Limited depth corneal punch

Abstract

A single-use adjustable depth trephine corneal punch device that allows a goal trephination depth of a donor cornea to be set and cut prior to a surgical procedure for cutting selected portions of an actual patient cornea. The corneal punch includes a punch block having a central well for receiving a donor cornea, a punch top mounted atop the punch block and having a central cylindrical opening coaxially aligned with the well, and means for cutting a selected portion of the donor cornea in the central well, wherein the means for cutting includes a punch blade mounted atop the punch top and through the opening for combined limited rotation less than about 312 degrees and limited axial movement from a reference or “start” point and into juxtaposed relation against the cornea and a limited axial downward movement during rotation wherein to make a shallow cut in the cornea.

Having thus described the invention, what is claimed is: 
     
         1 . A single-use adjustable depth trephine corneal punch for cutting selected portions of a cornea, comprising:
 (a) a punch block having a central well for receiving a donor cornea;   (b) a punch top mounted atop the punch block and having a central cylindrical opening coaxially aligned with the well, the punch top having a plurality of indicia circumferentially provided thereon; and   (c) means for cutting a selected portion of the donor cornea in the central well, the means for cutting includes a blade holder and a punch blade, the blade mounted atop the punch top and through the central cylindrical opening, the blade and the top cooperating for a combined limited rotation of the punch, the blade holder having a plurality of cutouts disposed therearound, each cutout corresponding to an associated indicia.   
     
     
         2 . The punch of  claim 1  wherein:
 the means for cutting further includes a reference cylinder mounted atop the punch top and a cutting assembly including the punch blade and a blade holder mounted in the cylinder for simultaneous rotation and axial movement through the opening. 
 
     
     
         3 . The punch of  claim 1  wherein the blade holder includes a top and bottom surface and an arcuate groove in the bottom surface for limiting rotation of the punch blade, the holder having first and second ends representing a start point and a final cut point of the blade. 
     
     
         4 . The punch of  claim 3  which further comprises:
 a guide pin which projects, is disposed on, and extends up from the punch top and into the groove for limiting rotational axial movement of the blade holder and associated blade. 
 
     
     
         5 . The punch of  claim 2  wherein the reference cylinder is formed with a radius of curvature to match the curvature of the well in the punch block to enable engagement with selective areas of the cornea. 
     
     
         6 . The punch of  claim 1  wherein:
 (a) the punch top has bottom pins which register with receiving holes in the punch block and an opposed extending top guide pin; 
 (b) the punch blade is cylindrical and further wherein; 
 (c) the blade holder rotates the punch blade; and 
 (d) the punch further includes an internally threaded reference cylinder. 
 
     
     
         7 . The punch of  claim 6  wherein the blade holder is externally threaded for connection to the internal threads of the reference cylinder, the blade holder further including a bottom surface having a groove for receiving the guide pin and wherein the guide pin and groove cooperate to limit rotation of the clockwise and/or counter-clockwise rotation of the blade holder. 
     
     
         8 . The punch of  claim 7  wherein the punch top has a contoured central well for receiving a donor cornea. 
     
     
         9 . The punch of  claim 1 , wherein the punch top has a contoured central well for receiving a donor cornea.