System and method for measuring and correcting astigmatism using laser generated corneal incisions

Abstract

A laser system that includes a laser source emitting a laser beam along an axis and a keratometer. The keratometer includes a first set of individual light sources that are equally spaced from one another along a first ring and that direct a first light toward an eye and a second set of individual light sources that are equally spaced from another along a second ring and direct a second light toward the eye, wherein the first ring and said second ring are co-planar and concentric with one another about the axis. The laser system includes a telecentric lens that receives the first light and second light reflected off of the eye and a detector that receives light from the telecentric lens and forms an image. The laser system also includes a processor that receives signals from said detector representative of the image and determines an astigmatism axis of the eye based on the signals.

1 . A laser system comprising:
 a laser source emitting a laser beam along an axis;   a keratometer comprising:
 a first set of individual light sources that are equally spaced from one another along a first ring and that direct a first light toward an eye; 
 a second set of individual light sources that are equally spaced from another along a second ring and direct a second light toward said eye, wherein said first ring and said second ring are co-planar and concentric with one another about said axis; 
 a telecentric lens that receives said first light and second light reflected off of said eye; 
 a detector that receives light from said telecentric lens and forms an image; 
 a processor that receives signals from said detector representative of said image and determines an astigmatism axis of said eye based on said signals. 
   
     
     
         2 . The laser system of  claim 1 , wherein said processor determines a corneal K value and orientation of said astigmatism axis based on said signals. 
     
     
         3 . The laser system of  claim 1 , wherein said keratometer is structured so as to reduce systematic errors in use of said laser system with said keratometer when compared with when stand-alone keratometers are used with the laser system. 
     
     
         4 . The laser system of  claim 1 , wherein said laser source and said keratometer are housed in a common housing. 
     
     
         5 . The laser system of  claim 4 , wherein said keratometer is structured so as to reduce systematic errors in the use of said laser system when compared with a hypothetical case when said laser system is used with stand-alone keratometers. 
     
     
         6 . The laser system of  claim 1 , wherein said processor is in communication with said laser source and controls said laser beam so that it cuts said eye based on said properties of said astigmatism axis. 
     
     
         7 . The laser system of  claim 1 , wherein said laser source generates femto second pulse laser beams. 
     
     
         8 . A method of determining properties of an eye, the method comprising:
 positioning an eye so that it receives a laser beam that is originally emitted by a laser source beam along an axis;   generating first light toward said eye from a first set of individual light sources that are equally spaced from one another along a first ring;   generating second light toward said eye from a second set of individual light sources that are equally spaced from another along a second ring and direct a second light toward said eye, wherein said first ring and said second ring are co-planar and concentric with one another about said axis;   forming an image of light reflected off of said eye from said first light and said second light; and   determining an astigmatism axis of said eye based on said image, wherein said laser source, said first set of individual light sources and said second set of individual light sources are integrated in a common housing so that systematic effects based on said laser source, said first set of individual light sources and said second set of individual light sources are reduced.   
     
     
         9 . The method of  claim 8 , further comprising determining a corneal K value and orientation of said astigmatism axis. 
     
     
         10 . The method of  claim 8 , wherein said astigmatism axis is not substantially affected by systematic effects. 
     
     
         11 . The method of  claim 8 , wherein prior to said positioning said eye and generating said first light and said second light, measuring properties of said astigmatism axis of said eye. 
     
     
         12 . The method of  claim 11 , wherein said measuring properties comprises measuring a corneal K value of said astigmatism axis. 
     
     
         13 . The method of  claim 11 , wherein said measuring properties is performed by a stand-alone keratometer. 
     
     
         14 . The method of  claim 13 , wherein said determining of said axis of astigmatism is used to compensate for cyclotorsion of said eye that occurs between measurements made by said stand-alone keratometer and said determining said astigmatism axis. 
     
     
         15 . A method of repairing an eye, the method comprising:
 positioning an eye so that it receives a laser beam that is originally emitted by a laser source beam along an axis; generating first light toward said eye from a first set of individual light sources that are equally spaced from one another along a first ring;   generating second light toward said eye from a second set of individual light sources that are equally spaced from another along a second ring and direct a second light toward said eye, wherein said first ring and said second ring are co-planar and concentric with one another about said axis;   forming an image of light reflected off of said eye from said first light and said second light;   determining an astigmatism axis of said eye based on said image; and   controlling said laser beam so that said laser beam performs a cutting of said eye based on said astigmatism axis of said eye.   
     
