Method and apparatus for precision laser surgery

Abstract

An eye laser system which includes a laser and a laser delivery system for delivering a laser beam generated by the laser to the eye and an eyetracking system which monitors movement of the eye and conveys eyetracking information to the laser delivery system with the eyetracking system including a non-invasive eye tilt reference marker. The reference marker projects an energy beam that is preferably visible so as to reflect off the iris of the eye and provide microscope and surgical field illumination. The reference marker includes a plurality of points arranged concentrically about the pupil of the eye and/or a concentric ring marking device. This arrangement provides information as to eye tilt for use in, for example, video frame review during an initial reference setting or a subsequent eye tracking stage. Also described are laser delivery systems including an eye tilt accommodation laser delivery systems that are well suited for use with the eyetracking system described above which provides an indication of eye tilt and provide data sufficient for determining an angle of eye tilt and hence an angle required by the laser accommodating system to provide a laser beam coincident with the axis of tilt for a tilted eye.

What is claimed is:  
     
         1 . An eye laser system, comprising: 
 a laser;    a laser delivery system for delivering a laser beam generated by said laser to an eye;    an eyetracking system which monitors movement of the eye and conveys eyetracking information to said laser delivery system, said eyetracking system including a non-invasive eye tilt reference marker.    
     
     
         2 . The laser system as recited in  claim 1  wherein said reference marker is a reference marker that projects an energy beam so as to reflect off the iris of the eye.  
     
     
         3 . The laser system as recited in  claim 2  wherein said reference marker includes a plurality of points arranged concentrically about the pupil of the eye.  
     
     
         4 . The laser system as recited in  claim 3  wherein there are at least three reference marker points reflected from the iris.  
     
     
         5 . The laser system as recited in  claim 4  wherein there are four reference marker points.  
     
     
         6 . The laser system as recited in  claim 5  wherein said eyetracker system includes a video frame developer and means for analyzing captured video frames.  
     
     
         7 . The laser system as recited in  claim 6  wherein said video frame developer includes a frame reference component that includes X and Y axis extensions and said four reference marker points land on respective extensions when the eye is in a reference setting.  
     
     
         8 . The laser system as recited in  claim 3  wherein said reference marker further comprises a ring illuminator.  
     
     
         9 . The laser system as recited in  claim 8  wherein said reference marker generates visible light that provides surgical illumination.  
     
     
         10 . The laser system as recited in  claim 1  wherein said reference marker provides a concentrically arranged pattern on said pupil which is concentric with said pupil.  
     
     
         11 . The laser system as recited in  claim 1  wherein said reference marker includes point marker lights positioned circumferentially about the laser beam path.  
     
     
         12 . The laser system as recited in  claim 11  wherein said point marker lights operate in the visible light spectrum.  
     
     
         13 . The laser system as recited in  claim 1  wherein said reference marker reflects a pattern on said eye that is concentric with respect to said pupil and further comprising means for determining eye tilt based on any non-concentric adjustment between a pupil reference point and said pattern.  
     
     
         14 . The laser system as recited in  claim 13  wherein said pattern includes a four equally spaced point pattern.  
     
     
         15 . The laser system as recited in  claim 13  wherein said analyzing means determining means for determining a tilt angle of said eye.  
     
     
         16 . An eyetracker system for use in determining eye tilt comprising a reference marker generating means for producing on an eye iris a pattern that indicates an eye tilt upon a tilt in said eye and means for generating an eye tilt existence signal to a laser delivery system.  
     
     
         17 . The eyetracker system as recited in  claim 16  wherein said pattern includes at least four equally spaced light points projected on the iris of an eye.  
     
     
         18 . The eyetracker system as recited in  claim 16  wherein said eye tilt determination means includes means for determining a tilt angle of said eye.  
     
     
         19 . A laser delivery system for use in an eye laser system, comprising a scan mirror and an ellipsoidal mirror positioned to accommodate eye tilt.  
     
     
         20 . A laser system comprising the laser delivery system recited in  claim 19  and further comprising a laser.  
     
     
         21 . A laser system as recited in  claim 20  and further comprising an eyetracker system with means for monitoring eye tilt.  
     
     
         22 . A laser system as recited in  claim 21  wherein said eyetracker system comprises reference point lights positioned so as to reflect off the iris so as to convey pupil adjustments through variations in a relative position of said point markers with respect to said pupil.  
     
     
         23 . A laser system as recited in  claim 21  wherein said eyetracker system comprises means for generating a concentric pattern on the iris of the eye being treated.  
     
     
         24 . A laser system comprising the laser delivery system recited in  claim 19  and a laser and an active crystal mask positioned in an optical path of said laser.