Patent ID: 6887232

Claim:
A closed-loop system for controlling intrastromal photoablation of stromal tissue of an eye, wherein gas bubbles resulting from the ablation of the tissue introduce induced optical aberrations, said system comprising: a source for generating an ablation laser beam to photoablate stromal tissue; a source for generating a diagnostic laser beam, with the diagnostic laser beam including a plurality of component beams; an active mirror for directing said diagnostic laser beam to a focal spot on the retina of the eye; a detector for using light of said diagnostic beam reflected from the retina through the bubbles to generate an induced wavefront having characteristics of the induced optical aberrations, together with a distorted wavefront having actual real-time characteristics of the cornea; a compensator for altering a predetermined desired wavefront by incorporating said induced wavefront therewith to create a rectified wavefront; a comparator for comparing said rectified wavefront with said distorted wavefront to create an error signal having a plurality of error segments; a means for reconfiguring said active mirror in response to said plurality of error segments to maintain said focal spot on the retina, wherein said active mirror comprises a plurality of separate reflective elements for individually reflecting respective component beams of the diagnostic beam, and wherein said reconfiguring means individually activates each said reflective element in response to a corresponding segment of said error signal; and a means for ceasing generation of said ablation beam when said error signal is substantially a nullity.