     
         16 . The method of  claim 15 , wherein said processor determines a corneal K value and orientation of said astigmatism axis based on said signals. 
     
     
         17 . The method of  claim 15 , wherein said astigmatism axis is not substantially affected by systematic effects. 
     
     
         18 . The method of  claim 15 , wherein said cutting of said eye generates a mark representative of an orientation of said astigmatism axis, the method comprising performing a capsulotomy based on said generated mark. 
     
     
         19 . The method of  claim 15 , wherein said cutting of said eye creates an LRI. 
     
     
         20 . The method of  claim 15 , wherein prior to said positioning said eye and generating said first light and said second light, measuring properties of said astigmatism axis of said eye. 
     
     
         21 . The method of  claim 20 , wherein said measuring properties comprises measuring a corneal K value and said astigmatism axis. 
     
     
         22 . The method of  claim 20 , wherein said measuring properties is performed by a stand-alone keratometer and said first set of individual light sources said second set of individual light sources are part of built-in keratometer of the same design that is contained in a common housing with said laser source. 
     
     
         23 . The method of  claim 22 , wherein said built-in keratometer measures said axis of astigmatism to compensate for cyclotorsion of said eye between measurements made by said stand-alone keratometer and measurements made by said built-in keratometer. 
     
     
         24 . A method of determining properties of an eye, the method comprising:
 measuring properties of an astigmatism axis of said eye with a stand-alone Placido ring measuring system;   positioning an eye so that it receives a laser beam that is originally emitted by a laser source beam along an axis;   generating at a built-in Placid ring measuring system a first annular-shaped light beam directed toward said eye, wherein said built-in Placido ring measuring system and said laser source are in a common housing;   generating at said built-in Placido ring measuring system a second annular-shaped light beam directed toward said eye;   forming an image of light reflected off of said eye from said first annular-shaped light beam and said second annular-shaped light beam; and   determining an astigmatism axis of said eye based on said image.   
     
     
         25 . The method of  claim 24 , wherein said built-in Placido ring measuring system measures said axis of astigmatism to compensate for cyclotorsion of said eye between measurements made by said stand-alone Placido ring measuring system and measurements made by said built-in Placido ring measuring system. 
     
     
         26 . The method of  claim 24 , wherein said built-in Placido ring measuring system is designed in all significant aspects to measure K values and axis of astigmatism in an identical manner and to produce identical results, except for those associated with cyclotorsion, as said stand-alone Placido ring measuring system. 
     
     
         27 . A method of repairing an eye, the method comprising:
 measuring properties of an astigmatism axis of said eye with a stand-alone Placido ring measuring system;   positioning an eye so that it receives a laser beam that is originally emitted by a laser source beam along an axis;   generating at a built-in Placid ring measuring system a first annular-shaped light beam directed toward said eye, wherein said built-in Placido ring measuring system and said laser source are in a common housing;   generating at said built-in Placido ring measuring system a second annular-shaped light beam directed toward said eye;   forming an image of light reflected off of said eye from said first annular-shaped light beam and said second annular-shaped light beam;   determining an astigmatism axis of said eye based on said image; and   controlling said laser beam so that said laser beam performs a cutting of said eye based on said astigmatism axis.   
     
     
         28 . The method of  claim 27 , wherein said cutting of said eye generates a mark representative of an orientation of said astigmatism axis, the method comprising performing a capsulotomy based on said generated mark. 
     
     
         29 . The method of  claim 27 , wherein said cutting of said eye creates an LRI. 
     
     
         30 . The method of  claim 27 , wherein said built-in Placido ring measuring system measures said axis of astigmatism to compensate for cyclotorsion of said eye between measurements made by said stand-alone Placido ring measuring system and measurements made by said built-in Placido ring measuring system. 
     
     
         31 . The method of  claim 27 , wherein said built-in Placido ring measuring system is designed in all significant aspects to measure K values and axis of astigmatism in an identical manner and to produce identical results, except for those associated with cyclotorsion, as said stand-alone Placido ring measuring system.