Method and apparatus for enhanced corneal accommodation

Abstract

A method and apparatus related to enhancing corneal accommodation to address the effect of presbyopia. Corneal/scleral topology measurements in accommodating and non-accommodating states are indicative of a presbyopic subject's nominal corneal accommodative power. A desired accommodative power intended to improve on the effect of presbyopia can be determined, suggesting a selective biomechanical intervention in the corneal structure outside of the optical zone to create flexure regions. These flexure regions would allow enhanced corneal accommodation upon presentation of an accommodating stimulus. Intervention could be in the form of, for example, corneal surface ablation, intrastromal ablation, conductive keratoplasty (CK), laser thermal keratoplasty (LTK), and corneal and/or scleral implants. An improved topology measuring apparatus having an improved field of view and other attributes is disclosed.

1 . A system for use in enhancing a subject's capacity to accommodate, comprising:
 a corneal topography measuring device;   a control system; and   a therapeutic device adapted to make a biomechanical alteration of a subject's corneal structure outside of an optical zone of the cornea, resulting in an inflection region in the corneal structure, which provides an enhanced corneal accommodative power, operatively connected to the control system,   
       wherein the control system is adapted to determine the parameters of the biomechanical alteration that creates the inflection region in the corneal tissue, further wherein said inflection region is located so as to allow increased flexure to the cornea in response to an accommodative stimulus. 
     
     
         2 . The system of  claim 1 , wherein the corneal topography measuring device is a rasterstereographic corneal topography system. 
     
     
         3 . The system of  claim 2 , wherein the corneal topography measuring device has a horizontal field of view equal to or greater than 15 mm and a vertical field of view equal to or greater than 11 mm. 
     
     
         4 . The system of  claim 2 , wherein the rasterstereographic corneal topography system has separate, offset Scheimpflug projection and imaging arms. 
     
     
         5 . The system of  claim 2 , wherein the rasterstereographic corneal topography system includes a pre-warped projection grid that provides a uniform grid spacing on a given reference surface. 
     
     
         6 . The system of  claim 2 , wherein the rasterstereographic corneal topography system has a projection ray and an imaging ray that are offset by about 24 degrees.