1 , in which the ring is sized for engagement of the inner edge of an iris in the gaps of the corner portions to hold the iris in an expanded open condition and enable access therethrough during an ophthalmic procedure. 
     
     
         3 . The device defined in  claim 2 , in which the connecting section of each corner portion forms an outward opening channel for reception of an inner edge portion of an iris. 
     
     
         4 . The device defined in  claim 3 , in which the connecting section of each corner portion is arcuate. 
     
     
         5 . The device defined in  claim 4 , in which the connecting section of each corner portion is a single loop spiraled inward from adjacent sides of the ring. 
     
     
         6 . The device defined in  claim 5 , in which the loop is helical. 
     
     
         7 . The device defined in  claim 5 , in which the loop has overlapping portions at an outer edge portion of the corner portion to overlie and underlie the inner edge of an iris, respectively. 
     
     
         8 . The device defined in  claim 4 , in which the connecting section of each corner portion is a 180 degree return bend forming a concave channel for reception of an edge portion of an iris. 
     
     
         9 . The device defined in  claim 3 , in which the connecting section of each corner portion has an upright inner portion limiting insertion of an iris edge segment in the channel. 
     
     
         10 . The device defined in  claim 9 , in which the upright inner portion of the connecting section extends diagonally across an edge portion of an iris when received in the channel. 
     
     
         11 . The device defined in  claim 9 , in which the upright inner portion of the connecting section does not extend diagonally across an edge portion of an iris when received in the channel. 
     
     
         12 . The device defined in  claim 2 , in which the strand is a length of plastic material having opposite ends joined together to form the continuous ring. 
     
     
         13 . The device defined in  claim 12 , including a drop of adhesive holding the opposite ends together. 
     
     
         14 . The device defined in  claim 13 , in which each of the opposite ends has an indented portion, the adhesive filing the indented portions and encircling the opposite ends adjacent to the indented portions. 
     
     
         15 . The device defined in  claim 12 , in which the strand is a length of surgical suture having opposite ends joined together to form the continuous ring, each of the opposite ends having an indented portion, and including a drop of adhesive filing the indented portions and encircling the opposite ends adjacent to the indented portions. 
     
     
         16 . The device defined in  claim 1 , in which the sides are of equal length. 
     
     
         17 . The device defined in  claim 1 , in which the ring is square. 
     
     
         18 . The device defined in  claim 1 , in which the ring is triangular.